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[ CAS No. 4105-21-9 ] {[proInfo.proName]}

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Chemical Structure| 4105-21-9
Chemical Structure| 4105-21-9
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Product Details of [ 4105-21-9 ]

CAS No. :4105-21-9 MDL No. :MFCD00219254
Formula : C13H10N2 Boiling Point : -
Linear Structure Formula :- InChI Key :KDHWCFCNNGUJCP-UHFFFAOYSA-N
M.W :194.23 Pubchem ID :201136
Synonyms :

Calculated chemistry of [ 4105-21-9 ]

Physicochemical Properties

Num. heavy atoms : 15
Num. arom. heavy atoms : 15
Fraction Csp3 : 0.0
Num. rotatable bonds : 1
Num. H-bond acceptors : 1.0
Num. H-bond donors : 0.0
Molar Refractivity : 60.63
TPSA : 17.3 Ų

Pharmacokinetics

GI absorption : High
BBB permeant : Yes
P-gp substrate : No
CYP1A2 inhibitor : Yes
CYP2C19 inhibitor : Yes
CYP2C9 inhibitor : No
CYP2D6 inhibitor : No
CYP3A4 inhibitor : No
Log Kp (skin permeation) : -5.43 cm/s

Lipophilicity

Log Po/w (iLOGP) : 2.4
Log Po/w (XLOGP3) : 2.9
Log Po/w (WLOGP) : 3.0
Log Po/w (MLOGP) : 2.27
Log Po/w (SILICOS-IT) : 2.52
Consensus Log Po/w : 2.62

Druglikeness

Lipinski : 0.0
Ghose : None
Veber : 0.0
Egan : 0.0
Muegge : 1.0
Bioavailability Score : 0.55

Water Solubility

Log S (ESOL) : -3.55
Solubility : 0.0553 mg/ml ; 0.000285 mol/l
Class : Soluble
Log S (Ali) : -2.92
Solubility : 0.231 mg/ml ; 0.00119 mol/l
Class : Soluble
Log S (SILICOS-IT) : -4.61
Solubility : 0.00481 mg/ml ; 0.0000248 mol/l
Class : Moderately soluble

Medicinal Chemistry

PAINS : 0.0 alert
Brenk : 0.0 alert
Leadlikeness : 1.0
Synthetic accessibility : 2.05

Safety of [ 4105-21-9 ]

Signal Word:Warning Class:N/A
Precautionary Statements:P261-P305+P351+P338 UN#:N/A
Hazard Statements:H302-H315-H319-H335 Packing Group:N/A
GHS Pictogram:

Application In Synthesis of [ 4105-21-9 ]

* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.

  • Downstream synthetic route of [ 4105-21-9 ]

[ 4105-21-9 ] Synthesis Path-Downstream   1~80

  • 1
  • [ 4105-21-9 ]
  • [ 4044-95-5 ]
YieldReaction ConditionsOperation in experiment
98% With N-Bromosuccinimide In acetonitrile at 20℃; for 1.5h; Darkness; regioselective reaction;
96.2% With oxygen; copper(I) bromide In N,N-dimethyl-formamide at 120℃; for 6h; 1 Example 1 Synthesis of 2-phenyl-3-bromoimidazo[1,2-a]pyridine Under the action of oxygen, 2-phenylimidazo[1,2-a]pyridine (1.5 mmol, 300 mg), bromineCuprous (1.8mmol, 266mg) and 8ml of N,N-dimethylformamide were then reacted in an oil bath at 120°C for 6h. The reaction solution was washed with water and saturated brine respectively, extracted with ethyl acetate, the organic layer was dried over anhydrous sodium sulfate, and separated by column chromatography to obtain 405 mg of 2-phenyl-3-bromoimidazo[1,2-a]pyridine in a yield of 405 mg. 96.2%
95% With N-Bromosuccinimide In acetonitrile at 20℃; for 2h;
95% With pyridine; oxygen; copper(ll) bromide In 1,2-dichloro-ethane at 70℃;
95% With dipotassium peroxodisulfate; sodium bromide In dichloromethane at 20℃; for 24h; Sealed tube;
95% With sodium carbonate; pyridinium hydrobromide perbromide In N,N-dimethyl-formamide at 25 - 43℃; for 0.5h; Sonication; Schlenk technique; Green chemistry; regioselective reaction; 3-Bromo-2-phenylimidazo[1,2-a]pyridine (3a); Typical Procedure A mixture of 2-phenylimidazo[1,2-a]pyridine (1a; 38.8 mg, 0.20 mmol), pyridinium tribromide (2a; 63.9 mg, 0.20 mmol) and Na2CO3 (21.2 mg, 0.2 mmol) in DMF (2.0 mL) in a Schlenk tube at r.t. was subjected to ultrasonic irradiation JP-120ST(Skymen) for 30 min. After the reaction was complete, the mixture was extracted with EtOAc (3 5 mL). The combined organic extracts were washed with brine (10 mL), dried over Na2SO4 and filtered. The solvent was removed under reduced pressure and the residue was purified by flash column chromatography (silica gel, 200-300 mesh) to give desired product 3a. Yield: 51.68 mg (95%); yellow solid; mp 85 °C. 1H NMR (400 MHz, CDCl3): = 8.20 (d, J = 6.8 Hz, 1H), 8.17 (d, J = 7.6 Hz, 2 H), 7.68 (d, J = 8.2 Hz, 1H), 7.52 (t, J = 7.8 Hz, 2 H), 7.43 (t, J = 7.8 Hz, 1H), 7.30-7.26 (m, 1H), 6.95 (t, J = 6.8 Hz, 1H). 13C NMR (101 MHz, CDCl3): = 145.39, 142.58, 132.73, 128.46, 128.32, 127.89, 125.19, 123.97, 117.58, 113.11, 91.75.
94% With sodium bromide In acetonitrile at 20℃; for 4h; Electrochemical reaction; General procedure for the electrochemical iodination of imidazo[1,2-a]pyridines General procedure: An undivided cell was equipped with a platinum plate (1.00.7 cm2) as the anode anda platinum plate (1.00.7 cm2) as the cathode and connected to a DC regulated powersupply. A mixture of imidazo[1,2-a]pyridine 1 (0.1 mmol) and NaI (2a, 0.2 mmol) in acetonitrile (3.0 mL) was added to an undivided cell. The reaction mixture was stirredand electrolyzed at a constant current of 5mA under room temperature for 4 h. Whenthe reaction was completed, electrodes were washed with ethanol (EtOH). The combinedorganic solvent was removed in vacuo. The residue was purified by flash chromatography(EtOAc:Hex, 1:5) to afford 3-iodo imidazo[1,2-a]pyridine 3.
93% With carbon tetrabromide; tetrabutylammonium tetrafluoroborate In methanol; acetonitrile Inert atmosphere; Heating; Electrochemical reaction;
92% With 1,3-dibromo-5,5-dimethylimidazolidine-2,4-dione In dimethyl sulfoxide at 50℃; for 1h; Sealed tube; 1 Synthesis of 3-bromo-2-phenylimidazo[1,2-α]pyridine: The substrate 48.5 mg (0.25 mmol) 2-phenylimidazo[1,2-α]pyridine, 71.5 mg (0.25 mmol) dibromohydantoin, 2.0 mL DMSO was added to a 30 mL sealed tube under an air environment, and then Seal the tube and put it into an ultrasonic cleaning machine (Jiekang ultrasonic cleaning machine, ultrasonic power is 70W, heating power is 60W, ultrasonic frequency is 40KHz), the reaction temperature is 50 , the reaction is 1h, after the reaction is completed, the reaction solution is cooled to At room temperature, 10 mL of saturated brine was added, extracted three times with 15 mL of ethyl acetate, and the organic layers were combined. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was removed under reduced pressure. The residue was separated by silica gel column chromatography (ethyl acetate/petroleum ether: 1/4 as eluent) to obtain 62.82 mg of yellow oily liquid. The rate is 92%.
90% With N-Bromosuccinimide at 20℃; for 1h;
88% With bromine In ethyl acetate at 90℃; for 1h;
85% With dipotassium peroxodisulfate; sodium bromide In water; acetonitrile at 80℃; for 1.5h; regioselective reaction; General procedure for the synthesis of 3-haloimidazo[1,2-a]pyridines 2: General procedure: Potassium persulfate (K2S2O8) (202.7mg, 0.75mmol) was added to a suspension of imidazo[1,2-a]pyridines 1 (0.5mmol) and sodium bromide (205.8mg, 2.0mmol) in acetonitrile/H2O (2:1 v/v, 3mL), and the reaction mixture was stirred at 80°C for 1.5h. After completion of the reaction, the reaction mixture was quenched by the addition of sat. aq Na2S2O3 (5mL). Further stirring was followed by extraction with EtOAc (2×20mL). The combined organic extracts were washed with H2O (20mL) and brine (20mL), dried over Na2SO4, filtered, and concentrated (aspirator). The residue was purified by column chromatography using EtOAc/hexanes as eluent to afford the corresponding product. 3-Bromo-2-phenylimidazo[1,2-a]pyridine (2a): Prepared from 2-phenylimidazo[1,2-a]pyridine (1a) (97.1mg, 0.5mmol), K2S2O8 (202.7mg, 0.75mmol) and NaBr (205.8mg, 2.0mmol). Colorless solid; yield: 116.1mg (85%); mp 62.0-64.0°C (lit. [10] 63-64.5°C); Rf =0.50 (30% EtOAc in hexanes). IR (neat): 2918, 1628, 1491, 1466, 1440, 1343, 980, 748, 690cm-1. 1H NMR (400MHz, CDCl3): δ=8.19 (d, J=7.0Hz, 1H), 8.15 (d, J=8.0Hz, 2H), 7.66 (d, J=9.1Hz, 1H), 7.51 (t, J=7.6Hz, 2H), 7.41 (t, J=7.4Hz, 1H), 7.27 (t, J=7.8Hz, 1H), 6.94 (t, J=6.8Hz, 1H). 13C NMR (100MHz, CDCl3): δ=145.5 (C), 142.7 (C), 132.9 (C), 128.6 (2×CH), 128.4 (CH), 128.0 (2×CH), 125.2 (CH), 124.1 (CH), 117.7 (CH), 113.2 (CH), 91.8 (C). HRMS (ESI-TOF): m/z [M+H]+ calcd for C13H10BrN2: 273.0027; found: 273.0020.
84% With carbon tetrabromide; (4,4'-di-tert-butyl-2,2'-dipyridyl)-bis-(2-phenylpyridine(-1H))-iridium(III) hexafluorophosphate In dimethyl sulfoxide at 20℃; for 7h; Inert atmosphere; Irradiation; Green chemistry; General procedure for the photocatalytic bromination of 2-arylimidazo[1,2-a]pyridines General procedure: An oven-dried flask was equipped with a magnetic stir bar, 2-arylimidazo[1,2-a]pyridines1 (0.1 mmol), carbon tetrabromide (2, 49.7 mg, 0.15 mmol), Ir(ppy)2(dtbbpy)PF6(1.8 mg, 0.002 mmol), and DMSO (1mL) under N2 atmosphere. The reaction mixture was then stirred for 7-21 h under irradiation using 5W blue LEDs (kmax 455 nm).Upon completion of the reaction, the mixture was concentrated in vacuum and purified by chromatography on silica gel (ethyl acetate:n-hexane 1:5) to afford 3-bromo-2-arylimidazo[1,2-a]pyridines 3. Yield: 84%; white solid; mp 63-65 C; 1H NMR (400 MHz, CDCl3): d 8.19 (d,J6.8 Hz, 1 H), 8.13 (d, J7.2 Hz, 2 H), 7.66 (d, J9.2 Hz, 1 H), 7.49 (t, J7.6 Hz,2H), 7.40 (t, J7.4 Hz, 1 H), 7.32-7.26 (m, 1 H), 6.95 (td, J6.9 Hz, 1.1 Hz, 1 H); 13CNMR (100 MHz, CDCl3): d 145.4, 142.6, 132.8, 128.5, 128.3, 127.9, 125.2, 124.0, 117.6,113.1, 91.8; HRMS (ESI) calcd for C13H10BrN2 [MH] 273.0027; found 273.0031
84% With [bis(acetoxy)iodo]benzene; ammonium bromide at 20℃; Inert atmosphere; regioselective reaction; Method 1: General procedure for the synthesis of 3-halo/thiocyanato-2-phenylimidazo[1,2-a]pyridinederivatives. General procedure: A mixture of 2-phenylimidazo[1,2-a]pyridine(1) (1 mmol), M-X (2a/2b/2c/2d) (1.5 mmol) and IBD (1.5 mmol)were taken in a mortar and the mixture ground with pestle until the solids melt ~15 min). A distinction odourof acetic acid was observed. The reaction was monitored by TLC and grinding continued till the startingmaterials disappear. The reaction mixture was extracted with ethyl acetate (30mL) and washed with water (10ml) to remove any remnant inorganic salts. The organic layer was separated and dried over Na2SO4. Solventwas removed in vacuo. The crude product thus obtained was purified by column chromatography (silicon60-120 mesh, and EtOAc: hexane, 5:95).
83% With N-Bromosuccinimide; sodium hydrogencarbonate In N,N-dimethyl-formamide at 50 - 70℃;
83% With sodium bromite; acetic acid In N,N-dimethyl-formamide at 60℃; for 10h; regioselective reaction;
80% With N-Bromosuccinimide In acetonitrile at 0 - 25℃; for 1h; 1 To a 100 mL round-bottom-flask was added 2-phenylimidazo[1 ,2-a]pyridine (5 g, 25.74 mmol) and acetonitrile (26 mL). The suspension was cooled to 0 °C. N BS (4.81 g, 27.03 mmol) was added portionwise over 10 min. The orange reaction was stirred at room temperature for 1 h. The reaction was concentrated in vacuo, then the residue was dissolved in EtOAc (40 mL) and washed with 1 M NaOH (30 mL). The aqueous layer was extracted with EtOAc (2 x 40 mL), and the combined organic layers were dried (Na2S04), filtered and concentrated to give a black solid. The solid was further purified by filtration over a silica plug, rinsing with EtOAc/heptanes/DCM. After concentration in vacuo, 5.6 g (80%) of brown solid were obtained. The molecular mass of the product was confirmed by LC-MS [M-H] 275.0.
77% With N-Bromosuccinimide In acetonitrile at 20℃; for 2h;
73% With dimethyl sulfoxide; ethylene dibromide at 80℃; for 12h;
71% With tetrabutylammomium bromide In acetonitrile at 20℃; for 0.5h; General procedure for the synthesis of 4a-4o General procedure: The respective 2-arylimidazo[1,2-a]pyridine (50 mg), Selectfluor (2 equivalents), and charged nucleophiles (2 equivalents) were stirred in 2 mL of acetonitrile or acetonitrile:water (2:8) mixture at room temperature. After 30 min, the reaction mixture was added into water and extracted with twice with EtOAc. The organic layers were combined, dried with Na2SO4 and evaporated under vaccum. The crude solid was then purified using column chromatography
69% With 1,3,5-tribromo-1,3,5-triazinane-2,4,6-trione In ethanol at 20℃; for 1h; Schlenk technique; Green chemistry; regioselective reaction;
With bromine; nitric acid
Multi-step reaction with 2 steps 1: trichlorophosphate / 3.5 h / 0 - 60 °C 2: N-Bromosuccinimide; tert.-butylhydroperoxide / water; acetonitrile / 60 °C

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[2]Current Patent Assignee: ZHENGZHOU UNIVERSITY - CN113861192, 2021, A Location in patent: Paragraph 0024-0025
[3]Location in patent: scheme or table Marhadour, Sophie; Bazin, Marc-Antoine; Marchand, Pascal [Tetrahedron Letters, 2012, vol. 53, # 3, p. 297 - 300]
[4]Zhou, Xiaoqiang; Yan, Hao; Ma, Chaowei; He, Yongqin; Li, Yamin; Cao, Jinhui; Yan, Rulong; Huang, Guosheng [Journal of Organic Chemistry, 2016, vol. 81, # 1, p. 25 - 31]
[5]Semwal, Rashmi; Ravi, Chitrakar; Kumar, Rahul; Meena, Ramavatar; Adimurthy, Subbarayappa [Journal of Organic Chemistry, 2019, vol. 84, # 2, p. 792 - 805]
[6]Jiang, Hongmei; Guo, Dingyi; Zhang, Yixin; Shen, Qin-Peng; Tang, Shiyun; You, Junheng; Huo, Yi; Wang, Huixian; Gui, Qing-Wen [Synthesis, 2020, vol. 52, # 18, p. 2713 - 2720]
[7]Park, Jin Wha; Kim, Yong Hwan; Kim, Dae Young [Synthetic Communications, 2020, vol. 50, # 5, p. 710 - 718]
[8]Zhou, Zhilin; Yuan, Yong; Cao, Yangmin; Qiao, Jin; Yao, Anjin; Zhao, Jing; Zuo, Wanqing; Chen, Wenjie; Lei, Aiwen [Chinese Journal of Chemistry, 2019, vol. 37, # 6, p. 611 - 615]
[9]Current Patent Assignee: HUNAN AGRICULTURAL UNIVERSITY - CN111004234, 2020, A Location in patent: Paragraph 0024-0028
[10]Das, Dharmendra; Bhutia, Zigmee T.; Panjikar, Padmini C.; Chatterjee, Amrita; Banerjee, Mainak [Journal of Heterocyclic Chemistry, 2020, vol. 57, # 11, p. 4099 - 4107]
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[15]Salgado-Zamora, Hector; Velazquez, Manuel; Mejia, Daniel; Campos-Aldrete; Jimenez, Rogelio; Cervantes, Humberto [Heterocyclic Communications, 2008, vol. 14, # 1-2, p. 27 - 32]
[16]Li, Junxuan; Tang, Jiayi; Wu, Yuanheng; He, Qiuxing; Yu, Yue [RSC Advances, 2018, vol. 8, # 9, p. 5058 - 5062]
[17]Current Patent Assignee: IDEMITSU KOSAN CO LTD - WO2019/155363, 2019, A1 Location in patent: Page/Page column 137
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[23]Singh, Davinder; Tali, Javeed Ahmad; Kumar, Gulshan; Shankar, Ravi [New Journal of Chemistry, 2021, vol. 45, # 44, p. 20551 - 20555]
  • 2
  • [ 4105-21-9 ]
  • [ 3672-37-5 ]
YieldReaction ConditionsOperation in experiment
98% With tert.-butylnitrite In acetonitrile at 70℃; for 0.25h; regioselective reaction;
90% With tert.-butylnitrite In acetonitrile at 70℃; for 0.25h; Preparation of 7b Initially, 3-iodo substituted imidazo pyridine (0.25 mmol, 80 mg) and t-BuONO (0.30mmol, 35mg) in 5 ml acetonitrile was taken in 25 ml round bottomed flask at 70°C for 15minutes stirring. After completion the reaction , the product was purified through columnchromatography using petroleum ether and ethyl acetate as eluents.
83% With sodium nitrite In water; acetic acid cooling;
81% With tert.-butylnitrite In acetonitrile at 90℃; for 18h; Sealed tube; 3-Nitrosoimidazo[1,2-a]pyridines 3; General Procedure General procedure: A 25 mL Schlenk tube equipped with a magnetic stirring bar was charged with substituted imidazopyridine 1 (0.3 mmol), t-BuONO (2; 0.6 mmol), and MeCN (2 mL). The tube was sealed and then the mixture was allowed to stir under an air atmosphere at 90 °C for 18 h. After completion of the reaction, the resulting solution was cooled to r.t., and the solvent was removed with the aid of a rotary evaporator. The residue was purified by column chromatography (silica gel, PE-EtOAc) to provide the desired product 3.
70% With sodium nitrite In water; acetic acid for 24h;
69% With sodium nitrite In acetonitrile at 20℃; for 0.5h; General procedure for the synthesis of 4a-4o General procedure: The respective 2-arylimidazo[1,2-a]pyridine (50 mg), Selectfluor (2 equivalents), and charged nucleophiles (2 equivalents) were stirred in 2 mL of acetonitrile or acetonitrile:water (2:8) mixture at room temperature. After 30 min, the reaction mixture was added into water and extracted with twice with EtOAc. The organic layers were combined, dried with Na2SO4 and evaporated under vaccum. The crude solid was then purified using column chromatography
28% With iodine; sodium nitrite In ethanol at 80℃; for 12h; regioselective reaction;
With acetic acid; sodium nitrite
With sulfuric acid; sodium acetate; sodium nitrite
With sodium nitrite In acetic acid
With acetic acid; sodium nitrite In water at 20℃; for 3h;
With sodium nitrite In water; acetic acid 1.B PREPARATION 1: (B) A mixture of 20 g. of 2-phenylimidazo[1,2-a]pyridine and 200 ml. of glacial acetic acid is stirred at room temperature until the 2-phenylimidazo[1,2-a]pyridine is completely dissolved. The acetic acid solution is diluted with 20 ml. of water and cooled to 0° to 5° C. in an ice-salt bath. A solution of 15 g. of NaNO2 in 50 ml. of water is added dropwise to the cooled acetic acid solution while the solution is constantly stirred by a mechanical stirrer. The temperature of the solution is kept below 5° C. during the addition of the NaNO2 solution and three hours thereafter. Three hours after the completion of NaNO2 addition, the reaction mixture is further stirred at room temperature for 12 more hours. The green precipitate is filtered and washed thoroughly with H2 O on a glass filter. The residue is recrystallized once from ethanol to yield 15 g., 3-nitroso-2-phenylimidazo[1,2-a]pyridine, m.p. 165°-167°.

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[3]Salgado-Zamora, Hector; Velazquez, Manuel; Mejia, Daniel; Campos-Aldrete; Jimenez, Rogelio; Cervantes, Humberto [Heterocyclic Communications, 2008, vol. 14, # 1-2, p. 27 - 32]
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[9]Matweew [1936, p. 1005,1010, 1011][Chemisches Zentralblatt, 1938, vol. 109, # I, p. 603]
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[12]Current Patent Assignee: Adhikary; Parimal K. - US4143142, 1979, A
  • 3
  • [ 504-29-0 ]
  • [ 98-86-2 ]
  • [ 4105-21-9 ]
YieldReaction ConditionsOperation in experiment
99% With tetra-n-butylammonium tetrafluoroborate; hydrogen iodide In ethanol at 50℃; for 24h; Electrochemical reaction; Schlenk technique; Green chemistry;
96% With oxygen In ethanol at 80℃; for 10h; Sealed tube;
92% With sodium iodide In toluene at 80℃; for 6h; Green chemistry;
90% With 4-dimethylaminopyridine; iodine at 20℃; for 2.5h; Sealed tube; 1 Example 1 One kind of 2-phenyl-imidazo [1,2-a] pyridine compounds in the synthesis method, comprising the steps of: Weighed 1.41 g (15 mmol) of 2-aminopyridine, 1.2 g (10 mmol) of acetophenone, 2.54 g (10 mmol) of iodine and 1.22 g (10 mmol) of 4-dimethylaminopyridine, placed 25 ml of a mechanical chemical reaction tank, parallel to feed another equally mechanical chemical reaction tank, fixed in Germany Lai Chi chemical reactor mechanical swing arm tightened after sealing.The reaction of the oscillation frequency of 30Hz at 90 minutes.1 the mixture was extracted with ethyl acetate and water, the combined ethyl acetate phase was collected and dried over anhydrous magnesium sulfate and filtered, the filtrate evaporated and purified by silica gel column chromatography: After completion of the reaction, the reaction mixture by volume of two cans 1 Analysis (eluent: petroleum ether the V / V ethyl acetate = 3: 1) to obtain 1.74 g of 2-phenyl-imidazo [1,2-a] pyridine pure state as a white solid in 90% yield .
90% With N-iodo-succinimide In water monomer at 80℃; for 6h; Green chemistry; 4.3 Typical procedure for the synthesis of 2-arylimidazo [1,2-a]pyridines A mixture of 2-aminopyridine 1a (94.11mg, 1mmol) and acetophenone 2a (120.15mg, 1mmol, 1 equiv.) in aqueous medium was stirred and heated at 80°C for 6h, after addition of NIS (224.98mg, 1mmol, 1 equiv.). After completion of the reaction (TLC), the mixture was cooled to room temperature and diluted with Et2O (10mL) and transferred into a separatory funnel. The organic layer was collected and further extracted with Et2O (2×10mL). The combined organic extract were dried (anh Na2SO4), filtered, then filtrate concentrated under rotary vacuum evaporation, and the residue was charged on to chromatography (100-200 mesh silica gel) column and eluted with EtOAc-hexane to afford pure 3a (192.36mg, 90%). All the remaining reactions were performed following this general procedure. 4.3.1 2-phenylimidazo[1,2-a]pyridine (3a) (ESI) yellowish solid; (90%), m. p. 135-137°C; 1H NMR (400MHz, CDCl3) δ 8.09 (d, J=6.7Hz, 1H), 7.94 (d, J=7.8Hz, 2H), 7.84 (s, 1H), 7.62 (d, J=9.1Hz, 1H), 7.42 (t, J=7.6Hz, 2H), 7.32 (t, J=7.3Hz, 1H), 7.19-7.10 (m, 1H), 6.75 (t, J=6.7Hz, 1H); 13C NMR (101MHz, CDCl3) δ 145.9, 145.9, 133.9, 128.9 (2C), 128.2, 126.2 (2C), 125.8, 124.9, 117.7, 112.6, 108.3; MS (ESI) (m/z) 194.93 (M)+.
90% With N-iodo-succinimide In water monomer at 80℃; for 6h; Green chemistry; 4.3 Typical procedure for the synthesis of 2-arylimidazo [1,2-a]pyridines A mixture of 2-aminopyridine 1a (94.11mg, 1mmol) and acetophenone 2a (120.15mg, 1mmol, 1 equiv.) in aqueous medium was stirred and heated at 80°C for 6h, after addition of NIS (224.98mg, 1mmol, 1 equiv.). After completion of the reaction (TLC), the mixture was cooled to room temperature and diluted with Et2O (10mL) and transferred into a separatory funnel. The organic layer was collected and further extracted with Et2O (2×10mL). The combined organic extract were dried (anh Na2SO4), filtered, then filtrate concentrated under rotary vacuum evaporation, and the residue was charged on to chromatography (100-200 mesh silica gel) column and eluted with EtOAc-hexane to afford pure 3a (192.36mg, 90%). All the remaining reactions were performed following this general procedure. 4.3.1 2-phenylimidazo[1,2-a]pyridine (3a) (ESI) yellowish solid; (90%), m. p. 135-137°C; 1H NMR (400MHz, CDCl3) δ 8.09 (d, J=6.7Hz, 1H), 7.94 (d, J=7.8Hz, 2H), 7.84 (s, 1H), 7.62 (d, J=9.1Hz, 1H), 7.42 (t, J=7.6Hz, 2H), 7.32 (t, J=7.3Hz, 1H), 7.19-7.10 (m, 1H), 6.75 (t, J=6.7Hz, 1H); 13C NMR (101MHz, CDCl3) δ 145.9, 145.9, 133.9, 128.9 (2C), 128.2, 126.2 (2C), 125.8, 124.9, 117.7, 112.6, 108.3; MS (ESI) (m/z) 194.93 (M)+.
89% With cyanamide; iodine In toluene at 110℃;
87% In ethanol at 70℃; for 24h;
86% Stage #1: acetophenone With NBS; 2,2'-azobisisobutyronitrile In ethyl acetate at 60℃; for 1h; Stage #2: 2-aminopyridine With anhydrous sodium carbonate In water monomer at 80℃; for 2h; 3.2.1. General Procedure for the Synthesis of Nitrogen-Containing Heterocycles General procedure: Synthesis of 3a is representative. To a solution of ethylbenzene (1a, 1 mmol, 107 mg) in ethylacetate:water (5:1, 6 mL) were added NBS (3.5 mmol, 628 mg) and AIBN (0.1 mmol, 16.5 mg) at roomtemperature, and the mixture was stirred at 65 °C for 1.5 h. The mixture was concentrated to drynessand then dissolved in water (5 mL), followed by reaction with 2-aminopyridine (2a, 1.2 mmol, 114 mg)and sodium carbonate (5 mmol, 534 mg) for 2 h at 80 °C. After completion of the reaction (as indicatedby TLC), the crude product was extracted with ethyl acetate (3 x 10 mL). The combined organic layerwas dried over anhydrous Na2SO4 and concentrated in vacuo. The crude product was purified bysilica gel column chromatography (PE/EA = 8/1-4/1, v/v) to give 3a (78% yield) as a white solid.
85% With ammonium acetate; iodine In chloroform at 20℃; for 1h; Procedure for the synthesis of 2-arylimidazo[1,2-a]pyridines (3a-r): General procedure: A mixture of 2-aminopyridine 1 (1.2 mmol), aryl methyl ketone 2a-r (1.0 mmol), I2 (1.0 mmol) and NH4OAc (2.0 mmol) in CHCl3 (10 mL) in a 25 mL round bottomed flask was stirred at room temperature until the completion of reaction (Table 2). The reaction mixture was further diluted with 20 mL of CHCl3, washed with saturated solution of Na2S2O3 (2x10 mL), water (1x10 mL), brine (1x10 mL) and finally dried over anhydrous Na2SO4. The solvent was removed and the residue after recrystallisation with EtOH afforded the desired 2-arylimidazo[1,2-a]pyridines (3a-r, 63-85%). For entries 2i and2n-q, reaction was performed under reflux.
84% With 1,10-Phenanthroline; Cu(OAc)2*H2O; zinc(II) iodide In 1,2-dichloro-benzene at 120℃; for 24h;
82% Stage #1: acetophenone With 1-butyl-3-methylimidazolium tribromide In neat (no solvent) at 30℃; for 0.0833333h; Stage #2: 2-aminopyridine With anhydrous sodium carbonate In neat (no solvent) at 30℃; for 0.666667h;
82% With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 24h;
82% With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 24h;
82% With copper (I) iodide; boron trifluoride diethyl ether complex In N,N-dimethyl-formamide at 60℃; for 24h; Typical Procedure for the Synthesis of 2- Phenylimidazo[1,2-a]pyridine (3a) 470 mg (5.0 mmol) of 2-aminopyridine 1a, 1200 mg (10 mmol) of acetophenone 2a, CuI 5 mol% (47 mg; 0.25 mmol), BF3·Et2O (45-50% purity); 10 mol%, 0.5 mmol) and DMF (2 mL) were placed in a 25-mL double-necked round-bottomed flask. The mixture was heated in an oil bath at 60 oC for 24 h under an oxygen atmosphere (balloon). After completion of the reaction, it was allowed to attain to room temperature and then the mixture was poured into 20 mL of sodium carbonate solution. The product was extracted with DCM (50 mL 3) and dried with anhydrous Na2SO4. Removal of the solvent under reduced pressure left a residue that was purified through column chromatography using silica gel (30% EtOAc/hexane) to afford 3a; yield: 0.799 g (82%).
81% With indium trifluoromethanesulfonate; copper (I) iodide; oxygen In 1-methyl-pyrrolidin-2-one at 100℃; for 30h; Schlenk technique;
80% Stage #1: acetophenone With [hydroxy(2,4-dinitrobenzenesulfonyloxy)iodo]benzene In acetonitrile for 1h; Heating; Stage #2: 2-aminopyridine With anhydrous sodium carbonate In acetonitrile at 20℃; for 1h;
80% Stage #1: 2-aminopyridine; acetophenone With iodine; 3-butyl-1-methyl-1H-imidazol-3-ium hexafluorophosphate at 30 - 35℃; for 2.5h; Sonication; Stage #2: With potassium carbonate In water monomer at 40 - 45℃; for 0.333333h; Sonication; General procedure for the synthesisof imidazo[1,2-a]pyridines derivatives usingultrasonic irradiation General procedure: A mixture of acetophenone 1 (0.51 mmol), 2-aminopyridine2 (1.17 mmol), iodine (0.61 mmol), and 20 mol%[BMIM]PF6 (0.10 mmol) were added into a 5-cm3 driedflat-bottom capped-vial equipped with magnetic bar andirradiated at 30-45 C at a frequency of 40 kHz for 1-3 h.The reaction temperature of ultrasonic bath was controlledmanually by addition or removal of small amounts water.Then, the excess aqueous K2CO3 (35%) was subsequentlyadded and further irradiated at the same frequency at40-45 C for 20 min to accomplish the cyclization. Aftercompletion, the mixture was diluted with CHCl3 and neutralizedusing 3.5 M HCl. The organic layer was separatedand the aqueous layer was extracted with CHCl3. Thecombined organic layer was dried with Na2SO4 and concentratedunder reduced pressure. The crude product wasfurther purified by column chromatography using ethylacetate/hexane (1:9-2:8) to give the desired product.
78% With iodine In 1,2-dichloro-benzene at 100℃; for 20h; Inert atmosphere;
78% With iodine In cyclohexane at 60℃; for 0.25h; Green chemistry; General procedure: Initially, 2-amino pyridine (0.25 mmol), substituted acetophenones (0.25 mmol), iodine(20 mol%, 13 mg), and cyclohexane (2 mL) were taken in 25-mL round-bottomed flaskand stirred at 60 °C. The stirring was continued for 15 min under this condition. Later,the reaction mixture diluted with 30 mL of water and collected the organic layer with ethylacetate. The organic layer was dried over Na2SO4 and concentrated under reduced pressure.The crude product was purified through column chromatography using petroleumether and ethyl acetate as an eluant.
77% With 5-ethyl-1,3,7,8-tetramethylalloxazinium triflate; iodine; oxygen In ethyl acetate at 70℃; for 32h;
72% With iodine In ethanol at 20℃; for 3h; Green chemistry;
71% With copper (I) iodide In 1,4-dioxane at 100℃; for 14h;
68% Stage #1: acetophenone With polymer-supported [(hydroxy(sulfonyloxy)iodo]benzene In acetonitrile for 16h; Heating; Stage #2: 2-aminopyridine With potassium carbonate In acetonitrile for 6h; Heating;
61% With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 24h;
41% With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In neat (no solvent) at 40℃; for 24h; Schlenk technique;
39% With iron(III) trichloride hexahydrate; iodine; oxygen In chlorobenzene at 110℃; for 20h; Green chemistry;
17% In benzene at 360 - 380℃; for 10h;
Multi-step reaction with 2 steps 1: iodine / 4 h / 110 °C / Neat (no solvent) 2: sodium hydroxide / water monomer / 1 h / 100 °C
With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 24h;
With copper (I) iodide In 1,4-dioxane at 100℃;
With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 12h; 1.2 Example 1 Step 2: Under oxygen protection,2-aminopyridine (0.5 mmol), acetophenone (10.0 mmol),Copper iodide (0.25 mmol) and boron trifluoride ether (0.14 mL) were added to 2 mL of DMF solvent and reacted at 60°C for 12 hours.After the reaction is completed, cool to room temperature, extract with ethyl acetate (30 mL) and dry over anhydrous sodium sulfate.Concentrated silica gel column chromatography (volume ratio of petroleum ether to ethyl acetate 3:1) was purified to give 2-phenylimidazo[1,2-a]pyridine.
With copper (I) iodide at 100℃; for 12h; Schlenk technique;
With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 12h; 1.1; 8.1; 9.1 Example 1 Step 1: 2-aminopyridine (0.5 mmol), acetophenone (10.0 mmol), cuprous iodide (0.25 mmol) and boron trifluoride diethyl ether (0.14 mL) were added to 2 mL of DMF solvent under oxygen protection.The reaction was carried out at 60 ° C for 12 hours;After the reaction is over, coldThe mixture was extracted with ethyl acetate (30 mL), dried over anhydrous sodium sulfate, and then evaporated to silica gel column chromatography (ethyl ether and ethyl acetate volume ratio of 3:1) to give 2-phenylimidazole [1, 2-a]pyridine.
With copper (I) iodide; boron trifluoride diethyl ether complex In N,N-dimethyl-formamide at 60℃; for 24h;
Stage #1: acetophenone With iodine; copper(II) oxide In methanol Reflux; Stage #2: 2-aminopyridine In methanol Reflux; Preparation of starting materials General procedure: Imidazopyridine derivatives 1 were prepared in accordance with literature methods: Finely powdered CuO (88 mg,1.1 mmol) and I2 (279 mg,1.1 mmol) were added to a solution of acetophenone derivatives (1 mmol) in anhydrous MeOH (20 mL). The mixture was refluxed for 1-10 h. When disappearance of the reactant (monitored by TLC), then added substituted 2-aminopyridine (1.0 mmol) at reflux for another 2 h. After the reaction completed, the mixture was filtered and the solvent was removed under reduced pressure. The residue was poured into 10% Na2S2O3 solution (50 mL), the mixture was extracted with EtOAc (3 50 mL), and the organic layer was dried (Na2SO4). Removal of the solvent and purification of the residue by column chromatography gave the desired product as yellow solid.
With Sodium hydrogenocarbonate In ethanol at 20℃; for 6h;
With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 12h; 3.1; 4.1; 5.1 Step one: under the protection of the oxygen, the 2 - aminopyridine (0.5 mmol), acetophenone (10.0 mmol), cuprous iodide (0.25 mmol) and boron trifluoride diethyl ether (0.14 ml) add 2 ml of DMF solvent, 60 °C reaction under 12 hour; after the reaction, cooling to room temperature, the ethyl acetate (30 ml) extraction, anhydrous sodium sulfate after drying, concentrated silica gel column chromatography (petroleum ether and ethyl acetate to the volume proportion 3:1) purification of imidazo [1, 2 - a] - pyridine compound.
With copper (I) iodide In 1,4-dioxane at 100℃; for 14h; 1. General procedure for the synthesis of 2-aryl imidazo[1,2-a]pyridines General procedure: acetophenones (5 mmol), 2-amino pyridines (1.2 equiv.),CuI and 1,4-dioxane (20 mL) wereadded to a 100 mL flask.The mixture was stirred at 100 °C under ambient air for 14 h, then theresulting mixture was concentrated by rotary evaporator. The crude product was purified over acolumn of silica gel (eluant: EtOAc:Hexanes, 1:2) to afford the desired product.
With copper (I) iodide; boron trifluoride diethyl ether complex; oxygen In N,N-dimethyl-formamide at 60℃; for 24h;

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  • 4
  • [ 4105-21-9 ]
  • [ 64413-90-7 ]
YieldReaction ConditionsOperation in experiment
97% With N-iodo-succinimide In acetonitrile at 20℃; for 5h; 72 Preparation 72; 3-iodo-2-phenylimidazo [1, [2-A] PYRIDINE] Treat a solution of 2-phenylimidazo [1, 2-a] pyridine (50 mg, 0.257 mmol) in acetonitrile (1.25 [ML)] with N-iodosuccinimide (NIS) (69 mg, 0.309 mmol) at room temperature for 5 hours. Dilute the mixture with ether (10 mL), wash with a saturated aqueous solution [OF NAHC03] (15 [ML)] and [NAHS03] [(40%,] 15 mL), dry [(NA2S04)] and concentrate in vacuo. A yellow solid is obtained, 80 mg, 97% yield. MS [(ES+)] : [FNLZ =] 321.0 (M+H) [+]
95% With 1,3-Diiodo-5,5-dimethyl-2,4-imidazolidinedione In dimethyl sulfoxide at 50℃; for 1h; Sealed tube; 3 Synthesis of 3-iodo-2-phenylimidazo[1,2-α]pyridine: The substrate 48.5 mg (0.25 mmol) 2-phenylimidazo[1,2-α]pyridine, 94.98 mg (0.25 mmol) diiodine, 2.0 mL DMSO was added to a 30 mL sealed tube under an air environment, and then Seal the tube and put it into an ultrasonic cleaning machine (Jiekang ultrasonic cleaning machine, ultrasonic power is 70W, heating power is 60W, ultrasonic frequency is 40KHz), the reaction temperature is 50 , the reaction is 1h, after the reaction is completed, the reaction solution is cooled to At room temperature, 10 mL of saturated brine was added, extracted three times with 15 mL of ethyl acetate, and the organic layers were combined. The organic layer was dried over anhydrous sodium sulfate, filtered, and the solvent was removed under reduced pressure.The residue was separated by silica gel column chromatography (ethyl acetate/petroleum ether: 1/4 as eluent) to obtain 76.03 mg of a yellow solid with a calculated yield of 95%.
95% With triiodoisocyanuric acid In ethanol at 20℃; for 0.166667h; Schlenk technique; Green chemistry; regioselective reaction;
92% With sodium iodide In acetonitrile at 20℃; for 4h; Electrochemical reaction; General procedure for the electrochemical iodination of imidazo[1,2-a]pyridines General procedure: An undivided cell was equipped with a platinum plate (1.00.7 cm2) as the anode anda platinum plate (1.00.7 cm2) as the cathode and connected to a DC regulated powersupply. A mixture of imidazo[1,2-a]pyridine 1 (0.1 mmol) and NaI (2a, 0.2 mmol) in acetonitrile (3.0 mL) was added to an undivided cell. The reaction mixture was stirredand electrolyzed at a constant current of 5mA under room temperature for 4 h. Whenthe reaction was completed, electrodes were washed with ethanol (EtOH). The combinedorganic solvent was removed in vacuo. The residue was purified by flash chromatography(EtOAc:Hex, 1:5) to afford 3-iodo imidazo[1,2-a]pyridine 3.3-Iodo-2-phenylimidazo[1,2-a]pyridine (3a): Yield: 92%; yellow solid; mp140-142 C; 1H NMR (400 MHz, CDCl3) d 8.24 (d, J 6.8 Hz, 1H), 8.08-8.05 (m, 2H),7.63 (d, J 8.4 Hz, 1H), 7.52-7.46 (m, 2H), 7.43-7.37 (m, 1H), 7.30-7.24 (m, 1H),6.97-6.92 (m, 1H); 13C NMR (100 MHz, CDCl3) d 148.0, 147.9, 133.4, 129.0, 128.5,128.4, 126.6, 125.7, 117.5, 113.3, 59.6; HRMS (ESI) calculated for C13H10IN2 [MH]320.9889; found 320.9893.
92% With N-iodo-succinimide at 20℃; for 1h;
91% With 4-(3-methylimidazolium)butanesulfonate; iodine In water at 20℃; for 2h; Sealed tube; Green chemistry; regioselective reaction; 3-Iodo-2-phenylimidazo[1,2-a]pyridine (2a);14e Typical Procedure To a mixture of 2-phenylimidazo[1,2-a]pyridine (1a, 39 mg, 0.2 mmol), molecular I2 (50 mg, 1 equiv), and 4-(3-methylimidazolium)butane-1-sulfonate (I, 9 mg, 20 mol%) in a sealed tube was added water (2 mL) and the mixture was stirred at r.t. for 2 h. After completion of the reaction (TLC), the mixture was extracted with EtOAc (20 mL). The organic phase was dried (anhyd Na2SO4) and concentrated under reduced pressure give the crude residue which was purified by column chromatography (silica gel, 60-120 mesh, petroleum ether/EtOAc, 9:1) to afford 2a as a white solid: yield: 58 mg (91%); mp 132-134 °C.
86% With pyridine; iodine at 50℃; for 5h;
85% With N-iodo-succinimide In acetonitrile at 20℃; for 1.5h; Darkness; Inert atmosphere; regioselective reaction;
84% With pyridine; iodine at 50℃; for 5h;
83% With N-iodo-succinimide In acetonitrile at 20℃; for 0.5h;
82% With iodine In 1,2-dichloro-benzene at 100℃; for 20h;
82% With dipotassium peroxodisulfate; sodium iodide In acetonitrile at 50℃; for 24h; Sealed tube;
80% With N-iodo-succinimide In acetonitrile at 20℃; for 3h; Preparation of 7a Initially, imidazo[1,2-a] pyridine (0.25 mmol, 49 mg) and NIS (0.30mmol, 68mg) were taken in acetonitrile (3ml) at room temp for for 3 hr. after completionof the reaction, the product was purified through column chromatography usingpetroleum ether and ethyl acetate as eluents.
80% With dipotassium peroxodisulfate; sodium iodide In water; acetonitrile at 60℃; for 2h; regioselective reaction; General procedure for the synthesis of 3-iodoimidazo[1,2-a]pyridines 3 General procedure: Potassium persulfate (K2S2O8) (270.0 mg, 1.0 mmol) was added to a suspension of imidazo[1,2-a]pyridines 1 (0.5 mmol) and sodium iodide (NaI, 374.8 mg, 2.5 mmol) in acetonitrile/H2O (2:1 v/v, 3 mL), and the reaction mixture was stirred at 60 °C. After completion of the reaction, the reaction mixture was quenched by the addition of sat. aq Na2S2O3 (5 mL). Further stirring was followed by extraction with EtOAc (2 × 20 mL). The combined organic layer was washed with H2O (20 mL), brine (20 mL), dried over Na2SO4, filtered, and concentrated (aspirator). The residue was purified by column chromatography using EtOAc/hexanes as the eluent to afford the corresponding product.
80% With N-Bromosuccinimide In N,N-dimethyl-formamide at 20℃; for 3h; Preparation of a Compound of Formula 6a (3-iodo-2-phenyl-imidazo [1, 2-a] pyridine) To a solution of 2-phenylimidazo [1, 2-a] pyridine (2.3 g, 0.01 mol) in DMF (15 mL) was added N-iodosuccinimide (2.7 g, 12 mmol) at room temperature. The solution was stirred at room temperature for 3 h. Water (30 mL) was added, and the solution was extracted with ethyl acetate (3 × 20 mL) . The combined organic layer was dried with Mg 2SO 4. The mixture was filtered and the filtrate was concentrated in vacuo. The residue was purified by silica gel flash column chromatography with 10%ethyl acetate in hexane as the mobile phase, to afford 3-iodo-2-phenyl-imidazo [1, 2-a] pyridine (2.6 g, 80%) as a white solid. LCMS (ESMS) : m/z: 321.9 (M ++1) .
78% With [bis(acetoxy)iodo]benzene; sodium iodide at 20℃; Inert atmosphere; regioselective reaction; Method 1: General procedure for the synthesis of 3-halo/thiocyanato-2-phenylimidazo[1,2-a]pyridinederivatives. General procedure: A mixture of 2-phenylimidazo[1,2-a]pyridine(1) (1 mmol), M-X (2a/2b/2c/2d) (1.5 mmol) and IBD (1.5 mmol)were taken in a mortar and the mixture ground with pestle until the solids melt ~15 min). A distinction odourof acetic acid was observed. The reaction was monitored by TLC and grinding continued till the startingmaterials disappear. The reaction mixture was extracted with ethyl acetate (30mL) and washed with water (10ml) to remove any remnant inorganic salts. The organic layer was separated and dried over Na2SO4. Solventwas removed in vacuo. The crude product thus obtained was purified by column chromatography (silicon60-120 mesh, and EtOAc: hexane, 5:95).
77% With sodium iodide In acetonitrile at 20℃; for 0.5h; General procedure for the synthesis of 4a-4o General procedure: The respective 2-arylimidazo[1,2-a]pyridine (50 mg), Selectfluor (2 equivalents), and charged nucleophiles (2 equivalents) were stirred in 2 mL of acetonitrile or acetonitrile:water (2:8) mixture at room temperature. After 30 min, the reaction mixture was added into water and extracted with twice with EtOAc. The organic layers were combined, dried with Na2SO4 and evaporated under vaccum. The crude solid was then purified using column chromatography
75% With copper(l) iodide In 1-methyl-pyrrolidin-2-one at 120℃; for 17h;
73% With N-iodo-succinimide In acetonitrile at 20℃; for 1h;
72% With iodine In pyridine at 50℃; for 5h; 13 Synthesis Example 13: Synthesis of Intermediate 11 400 g (2 mmol) of Intermediate 10 was dissolved in 10 mL of pyridine, and 760 g (3 mmol) of iodine was added thereto. The mixture was stirred at 50°C for 5 hours, and an oxalic acid solution was added thereto to terminate the reaction. The mixture was subjected to extraction using 10 mL of dichloro methane, and then an organic layer was collected and dried using magnesium sulfate to evaporate the solvent. The residue was separated and purified using silica gel column chromatography to obtain 462 mg (yield: 72%) of Intermediate 11. This compound was identified using HR-MS. C13H9lN2 Calculated value: 319.9810; Measured value: 319.9813
72% With pyridine; iodine at 50℃; for 5h; Synthesis of Intermediate 6 2.52 g (13 mmol) of Intermediate 5 was dissolved in 50 mL of pyridine, and 4.95 g (19.5 mmol) of iodine was added thereto. The mixture was stirred at 50°C for 5 hours, and then an oxalic acid solution was added thereto to terminate the reaction. The mixture was subjected to extraction using 50 mL of dichloromethane, and an organic layer was collected and dried using magnesium sulfate to evaporate the solvent. The residue was separated and purified using silica gel column chromatography to obtain 3 g (yield: 72%) of Intermediate 6. This compound was identified using HR-MS. C13H91N2 calc.: 319.9810; found: 319.9814
72% With pyridine; iodine at 50℃; for 5h; 400 mg (2 mmol) of intermediate 4 was dissolved in 10 mL of pyridine, and 760 mg (3 mmol) of iodine was added. The reaction product was stirred at 50°C for 5 hours, and an aqueous solution of oxalic acid was added to the reaction product, thereby completing the reaction. The reaction product was extracted with 10 mL of dichloromethane. Then, an organic layer was collected and dried using magnesium sulfate to evaporate the solvent. The residue was separated and purified using silica gel column chromatography to obtain 462 mg (yield: 72%) of Intermediate 5. This compound was identified using HR-MS. C13H9IN2calc.: 319.9810; found: 319.9811
48% Stage #1: 2-phenylimidazo[1,2-a]pyridine With iodine; 6-iodo-2-phenylimidazo[1,2-a]pyridine; 3-butyl-1-methyl-1H-imidazol-3-ium hexafluorophosphate at 30 - 35℃; for 2.5h; Sonication; Stage #2: With potassium carbonate In water at 100℃; for 1h; Irradiation; General procedure for the synthesisof imidazo[1,2-a]pyridines derivatives usingultrasonic irradiation General procedure: A mixture of acetophenone 1 (0.51 mmol), 2-aminopyridine2 (1.17 mmol), iodine (0.61 mmol), and 20 mol%[BMIM]PF6 (0.10 mmol) were added into a 5-cm3 driedflat-bottom capped-vial equipped with magnetic bar andirradiated at 30-45 C at a frequency of 40 kHz for 1-3 h.The reaction temperature of ultrasonic bath was controlledmanually by addition or removal of small amounts water.Then, the excess aqueous K2CO3 (35%) was subsequentlyadded and further irradiated at the same frequency at40-45 C for 20 min to accomplish the cyclization. Aftercompletion, the mixture was diluted with CHCl3 and neutralizedusing 3.5 M HCl. The organic layer was separatedand the aqueous layer was extracted with CHCl3. Thecombined organic layer was dried with Na2SO4 and concentratedunder reduced pressure. The crude product wasfurther purified by column chromatography using ethylacetate/hexane (1:9-2:8) to give the desired product.
46% With [bis(acetoxy)iodo]benzene; iodine In water at 20℃; for 0.5h;
16% With dmap; copper(l) iodide In N,N-dimethyl-formamide at 90℃; for 12h; Sealed tube;
With N-iodo-succinimide; potassium hydroxide In acetonitrile at 20℃; for 4h;
Multi-step reaction with 2 steps 1: trichlorophosphate / 3.5 h / 0 - 60 °C 2: iodine; dihydrogen peroxide / water; 1,2-dichloro-ethane / 12 h / 60 °C
Multi-step reaction with 2 steps 1: trichlorophosphate / 3.5 h / 0 - 60 °C 2: iodine; tert.-butylhydroperoxide / water; acetonitrile / 60 °C

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  • 5
  • [ 4105-21-9 ]
  • [ 34658-68-9 ]
YieldReaction ConditionsOperation in experiment
Multi-step reaction with 2 steps 1: 83 percent / N-iodosuccinimide / acetonitrile / 0.5 h / 20 °C 2: 85 percent / Pd(PPh3)4; aq. NaOH / 1,2-dimethoxy-ethane / 6 h / 75 °C
Multi-step reaction with 2 steps 1.1: tris[2-phenylpyridinato-C2,N]iridium(III); dipotassium hydrogenphosphate / acetonitrile / 12 h / 25 °C / Inert atmosphere; Irradiation 2.1: samarium diiodide / tetrahydrofuran / 0.08 h / 20 °C / Inert atmosphere 2.2: 0.5 h / 80 °C / Inert atmosphere
  • 6
  • [ 1142-19-4 ]
  • [ 4105-21-9 ]
  • [ 306278-24-0 ]
YieldReaction ConditionsOperation in experiment
96% With copper(l) iodide; oxygen In dimethyl sulfoxide at 110℃; regioselective reaction; 4.2. General procedure for chalcogenylation of azaheterocycles with dichalcogenides General procedure: A mixture of azaheterocycles 1 or 4 (0.20 mmol), dichalcogenides 2 (0.10 mmol), and CuI (0.020 mmol, 10 mol %) in DMSO (2.0 mL) was stirred at 110 °C under air atmosphere for 10-18 h until complete consumption of staring material as monitored by TLC. The solution was then cooled to room temperature, diluted with ethyl acetate (10 mL), washed with H2O (3×10 mL), dried over Na2SO4, filtered, and evaporated under vacuum. The crude product was purified by column chromatography on silica gel (eluting with PE/EA=25/1 to 4/1) to afford the desired products 3 or 5.
90% With tert-butylammonium hexafluorophosphate(V) In methanol; acetonitrile at 40℃; for 2h; Electrochemical reaction; Green chemistry;
89% With 1-benzyl-3-butyl-2-ethylimidazolium tetrafluoroborate; caesium carbonate at 80℃; for 15h; Green chemistry;
89% With ammonium iodide; water; acetic acid; dimethyl sulfoxide at 110℃; for 6h; Green chemistry; regioselective reaction; 14 4.2.1. General procedure for synthesis General procedure: N-heteroarene (0.25 mmol), diorganyl dichalcogenide (0.125 mmol) NH4I (0.025 mmol, 10 mol%, 3.6 mg), acetic acid (1 eq.) and the mixture of DMSO/H2O (2.5:2.5 eq.) were placed into a round-bottom flask. The reaction was stirred at 110 °C in an oil bath for appropriate time (Tables 3-6). After the completion of the reaction, the mixture was cooled to room temperature, quenched with water and the aqueous layer was extracted with EtOAc. The organic phase was dried over MgSO4, filtered, and the volatiles were completely removed under vacuum to give the crude product. Purification by flash chromatography on silica with a mixture of Hexane/EtOAc as eluent furnished the desired chalcogenated product.

  • 7
  • [ 100-32-3 ]
  • [ 4105-21-9 ]
  • [ 295363-15-4 ]
YieldReaction ConditionsOperation in experiment
92% With copper(l) iodide; oxygen; In dimethyl sulfoxide; at 110℃; General procedure: A mixture of azaheterocycles 1 or 4 (0.20 mmol), dichalcogenides 2 (0.10 mmol), and CuI (0.020 mmol, 10 mol %) in DMSO (2.0 mL) was stirred at 110 C under air atmosphere for 10-18 h until complete consumption of staring material as monitored by TLC. The solution was then cooled to room temperature, diluted with ethyl acetate (10 mL), washed with H2O (3×10 mL), dried over Na2SO4, filtered, and evaporated under vacuum. The crude product was purified by column chromatography on silica gel (eluting with PE/EA=25/1 to 4/1) to afford the desired products 3 or 5.
  • 8
  • [ 103-19-5 ]
  • [ 4105-21-9 ]
  • [ 131947-30-3 ]
YieldReaction ConditionsOperation in experiment
89% With copper(l) iodide; oxygen; In dimethyl sulfoxide; at 110℃; General procedure: A mixture of azaheterocycles 1 or 4 (0.20 mmol), dichalcogenides 2 (0.10 mmol), and CuI (0.020 mmol, 10 mol %) in DMSO (2.0 mL) was stirred at 110 C under air atmosphere for 10-18 h until complete consumption of staring material as monitored by TLC. The solution was then cooled to room temperature, diluted with ethyl acetate (10 mL), washed with H2O (3×10 mL), dried over Na2SO4, filtered, and evaporated under vacuum. The crude product was purified by column chromatography on silica gel (eluting with PE/EA=25/1 to 4/1) to afford the desired products 3 or 5.
76% With ammonium iodide; water; acetic acid; dimethyl sulfoxide; at 110℃; for 6h;Green chemistry; General procedure: N-heteroarene (0.25 mmol), diorganyl dichalcogenide (0.125 mmol) NH4I (0.025 mmol, 10 mol%, 3.6 mg), acetic acid (1 eq.) and the mixture of DMSO/H2O (2.5:2.5 eq.) were placed into a round-bottom flask. The reaction was stirred at 110 C in an oil bath for appropriate time (Tables 3-6). After the completion of the reaction, the mixture was cooled to room temperature, quenched with water and the aqueous layer was extracted with EtOAc. The organic phase was dried over MgSO4, filtered, and the volatiles were completely removed under vacuum to give the crude product. Purification by flash chromatography on silica with a mixture of Hexane/EtOAc as eluent furnished the desired chalcogenated product.
  • 9
  • [ 5335-84-2 ]
  • [ 4105-21-9 ]
  • [ 1310492-88-6 ]
YieldReaction ConditionsOperation in experiment
93% With copper(l) iodide; oxygen In dimethyl sulfoxide at 110℃; regioselective reaction; 4.2. General procedure for chalcogenylation of azaheterocycles with dichalcogenides General procedure: A mixture of azaheterocycles 1 or 4 (0.20 mmol), dichalcogenides 2 (0.10 mmol), and CuI (0.020 mmol, 10 mol %) in DMSO (2.0 mL) was stirred at 110 °C under air atmosphere for 10-18 h until complete consumption of staring material as monitored by TLC. The solution was then cooled to room temperature, diluted with ethyl acetate (10 mL), washed with H2O (3×10 mL), dried over Na2SO4, filtered, and evaporated under vacuum. The crude product was purified by column chromatography on silica gel (eluting with PE/EA=25/1 to 4/1) to afford the desired products 3 or 5.
93% With ammonium iodide; water; acetic acid; dimethyl sulfoxide at 110℃; for 6h; Green chemistry; regioselective reaction; 15 4.2.1. General procedure for synthesis General procedure: N-heteroarene (0.25 mmol), diorganyl dichalcogenide (0.125 mmol) NH4I (0.025 mmol, 10 mol%, 3.6 mg), acetic acid (1 eq.) and the mixture of DMSO/H2O (2.5:2.5 eq.) were placed into a round-bottom flask. The reaction was stirred at 110 °C in an oil bath for appropriate time (Tables 3-6). After the completion of the reaction, the mixture was cooled to room temperature, quenched with water and the aqueous layer was extracted with EtOAc. The organic phase was dried over MgSO4, filtered, and the volatiles were completely removed under vacuum to give the crude product. Purification by flash chromatography on silica with a mixture of Hexane/EtOAc as eluent furnished the desired chalcogenated product.
90% With 1-benzyl-3-butyl-2-ethylimidazolium tetrafluoroborate; caesium carbonate at 80℃; for 15h; Green chemistry;
  • 10
  • [ 108-86-1 ]
  • [ 4105-21-9 ]
  • [ 85102-26-7 ]
YieldReaction ConditionsOperation in experiment
95% With palladium diacetate; potassium carbonate; tricyclohexylphosphine tetrafluoroborate; Trimethylacetic acid In N,N-dimethyl acetamide at 100℃; for 16h; Inert atmosphere; Sealed vessel; Representative Suzuki coupling-direct halogenation sequence procedure: 2-(3,5-dichlorophenyl)-3-(3-pyridyl)imidazo[1,2-a]pyridine (1d). General procedure: To a 10 mL vial with a magnetic stir bar was added 2c (280 mg, 1.1 mmol), 3-bromopyridine (168 mg, 1.1 mmol), Pd(OAc)2 (2% mol, 5 mg), PCy3.HBF4 (4% mol, 16 mg), PivOH (33 mg, 0.3 mmol) and K2CO3 (221 mg, 1.6 mmol) in DMA (4 mL). The vial was sealed and purged with argon through the septum inlet for 10 min. The suspension was then heated at 100 °C for 15 h. After cooling, the resulting mixture was diluted with EtOAc and water and the organic layer was extracted twice with EtOAc. The combined organic layers were washed with brine and water, dried over Na2SO4, filtered and concentrated under vacuum. The crude product was purified by silica gel chromatography using petroleum ether/EtOAc (4:1) as eluent. Trituration with diisopropylic ether afforded 2-(3,5-dichlorophenyl)-3-(3-pyridyl)imidazo[1,2-a]pyridine 1d as a beige powder (250 mg, 69% yield).
95% With tricyclohexylphosphine tetrafluoroborate; palladium diacetate; potassium carbonate; trimethylpyruvic acid In N,N-dimethyl acetamide at 100℃; for 16h; Inert atmosphere; 1 2,3-Diphenylimidazo[1,2-a]pyridine (11) Compound was obtained following the representative procedure, using 2-phenylimidazo[1,2-a]pyridine 2 (300 mg, 1.5 mmol, 1 equiv), bromobenzene (158 μL, 1.5 mmol, 1 equiv) and heating for 16 h. The crude product was purified by silica gel chromatography using petroleum ether/ethyl acetate (7/3) as eluent to afford 2,3-diphenylimidazo[1,2-a]pyridine 11 as a beige powder (397 mg, 95% yield). Rf = 0.58 (petroleum ether/EtOAc: 7/3); Mp = 149-150 °C (lit. [30] : 150 °C). 1H NMR (400 MHz, DMSO-d6): δ 8.05 (d, 1H, 3J = 6.8 Hz, H5), 7.71 (d, 1H, 3J = 9.2 Hz, H8), 7.65-7.59 (m, 5H, Ha, He and Hf), 7.54 (dd, 2H, 3J = 6.4 Hz, 4J = 1.6 Hz, Hd), 7.38-7.27 (m, 4H, H7, Hb and Hc), 6.93 (ddd, 1H, 3J = 7.6 Hz, 3J = 6.8 Hz, 4J = 0.8 Hz, H6). 13C NMR (100 MHz, DMSO-d6): δ 144.15 (C), 141.42 (C), 134.38 (C), 130.86 (2Cd), 129.84 (2Ce), 129.56 (C), 129.25 (Cf), 128.44 (2Cb), 127.62 (2Ca), 127.58 (Cc), 125.37 (C7), 123.88 (C5), 120.88 (C), 117.09 (C8), 112.89 (C6). IR (KBr) cm-1: 3061 (νC-Har), 1508, 1443 (νC=C and νC=N). MS (ESI) m/z (%): 271.1 (100) [M + H]+. Anal. Calcd for C19H14N2: C, 84.42; H, 5.22; N, 10.36. Found: C, 84.21; H, 5.20; N, 10.52.
92% With chloro(1,5-cyclooctadiene)rhodium(I) dimer; potassium carbonate; triphenylphosphine In 1-methyl-pyrrolidin-2-one at 100℃; for 20h; regioselective reaction; Synthesis of 3aa: A mixture of 1a (0.5 mmol), 2a (0.6mmol), [Rh(cod)Cl]2 (2.5 mol %), PPh3 (8 mol %), K2CO3 (1.0 mmol) in NMP (3 mL) is stirred for 20 h at 100 oC. After completion of the reaction (monitored by TLC), 10mL water was added. The aqueous solution was extracted with diethyl ether (3 × 10 mL) and the combined extract was dried with anhydrous MgSO4. The solvent was removed andthe crude product was separated by column chromatography (eluted with petroleum ether : ethyl acetate = 2:1) to give a pure sample of 3aa.
60% With potassium acetate; palladium diacetate at 150℃; for 24h;
59% With potassium acetate; palladium diacetate In N,N-dimethyl acetamide Inert atmosphere; Microwave irradiation; Sealed tube;
With potassium acetate; palladium diacetate at 220℃; for 1h; Microwave irradiation; Green chemistry;

  • 11
  • [ 586-78-7 ]
  • [ 4105-21-9 ]
  • 3-(4-nitrophenyl)-2-phenylimidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
93% With palladium diacetate; potassium carbonate; tricyclohexylphosphine tetrafluoroborate; Trimethylacetic acid In N,N-dimethyl acetamide at 100℃; for 36h; Inert atmosphere; Sealed vessel; Representative Suzuki coupling-direct halogenation sequence procedure: 2-(3,5-dichlorophenyl)-3-(3-pyridyl)imidazo[1,2-a]pyridine (1d). General procedure: To a 10 mL vial with a magnetic stir bar was added 2c (280 mg, 1.1 mmol), 3-bromopyridine (168 mg, 1.1 mmol), Pd(OAc)2 (2% mol, 5 mg), PCy3.HBF4 (4% mol, 16 mg), PivOH (33 mg, 0.3 mmol) and K2CO3 (221 mg, 1.6 mmol) in DMA (4 mL). The vial was sealed and purged with argon through the septum inlet for 10 min. The suspension was then heated at 100 °C for 15 h. After cooling, the resulting mixture was diluted with EtOAc and water and the organic layer was extracted twice with EtOAc. The combined organic layers were washed with brine and water, dried over Na2SO4, filtered and concentrated under vacuum. The crude product was purified by silica gel chromatography using petroleum ether/EtOAc (4:1) as eluent. Trituration with diisopropylic ether afforded 2-(3,5-dichlorophenyl)-3-(3-pyridyl)imidazo[1,2-a]pyridine 1d as a beige powder (250 mg, 69% yield).
93% With tricyclohexylphosphine tetrafluoroborate; palladium diacetate; potassium carbonate; trimethylpyruvic acid In N,N-dimethyl acetamide at 100℃; for 36h; Inert atmosphere; 6 3-(4-Nitrophenyl)-2-phenylimidazo[1,2-a]pyridine (16) Compound was obtained following the representative procedure, using 2-phenylimidazo[1,2-a]pyridine 2 (300 mg, 1.5 mmol, 1 equiv), 1-bromo-4-nitrobenzene (304 mg, 1.5 mmol, 1 equiv) and heating for 36 h. The crude product was purified by silica gel chromatography using cyclohexane/ethyl acetate (8/2) as eluent to afford 3-(4-nitrophenyl)-2-phenylimidazo[1,2-a]pyridine 16 as an orange powder (441 mg, 93% yield). Rf = 0.24 (petroleum ether/EtOAc: 7/3); Mp = 141-142 °C. 1H NMR (400 MHz, DMSO-d6): δ 8.43 (d, 2H, 3J = 9.0 Hz, He), 8.29 (d, 1H, 3J = 7.2 Hz, H5), 7.84 (d, 2H, 3J = 9.0 Hz, Hd), 7.76 (d, 1H, 3J = 9.2 Hz, H8), 7.59 (d, 2H, 3J = 6.4 Hz, Ha), 7.45-7.35 (m, 4H, H7, Hb and Hc), 7.01 (ddd, 1H, 3J = 8.0 Hz, 3J = 7.2 Hz, 4J = 1.2 Hz, H6). 13C NMR (100 MHz, DMSO-d6): δ 147.29 (C), 145.00 (C), 143.11 (C), 136.45 (C), 133.86 (C), 131.89 (2Cd), 128.68 (2Cb), 128.16 (2Ca), 128.08 (Cc), 126.27 (C7), 124.79 (2Ce), 124.17 (C5), 118.96 (C), 117.27 (C8), 113.41 (C6). IR (KBr) cm-1: 3024 (νC-Har), 1516 (νasNO2), 1345 (νsyNO2), 854 (νC-N). MS (ESI) m/z (%): 316.1 (100) [M + H]+. Anal. Calcd for C19H13N3O2: C, 72.37; H, 4.16; N, 13.33. Found: C, 72.27; H, 4.25; N, 13.56.
With potassium acetate; palladium diacetate at 220℃; for 1h; Microwave irradiation; Green chemistry;
  • 12
  • [ 591-50-4 ]
  • [ 4105-21-9 ]
  • [ 85102-26-7 ]
YieldReaction ConditionsOperation in experiment
89% With copper(l) iodide; 1,10-Phenanthroline; potassium <i>tert</i>-butylate In N,N-dimethyl-formamide at 140℃; for 24h; Air atmosphere;
88% With copper(l) iodide; palladium diacetate; caesium carbonate; triphenylphosphine In 1,4-dioxane at 105℃; for 15h;
87% With copper(l) iodide; palladium diacetate; caesium carbonate; triphenylphosphine In 1,4-dioxane at 150℃; for 15h; Inert atmosphere; Sealed tube;
84% With cobalt(II) chloride hexahydrate; potassium acetate In N,N-dimethyl-formamide at 150℃; for 24h;
33% With palladium diacetate; potassium hydroxide In water at 100℃; for 48h; Inert atmosphere; General procedure for the direct arylation on water General procedure: The mixture of 1 (0.1g), 2/2'/2"(1.5 equivalent), Pd(OAc)2 (5 mol%), KOH (3 equivalent) in 4 mL of nitrogen purged deionised water were stirred at 100 °C. The reaction was carried out under nitrogen atmosphere. The progress of reaction was monitored using TLC. Upon completion of the reaction, silica gel was added and the mixture was evaporated under vacuum. The resulted mixture was purified by column chromatography using EtOAc:Petroleum ether (0.4:0.6 to 0.8:0.2, EtOAc:Petroleum ether) to afford pure 3-aryl imidazo[1,2-a]pyridines 3 and 4.
With palladium diacetate; silver carbonate In toluene at 120℃; for 2h; Sealed tube; regioselective reaction;

  • 13
  • [ 104-92-7 ]
  • [ 4105-21-9 ]
  • [ 1416319-50-0 ]
YieldReaction ConditionsOperation in experiment
81% With tricyclohexylphosphine tetrafluoroborate; palladium diacetate; potassium carbonate; trimethylpyruvic acid In N,N-dimethyl acetamide at 100℃; for 24h; Inert atmosphere; 3 3-(4-Methoxyphenyl)-2-phenylimidazo[1,2-a]pyridine (13) compound was obtained following the representative procedure, using 2-phenylimidazo[1,2-a]pyridine 2 (300 mg, 1.5 mmol, 1 equiv), 1-bromo-4-methoxybenzene (194 μL, 1.5 mmol, 1 equiv) and heating for 24 h. The crude product was purified by silica gel chromatography using cyclohexane/ethyl acetate (8/2) as eluent and trituration with petroleum ether afforded 3-(4-methoxyphenyl)-2-phenylimidazo[1,2-a]pyridine 13 as a beige powder (376 mg, 81% yield). Rf = 0.36 (petroleum ether/EtOAc: 7/3); Mp = 129-130 °C. 1H NMR (400 MHz, DMSO-d6): δ 7.99 (d, 1H, 3J = 6.8 Hz, H5), 7.69-7.65 (m, 3H, H8 and Ha), 7.45 (d, 2H, 3J = 8.6 Hz, Hd), 7.36-7.26 (m, 4H, H7, Hb and Hc), 7.19 (d, 2H, 3J = 8.6 Hz, He), 6.91 (ddd, 1H, 3J = 7.6 Hz, 3J = 6.8 Hz, 4J = 0.8 Hz, H6), 3.89 (s, 3H, OMe). 13C NMR (100 MHz, DMSO-d6): δ 159.86 (C-O), 143.96 (C), 141.13 (C), 134.53 (C), 132.31 (2Cd), 128.43 (2Cb), 127.45 (2Ca), 127.43 (Cc), 125.15 (C7), 123.92 (C5), 121.37 (C), 120.73 (C), 117.01 (C8), 115.32 (2Ce), 112.72 (C6), 55.42 (OMe). IR (KBr) cm-1: 3040 (νC-Har), 1609, 1509 (νC=C and νC=N), 1240 (νC-O). MS (ESI) m/z (%): 301.1 (100) [M + H]+. Anal. Calcd for C20H16N2O: C, 79.98; H, 5.37; N, 9.33. Found: C, 80.23; H, 5.69; N, 9.34.
With potassium acetate; palladium diacetate at 220℃; for 2h; Microwave irradiation; Green chemistry;
  • 14
  • [ 33527-94-5 ]
  • [ 4105-21-9 ]
  • [ 1416319-51-1 ]
YieldReaction ConditionsOperation in experiment
53% With tricyclohexylphosphine tetrafluoroborate; palladium diacetate; potassium carbonate; trimethylpyruvic acid In N,N-dimethyl acetamide at 100℃; for 12h; Inert atmosphere; 4 4-(2-Phenylimidazo[1,2-a]pyridin-3-yl)phenol (14) Compound was obtained following the representative procedure, using 2-phenylimidazo[1,2-a]pyridine 2 (300 mg, 1.5 mmol, 1 equiv), 4-iodophenyl acetate (394 mg, 1.5 mmol, 1 equiv) and heating for 12 h. The crude product was purified by silica gel chromatography using petroleum ether/dichloromethane (1/1) as eluent to afford 4-(2-phenylimidazo[1,2-a]pyridin-3-yl)phenol 14 as a white powder (228 mg, 53% yield). Rf = 0.21 (petroleum ether/EtOAc: 7/3); Mp = 296-297 °C. 1H NMR (400 MHz, DMSO-d6): δ 9.97 (s, 1H, OH), 7.99 (d, 1H, 3J = 6.2 Hz, H5), 7.68-7.66 (m, 3H, H8 and Ha), 7.34-7.27 (m, 6H, H7, Hb, Hc and Hd), 7.01 (d, 2H, 3J = 8.4 Hz, He), 6.91 (dd, 1H, 3J = 3J' = 6.2 Hz, H6). 13C NMR (100 MHz, DMSO-d6): δ 158.31 (C-O), 143.90 (C), 140.94 (C), 134.64 (C), 132.29 (2Cd), 128.45 (2Cb), 127.45 (2Ca), 127.43 (Cc), 125.11 (C7), 123.98 (C5), 121.18 (C), 119.61 (C), 117.00 (C8), 116.77 (2Ce), 112.69 (C6). IR (KBr) cm-1: 1607, 1483 (νC=C and νC=N), 1275, 1234 (νC-O). MS (ESI) m/z (%): 287.0 (100) [M + H]+. Anal. Calcd for C19H14N2O: C, 79.70; H, 4.93; N, 9.78. Found: C, 79.99; H, 4.66; N, 9.59.
  • 15
  • [ 623-00-7 ]
  • [ 4105-21-9 ]
  • [ 1416319-53-3 ]
YieldReaction ConditionsOperation in experiment
99% With tricyclohexylphosphine tetrafluoroborate; palladium diacetate; potassium carbonate; trimethylpyruvic acid In N,N-dimethyl acetamide at 100℃; for 36h; Inert atmosphere; 7 -(2-Phenylimidazo[1,2-a]pyridin-3-yl)benzonitrile (17) Compound was obtained following the representative procedure, using 2-phenylimidazo[1,2-a]pyridine 2 (300 mg, 1.5 mmol, 1 equiv), 4-bromobenzonitrile (274 mg, 1.5 mmol, 1 equiv) and heating for 18 h. The crude product was purified by silica gel chromatography using cyclohexane/ethyl acetate (8/2) as eluent and trituration with diisopropylic ether afforded 4-(2-phenylimidazo[1,2-a]pyridin-3-yl)benzonitrile 17 as a beige powder (439 mg, 99% yield). Rf = 0.26 (petroleum ether/EtOAc: 7/3); Mp = 186-187 °C. 1H NMR (400 MHz, DMSO-d6): δ 8.22 (d, 1H, 3J = 6.8 Hz, H5), 8.07 (d, 2H, 3J = 8.4 Hz, He), 7.77-7.73 (m, 3H, H8 and Hd), 7.58 (d, 2H, 3J = 6.8 Hz, Ha), 7.43-7.31 (m, 4H, H7, Hb and Hc), 6.98 (dd, 1H, 3J = 3J' = 6.8 Hz, H6). 13C NMR (100 MHz, DMSO-d6): δ 144.77 (C), 142.63 (C), 134.48 (C), 133.86 (C), 133.59 (2Ce), 131.66 (2Cd), 128.67 (2Cb), 128.08 (2Ca), 128.04 (Cc), 126.20 (C7), 124.15 (C5), 119.36 (CN), 118.82 (C), 117.18 (C8), 113.37 (C6), 111.45 (C-CN). IR (KBr) cm-1: 3038 (νC-Har), 2226 (νC≡N), 1604, 1508 (νC=C and νC=N). MS (ESI) m/z (%): 296.1 (100) [M + H]+. Anal. Calcd for C20H13N3: C, 81.34; H, 4.44; N, 14.23. Found: C, 81.51; H, 4.80; N, 14.48.
96% With C32H33Cl2NOPd; potassium carbonate; Trimethylacetic acid In N,N-dimethyl acetamide at 130℃; for 4h;
  • 16
  • [ 3032-81-3 ]
  • [ 4105-21-9 ]
  • [ 1416319-55-5 ]
YieldReaction ConditionsOperation in experiment
68% With tricyclohexylphosphine tetrafluoroborate; palladium diacetate; potassium carbonate; trimethylpyruvic acid; In N,N-dimethyl acetamide; at 100℃; for 12h;Inert atmosphere; Compound was obtained following the representative procedure, using 2-phenylimidazo[1,2-a]pyridine 2 (300 mg, 1.5 mmol, 1 equiv), <strong>[3032-81-3]1,3-dichloro-5-iodobenzene</strong> (410 mg, 1.5 mmol, 1 equiv) and heating for 12 h. The crude product was purified by silica gel chromatography using dichloromethane as eluent and trituration with methanol afforded 3-(3,5-dichlorophenyl)-2-phenylimidazo[1,2-a]pyridine 19 as a white powder (347 mg, 68percent yield). Rf = 0.60 (petroleum ether/EtOAc: 7/3); Mp = 210-211 °C. 1H NMR (400 MHz, DMSO-d6): delta 8.19 (d, 1H, 3J = 6.8 Hz, H5), 7.84 (t, 1H, 4J = 1.6 Hz, He), 7.73 (d, 1H, 3J = 9.2 Hz, H8), 7.65 (d, 2H, 4J = 1.6 Hz, Hd), 7.61 (d, 2H, 3J = 7.2 Hz, Ha), 7.42-7.32 (m, 4H, H7, Hb and Hc), 6.98 (dd, 1H, 3J = 3J' = 6.8 Hz, H6). 13C NMR (100 MHz, DMSO-d6): delta 144.55 (C), 142.40 (C), 135.27 (2C-Cl), 133.86 (C), 133.16 (C), 129.61 (2Cd), 128.87 (Ce), 128.64 (2Cb), 127.96 (Cc), 127.85 (2Ca), 125.96 (C7), 124.43 (C5), 118.18 (C), 117.05 (C8), 113.16 (C6). IR (KBr) cm-1: 3036 (nuC-Har), 1590, 1560 (nuC=C and nuC=N), 776, 750 (nuC-Cl). MS (ESI) m/z (percent): 339.0 (100) [M + H]+, 341.0 (80) [M + H + 2]+, 343.0 (15) [M + H + 4]+. Anal. Calcd for C19H12Cl2N2: C, 67.27; H, 3.57; N, 8.26. Found: C, 67.50; H, 3.23; N, 7.98.
  • 17
  • [ 19524-06-2 ]
  • [ 4105-21-9 ]
  • [ 1353511-55-3 ]
YieldReaction ConditionsOperation in experiment
85% With tricyclohexylphosphine tetrafluoroborate; palladium diacetate; potassium carbonate; trimethylpyruvic acid In N,N-dimethyl acetamide at 100℃; for 16h; Inert atmosphere; 11 2-Phenyl-3-(pyridin-4-yl)imidazo[1,2-a]pyridine (21) Compound was obtained following the representative procedure, using 2-phenylimidazo[1,2-a]pyridine 2 (300 mg, 1.5 mmol, 1 equiv), 4-bromopyridine hydrochloride (292 mg, 1.5 mmol, 1 equiv) and heating for 16 h. The crude product was purified by silica gel chromatography using petroleum ether/ethyl acetate (6/4) as eluent and trituration with diisopropylic ether afforded 2-phenyl-3-(pyridin-4-yl)imidazo[1,2-a]pyridine 21 as a yellow powder (347 mg, 85% yield). Rf = 0.08 (petroleum ether/EtOAc: 7/3); Mp = 181-182 °C. 1H NMR (400 MHz, DMSO-d6): δ 8.78 (d, 2H, 3J = 6.0 Hz, He), 8.30 (d, 1H, 3J = 7.0 Hz, H5), 7.75 (d, 1H, 3J = 9.2 Hz, H8), 7.60-7.56 (m, 4H, Ha and Hd), 7.44-7.33 (m, 4H, H7, Hb and Hc), 6.99 (ddd, 1H, 3J = 8.0 Hz, 3J = 7.0 Hz, 4J = 1.2 Hz, H6). 13C NMR (100 MHz, DMSO-d6): δ 150.98 (2Ce), 144.95 (C), 142.96 (C), 137.47 (C), 133.88 (C), 128.64 (2Cb), 128.12 (2Cd), 128.07 (Cc), 126.19 (C7), 125.05 (2Ca), 124.21 (C5), 118.36 (C), 117.25 (C8), 113.37 (C6). IR (KBr) cm-1: 3043 (νC-Har), 1594, 1507 (νC=C and νC=N). MS (ESI) m/z (%): 272.1 (100) [M + H]+. Anal. Calcd for C18H13N3: C, 79.68; H, 4.83; N, 15.49. Found: C, 79.66; H, 4.89; N, 15.76.
  • 18
  • [ 110-86-1 ]
  • [ 19433-17-1 ]
  • [ 4105-21-9 ]
YieldReaction ConditionsOperation in experiment
95% With copper(l) iodide; oxygen In 1-methyl-pyrrolidin-2-one at 100℃; Imidazo[1,2-a]pyridines 3; General Procedure The appropriate ketoxime acetate 1 (0.5 mmol), CuI (10 mol%, 9.5mg), and pyridine derivative 2 (0.6 mmol) were added successively toNMP (1.5 mL) in a 25 mL round-bottomed flask, and the mixture wasstirred at 100 °C under dry air for 4-6 h. When the reaction was complete(TLC), the mixture was cooled to r.t., and the reaction wasquenched with 30% aq NH3 (5 mL). The mixture was extracted withEtOAc (10 mL), and the extracts were washed with H2O (10 mL) andbrine (10 mL). The organic layer was removed under reduced pressureto give a crude product that was further purified by chromatography(silica gel, PE-EtOAc). 2-Phenylimidazo[1,2-a]pyridine (3aa)Yellow solid; yield: 92.2 mg (95%).1H NMR (400 MHz, CDCl3): δ = 8.07 (d, J = 6.4 Hz, 1 H), 7.96 (d, J = 7.6Hz, 2 H), 7.82 (s, 1 H), 7.62 (d, J = 9.2 Hz, 1 H), 7.45-7.41 (m, 2 H),7.34-7.31 (m, 1 H), 7.16-7.12 (m, 1 H), 6.75-6.72 (m, 1 H).13C NMR (100 MHz, CDCl3): δ = 145.7, 145.6, 133.7, 128.6, 127.9,125.9, 125.5, 124.6, 117.4, 112.3, 108.1.HRMS (ESI): m/z [M + H]+ calcd for C13H11N2: 195.0917; found:195.0922.
81% With copper(l) iodide; lithium carbonate In N,N-dimethyl-formamide at 95℃; for 2h;
  • 19
  • [ 14150-95-9 ]
  • [ 536-74-3 ]
  • [ 4105-21-9 ]
YieldReaction ConditionsOperation in experiment
75% Stage #1: 2-aminopyridine N-oxide With trifluoroacetic acid In dichloromethane for 0.166667h; Stage #2: phenylacetylene With dichloro(pyridine-2-carboxylato)gold(III) In dichloromethane at 40℃; for 15h; regioselective reaction;
  • 20
  • [ 504-29-0 ]
  • [ 75-52-5 ]
  • [ 100-52-7 ]
  • [ 4105-21-9 ]
YieldReaction ConditionsOperation in experiment
76% With iron(III) chloride In N,N-dimethyl-formamide at 110℃; for 5h; 2-Phenylimidazo[1,2-a]pyridine (5aba) General procedure: mixture of 2-aminopyridine 1a (94 mg, 1 mmol) and 4-chlorobenzaldehyde 2a (154 mg,1.1 mmol) was heated in presence of anhydrous FeCl3 (20 mol%) in nitromethane 3a (2 mL)and DMF (1 mL) at 110 °C for 5h (TLC). After completion, the reaction mixture was cooledto room temperature and extracted with dichloromethane (10 mL) followed by washing withbrine (5 mL) and dried over Na2SO4. After evaporation of solvent the crude product waspurified by column chromatography on silica gel using petroleum ether/ethylacetate (3:1 to2:1) as eluent. Yellowish white solid. Mp. 138-140 C; Yield: 78%; 1H NMR (400 MHz,CDCl3): δ 8.09 (d, J = 6.8 Hz, 1H), 7.87 (d, J = 8.8 Hz, 2H), 7.81 (s, 1H), 7.61 (d, J = 8.8 Hz,1H), 7.40 (d, J = 8.4 Hz, 2H), 7.19-7.14 (m, 1H), 6.77 (t, J = 6.4 Hz, 1H); 13C NMR (100MHz, CDCl3): δ 145.8, 144.7, 133.8, 132.3, 129.0, 127.3, 125.7, 125.0, 117.6, 112.7, 108.3.
70% With iron(III) chloride; tetra-(n-butyl)ammonium iodide at 90℃; for 4h;
70% With polyethylen glycol PEG-400 for 8h; Green chemistry; General procedure General procedure: A mixture of the requisite 2-aminopyridine (0.5 mmol), benzaldehyde (0.6 mmol), MeNO2 or EtNO2 (15 equiv) was taken in PEG (5 mL) and stirred at 90 °C for the appropriate time. After completion of the reaction, as monitored by TLC, the reaction mixture was poured into H2O and extracted with EtOAc. The organic layer was removed under reduced pressure and the crude product was purified by column chromatography. The recovered PEG could be reused for a number of cycles without significant loss of activity.
With iron(III) chloride In N,N-dimethyl-formamide at 110℃; for 5h;

  • 21
  • [ 67-68-5 ]
  • [ 4105-21-9 ]
  • [ 3672-39-7 ]
YieldReaction ConditionsOperation in experiment
80% With oxygen; copper diacetate; acetic acid at 120℃; for 24h;
76% With iron(III) chloride; oxygen; acetic acid at 100℃; for 12h; chemoselective reaction; Typical procedure for aerobic iron(III)-catalyzed direct formylation of imidazo[1,2-a]pyridine to form 3-formylimidazo[1,2-a]pyridine General procedure: FeCl3 (0.025 mmol, 4 mg) and AcOH (0.1 mmol, 6 mg) was mixed with DMSO (3 mL) in a glass vial or round-bottom flask equipped with a magnetic stirring bar. Then, substrate 1 (0.5 mmol) was added. The mixture was stirred under an dioxygen atmosphere (1 atm) at 100°C for 12 h. After cooling down to room temperature, 5 mL of ethyl acetate was added and removal of the DMSO with brine, the residue was purified by flash chromatography on silica gel to obtain the desired product 2 using light petroleum ether/ethyl acetate (4:1, v/v) as eluent, which furnished the 3-formylimidazo[1,2-a]pyridine.
50% With di-tert-butyl peroxide In water at 125℃; for 18h; regioselective reaction;
  • 22
  • [ 910209-21-1 ]
  • [ 4105-21-9 ]
  • 3-(cyclopropylthio)-2-phenylimidazo[1,2-a]pyridine [ No CAS ]
  • 23
  • [ 16642-95-8 ]
  • [ 4105-21-9 ]
  • [ 6667-08-9 ]
  • 24
  • [ 2789-88-0 ]
  • [ 4105-21-9 ]
  • 5,6-di-p-tolylnaphtho[1′,2′:4,5]imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
87% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; copper(II) acetate monohydrate; caesium carbonate; In toluene; at 125℃; for 7h;Inert atmosphere; General procedure: In a oven-dried RBF, a solution of Imidazo[1,2,-a]pyridines derivatives 1 (0.5 mmol) and alkyne2 in toluene (2 mL) [Cp*RhCl2]2 (5 mol%), Cu(OAc)2·H2O (2 equiv), Cs2CO3 (30 mol%) wereadded under inert atmosphere. The resulting reaction mixture was heated at 125 C for 7 h.Progression of the reaction was monitored by TLC, while noticing complete consumption ofImidazo[1,2,-a]pyridines derivatives, reaction was brought to room temperature. The additionalamount of acrylate also added if required for complete conversion. The reaction mixture wasdiluted with ethyl acetate (10 mL) and water (15 mL) and then filtered through a plug of celite.The layers were separated, and the organic layer was washed with aqueous saturated brinesolution, dried over Na2SO4. Organic layer was concentrated under reduced pressure.The crudematerial so obtained was purified by column chromatography on silica gel (hexane: ethylacetate :: 70:30). The structure and purity of known starting materials were confirmed by comparison oftheir physical and spectral data (1H NMR, 13C NMR and HRMS ).
80% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; cobalt(II) diacetate tetrahydrate; In N,N-dimethyl-formamide; at 110℃; for 2h;Sealed tube; General procedure: A 10 mL vial was charged the requisite 2-arylimidazo[1,2-a]pyridine derivatives (1.0 equiv), internal alkynes (2.0 equiv), Co(OAc)2·4H2O (1.2 equiv) and [RhCp*Cl2]2 (5 mol%) in DMF (1 mL). The vial was sealed, heated to 110 C and stirred for 2 h. The resulting mixture was analyzed by TLC. After cooling to room temperature, the mixture was concentrated in vacuo. The products were isolated by silica gel with ethyl acetate and petroleum ether as the eluent to afford the desired products.
  • 25
  • [ 2132-62-9 ]
  • [ 4105-21-9 ]
  • 5,6-bis(4-methoxyphenyl)naphtho[1′,2′:4,5]imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
92% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; copper(II) acetate monohydrate; caesium carbonate; In toluene; at 125℃; for 7h;Inert atmosphere; General procedure: In a oven-dried RBF, a solution of Imidazo[1,2,-a]pyridines derivatives 1 (0.5 mmol) and alkyne2 in toluene (2 mL) [Cp*RhCl2]2 (5 mol%), Cu(OAc)2·H2O (2 equiv), Cs2CO3 (30 mol%) wereadded under inert atmosphere. The resulting reaction mixture was heated at 125 C for 7 h.Progression of the reaction was monitored by TLC, while noticing complete consumption ofImidazo[1,2,-a]pyridines derivatives, reaction was brought to room temperature. The additionalamount of acrylate also added if required for complete conversion. The reaction mixture wasdiluted with ethyl acetate (10 mL) and water (15 mL) and then filtered through a plug of celite.The layers were separated, and the organic layer was washed with aqueous saturated brinesolution, dried over Na2SO4. Organic layer was concentrated under reduced pressure.The crudematerial so obtained was purified by column chromatography on silica gel (hexane: ethylacetate :: 70:30). The structure and purity of known starting materials were confirmed by comparison oftheir physical and spectral data (1H NMR, 13C NMR and HRMS ).
84% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; cobalt(II) diacetate tetrahydrate; In N,N-dimethyl-formamide; at 110℃; for 2h;Sealed tube; General procedure: A 10 mL vial was charged the requisite 2-arylimidazo[1,2-a]pyridine derivatives (1.0 equiv), internal alkynes (2.0 equiv), Co(OAc)2·4H2O (1.2 equiv) and [RhCp*Cl2]2 (5 mol%) in DMF (1 mL). The vial was sealed, heated to 110 C and stirred for 2 h. The resulting mixture was analyzed by TLC. After cooling to room temperature, the mixture was concentrated in vacuo. The products were isolated by silica gel with ethyl acetate and petroleum ether as the eluent to afford the desired products.
  • 26
  • [ 1820-42-4 ]
  • [ 4105-21-9 ]
  • 5,6-bis(4-chlorophenyl)naphtho[1′,2′:4,5]imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
88% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; cobalt(II) diacetate tetrahydrate In N,N-dimethyl-formamide at 110℃; for 2h; Sealed tube; 4.2. General procedure for annulation of 2-arylimidazo[1,2-a]pyridine derivatives General procedure: A 10 mL vial was charged the requisite 2-arylimidazo[1,2-a]pyridine derivatives (1.0 equiv), internal alkynes (2.0 equiv), Co(OAc)2·4H2O (1.2 equiv) and [RhCp*Cl2]2 (5 mol%) in DMF (1 mL). The vial was sealed, heated to 110 °C and stirred for 2 h. The resulting mixture was analyzed by TLC. After cooling to room temperature, the mixture was concentrated in vacuo. The products were isolated by silica gel with ethyl acetate and petroleum ether as the eluent to afford the desired products.
78% With silver hexafluoroantimonate; dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; silver(I) acetate In 1,2-dichloro-ethane at 100℃; for 12h; Sealed tube;
64% With tris(acetonitrile)(η5-pentamethylcyclopentadienyl)rhodium(III) hexafluoroantimonate; copper diacetate In toluene at 110℃; for 12h;
  • 27
  • [ 4105-21-9 ]
  • [ 119757-51-6 ]
  • 5,6-bis(4-(trifluoromethyl)phenyl)naphtho[1′,2′:4,5]imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
97% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; cobalt(II) diacetate tetrahydrate; In N,N-dimethyl-formamide; at 110℃; for 2h;Sealed tube; General procedure: A 10 mL vial was charged the requisite 2-arylimidazo[1,2-a]pyridine derivatives (1.0 equiv), internal alkynes (2.0 equiv), Co(OAc)2·4H2O (1.2 equiv) and [RhCp*Cl2]2 (5 mol%) in DMF (1 mL). The vial was sealed, heated to 110 C and stirred for 2 h. The resulting mixture was analyzed by TLC. After cooling to room temperature, the mixture was concentrated in vacuo. The products were isolated by silica gel with ethyl acetate and petroleum ether as the eluent to afford the desired products.
  • 28
  • [ 2765-16-4 ]
  • [ 4105-21-9 ]
  • 5,6-di-m-tolylnaphtho[1′,2′:4,5]imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
80% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; copper(II) acetate monohydrate; caesium carbonate In toluene at 125℃; for 7h; Inert atmosphere; General procedure for the reactions of Imidazo[1,2,-a]pyridines with alkynes General procedure: In a oven-dried RBF, a solution of Imidazo[1,2,-a]pyridines derivatives 1 (0.5 mmol) and alkyne2 in toluene (2 mL) [Cp*RhCl2]2 (5 mol%), Cu(OAc)2·H2O (2 equiv), Cs2CO3 (30 mol%) wereadded under inert atmosphere. The resulting reaction mixture was heated at 125 °C for 7 h.Progression of the reaction was monitored by TLC, while noticing complete consumption ofImidazo[1,2,-a]pyridines derivatives, reaction was brought to room temperature. The additionalamount of acrylate also added if required for complete conversion. The reaction mixture wasdiluted with ethyl acetate (10 mL) and water (15 mL) and then filtered through a plug of celite.The layers were separated, and the organic layer was washed with aqueous saturated brinesolution, dried over Na2SO4. Organic layer was concentrated under reduced pressure.The crudematerial so obtained was purified by column chromatography on silica gel (hexane: ethylacetate :: 70:30). The structure and purity of known starting materials were confirmed by comparison oftheir physical and spectral data (1H NMR, 13C NMR and HRMS ).
47% With silver hexafluoroantimonate; dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; silver(I) acetate In 1,2-dichloro-ethane at 100℃; for 12h; Sealed tube;
  • 29
  • [ 137897-99-5 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-[(3,5-dichlorophenyl)thio]imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
85% With dihydrogen peroxide; iodine In ethanol at 25℃; for 18h; Green chemistry; 6-Phenyl-5-(phenylthio)imidazo[2,1-b]thiazole (3aa);20d TypicalProcedure General procedure: A 15-mL tube with a Teflon cap, equipped with a magnetic stirring bar, was charged with substrate 1a (0.20 mmol), diphenyl disulfide (0.10 mmol, 0.5 equiv), and I2 (20 mol %); H2O2 (2 equiv) and EtOH (2mL) were then added sequentially. The tube was capped and stirred at 25 °C for 18 h, the crude mixture was diluted with EtOAc, and washed with sat. aq Na2S2O3 solution (3 × 10 mL). The organic phase was dried (MgSO4), filtered through a Celite pad, and washed with EtOAc. The filtrate was concentrated in vacuo, and the resulting residue was purified by column chromatography (hexane - EtOAc) to afford product 3aa as a light yellow solid; yield: 56.8 mg (92%).
  • 30
  • [ 6911-51-9 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-(thiophen-2-ylthio)imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
92% With dihydrogen peroxide; iodine In ethanol at 25℃; for 18h; Green chemistry; 6-Phenyl-5-(phenylthio)imidazo[2,1-b]thiazole (3aa);20d TypicalProcedure General procedure: A 15-mL tube with a Teflon cap, equipped with a magnetic stirring bar, was charged with substrate 1a (0.20 mmol), diphenyl disulfide (0.10 mmol, 0.5 equiv), and I2 (20 mol %); H2O2 (2 equiv) and EtOH (2mL) were then added sequentially. The tube was capped and stirred at 25 °C for 18 h, the crude mixture was diluted with EtOAc, and washed with sat. aq Na2S2O3 solution (3 × 10 mL). The organic phase was dried (MgSO4), filtered through a Celite pad, and washed with EtOAc. The filtrate was concentrated in vacuo, and the resulting residue was purified by column chromatography (hexane - EtOAc) to afford product 3aa as a light yellow solid; yield: 56.8 mg (92%).
  • 31
  • [ 28588-75-2 ]
  • [ 4105-21-9 ]
  • 3-[(2-methylfuran-3-yl)thio]-2-phenylimidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
88% With dihydrogen peroxide; iodine In ethanol at 25℃; for 18h; Green chemistry; 6-Phenyl-5-(phenylthio)imidazo[2,1-b]thiazole (3aa);20d TypicalProcedure General procedure: A 15-mL tube with a Teflon cap, equipped with a magnetic stirring bar, was charged with substrate 1a (0.20 mmol), diphenyl disulfide (0.10 mmol, 0.5 equiv), and I2 (20 mol %); H2O2 (2 equiv) and EtOH (2mL) were then added sequentially. The tube was capped and stirred at 25 °C for 18 h, the crude mixture was diluted with EtOAc, and washed with sat. aq Na2S2O3 solution (3 × 10 mL). The organic phase was dried (MgSO4), filtered through a Celite pad, and washed with EtOAc. The filtrate was concentrated in vacuo, and the resulting residue was purified by column chromatography (hexane - EtOAc) to afford product 3aa as a light yellow solid; yield: 56.8 mg (92%).
  • 32
  • [ 2127-03-9 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-(pyridin-2-ylthio)imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
91% With dihydrogen peroxide; iodine In ethanol at 60℃; for 18h; Green chemistry; 6-Phenyl-5-(phenylthio)imidazo[2,1-b]thiazole (3aa);20d TypicalProcedure General procedure: A 15-mL tube with a Teflon cap, equipped with a magnetic stirring bar, was charged with substrate 1a (0.20 mmol), diphenyl disulfide (0.10 mmol, 0.5 equiv), and I2 (20 mol %); H2O2 (2 equiv) and EtOH (2mL) were then added sequentially. The tube was capped and stirred at 25 °C for 18 h, the crude mixture was diluted with EtOAc, and washed with sat. aq Na2S2O3 solution (3 × 10 mL). The organic phase was dried (MgSO4), filtered through a Celite pad, and washed with EtOAc. The filtrate was concentrated in vacuo, and the resulting residue was purified by column chromatography (hexane - EtOAc) to afford product 3aa as a light yellow solid; yield: 56.8 mg (92%).
  • 33
  • [ 130755-46-3 ]
  • [ 4105-21-9 ]
  • 5-amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(2-phenylimidazo[1,2-a]pyridin-3-yl)thio]-1H-pyrazole-3-carbonitrile [ No CAS ]
YieldReaction ConditionsOperation in experiment
87% With dihydrogen peroxide; iodine In ethanol at 60℃; for 18h; Green chemistry; 6-Phenyl-5-(phenylthio)imidazo[2,1-b]thiazole (3aa);20d TypicalProcedure General procedure: A 15-mL tube with a Teflon cap, equipped with a magnetic stirring bar, was charged with substrate 1a (0.20 mmol), diphenyl disulfide (0.10 mmol, 0.5 equiv), and I2 (20 mol %); H2O2 (2 equiv) and EtOH (2mL) were then added sequentially. The tube was capped and stirred at 25 °C for 18 h, the crude mixture was diluted with EtOAc, and washed with sat. aq Na2S2O3 solution (3 × 10 mL). The organic phase was dried (MgSO4), filtered through a Celite pad, and washed with EtOAc. The filtrate was concentrated in vacuo, and the resulting residue was purified by column chromatography (hexane - EtOAc) to afford product 3aa as a light yellow solid; yield: 56.8 mg (92%).
  • 34
  • [ 123577-99-1 ]
  • [ 4105-21-9 ]
  • 1-(3,5-difluorophenyl)-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)ethane-1,2-dione [ No CAS ]
  • 35
  • [ 4105-21-9 ]
  • [ 1972-28-7 ]
  • [ 3720-04-5 ]
YieldReaction ConditionsOperation in experiment
95% With iron(III) chloride; In acetonitrile; at 80℃; for 12h; General procedure: 15 mL tube with a Teflon cap, equipped with a magnetic stirringbar, was charged with substrate 1a (40 mg, 0.20 mmol), DEAD (52 mg,0.3 mmol, 1.5 equiv), and FeCl3 (3 mg, 10 mol%). After the addition of MeCN (2 mL), the tube was capped and the contents were stirred at 80 C for 12 h. After cooling to r.t., the crude mixture was diluted with EtOAc, and the EtOAc layer was washed with brine (3 × 10 mL). The combined organic phases were dried (anhyd Na2SO4), filtered througha Celite pad, and washed with EtOAc. The filtrate was concentrated invacuo, and the resulting residue was purified by column chromatography (hexane-EtOAc) to afford product 3 as a light yellow solid
  • 36
  • [ 5216-36-4 ]
  • [ 4105-21-9 ]
  • C29H16N4 [ No CAS ]
YieldReaction ConditionsOperation in experiment
52% With tris(acetonitrile)(η5-pentamethylcyclopentadienyl)rhodium(III) hexafluoroantimonate; copper diacetate In toluene at 110℃; for 12h;
  • 37
  • [ 288-13-1 ]
  • [ 4044-98-8 ]
  • 2-phenyl-6-(1H-pyrazol-1-yl)imidazo[1,2-a]pyridine [ No CAS ]
  • 2-phenyl-5-(1H-pyrazol-1-yl)imidazo[1,2-a]pyridine [ No CAS ]
  • [ 4105-21-9 ]
  • 38
  • [ 15894-04-9 ]
  • [ 61982-63-6 ]
  • 6-[(4-fluorobenzyl)thio]-2-phenylimidazo[1,2-a]pyridine [ No CAS ]
  • [ 4105-21-9 ]
YieldReaction ConditionsOperation in experiment
1: 45% 2: 20% With iron(II) chloride tetrahydrate; caesium carbonate; copper(II) oxide In N,N-dimethyl-formamide at 135℃; for 72h; Sealed tube; Inert atmosphere; regioselective reaction; S-Arylation/Alkylation Reaction General Procedure General procedure: Under an argon atmosphere, Cs2CO3 (203 mg, 0.624 mmol), CuO(2mg, 0.031mmol), and FeCl2·4H2O (19 mg, 0.093 mmol) were placedas a suspension in DMF (3 mL) in a sealed tube. After stirring for 5 minunder argon, 1 (100 mg, 0.312 mmol) and the respective thiol (0.624mmol) were added to the mixture and then heated to 135 °C. After 24h at this temperature, the mixture was cooled to r.t. and diluted withEtOAc (10 mL) and filtered on Celite. The filtrate was washed with aq5 N NaOH (2 × 5 mL) and H2O (2 × 5 mL) and dried (MgSO4). After filtrationand concentration under reduced pressure, the crude productwas purified by flash chromatography on silica gel.
  • 39
  • [ 4105-21-9 ]
  • [ 583-53-9 ]
  • 1-phenylbenzo[a]imidazo[5,1,2-cd]indolizine [ No CAS ]
YieldReaction ConditionsOperation in experiment
77% With palladium diacetate; potassium carbonate; XPhos In N,N-dimethyl-formamide at 160℃; for 24h; Schlenk technique; Tandem Synthesis of Benzo[a]imidazo[5,1,2-cd]indolizines General procedure: A 10 mL Schlenk tube equipped with a magnetic stirring bar was charged with 2-arylimidazo[1,2-a]pyridine 1 (0.2 mmol, 1.0 equiv), o-dihaloarene2 (0.3 mmol, 1.5 equiv), and K2CO3 (82.9 mg, 0.6 mmol, 3.0 equiv). To this mixture were added Pd(OAc)2 (0.02 mmol, 4.5 mg)and Xphos (0.04 mmol, 19.1 mg), followed by DMF (2.0 mL) via a syringe at r.t. The tube was sealed and kept in a preheated oil bath at 160 °C for 24 h. The mixture was cooled to r.t., quenched with H2O (5mL), and diluted with CH2Cl2 (10 mL). The layers were separated and the aqueous layer was extracted with CH2Cl2 (3 × 5 mL). The combined organic extracts were dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was then purified by flash chromatography on silica gel (H), eluting with 5-20% EtOAc-petroleum ether.
  • 40
  • [ 694-80-4 ]
  • [ 4105-21-9 ]
  • 1-phenylbenzo[a]imidazo[5,1,2-cd]indolizine [ No CAS ]
YieldReaction ConditionsOperation in experiment
80% With palladium diacetate; potassium carbonate; XPhos In N,N-dimethyl-formamide at 160℃; for 24h; Schlenk technique; Tandem Synthesis of Benzo[a]imidazo[5,1,2-cd]indolizines General procedure: A 10 mL Schlenk tube equipped with a magnetic stirring bar was charged with 2-arylimidazo[1,2-a]pyridine 1 (0.2 mmol, 1.0 equiv), o-dihaloarene2 (0.3 mmol, 1.5 equiv), and K2CO3 (82.9 mg, 0.6 mmol, 3.0 equiv). To this mixture were added Pd(OAc)2 (0.02 mmol, 4.5 mg)and Xphos (0.04 mmol, 19.1 mg), followed by DMF (2.0 mL) via a syringe at r.t. The tube was sealed and kept in a preheated oil bath at 160 °C for 24 h. The mixture was cooled to r.t., quenched with H2O (5mL), and diluted with CH2Cl2 (10 mL). The layers were separated and the aqueous layer was extracted with CH2Cl2 (3 × 5 mL). The combined organic extracts were dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was then purified by flash chromatography on silica gel (H), eluting with 5-20% EtOAc-petroleum ether.
  • 41
  • [ 24932-48-7 ]
  • [ 4105-21-9 ]
  • 7,8-dimethyl-1-phenylbenzo[a]imidazo[5,1,2-cd]indolizine [ No CAS ]
YieldReaction ConditionsOperation in experiment
82% With palladium diacetate; potassium carbonate; XPhos In N,N-dimethyl-formamide at 160℃; for 24h; Schlenk technique; Tandem Synthesis of Benzo[a]imidazo[5,1,2-cd]indolizines General procedure: A 10 mL Schlenk tube equipped with a magnetic stirring bar was charged with 2-arylimidazo[1,2-a]pyridine 1 (0.2 mmol, 1.0 equiv), o-dihaloarene2 (0.3 mmol, 1.5 equiv), and K2CO3 (82.9 mg, 0.6 mmol, 3.0 equiv). To this mixture were added Pd(OAc)2 (0.02 mmol, 4.5 mg)and Xphos (0.04 mmol, 19.1 mg), followed by DMF (2.0 mL) via a syringe at r.t. The tube was sealed and kept in a preheated oil bath at 160 °C for 24 h. The mixture was cooled to r.t., quenched with H2O (5mL), and diluted with CH2Cl2 (10 mL). The layers were separated and the aqueous layer was extracted with CH2Cl2 (3 × 5 mL). The combined organic extracts were dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was then purified by flash chromatography on silica gel (H), eluting with 5-20% EtOAc-petroleum ether.
  • 42
  • [ 6627-51-6 ]
  • [ 4105-21-9 ]
  • 7-methyl-1-phenylbenzo[a]imidazo[5,1,2-cd]indolizine [ No CAS ]
YieldReaction ConditionsOperation in experiment
86% With palladium diacetate; potassium carbonate; XPhos In N,N-dimethyl-formamide at 160℃; for 24h; Schlenk technique; Tandem Synthesis of Benzo[a]imidazo[5,1,2-cd]indolizines General procedure: A 10 mL Schlenk tube equipped with a magnetic stirring bar was charged with 2-arylimidazo[1,2-a]pyridine 1 (0.2 mmol, 1.0 equiv), o-dihaloarene2 (0.3 mmol, 1.5 equiv), and K2CO3 (82.9 mg, 0.6 mmol, 3.0 equiv). To this mixture were added Pd(OAc)2 (0.02 mmol, 4.5 mg)and Xphos (0.04 mmol, 19.1 mg), followed by DMF (2.0 mL) via a syringe at r.t. The tube was sealed and kept in a preheated oil bath at 160 °C for 24 h. The mixture was cooled to r.t., quenched with H2O (5mL), and diluted with CH2Cl2 (10 mL). The layers were separated and the aqueous layer was extracted with CH2Cl2 (3 × 5 mL). The combined organic extracts were dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was then purified by flash chromatography on silica gel (H), eluting with 5-20% EtOAc-petroleum ether.
  • 43
  • [ 4105-21-9 ]
  • [ 119757-51-6 ]
  • 5,6-bis(4-(trifluoromethyl)phenyl)naphtho[1′,2′:4,5]imidazo[1,2-a]pyridine [ No CAS ]
  • 2-phenyl-3,4-bis(4-(trifluoromethyl)phenyl)imidazo[5,1,2-cd]-indolizine [ No CAS ]
  • 44
  • [ 399-25-7 ]
  • [ 4105-21-9 ]
  • 3-(1-(2-fluorophenyl)-2-nitroethyl)-2-phenylimidazo[1,2-a]pyridine [ No CAS ]
  • 45
  • [ 1147550-11-5 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-thiocyanatoimidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
99% With N,N,N-trimethylbenzenemethanaminium dichloroiodate In lithium hydroxide monohydrate; dimethyl sulfoxide at 70℃; for 1h; regioselective reaction; General Procedure General procedure: To a stirred solution of anilines 14a-g' or other substrates (20a-d; 22a-b) (0.27-0.47 mmol), ammonium thiocyanate (1.1 equiv) in 9:1 DMSO:H2O (3.4-6.0 mL; 80 mM final concentration), was added benzyltrimethylammonium dichloroiodate (1.2 equiv). The reaction mixture was heated at 70°C for 1 hour, then allowed to cool to ambient temperature. H2O (25 mL) was added. The mixture was diluted using ethyl acetate, and the organic layer was separated. The aqueous layer was partitioned with EtOAc (2 x 20 mL) and the combined organic layers were washed with 10% aqueous sodium dithionite (2 x 20 mL), followed by saturated sodium bicarbonate solution (2 x 20 mL) and then water (2 X 20 mL). The organic layer was dried over anhydrous magnesium sulfate and the solvents were evaporated. The crude product was then purified using flash chromatography (EtOAc/Hexanes) to give pure 15a-g', 21a-d, and 23a-b.
93% With oxygen; Eosin In acetonitrile for 3h; Irradiation;
89% With air; alizarine red S-sensitized TiO2 In tetrahydrofuran at 25℃; for 24h; Irradiation; Green chemistry; regioselective reaction;
89% With carbon nitride g-C3N4; air at 20℃; for 12h; Irradiation; Green chemistry;
85% With tetra-n-butylammonium hexafluoridophosphate In acetonitrile at 20℃; for 6h; Electrochemical reaction; regioselective reaction;
74% With potassium peroxodisulfate In acetonitrile at 20℃; for 18h; regioselective reaction;

  • 46
  • [ 3425-46-5 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-selenocyanatoimidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
92% With [bis(acetoxy)iodo]benzene; iodine In water at 20℃; for 0.5h; Sealed tube; Green chemistry;
82% With N-chloro-succinimide In ethanol at 20℃;
65% With tert-butylammonium hexafluorophosphate(V) In acetonitrile at 20℃; for 6h; Electrochemical reaction; regioselective reaction;
65% With tert-butylammonium hexafluorophosphate(V); platinum In acetonitrile at 20℃; for 6h; Electrochemical reaction; regioselective reaction; 2 General Procedure for the Electrochemical Reaction General procedure: To an undivided three-necked flask (25 mL) were added 2-phenylimidazo[1,2-a]pyridine (1a,38.8 mg, 0.2 mmol), NH4SCN (2a, 30.5 mg, 0.4 mmol, 2 equiv.), nBu4NPF6 (194 mg, 0.5 mmol,2.5 equiv.) and CH3CN (10 mL). The flask was equipped with platinum plate electrodes (10 mm ×10 mm) as the anode and cathode. The reaction mixture was electrolyzed and stirred at a constant current (5 mA) under air at room temperature for 6 h. After the reaction was completed, themixture was diluted with water (30 mL) and then extracted with DCM (10 mL × 3). The combinedorganic phases were dried over anhydrous Na2SO4, filtered, concentrated in vacuo and the crudeproduct was obtained. The residue was purified by silica gel chromatography using petroleumether/ethyl acetate (5:1) as eluent to give the desired product 3a.
51% With oxygen; eosin y In acetonitrile for 3h; Irradiation;

  • 47
  • [ 333-20-0 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-thiocyanatoimidazo[1,2-a]pyridine 6a [ No CAS ]
YieldReaction ConditionsOperation in experiment
88% With [bis(acetoxy)iodo]benzene; iodine In water at 20℃; for 12h; Sealed tube; Green chemistry;
83% With dipotassium peroxodisulfate In 1,2-dichloro-ethane at 25℃; for 18h; Schlenk technique; Sealed tube; regioselective reaction;
83% With [bis(acetoxy)iodo]benzene at 20℃; Inert atmosphere; regioselective reaction; Method 1: General procedure for the synthesis of 3-halo/thiocyanato-2-phenylimidazo[1,2-a]pyridinederivatives. General procedure: A mixture of 2-phenylimidazo[1,2-a]pyridine(1) (1 mmol), M-X (2a/2b/2c/2d) (1.5 mmol) and IBD (1.5 mmol)were taken in a mortar and the mixture ground with pestle until the solids melt ~15 min). A distinction odourof acetic acid was observed. The reaction was monitored by TLC and grinding continued till the startingmaterials disappear. The reaction mixture was extracted with ethyl acetate (30mL) and washed with water (10ml) to remove any remnant inorganic salts. The organic layer was separated and dried over Na2SO4. Solventwas removed in vacuo. The crude product thus obtained was purified by column chromatography (silicon60-120 mesh, and EtOAc: hexane, 5:95).
83% With [bis(acetoxy)iodo]benzene; iodine In water at 20℃; for 12h; regioselective reaction;
73% In acetonitrile at 20℃; for 0.5h; General procedure for the synthesis of 4a-4o General procedure: The respective 2-arylimidazo[1,2-a]pyridine (50 mg), Selectfluor (2 equivalents), and charged nucleophiles (2 equivalents) were stirred in 2 mL of acetonitrile or acetonitrile:water (2:8) mixture at room temperature. After 30 min, the reaction mixture was added into water and extracted with twice with EtOAc. The organic layers were combined, dried with Na2SO4 and evaporated under vaccum. The crude solid was then purified using column chromatography

  • 48
  • [ 104-09-6 ]
  • [ 4105-21-9 ]
  • 1-(2-Phenylimidazo[1,2-a]pyridin-3-yl)-2-(p-tolyl)ethane-1,2-dione [ No CAS ]
YieldReaction ConditionsOperation in experiment
70% With [2,2]bipyridinyl; copper(I) bromide In toluene at 100℃; for 13h; 3 General procedure for dicarbonylation of imidazoheterocycles A mixture of imidazoheterocycles (0.52mmol), phenyl acetaldehyde (0.62mmol), CuBr (0.052mmol), 2,2-bipyridine (0.052mmol) in toluene (8mL) was heated at 100°C for 12-17h (TLC). Toluene was evaporated and the reaction mixture was directly subjected to silica gel column chromatography (Hexane/EtOAc, 9:1) to yield the dicarbonylated product 3, 5 as colored products in pure form.
  • 49
  • [ 5703-26-4 ]
  • [ 4105-21-9 ]
  • 1-(4-methoxyphenyl)-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)ethane-1,2-dione [ No CAS ]
YieldReaction ConditionsOperation in experiment
72% With [2,2]bipyridinyl; copper(I) bromide In toluene at 100℃; for 14h; 3 General procedure for dicarbonylation of imidazoheterocycles A mixture of imidazoheterocycles (0.52mmol), phenyl acetaldehyde (0.62mmol), CuBr (0.052mmol), 2,2-bipyridine (0.052mmol) in toluene (8mL) was heated at 100°C for 12-17h (TLC). Toluene was evaporated and the reaction mixture was directly subjected to silica gel column chromatography (Hexane/EtOAc, 9:1) to yield the dicarbonylated product 3, 5 as colored products in pure form.
  • 50
  • [ 4251-65-4 ]
  • [ 4105-21-9 ]
  • 1-(4-chlorophenyl)-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)ethane-1,2-dione [ No CAS ]
YieldReaction ConditionsOperation in experiment
82% With [2,2]bipyridinyl; copper(I) bromide; In toluene; at 100℃; for 14h; A mixture of imidazoheterocycles (0.52mmol), phenyl acetaldehyde (0.62mmol), CuBr (0.052mmol), 2,2-bipyridine (0.052mmol) in toluene (8mL) was heated at 100C for 12-17h (TLC). Toluene was evaporated and the reaction mixture was directly subjected to silica gel column chromatography (Hexane/EtOAc, 9:1) to yield the dicarbonylated product 3, 5 as colored products in pure form.
  • 51
  • [ 27200-79-9 ]
  • [ 4105-21-9 ]
  • 1-(4-bromophenyl)-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)ethane-1,2-dione [ No CAS ]
YieldReaction ConditionsOperation in experiment
82% With [2,2]bipyridinyl; copper(I) bromide; In toluene; at 100℃; for 14h; A mixture of imidazoheterocycles (0.52mmol), phenyl acetaldehyde (0.62mmol), CuBr (0.052mmol), 2,2-bipyridine (0.052mmol) in toluene (8mL) was heated at 100C for 12-17h (TLC). Toluene was evaporated and the reaction mixture was directly subjected to silica gel column chromatography (Hexane/EtOAc, 9:1) to yield the dicarbonylated product 3, 5 as colored products in pure form.
  • 52
  • [ 1736-67-0 ]
  • [ 4105-21-9 ]
  • 1-(4-fluorophenyl)-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)ethane-1,2-dione [ No CAS ]
YieldReaction ConditionsOperation in experiment
85% With [2,2]bipyridinyl; copper(I) bromide In toluene at 100℃; for 13h; 3 General procedure for dicarbonylation of imidazoheterocycles A mixture of imidazoheterocycles (0.52mmol), phenyl acetaldehyde (0.62mmol), CuBr (0.052mmol), 2,2-bipyridine (0.052mmol) in toluene (8mL) was heated at 100°C for 12-17h (TLC). Toluene was evaporated and the reaction mixture was directly subjected to silica gel column chromatography (Hexane/EtOAc, 9:1) to yield the dicarbonylated product 3, 5 as colored products in pure form.
  • 53
  • [ 27126-76-7 ]
  • [ 4105-21-9 ]
  • (2-phenylimidazo-[1,2-a]pyridin-3-yl)phenyl-iodonium 4-methylbenzenesulfonic acid [ No CAS ]
YieldReaction ConditionsOperation in experiment
85% In acetone at 20℃; for 4h; Inert atmosphere; Compound 43 lodonium, (2-phenylimidazo- [1,2-alpyridin-3-yl)phenyl-, salt with 4- methylbenzenesulfonic acid (1:1) Compound 43 lodonium, (2-phenylimidazo- [1,2-alpyridin-3-yl)phenyl-, salt with 4- methylbenzenesulfonic acid (1:1)[0146] A mixture of imidazo[1,2-a]pyridine,2-phenyl- (200 mg, 1.03 mmol) and[hydroxy(tosyloxy)iodo]benzene (96%, 422 mg, 1.03 mmol) in acetone (8 mL) was stuffedroom temperature under an argon atmosphere for 4 hours. Initially, the reaction mix is ayellow solution but after 30 minutes a white precipitate formed. Additional acetone (3 mL)was added and stuffing was continued. After 4 hours the suspension was diluted with Et20(400 mL) and the solid was collected by suction filtration. The solid was washed with Et20(100 mL) and dried in vacuo at room temperature to give the product (498 mg, 85%); m.p.119-122 °C.Nuclear Magnetic Resonance Spectroscopy:1H NMR (600 MHz, DMSO-d6): ö 9.11-9.10 (d, 1H); 7.91-7.90 (d, 2H); 7.87-7.84 (m, 3H);7.64-7.57 (m, 5H); 7.46-7.43 (m, 4H); 7.32-7.30 (t, 1H); 7.11-7.09 (d, 2H); 2.28 (s, 3H).Mass Spectroscopy:Method of Ionization: Electrospray (positive ion) Calc’d for (C19H141N2)+ = 397.0 Found:mlz (relative intensity) 397.3 (100%, M+).
  • 54
  • [ 667-27-6 ]
  • [ 4105-21-9 ]
  • ethyl 2,2-difluoro-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)acetate [ No CAS ]
YieldReaction ConditionsOperation in experiment
90% With fac-Ir(ppy)<SUB>3</SUB>; potassium carbonate In dimethyl sulfoxide at 20℃; for 24h; Inert atmosphere; Irradiation; regioselective reaction; 1 4.2. General procedure for the synthesis of difluoroacetylated imidazo[1,2-a]pyridines General procedure: To a mixture of imidazo[1,2-a]pyridines 1 (0.30mmol), BrCF2COOEt (0.6mmol), and K2CO3 (0.6mmol) in 3.0mL of DMSO was added fac-Ir(ppy)3 (0.006mmol, 2.0 mol%) under N2 atmosphere. The solution was stirred at room temperature under 5W blue LED irradiation for 24h. Then the reaction mixture was diluted by adding EtOAc and brine. The aqueous layer was extracted with EtOAc. The combined organic layer was dried over MgSO4, filtered and concentrated. The residue was purified by flash column chromatography (petroleum ether/ethyl acetate 5:1 as the eluant) on silica gel to give the desired the pure product 2. 4.2.1 Ethyl 2,2-difluoro-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)acetate (2a)25 (0011) 1H NMR (500MHz, CDCl3): δ 8.54 (d, 1H, J=7.0Hz), 7.71 (d, 1H, J=9.5Hz), 7.65 (d, 2H, J=6.5Hz), 7.47-.42 (m, 3H), 7.38-7.34 (m, 1H), 3.97 (q, 2H, J=7.0Hz), 1.15 (t, 3H, J=7.0Hz). 13C NMR (125MHz, CDCl3): δ 162.35 (t, J=34.3Hz), 148.13, 146.23, 133.35, 129.64, 128.80, 128.13, 126.78, 126.61 (t, J=5.4Hz), 117.88, 113.48, 111.48 (t, J=28.8Hz), 111.48 (t, J=246.4Hz), 63.65, 13.60. 19F NMR (470MHz, CDCl3): δ -98.53 (s, 2F).
75% With copper(I) oxide; 1,10-Phenanthroline; potassium carbonate In acetonitrile at 80℃; for 10h; Sealed tube;
  • 55
  • [ 137-26-8 ]
  • [ 4105-21-9 ]
  • 2-phenylimidazo[1,2-a]pyridin-3-yl dimethylcarbamodithioate [ No CAS ]
YieldReaction ConditionsOperation in experiment
78% With trifluoroacetic acid In 1,4-dioxane at 120℃; for 15h; regioselective reaction;
78% With trifluoroacetic acid In 1,4-dioxane at 120℃; for 15h; 7 Example 7 Add 58.3mg (0.3mmol) of imidazo[1,2-a]pyridine as shown below and 108.2mg (0.45mmol) of tetramethylthiuram disulfide substrate into the reaction tube with a stirrer, and then add After adding 51.3 mg (0.45 mmol) of additive TFA, adding 1,4-dioxane (2 ml) solvent to dissolve it, stirring at 120 OC for 15 hours, spin-drying, and separating by silica gel chromatography to obtain the target product with a yield of 78%.
69% With iron(III) trifluoride; iodine In 1,2-dichloro-ethane at 80℃; for 3h;
  • 56
  • [ 98-60-2 ]
  • [ 4105-21-9 ]
  • [ 306278-24-0 ]
YieldReaction ConditionsOperation in experiment
90% With copper(l) iodide; triphenylphosphine In toluene at 130℃; for 24h; regioselective reaction;
75% Stage #1: 4-chlorobenzenesulfonyl chloride With hydrazine hydrate In tetrahydrofuran for 1h; Sealed tube; Cooling with ice; Green chemistry; Stage #2: 2-phenylimidazo[1,2-a]pyridine In tetrahydrofuran at 135℃; for 20h; Sealed tube; Green chemistry; General procedure for the synthesis of compounds 3a-q General procedure: Hydrazine (3.0 equiv.) was added to a pressure tube withTHF (0.5 mL), sulfonyl chloride 2a (1.5 equiv.) was addedslowly under ice bath and stirred for 1 h. Then imidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.) was added into and themixture were stirred at 135 C. After 20 h, the reaction wascooled down to room temperature, diluted with dichloromethane(2 mL), washed with brine (1 mL), dried over anhydrousNa2SO4 and concentrated under vacuum. The residuewas purified by flash chromatography (Petroleum ether:EtOAc 40:1) on silica gel to give the desired product 3a asa colorless oil in an 82% yield.
  • 57
  • [ 98-09-9 ]
  • [ 4105-21-9 ]
  • [ 297139-61-8 ]
YieldReaction ConditionsOperation in experiment
88% Stage #1: benzenesulfonyl chloride With hydrazine hydrate In tetrahydrofuran for 1h; Sealed tube; Cooling with ice; Green chemistry; Stage #2: 2-phenylimidazo[1,2-a]pyridine In tetrahydrofuran at 135℃; for 20h; Sealed tube; Green chemistry; General procedure for the synthesis of compounds 3a-q General procedure: Hydrazine (3.0 equiv.) was added to a pressure tube withTHF (0.5 mL), sulfonyl chloride 2a (1.5 equiv.) was addedslowly under ice bath and stirred for 1 h. Then imidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.) was added into and themixture were stirred at 135 C. After 20 h, the reaction wascooled down to room temperature, diluted with dichloromethane(2 mL), washed with brine (1 mL), dried over anhydrousNa2SO4 and concentrated under vacuum. The residuewas purified by flash chromatography (Petroleum ether:EtOAc 40:1) on silica gel to give the desired product 3a asa colorless oil in an 82% yield.
81% With copper(l) iodide; triphenylphosphine In toluene at 130℃; for 24h; regioselective reaction;
64% With hydrogen bromide; tetra-(n-butyl)ammonium iodide In water at 50℃; for 2h; Green chemistry;
  • 58
  • [ 2009-97-4 ]
  • [ 4105-21-9 ]
  • ethyl 6-methylnaphtho[1',2':4,5]imidazo[1,2-a]pyridine-5-carboxylate [ No CAS ]
YieldReaction ConditionsOperation in experiment
82% With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; acetic acid In 1,2-dichloro-ethane at 140℃; for 2h; Sealed tube; regioselective reaction;
82% Stage #1: ethyl 2-diazo-3-oxobutanoate; 2-phenylimidazo[1,2-a]pyridine With dichloro(pentamethylcyclopentadienyl)rhodium (III) dimer; acetic acid In 1,2-dichloro-ethane at 140℃; for 2h; Green chemistry; Stage #2: Sealed tube; Green chemistry; 26 Example 26 1a (97mg, 0.5mmol), 2h (117mg, 0.75mmol),1,2-dichloroethane (3 mL), dichloro (pentamethylcyclopentadienyl) complex (III) dimer (15.5 mg, 0.025 mmol) and acetic acid (60 mg, 1 mmol), and then The pressure tube was sealed and placed in a 140C oil bath for 2 h.After the reaction was completed, it was cooled to room temperature, filtered with suction, dried, and separated through a silica gel column (petroleum ether / ethyl acetate = 3/1) to obtain a white solid product 3h (125mg, 82%).
55% With C14H23O4Rh; trifluoroacetic acid In ethanol at 80℃; for 12h; Sealed tube; Inert atmosphere; Schlenk technique;
  • 59
  • [ 621-08-9 ]
  • [ 4105-21-9 ]
  • 3,3'-(phenylmethylene)bis(2-phenylimidazo[1,2-a]pyridine) [ No CAS ]
YieldReaction ConditionsOperation in experiment
84% With phosphoric acid In toluene at 145℃; for 24h; regioselective reaction;
  • 60
  • [ 2206-27-1 ]
  • [ 4105-21-9 ]
  • d2-bis(2-phenylimidazo[1,2-a]pyridin-3-yl)methane [ No CAS ]
  • 61
  • [ 3278-34-0 ]
  • [ 4105-21-9 ]
  • ethyl 2-(2-phenylimidazo[1,2-a]pyridin-3-yl)acetate [ No CAS ]
YieldReaction ConditionsOperation in experiment
70% With dilauryl peroxide; In 1,2-dichloro-ethane; at 85℃;Microwave irradiation; General procedure: A solution of the corresponding xanthate (2 mmol) and Imidazo[1,2-a]pyridines (1 mmol) in 1,2-Dichloroethane [0.1 M] was irradiated in a Biotage microwave (100 W) at 85 C, then, dilauroyl peroxide (2 equiv) was added portionwise (0.28 equiv/15min), the organic solvent was removed under reduced pressure and the crude residue was purified by flash chromatography. Ethyl 2-(2-phenylimidazo[1,2-a]pyridin-3-yl)acetate. (18a) This residue was purified by flash chromatography (7:3 hexane/EtOAc) to give 18a (70%) as yellow oil. IR (film) /cm-1 : 2924, 1713, 1508, 1350, 1150, 745, 692, 541; 1H NMR (300 MHz, CDCl3) delta/ppm: 8.04 (d, J=9.0 Hz, 1H), 7.81 (m, 2H), 7.60 (d, J=9.0 Hz, 1H), 7.42 (m, 2H), 7.32 (m, 1H), 7.14 (m, 1H), 6.77 (t, J=6.0 Hz, 1H), 4.15 (q, J=6.0 Hz, 2H), 3.97 (s, 2H), 1.20 (t, J=6.0 Hz, 3H) ; 13C NMR (75 MHz, CDCl3) delta/ppm: 169.1, 144.7, 144.2, 133.8, 128.37, 128.34, 127.6, 124.2, 123.5, 117.2, 112.7, 112.1, 61.3, 30.5, 13.9; MS (DART+), m/z: 281 (M+H); HRMS m/z calcd for C17H17N2O2 [M+H], 281.12900; found 281.12958
56% With tris[2-phenylpyridinato-C2,N]iridium(III); N,N-dimethyl-formamide; at 24℃;Inert atmosphere; UV-irradiation; General procedure: In a 4.0mL glass vial equipped with a stirring bar, were added the corresponding xanthate (0.2mmol, 2.0 equiv.), the radical acceptor (0.1mmol, 1.0 equiv.) (alkene 2 or 5; or heterocycle 10-12), Ir(ppy)3 (0.002mmol, 0.02 equiv.) and DMF (0.4mL, [0.25M]). Next, the resulting solution was degassed by three consecutive freeze-pump-thaw cycles and placed under argon atmosphere. Finally, the reaction mixture was stirred and irradiated in a Blue LEDs reactor (12W) at 24C during 12-14h. After that, the mixture was concentrated in vacuo and the product was purified by flash column chromatography on silica gel.
  • 62
  • [ 4105-21-9 ]
  • [ 218966-77-9 ]
  • diethyl 2-(2-phenylimidazo[1,2-a]pyridin-3-yl)malonate [ No CAS ]
YieldReaction ConditionsOperation in experiment
92% With dilauryl peroxide In 1,2-dichloro-ethane at 85℃; Microwave irradiation; regioselective reaction; General procedure for the preparation of to Imidazo[1,2-a]pyridines 18a-18v under microwave heating General procedure: A solution of the corresponding xanthate (2 mmol) and Imidazo[1,2-a]pyridines (1 mmol) in 1,2-Dichloroethane [0.1 M] was irradiated in a Biotage microwave (100 W) at 85 °C, then, dilauroyl peroxide (2 equiv) was added portionwise (0.28 equiv/15min), the organic solvent was removed under reduced pressure and the crude residue was purified by flash chromatography.
75% With dilauryl peroxide In 1,2-dichloro-ethane at 84℃; for 12h;
68% With tris[2-phenylpyridinato-C2,N]iridium(III); N,N-dimethyl-formamide at 24℃; Inert atmosphere; UV-irradiation; regioselective reaction; 1 General procedure for the xanthate transfer group reaction and oxidative addition to aromatic systems General procedure: In a 4.0mL glass vial equipped with a stirring bar, were added the corresponding xanthate (0.2mmol, 2.0 equiv.), the radical acceptor (0.1mmol, 1.0 equiv.) (alkene 2 or 5; or heterocycle 10-12), Ir(ppy)3 (0.002mmol, 0.02 equiv.) and DMF (0.4mL, [0.25M]). Next, the resulting solution was degassed by three consecutive freeze-pump-thaw cycles and placed under argon atmosphere. Finally, the reaction mixture was stirred and irradiated in a Blue LEDs reactor (12W) at 24°C during 12-14h. After that, the mixture was concentrated in vacuo and the product was purified by flash column chromatography on silica gel.
  • 63
  • [ 49762-80-3 ]
  • [ 4105-21-9 ]
  • 1-(2-phenylimidazo[1,2-a]pyridin-3-yl)propan-2-one [ No CAS ]
YieldReaction ConditionsOperation in experiment
84% With dilauryl peroxide In 1,2-dichloro-ethane at 85℃; Microwave irradiation; regioselective reaction; General procedure for the preparation of to Imidazo[1,2-a]pyridines 18a-18v under microwave heating General procedure: A solution of the corresponding xanthate (2 mmol) and Imidazo[1,2-a]pyridines (1 mmol) in 1,2-Dichloroethane [0.1 M] was irradiated in a Biotage microwave (100 W) at 85 °C, then, dilauroyl peroxide (2 equiv) was added portionwise (0.28 equiv/15min), the organic solvent was removed under reduced pressure and the crude residue was purified by flash chromatography.
79% With dilauryl peroxide In 1,2-dichloro-ethane at 84℃; for 12h;
  • 64
  • [ 56817-84-6 ]
  • [ 4105-21-9 ]
  • 1-phenyl-2-(2-phenylimidazo[1,2-a]pyridin-3-yl)ethan-1-one [ No CAS ]
YieldReaction ConditionsOperation in experiment
80% With dilauryl peroxide In 1,2-dichloro-ethane at 85℃; Microwave irradiation; regioselective reaction; General procedure for the preparation of to Imidazo[1,2-a]pyridines 18a-18v under microwave heating General procedure: A solution of the corresponding xanthate (2 mmol) and Imidazo[1,2-a]pyridines (1 mmol) in 1,2-Dichloroethane [0.1 M] was irradiated in a Biotage microwave (100 W) at 85 °C, then, dilauroyl peroxide (2 equiv) was added portionwise (0.28 equiv/15min), the organic solvent was removed under reduced pressure and the crude residue was purified by flash chromatography.
65% With dilauryl peroxide In 1,2-dichloro-ethane at 84℃; for 12h;
  • 65
  • [ 59463-54-6 ]
  • [ 4105-21-9 ]
  • 2-(2-phenylimidazo[1,2-a]pyridin-3-yl)acetonitrile [ No CAS ]
YieldReaction ConditionsOperation in experiment
90% With tris[2-phenylpyridinato-C2,N]iridium(III); N,N-dimethyl-formamide at 24℃; Inert atmosphere; UV-irradiation; regioselective reaction; 1 General procedure for the xanthate transfer group reaction and oxidative addition to aromatic systems General procedure: In a 4.0mL glass vial equipped with a stirring bar, were added the corresponding xanthate (0.2mmol, 2.0 equiv.), the radical acceptor (0.1mmol, 1.0 equiv.) (alkene 2 or 5; or heterocycle 10-12), Ir(ppy)3 (0.002mmol, 0.02 equiv.) and DMF (0.4mL, [0.25M]). Next, the resulting solution was degassed by three consecutive freeze-pump-thaw cycles and placed under argon atmosphere. Finally, the reaction mixture was stirred and irradiated in a Blue LEDs reactor (12W) at 24°C during 12-14h. After that, the mixture was concentrated in vacuo and the product was purified by flash column chromatography on silica gel.
79% With dilauryl peroxide In 1,2-dichloro-ethane at 84℃; for 12h;
73% With dilauryl peroxide In 1,2-dichloro-ethane at 85℃; Microwave irradiation; regioselective reaction; General procedure for the preparation of to Imidazo[1,2-a]pyridines 18a-18v under microwave heating General procedure: A solution of the corresponding xanthate (2 mmol) and Imidazo[1,2-a]pyridines (1 mmol) in 1,2-Dichloroethane [0.1 M] was irradiated in a Biotage microwave (100 W) at 85 °C, then, dilauroyl peroxide (2 equiv) was added portionwise (0.28 equiv/15min), the organic solvent was removed under reduced pressure and the crude residue was purified by flash chromatography.
  • 66
  • [ 36635-61-7 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-(tosylmethyl)imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
94% With iron(III) chloride In water at 100℃; for 22h; Sealed tube; Schlenk technique; Inert atmosphere; Green chemistry; regioselective reaction;
94% With iron(III) chloride In water at 90℃; for 24h; Inert atmosphere; Schlenk technique; 1 Example 1 The preparation method was carried out by adding 0.1mmol of a 2-phenylimidazo[1,2-a]pyridine compound, 0.2 mmol of p-toluenesulfonylmethylisonitrile, to a 10 mL Schlenk tube under an argon atmosphere, 0.02 mmol of ferric chloride, water and 7% polyethylene glycol 400 (volume ratio 1: 1) 2 mL, 90 °C for 24 hours; after the reaction, the mixture was extracted with methylene chloride and concentrated under reduced pressure. Gel 200-300 mesh, eluent: ethyl acetate / petroleum ether gradient elution, the ratio from 0/100 to 100/0), dried to a white solid in 94% yield.
  • 67
  • 1-fluoro-4-((isocyanomethyl)sulfonyl)benzene [ No CAS ]
  • [ 4105-21-9 ]
  • 3-(((4-fluorophenyl)sulfonyl)methyl)-2-phenylimidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
91% With iron(III) chloride In water at 100℃; for 22h; Sealed tube; Schlenk technique; Inert atmosphere; Green chemistry; regioselective reaction;
91% With iron(III) chloride In water at 120℃; for 20h; Inert atmosphere; Schlenk technique; 15 Example 15 The preparation method was carried out by adding 0.1mmol of a 2-phenylimidazo[1,2-a]pyridine compound, 0.2 mmol of 1-fluoro-4-((isocyanatemethyl)sulfonyl)benzene, to a 10 mL Schlenk tube under an argon atmosphere, 0.02 mmol of ferric chloride, water and polyethylene glycol 400 (volume ratio 1: 1) 2 mL, 120 °C for 20 hours; after the reaction, the mixture was extracted with methylene chloride and concentrated under reduced pressure. Gel 200-300 mesh, eluent: ethyl acetate / petroleum ether gradient elution, the ratio from 0/100 to 100/0), dried to a white solid in 91% yield.
  • 68
  • [ 36635-63-9 ]
  • [ 4105-21-9 ]
  • 2-phenyl-3-((phenylsulfonyl)methyl)imidazo[1,2-a]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
96% With iron(III) chloride In water at 100℃; for 22h; Sealed tube; Schlenk technique; Inert atmosphere; Green chemistry; regioselective reaction;
96% With iron(III) chloride In water at 100℃; for 22h; Inert atmosphere; Schlenk technique; 16 Example 16 The preparation method was carried out by adding 0.1mmol of a 2-phenylimidazo[1,2-a]pyridine compound, 0.2 mmol of ((isocyanomethyl)sulfonyl)benzene, to a 10 mL Schlenk tube under an argon atmosphere, 0.02 mmol of ferric chloride, water and polyethylene glycol 400 (volume ratio 1: 1) 2 mL, 100 °C for 22 hours; after the reaction, the mixture was extracted with methylene chloride and concentrated under reduced pressure. Gel 200-300 mesh, eluent: ethyl acetate / petroleum ether gradient elution, the ratio from 0/100 to 100/0), dried to a white solid in 96% yield.
  • 69
  • [ 4105-21-9 ]
  • [ 3649-46-5 ]
YieldReaction ConditionsOperation in experiment
95% With palladium diacetate; bis(pinacol)diborane In water at 20℃; for 10h; Schlenk technique; Inert atmosphere;
95% With palladium diacetate; caesium carbonate; bis(pinacol)diborane In water at 20℃; for 10h; Inert atmosphere; Green chemistry; 4 Example 4: A solution of 0.6 mmol of bis(pinacolato)diboron, 0.02 mmol of palladium acetate and 00.1 mmol of cesium carbonate were added to the reaction tube, after filling with nitrogen, 0.2 mmol of 2-phenylimidazo[1,2-a]pyridine and 2 ml of water were injected into the reaction tube, the reaction was stirred at room temperature for 10 h, the reaction was followed by TLC and GC to determine the specific reaction time. After cooling to room temperature and mixing well with ethyl acetate, the mixed solution was diluted with ethyl acetate. After concentration, the organic phases were combined, using petroleum ether: ethyl acetate = 20:1 eluent, the product was obtained by columnation, the yield was 73%. The suitability of the substrate was studied under the standard conditions of the present invention to demonstrate that the technical proposal of the present invention has good functional group compatibility, the substrate range is as follows:
86% With methanol; palladium diacetate; 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane In dichloromethane at 25℃; for 12h; Schlenk technique; Inert atmosphere; 46 Replace the gas environment in the Shrek tube with a nitrogen environment, add 2-phenylimidazo [1,2-a] pyridine 0.25mmol, palladium acetate 0.025mmol, dichloromethane 2mL, methanol 27.5mmol, add Pinna under stirring The alcohol borane was 0.55 mmol and reacted at room temperature for 12 h. The reaction solution obtained after the completion of the reaction was subjected to column chromatography. The target product obtained in 86% yield was a white solid.
86% With methanol; palladium diacetate; 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane In dichloromethane at 25℃; for 12h; Sealed tube; Inert atmosphere; chemoselective reaction;

  • 70
  • [ 96464-10-7 ]
  • [ 67-68-5 ]
  • [ 4105-21-9 ]
  • bis(2-phenylimidazo[1,2-a]pyridin-3-yl)methane [ No CAS ]
  • 2-(4-bromophenyl)-6-chloro-3-((2-phenylimidazo[1,2-a]pyridin-3-yl)methyl)imidazo[1,2-a]pyridine [ No CAS ]
  • bis(2-(4-bromophenyl)-6-chloroimidazo[1,2-a]pyridin-3-yl)methane [ No CAS ]
YieldReaction ConditionsOperation in experiment
1: 31% 2: 16% 3: 13% With dihydrogen peroxide In water at 125℃; for 23h; regioselective reaction;
  • 71
  • [ 696-62-8 ]
  • [ 4105-21-9 ]
  • 3-((4-methoxyphenyl)thio)-2-phenylimidazo[1,2-α]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
96% With sulfur; copper(l) iodide; sodium carbonate In N,N-dimethyl-formamide at 130℃; for 24h; Inert atmosphere; regioselective reaction;
82% With copper(l) iodide; potassium carbonate; sulfur In N,N-dimethyl-formamide at 120℃; for 12h; Sealed tube; Green chemistry; regioselective reaction; 4.2. General procedure General procedure: 2-Phenylimidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.), sulfur(2.0 equiv.), K2CO3 (0.5 equiv.) and halide (1.0 equiv.) were added to a dried flask with DMF (0.5 mL), followed by the addition of CuI (0.2 equiv.) The mixture was stirred under air at 120 C. After 12 h, the reaction was cooled down to room temperature, diluted with ethylacetate, washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by flashch romatography (Petroleum ether: EtOAc 30:1) on silica gel to give the desired product 2a as a yellow oil in an 89% yield.
81% With copper(l) iodide; sodium thiosulfate In N,N-dimethyl-formamide at 120℃; for 12h; regioselective reaction;
81% With copper(l) iodide; 1,10-Phenanthroline; 1,4-diazabicyclo [2.2.2] octane-1,4-diium-1,4-disulfinate; potassium <i>tert</i>-butylate In N,N-dimethyl-formamide at 140℃; for 24h; Sealed tube; Inert atmosphere;

  • 72
  • [ 4105-21-9 ]
  • [ 74-88-4 ]
  • [ 5000-95-3 ]
YieldReaction ConditionsOperation in experiment
87% With copper(l) iodide; potassium carbonate; sulfur In N,N-dimethyl-formamide at 120℃; for 12h; Sealed tube; Green chemistry; regioselective reaction; 4.2. General procedure General procedure: 2-Phenylimidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.), sulfur(2.0 equiv.), K2CO3 (0.5 equiv.) and halide (1.0 equiv.) were added to a dried flask with DMF (0.5 mL), followed by the addition of CuI (0.2 equiv.) The mixture was stirred under air at 120 C. After 12 h, the reaction was cooled down to room temperature, diluted with ethylacetate, washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by flashch romatography (Petroleum ether: EtOAc 30:1) on silica gel to give the desired product 2a as a yellow oil in an 89% yield.
65% With copper(l) iodide; sodium thiosulfate In N,N-dimethyl-formamide at 120℃; for 12h; regioselective reaction;
  • 73
  • [ 100-39-0 ]
  • [ 4105-21-9 ]
  • 3-(benzylthio)-2-phenylimidazo[1,2-α]pyridine [ No CAS ]
YieldReaction ConditionsOperation in experiment
84% With copper(l) iodide; 1,10-Phenanthroline; 1,4-diazabicyclo [2.2.2] octane-1,4-diium-1,4-disulfinate; potassium <i>tert</i>-butylate In N,N-dimethyl-formamide at 140℃; for 24h; Sealed tube; Inert atmosphere;
75% With copper(l) iodide; potassium carbonate; sulfur In N,N-dimethyl-formamide at 120℃; for 12h; Sealed tube; Green chemistry; regioselective reaction; 4.2. General procedure General procedure: 2-Phenylimidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.), sulfur(2.0 equiv.), K2CO3 (0.5 equiv.) and halide (1.0 equiv.) were added to a dried flask with DMF (0.5 mL), followed by the addition of CuI (0.2 equiv.) The mixture was stirred under air at 120 C. After 12 h, the reaction was cooled down to room temperature, diluted with ethylacetate, washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by flashch romatography (Petroleum ether: EtOAc 30:1) on silica gel to give the desired product 2a as a yellow oil in an 89% yield.
73% With copper(l) iodide; sodium thiosulfate In N,N-dimethyl-formamide at 120℃; for 12h; regioselective reaction;
62% With N,N,N,N,-tetramethylethylenediamine; sulfur In acetonitrile at 100℃; for 24h;
59% With N,N,N,N,-tetramethylethylenediamine; sulfur In acetonitrile at 100℃; for 24h; 14 This example mainly aims to synthesize the compound of the formula (16). The synthesis route is as follows: specifically includes the following steps: the compound of the above formula (1a) and sulfur powder and the compound of the formula (2i) in a molar ratio of 1:2 : 1.5 The reaction is carried out under the conditions of the base TMEDA and the solvent CH3CN. The molar equivalent of the base TMEDA is 1 eq of the compound of the formula (1a), wherein the amount of the compound of the formula (1a) is 0.2 mmoL, and the solvent CH3CN is 2 mL, which is added to 10 mL in order. The reaction tube was stirred at 100° C. for 24 hours; after the reaction was completed, the mixture was cooled, the mixture was diluted with AcOEt, and the mixture was washed with water. The resulting organic phase was extracted and dried over anhydrous sodium sulfate. The filtrate was filtered off with suction and the solvent was removed by rotary evaporation. The residue was chromatographed on silica gel, eluted with petroleum ether/ethyl acetate, checked by TLC, and the product-containing effluent was combined. The solvent was distilled off on a rotary evaporator and dried in vacuo to give a brown liquid, which was a compound of formula (16). 59%.

  • 74
  • [ 109-69-3 ]
  • [ 4105-21-9 ]
  • [ 6667-08-9 ]
YieldReaction ConditionsOperation in experiment
80% With copper(l) iodide; potassium carbonate; sulfur In N,N-dimethyl-formamide at 120℃; for 12h; Sealed tube; Green chemistry; regioselective reaction; 4.2. General procedure General procedure: 2-Phenylimidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.), sulfur(2.0 equiv.), K2CO3 (0.5 equiv.) and halide (1.0 equiv.) were added to a dried flask with DMF (0.5 mL), followed by the addition of CuI (0.2 equiv.) The mixture was stirred under air at 120 C. After 12 h, the reaction was cooled down to room temperature, diluted with ethylacetate, washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by flashch romatography (Petroleum ether: EtOAc 30:1) on silica gel to give the desired product 2a as a yellow oil in an 89% yield.
78% With N,N,N,N,-tetramethylethylenediamine; sulfur at 120℃; for 24h;
75% With copper(l) iodide; sodium thiosulfate In N,N-dimethyl-formamide at 120℃; for 12h; regioselective reaction;
  • 75
  • [ 637-87-6 ]
  • [ 4105-21-9 ]
  • [ 306278-24-0 ]
YieldReaction ConditionsOperation in experiment
78% With copper(l) iodide; potassium carbonate; sulfur In N,N-dimethyl-formamide at 120℃; for 12h; Sealed tube; Green chemistry; regioselective reaction; 4.2. General procedure General procedure: 2-Phenylimidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.), sulfur(2.0 equiv.), K2CO3 (0.5 equiv.) and halide (1.0 equiv.) were added to a dried flask with DMF (0.5 mL), followed by the addition of CuI (0.2 equiv.) The mixture was stirred under air at 120 C. After 12 h, the reaction was cooled down to room temperature, diluted with ethylacetate, washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by flashch romatography (Petroleum ether: EtOAc 30:1) on silica gel to give the desired product 2a as a yellow oil in an 89% yield.
60% With copper(l) iodide; sodium thiosulfate In N,N-dimethyl-formamide at 120℃; for 12h; regioselective reaction;
52% With copper(l) iodide; 1,10-Phenanthroline; 1,4-diazabicyclo [2.2.2] octane-1,4-diium-1,4-disulfinate; potassium <i>tert</i>-butylate In N,N-dimethyl-formamide at 140℃; for 24h; Sealed tube; Inert atmosphere;
  • 76
  • [ 636-98-6 ]
  • [ 4105-21-9 ]
  • [ 295363-15-4 ]
YieldReaction ConditionsOperation in experiment
82% With copper(l) iodide; sodium thiosulfate In N,N-dimethyl-formamide at 120℃; for 12h; regioselective reaction;
75% With copper(l) iodide; potassium carbonate; sulfur In N,N-dimethyl-formamide at 120℃; for 12h; Sealed tube; Green chemistry; regioselective reaction; 4.2. General procedure General procedure: 2-Phenylimidazo[1,2-a]pyridine 1a (0.5 mmol, 1.0 equiv.), sulfur(2.0 equiv.), K2CO3 (0.5 equiv.) and halide (1.0 equiv.) were added to a dried flask with DMF (0.5 mL), followed by the addition of CuI (0.2 equiv.) The mixture was stirred under air at 120 C. After 12 h, the reaction was cooled down to room temperature, diluted with ethylacetate, washed with brine, dried over anhydrous Na2SO4 and concentrated under vacuum. The residue was purified by flashch romatography (Petroleum ether: EtOAc 30:1) on silica gel to give the desired product 2a as a yellow oil in an 89% yield.
  • 77
  • [ 89-98-5 ]
  • [ 4105-21-9 ]
  • C20H12N2O [ No CAS ]
YieldReaction ConditionsOperation in experiment
95% With tetrabutylammomium bromide; palladium diacetate; potassium carbonate; 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene In N,N-dimethyl acetamide; water at 140℃; for 24h;
95% With tetrabutylammomium bromide; palladium diacetate; potassium carbonate; 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene In N,N-dimethyl acetamide; water at 140℃; for 24h; 36 In a 10 ml flask,Add the magnet,2-phenylimidazo [1,2-a] pyridine (0.3 mmol) was added,2-chlorobenzaldehyde (0.9 mmol),Potassium carbonate (0.9 mmol),Tetrabutylammonium bromide (0.9 mmol),Palladium acetate (5 mol%),4,5-bis (diphenylphosphino) -9,9-dimethylXanthene (10mol%),N, N-dimethylacetamide (4 mL),Water (0.1 mL).The reaction mixture was reacted in a 140 ° oil bath for 24 hours,Cooled to room temperature,An appropriate amount of water was added and extracted three times with ethyl acetate,Combine organic phase,Dried over anhydrous magnesium sulfate,Concentrated by filtration, concentrated column chromatography,The product was separated 84 mg,Yield 95%.
  • 78
  • [ 54439-75-7 ]
  • [ 4105-21-9 ]
  • C21H14N2O2 [ No CAS ]
YieldReaction ConditionsOperation in experiment
87% With tetrabutylammomium bromide; palladium diacetate; potassium carbonate; 4,5-bis(diphenylphos4,5-bis(diphenylphosphino)-9,9-dimethylxanthenephino)-9,9-dimethylxanthene; In N,N-dimethyl acetamide; water; at 150℃; for 24h; In a 10 ml flask,Add the magnet,2-phenylimidazo [1,2-a] pyridine (0.3 mmol) was added,<strong>[54439-75-7]2-<strong>[54439-75-7]chloro-4-methoxybenzaldehyde</strong></strong> (0.9 mmol)Potassium carbonate (0.9 mmol),Tetrabutylammonium bromide (0.9 mmol),Palladium acetate (5 molpercent),4,5-bis (diphenylphosphino) -9,9-dimethylXanthene (10molpercent),N, N-dimethylacetamide (4 mL),Water (0.1 mL).The reaction mixture was reacted at 150 ° C for 24 hours,Cooled to room temperature,An appropriate amount of water was added and extracted three times with ethyl acetate,Combine organic phase,Dried over anhydrous magnesium sulfate,Concentrated by filtration, concentrated column chromatography,Separated product 85mg,Yield 87percent.
  • 79
  • [ 4105-21-9 ]
  • 1,2-bis(2-phenylimidazo[1,2-a]pyridin-3-yl)diselane [ No CAS ]
YieldReaction ConditionsOperation in experiment
86% With selenium; copper(l) iodide; 1,10-Phenanthroline In dimethyl sulfoxide at 130℃; for 1.5h; General experimental procedure for the synthesis of bis(imidazo[1,2-a]pyridin-3-yl)dieselenides (2) or monoselenides (3) General procedure: A solution of 2-phenylimidazo[1,2-a]pyridine (1, 2.0 mmol), selenium powder (2.0 mmol, 1 equiv for 2 or 1.0 mmol, 0.5 equiv for 3), CuI (38 mg, 0.2 mmol, 10 mol %), and 1,10-phenanthoroline (36 mg, 0.2 mmol, 10 mol %) in DMSO (8 mL) was heated at 130 °C under an air atmosphere. The reaction was completed, the mixture was allowed to cool to room temperature, and diluted with CH2Cl2 (20 mL) and water (20 mL). The reaction mixture was separated, and the aqueous layer was extracted with CH2Cl2 (20 mL × 2). The combined organic layer was washed with 5% aqueous ammonia (20 mL × 2), dried over anhydrous MgSO4, and concentrated under reduced pressure. The crude residue was purified by column chromatography on silica gel with hexane/AcOEt to afford 2 or 3. All the products were characterized by NMR analysis (1H, 13C, 19F, and 77Se), IR spectroscopy, and low- and high-resolution mass spectrometry. However, 77Se signals in the NMRs of 2d and 2h could not be observed.
70% With selenium; copper(l) iodide; oxygen In N,N-dimethyl-formamide at 130℃; for 30h; Schlenk technique;
22% With selenium; copper(l) iodide; 1,10-Phenanthroline In acetonitrile at 80℃; for 24h; Bis(2-phenylimidazo[1,2-a]pyridine-3-yl)diselenide (2a)32 A solution of 2-phenylimidazo[1,2-a]pyridine (1a) (0.75 mmol), selenium powder (80 mg, 0.75 mmol, 1 equiv), CuI (14 mg, 0.075 mmol, 10 mol%) and 1,10-phenanthroline (15 mg, 0.075 mmol, 10 mol%) in DMSO (6 mL) was heated at 130 °C under an air atmosphere for 2 h. After the reaction was complete, the mixture was allowed to cool to room temperature and diluted with CH2Cl2 (20 mL) and H2O (20 mL). The reaction mixture was separated, and the aqueous layer was extracted with CH2Cl2 (2 × 20 mL). The combined organic layer was washed with 5% aqueous ammonia (30 mL) and brine (30 mL), dried over anhydrous MgSO4 and concentrated under reduced pressure. The crude residue was purified by column chromatography on silica gel to afford 2a. Using TMEDA instead of 1,10-phenanthroline resulted in a 40% yield of 3a (see Table 1, entry 11). Yield: 178 mg (87%); red plates (CH2Cl2-hexane); mp 205-206.5 °C; Rf = 0.3 (EtOAc). 1H NMR (400 MHz, CDCl3): δ = 6.62 (td, J = 6.8, 1.0 Hz, 2 H, Ar-H), 7.14-7.24 (m, 8 H, Ar-H), 7.46 (d, J = 8.8 Hz, 2 H, Ar-H), 7.71-7.73 (m, 4 H, Ar-H), 7.91 (dd, J = 6.8, 1.0 Hz, 2 H, Ar-H). 13C NMR (100 MHz, CDCl3): δ = 103.2 (s), 112.9 (d), 117.3 (d), 125.3(d), 126.6 (d), 127.8 (d), 128.2 (d), 128.5 (d), 132.8 (s), 147.8 (s), 153.0(s). MS (EI, 70 eV): m/z (%) = 75 (70), 93 (70), 195 (70), 275 (100), 547 (30) [M + H]+. Anal. Calcd for C26H18N4Se2: C, 57.37; H, 3.33; N, 10.29. Found: C,57.23; H: 3.27; N, 10.32.
Multi-step reaction with 2 steps 1.1: dimethyl sulfoxide / 0.5 h / 25 °C 2.1: sodium tetrahydroborate / tetrahydrofuran; ethanol / 2 h / 0 - 25 °C 2.2: 0.5 h

  • 80
  • [ 4105-21-9 ]
  • [ 590-17-0 ]
  • 2-(2-phenylimidazo[1,2-a]pyridin-3-yl)acetonitrile [ No CAS ]
YieldReaction ConditionsOperation in experiment
87% With fac-tris(2-phenylpyridinato-N,C2')iridium(III); sodium hydrogencarbonate In dimethyl sulfoxide at 20℃; for 12h; Schlenk technique; Inert atmosphere; Irradiation; Sealed tube; regioselective reaction;
87% With tris[2-phenylpyridinato-C2,N]iridium(III); sodium hydrogencarbonate In dimethyl sulfoxide at 20℃; for 12h; Inert atmosphere; Microwave irradiation; 1.1 Embodiment 1 preparation 3-cyanomethyl-2-phenylimidazo[1,2-a]pyridine Step 1, under nitrogen protection conditions, the 2-phenylimidazo[1,2-a]pyridine (0.97 g, 5 mmol) is added 100 ml in the reaction bottle, to join the fac - Ir (ppy)3(65.5 Mg, 2 µM %), sodium bicarbonate (0.84 g, 10 mmol), bromine second grade nitrile 1.39 ml (2.40 g, 20 mmol), 30 ml dimethyl sulfoxide as solvent, reaction at room temperature, in the 5 W blue LED lamp irradiation, stirring 12 h, water quenching reaction, dichloromethane is used for extraction (60 ml × 3), 50 ml saturated salt water washing, drying with anhydrous sodium sulfate, concentrated under vacuum conditions, in order to column chromatographic purification, separation to obtain white solid 3-cyanomethyl-2-phenylimidazo[1,2-a]pyridine1.01 g, yield is 87%
81% With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 0.5h; Irradiation; Sealed tube; Inert atmosphere;
Same Skeleton Products
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