* 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.
With hydrazine hydrate In ethanol at 70℃; for 4 h;
General procedure: In a typical reaction, 5.0 mg of Pd-gCN (5.0 wtpercent of Pd) catalyst was added to the solution of 1.0 mM of nitroarene in ethanol (2 mL)and 2 mM (1.2 equiv. 0.07 mL) of 60percent of hydrazine hydrate. The mixture was placed into a 10 mL round-bottom flask at the reflux temperature (70° C) for the 4 h and then allowed to cool at room temperature. The resultant material was filtered and the filtrate was subjected to column chromatography over silica gel to obtain the corresponding products. For di-nitroarenes substrates 4.0 mM(2.4 equiv. 0.14 mL) of 60percent of hydrazine hydrate solution was used.
86%
With iron(III) chloride hexahydrate; pyrographite; hydrazine hydrate In 1,4-dioxane for 5 h; Reflux
General procedure: A well-stirred mixture of 1a–1b (0.1064mol), FeCl3·6H2O (4.3g, 0.016mol) and activated carbon (0.38g, 0.0319mol) in 1,4-dioxane (200mL) was heated to 50°C, and then hydrazine hydrate (66.5g, 1.0638mol) was added drop-wise at this temperature. After the completion of addition, the mixture was refluxed for 5h. The precipitate was removed by hot filtration and the filtrate was concentrated to give a yellow viscous substance. The residue was quenched with water (200mL) to stir for 30min, filtered, washed with a small amount of water and dried to give 2a–2b.
Reference：
[1] Applied Catalysis A: General, 2016, vol. 523, p. 31 - 38
[2] European Journal of Medicinal Chemistry, 2015, vol. 96, p. 369 - 380
[3] Zeitschrift fur Naturforschung - Section B Journal of Chemical Sciences, 1996, vol. 51, # 6, p. 757 - 764
[4] Recueil des Travaux Chimiques des Pays-Bas, 1943, vol. 62, p. 177,181, 183
[5] Farmaco, Edizione Scientifica, 1983, vol. 38, # 4, p. 219 - 231
[6] Patent: EP1202724, 2003, B1,
[7] Patent: EP1202724, 2003, B1,
2
[ 636-98-6 ]
[ 109-97-7 ]
[ 52768-17-9 ]
[ 4533-42-0 ]
Yield
Reaction Conditions
Operation in experiment
74%
at 135℃; for 4 h;
General procedure: A mixture of pyrrole (3 ml), Cs2CO3 (1.96 g, 6 mmol), Cu0/4A or Cu2+/4A (0.3 g) and the appropriate aryl halide (3 mmol) were stirred at 135 °C (bath temperature) for 4–36 h. Before adding to the mixture, Cu2+/4A was preheated at ca. 150 °C for 1 h. The mixture was filtered, the solid was washed with dichloromethane. The filtrate was extracted with deionised water (2 x 40 ml). The organic phase was dried over Na2SO4 and concentrated in vacuum. The residue was distilled and clarified. Certain products (3c, 3f) were purified by recrystallization from MeOH.
General procedure: Amine (1 mmol), 2,5-dimethoxytetrahydrofuran (1.1 mmol)and L-(+)-tartaric acid–choline chloride based DES (1.5 g) were added to a 50 mL round bottom flask and the reaction mixturewas stirred at 90 °C. The progress of the reaction was monitoredby TLC. After completion of the reaction, the mixture was cooled to room temperature and the product was extracted with ethyl acetate.After the evaporation of the solvent, the residue was purified by columnchromatography on silica gel to afford the pure product. The DES wasdried under vacuumand reused for the next cycle.
85%
With ionic liquid immobilized on γ-Fe2O3(at)SiO2 nanoparticles In water at 100℃; for 1 h;
General procedure: To a solution of amine (1 mmol) in water (2 ml) was added tetrahydro-2,5-dimethoxyfuran (1.1 mmol) and γ-Fe2O3(at)SiO2–Sb-IL (0.08 g). The reaction mixture was stirred at 100 °C for a certain period of time as required to complete the reaction. During that time, the reaction was monitored constantly by TLC. After completion of the reaction, the catalyst was removed by using a magnet and washed with ethyl acetate. The aqueous solution was extracted by ethyl acetate (3 × 5 ml). The combined organic phase was dehydrated with anhydrous sodium sulfate. After the evaporation of the solvent, the residue was purified by silica gel flash chromatography using petroleum ether/ethyl acetate as the eluent to afford the pure product.
62%
With magnesium iodide etherate In acetonitrile at 80℃; for 12 h;
General procedure: A Schlenk reaction tube was charged with primary aromatic amine (5.0 mmol), 2,5-dimethoxytetrahydrofuran (6.0 mmol), MgI2 etherate (10percent mmol), and acetonitrile (10 mL). The reaction mixture was stirred at 80 °C for several hours and then concentrated in vacuo. The residue was purified by flash column chromatography on a silica gel to give the desired product.
Reference：
[1] Journal of the Iranian Chemical Society, 2011, vol. 8, # 3, p. 851 - 856
[2] Synlett, 2009, # 14, p. 2245 - 2248
[3] ChemCatChem, 2013, vol. 5, # 12, p. 3743 - 3749
[4] Journal of Molecular Liquids, 2014, vol. 198, p. 259 - 262,4
[5] Asian Journal of Chemistry, 2013, vol. 25, # 1, p. 501 - 504
[6] Synthetic Communications, 2012, vol. 42, # 16, p. 2471 - 2477
[7] Monatshefte fur Chemie, 2013, vol. 144, # 3, p. 405 - 409
[8] Applied Catalysis A: General, 2013, vol. 457, p. 34 - 41
[9] Journal of Chemical Research, 2009, # 1, p. 14 - 16
[10] RSC Advances, 2015, vol. 5, # 93, p. 76221 - 76228
[11] Tetrahedron, 2011, vol. 67, # 5, p. 898 - 903
[12] Journal of Heterocyclic Chemistry, 2000, vol. 37, # 1, p. 15 - 24
[13] Chemical Physics Letters, 2003, vol. 367, # 1-2, p. 62 - 71
[14] Patent: EP1202724, 2003, B1,
[15] Synthetic Communications, 2012, vol. 42, # 4, p. 548 - 553
[16] Bioorganic and Medicinal Chemistry, 2017, vol. 25, # 6, p. 1778 - 1786
[17] Patent: CN106565682, 2017, A, . Location in patent: Paragraph 0117; 0119; 0120; 0121
4
[ 636-98-6 ]
[ 109-97-7 ]
[ 4533-42-0 ]
Yield
Reaction Conditions
Operation in experiment
98%
With copper phthalocyanine; sodium hydroxide In dimethyl sulfoxide at 100℃;
General procedure: In a 50mL RB, N−H heterocycles (1.0mmol), aryl halide (1mmol), Cu(II)Pc (0.01mmol), NaOH (1.5mmol) and DMSO (2mL) was added. This reaction mixture was stirred to a preheated oil bath at 100°C for 8–12h. After completion of the reaction, it was cooled to room temperature and 20mL ethyl acetate was added. It was filtered; solid catalyst was separated and washed with 2×5mL ethyl acetate. The washing and filtrate were combined and washed with water. Ethyl acetate was removed under reduced pressure and product was purified with column chromatography.
97%
With copper(I) oxide; caesium carbonate; N-phenyl-2-pyridincarboxamide-1-oxide In dimethyl sulfoxide at 120℃; for 20 h; Inert atmosphere
General procedure: In 50 mL round bottom flask, aryl halide (1.0 mmol), pyrazole (1.2 mmol), ligand (0.04 mmol), Cu2O (0.10 mmol), cesium carbonate (2.0 mmol), and dry solvent (20 mL) were placed under nitrogen atmosphere. The reaction mixture was heated in oil bath up to specified temperature under constant stirring for 20 h and then allowed to cool to room temperature. The reaction mixture was filtered through a plug of Celite in a fritted filter funnel and washed with ethyl acetate. If DMSO is used as solvent, it is extracted by washing the filtrate with 25 mL water for three times. The organic phase was dried over anhydrous MgSO4 and was removed under reduced pressure to provide the crude product which was purified by column chromatography on silica gel, using hexane and ethyl acetate in 3:1 ratio, respectively, as an eluent.
Reference：
[1] RSC Advances, 2014, vol. 4, # 83, p. 44105 - 44116
[2] Tetrahedron Letters, 2017, vol. 58, # 31, p. 3044 - 3048
[3] Tetrahedron Letters, 2016, vol. 57, # 20, p. 2197 - 2200
[4] Advanced Synthesis and Catalysis, 2008, vol. 350, # 9, p. 1253 - 1257
[5] Green Chemistry, 2018, vol. 20, # 23, p. 5346 - 5357
[6] Tetrahedron Letters, 2009, vol. 50, # 21, p. 2585 - 2588
[7] Journal of Organic Chemistry, 2018, vol. 83, # 12, p. 6408 - 6422
[8] Tetrahedron Letters, 2010, vol. 51, # 4, p. 669 - 671
[9] Organic Letters, 2004, vol. 6, # 14, p. 2405 - 2408
[10] Chemistry - A European Journal, 2016, vol. 22, # 2, p. 783 - 801
[11] Applied Catalysis A: General, 2016, vol. 523, p. 31 - 38
5
[ 109-97-7 ]
[ 100-00-5 ]
[ 4533-42-0 ]
Yield
Reaction Conditions
Operation in experiment
92%
With copper(I) oxide; caesium carbonate; N-phenyl-2-pyridincarboxamide-1-oxide In dimethyl sulfoxide at 120℃; for 20 h; Inert atmosphere
General procedure: In 50 mL round bottom flask, aryl halide (1.0 mmol), pyrazole (1.2 mmol), ligand (0.04 mmol), Cu2O (0.10 mmol), cesium carbonate (2.0 mmol), and dry solvent (20 mL) were placed under nitrogen atmosphere. The reaction mixture was heated in oil bath up to specified temperature under constant stirring for 20 h and then allowed to cool to room temperature. The reaction mixture was filtered through a plug of Celite in a fritted filter funnel and washed with ethyl acetate. If DMSO is used as solvent, it is extracted by washing the filtrate with 25 mL water for three times. The organic phase was dried over anhydrous MgSO4 and was removed under reduced pressure to provide the crude product which was purified by column chromatography on silica gel, using hexane and ethyl acetate in 3:1 ratio, respectively, as an eluent.
80%
With cerium(IV) oxide; potassium hydroxide In dimethyl sulfoxide at 110℃; for 8 h; Air atmosphere
General procedure: In a 25 mL round bottomed flask was taken a mixture of phenol/amine/thiophenol (1.2 mmol, 0.112 g), 4-nitrochlorobenzene (1 mmol, 0.157 g), base KOH (1.2 mmol, 0.08 g) and 1 mL DMSO was added. Further 2.5 mol percent catalyst (4.5 mg) was added to the reaction mixture. The reaction mixture was heated to 110 °C for appropriate time. Reaction is monitored on TLC. After completion of the reaction the catalyst was separated by centrifugation and subsequently washed with dichloromethane. The reaction mixture was diluted with water and the product was extracted by dichoromethane (3 .x. 10 cm3). The organic layer was dried over anhydrous sodium sulfate and was evaporated under reduced pressure to give the product. The product was purified by column chromatography by using pet ether and ethyl acetate solvent system. The purified product was then confirmed by its spectral analysis after analyzing by IR, 1H NMR, and mass spectra.
Reference：
[1] Synlett, 2008, # 19, p. 3068 - 3072
[2] European Journal of Organic Chemistry, 2010, # 19, p. 3621 - 3630
[3] RSC Advances, 2014, vol. 4, # 83, p. 44105 - 44116
[4] Tetrahedron Letters, 2016, vol. 57, # 20, p. 2197 - 2200
[5] Synthetic Communications, 2008, vol. 38, # 4, p. 626 - 636
[6] Advanced Synthesis and Catalysis, 2007, vol. 349, # 11-12, p. 1938 - 1942
[7] Journal of the American Chemical Society, 2005, vol. 127, # 28, p. 9948 - 9949
[8] Tetrahedron Letters, 2011, vol. 52, # 41, p. 5220 - 5223
[9] Journal of Organic Chemistry, 2007, vol. 72, # 23, p. 8943 - 8946
[10] Letters in Organic Chemistry, 2010, vol. 7, # 3, p. 212 - 218
6
[ 109-97-7 ]
[ 350-46-9 ]
[ 4533-42-0 ]
Yield
Reaction Conditions
Operation in experiment
95.6%
With potassium carbonate In N,N-dimethyl-formamide at 100℃; for 0.5 h;
General procedure: A well-stirred mixture of pyrrole/indole (0.128mol) and K2CO3 (35.4g, 0.257mol) in DMF (150mL) was heated at 100°C for 30min. Then, p-fluoronitrobenzene (21.6g, 0.153mol) was added and the mixture was stirred for another 5h. Upon cooling to room temperature, the mixture was poured into water (300mL) to stir for 30min and filtered. The residue was washed with water, dried to give crude product and then treated with diethyl ether to afford 1a–1b.
38%
With potassium hydroxide In dimethyl sulfoxide at 80℃; for 16 h;
General procedure: A mixture of 2-fluorobenzamide (1a, 69.5 mg, 0.5 mmol), MeOH (ca. 32.0 mg, 1.0 mmol), KOH (56.0 mg, 1.0 mmol) and DMSO (2.0 mL) in a 25 mL screw-capped thick-walled Pyrex tube was stirred at room temperature for 16 h, and then water (10 mL) was added to the reaction mixture with stirring, and the mixture was extracted with ethyl acetate three times (3 * 10 mL). The combined organic phases were dried over Na2SO4 overnight. The filtered solution was concentrated under reduced pressure, and the crude residue was purified by column chromatography on silica gel with the use of petroleum ether/ethyl acetate/trimethylamine (gradient mixture ratio from 6:1:0.05 to 2:1:0.05 in volume) to afford 2aa as a white solid in 80percent yield (60.7 mg).
Reference：
[1] European Journal of Medicinal Chemistry, 2015, vol. 96, p. 369 - 380
[2] Synthetic Communications, 2008, vol. 38, # 4, p. 626 - 636
[3] Journal of the American Chemical Society, 2005, vol. 127, # 28, p. 9948 - 9949
[4] Advanced Synthesis and Catalysis, 2007, vol. 349, # 11-12, p. 1938 - 1942
[5] Russian Journal of Organic Chemistry, 2008, vol. 44, # 10, p. 1517 - 1521
[6] Tetrahedron, 2018, vol. 74, # 2, p. 303 - 307
7
[ 109-97-7 ]
[ 586-78-7 ]
[ 4533-42-0 ]
Yield
Reaction Conditions
Operation in experiment
94%
With copper(I) oxide; caesium carbonate; N-phenyl-2-pyridincarboxamide-1-oxide In dimethyl sulfoxide at 120℃; for 20 h; Inert atmosphere
General procedure: In 50 mL round bottom flask, aryl halide (1.0 mmol), pyrazole (1.2 mmol), ligand (0.04 mmol), Cu2O (0.10 mmol), cesium carbonate (2.0 mmol), and dry solvent (20 mL) were placed under nitrogen atmosphere. The reaction mixture was heated in oil bath up to specified temperature under constant stirring for 20 h and then allowed to cool to room temperature. The reaction mixture was filtered through a plug of Celite in a fritted filter funnel and washed with ethyl acetate. If DMSO is used as solvent, it is extracted by washing the filtrate with 25 mL water for three times. The organic phase was dried over anhydrous MgSO4 and was removed under reduced pressure to provide the crude product which was purified by column chromatography on silica gel, using hexane and ethyl acetate in 3:1 ratio, respectively, as an eluent.
58%
With copper(II) ferrite; potassium <i>tert</i>-butylate In N,N-dimethyl-formamide at 155℃; for 24 h; Inert atmosphere
General procedure: To a solution of N-heterocycle (1 equiv), bromobenzene (1.02 equiv) and tBuOK (2 equiv) in dry DMF, CuFe2O4 (10 mol percent) was added and heated at reflux for 24 h under N2 atmosphere. After cooling to room temperature, the mixture was diluted with ethyl acetate and the catalyst was separated by a magnetic separator. The catalyst was washed with ethyl acetate. The combined ethyl acetate layer was washed with water (twice), dried over anhydrous Na2SO4, and concentrated to yield the crude product, which was further purified by silica gel column chromatography using petroleum ether/ethyl acetate to yield N-arylated product.
Reference：
[1] RSC Advances, 2014, vol. 4, # 83, p. 44105 - 44116
[2] Tetrahedron Letters, 2016, vol. 57, # 20, p. 2197 - 2200
[3] New Journal of Chemistry, 2017, vol. 41, # 8, p. 3082 - 3088
[4] Tetrahedron Letters, 2011, vol. 52, # 16, p. 1924 - 1927
[5] Tetrahedron Letters, 2010, vol. 51, # 4, p. 669 - 671
8
[ 636-98-6 ]
[ 51-35-4 ]
[ 4533-42-0 ]
Yield
Reaction Conditions
Operation in experiment
78%
With copper(l) iodide; caesium carbonate In dimethyl sulfoxide at 110℃; for 24 h;
General procedure: to a stirred solution of iodo benzene (1.0 mmol) and trans-4-hydroxy-L-proline (2.0 equiv) in dry DMSO (3.0 mL) at rt was added CuI (20 mol percent) followed by Cs2CO3 (2.5 equiv) and heated at 110 °C for 24 h. The progress of the reaction was monitored by TLC. After the reaction was complete, the reaction mixture was allowed to cool, and a 1:1 mixture of ethyl acetate/water (20 mL) was added. The combined organic extracts were dried with anhydrous Na2SO4. The solvent and volatiles were completely removed under vacuum to give the crude product, which was purified by column chromatography on silica gel (petroleum ether/ethyl acetate, 9:1) to afford the corresponding coupling product.
70%
With copper(II) ferrite; caesium carbonate In dimethyl sulfoxide at 100℃; for 20 h; Inert atmosphere
General procedure: To astirred solution of: Aryl iodide (1.0 mmol), trans-4-Hydroxy-L-proline (1.5 mmol), nano CuFe2O4 (0.01 mmol), base (2 equiv), solvent (3.0 mL), 20h, 100 oC. The progress of the reaction was monitored by TLC. After the reaction was complete CuFe2O4 nano were placed on the bottom of the flask by a neodymium magnet, and the supernatant solution was removed. The crude residue was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were extracted with water, saturated brine solution, and dried over anhydrous Na2SO4.The organic layers were evaporated under reduced pressure and the resulting crude product was purified by column chromatography to give the corresponding N-substituted pyrrole in excellent yields. The identity and purity of the product were confirmed by 1H,13C NMR, and mass spectra.
With potassium nitrite; copper(II) bis(trifluoromethanesulfonate) In dimethyl sulfoxide at 130℃; for 48 h; Inert atmosphere; Sealed tube
General procedure: An oven dried pressure tube was charged with haloarenes (0.5 mmol), copper(II) triflate (45 mg, 0.125 mmol), KNO2 (128 mg, 1.5 mmol) and anhydrous DMSO (0.6 mL) under nitrogen atmosphere. The tube was sealed with a teflon screw cap having mininert valve and nitrogen is purged through it for 5 min. It is stirred at room temperature for 10 min and then the temperature was gradually increased to 130 oC and is maintained at the same for 48 h. The reaction mixture was then cooled to room temperature, washed with excess ice cold water and extracted with ethyl acetate (3 x 10 mL). The combined organic extracts were dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure to give the crude product which was purified by column chromatography using silica gel (Table 2, entries 1-18) or basic alumina (Table 2, entries 19-23) and a mixture of ethyl acetate and hexane as the eluent to afford the desired products in good yields.
Reference：
[1] Journal of the American Chemical Society, 2009, vol. 131, # 36, p. 12898 - 12899
11
[ 636-98-6 ]
[ 109-97-7 ]
[ 52768-17-9 ]
[ 4533-42-0 ]
Yield
Reaction Conditions
Operation in experiment
74%
at 135℃; for 4 h;
General procedure: A mixture of pyrrole (3 ml), Cs2CO3 (1.96 g, 6 mmol), Cu0/4A or Cu2+/4A (0.3 g) and the appropriate aryl halide (3 mmol) were stirred at 135 °C (bath temperature) for 4–36 h. Before adding to the mixture, Cu2+/4A was preheated at ca. 150 °C for 1 h. The mixture was filtered, the solid was washed with dichloromethane. The filtrate was extracted with deionised water (2 x 40 ml). The organic phase was dried over Na2SO4 and concentrated in vacuum. The residue was distilled and clarified. Certain products (3c, 3f) were purified by recrystallization from MeOH.
With hydrazine hydrate; In ethanol; at 70℃; for 4h;
General procedure: In a typical reaction, 5.0 mg of Pd-gCN (5.0 wt% of Pd) catalyst was added to the solution of 1.0 mM of nitroarene in ethanol (2 mL)and 2 mM (1.2 equiv. 0.07 mL) of 60% of hydrazine hydrate. The mixture was placed into a 10 mL round-bottom flask at the reflux temperature (70 C) for the 4 h and then allowed to cool at room temperature. The resultant material was filtered and the filtrate was subjected to column chromatography over silica gel to obtain the corresponding products. For di-nitroarenes substrates 4.0 mM(2.4 equiv. 0.14 mL) of 60% of hydrazine hydrate solution was used.
86%
With iron(III) chloride hexahydrate; pyrographite; hydrazine hydrate; In 1,4-dioxane; for 5h;Reflux;
General procedure: A well-stirred mixture of 1a-1b (0.1064mol), FeCl3·6H2O (4.3g, 0.016mol) and activated carbon (0.38g, 0.0319mol) in 1,4-dioxane (200mL) was heated to 50C, and then hydrazine hydrate (66.5g, 1.0638mol) was added drop-wise at this temperature. After the completion of addition, the mixture was refluxed for 5h. The precipitate was removed by hot filtration and the filtrate was concentrated to give a yellow viscous substance. The residue was quenched with water (200mL) to stir for 30min, filtered, washed with a small amount of water and dried to give 2a-2b.
82.1%
With palladium on activated charcoal; hydrazine hydrate; In ethanol; at 20℃; for 0.5h;
Dissolve intermediate c1 (7.3g, 0.039mol) in EtOH (50mL),Add Pd / C (0.73g, 6.93mmol), N2H4H2O (19.5g, 0.039mol),Reaction at room temperature for 0.5h, suction filtration, and pouring the filtrate into 200mL water,Extracted with dichloromethane (50mL × 3), separated the organic phase and dried over anhydrous sodium sulfate.After filtration, the filtrate was concentrated, and the product was separated by silica gel column chromatography to obtain 5.04 g, with a yield of 82.1%.
78.5%
With hydrazine hydrate; palladium on activated charcoal; In ethanol; for 12h;Reflux; Inert atmosphere;
2) 3.3 g of N-(4-nitrophenyl)pyrrole was added to a 250 mL three-necked flask.0.1gPd/C, 2.5mL hydrazine hydrate, 80mL ethanol, heated under reflux in N2 atmosphere for 12h,Filtering, distilling off the solvent;Recrystallization from 100 mL petroleum ether gave N-(4-aminophenyl)pyrrole,Yield 78.5%;
EXAMPLE 10B 4-Pyrrol-1-yl-phenylamine (10a) Catalytic reduction (H2/RaNi (5 g) /THF) of 1-(4-nitro-phenyl)- 1H-pyrrole (9.69 g, 0.05149 mole) at 51 psi gave crude product as an oil (Scheme 3B). The product was purified by silica column chromatography. Elution with CH2Cl2 (Rf = 0.13) gave the pure product as white solid. Yield 8.06 g (99 %); mp 80-81 C.
EXAMPLE 10B 4-Pyrrol-1-yl-phenylamine (10a) Catalytic reduction (H2/RaNi (5 g) /THF) of 1-(4-nitro-phenyl)- 1H-pyrrole (9.69 g, 0.05149 mole) at 51 psi gave crude'product as an oil (Scheme 3B). The product was purified by silica column chromatography. Elution with CH2Cl2 (Rf = 0.13) gave the pure product as white solid. Yield 8.06 g (99 %); mp 80-81 C.
With potassium carbonate In N,N-dimethyl-formamide at 100℃; for 0.5h;
5.2.1 Preparation of 1-(4-nitrophenyl)-1H-pyrrole/indole (1a-1b)
General procedure: A well-stirred mixture of pyrrole/indole (0.128mol) and K2CO3 (35.4g, 0.257mol) in DMF (150mL) was heated at 100°C for 30min. Then, p-fluoronitrobenzene (21.6g, 0.153mol) was added and the mixture was stirred for another 5h. Upon cooling to room temperature, the mixture was poured into water (300mL) to stir for 30min and filtered. The residue was washed with water, dried to give crude product and then treated with diethyl ether to afford 1a-1b.
90%
With potassium carbonate In N,N-dimethyl-formamide at 110℃; for 1.5h;
85%
With potassium carbonate In N,N-dimethyl-formamide at 120℃; for 2h;
84%
With potassium carbonate In N,N-dimethyl-formamide at 120℃; for 2h;
80%
With sodium hydroxide In dimethyl sulfoxide at 20 - 22℃; for 3h;
68.9%
Stage #1: pyrrole With potassium carbonate In N,N-dimethyl-formamide at 100℃; for 0.5h; Inert atmosphere;
Stage #2: 4-Fluoronitrobenzene In N,N-dimethyl-formamide for 5h; Reflux; Inert atmosphere;
1.1; 2.1
1) Add 4.2 g of pyrrole to a 250 mL three-necked flask,80 mL of DMF, 17.9 g of K2CO3, stirred at 100 ° C for 30 min in N 2 atmosphere.Add 10.8 g of p-fluoronitrobenzene and heat to reflux for 5 h;After the reaction is completed, the solution is cooled to room temperature.Add cold water, precipitate, filter; wash the precipitate 3 times with water, dry;The obtained crude product was treated with 100 mL of diethyl ether.Obtaining N-p-nitrophenylpyrrole,Yield 68.9%;
38%
With potassium hydroxide In dimethyl sulfoxide at 80℃; for 16h;
3.5 4.2. Typical procedure for the synthesis of 2aa
General procedure: A mixture of 2-fluorobenzamide (1a, 69.5 mg, 0.5 mmol), MeOH (ca. 32.0 mg, 1.0 mmol), KOH (56.0 mg, 1.0 mmol) and DMSO (2.0 mL) in a 25 mL screw-capped thick-walled Pyrex tube was stirred at room temperature for 16 h, and then water (10 mL) was added to the reaction mixture with stirring, and the mixture was extracted with ethyl acetate three times (3 * 10 mL). The combined organic phases were dried over Na2SO4 overnight. The filtered solution was concentrated under reduced pressure, and the crude residue was purified by column chromatography on silica gel with the use of petroleum ether/ethyl acetate/trimethylamine (gradient mixture ratio from 6:1:0.05 to 2:1:0.05 in volume) to afford 2aa as a white solid in 80% yield (60.7 mg).
With copper(l) iodide; caesium carbonate In dimethyl sulfoxide at 110℃; for 24h;
General procedure for the synthesis of N-aryl pyrroles.
General procedure: to a stirred solution of iodo benzene (1.0 mmol) and trans-4-hydroxy-L-proline (2.0 equiv) in dry DMSO (3.0 mL) at rt was added CuI (20 mol %) followed by Cs2CO3 (2.5 equiv) and heated at 110 °C for 24 h. The progress of the reaction was monitored by TLC. After the reaction was complete, the reaction mixture was allowed to cool, and a 1:1 mixture of ethyl acetate/water (20 mL) was added. The combined organic extracts were dried with anhydrous Na2SO4. The solvent and volatiles were completely removed under vacuum to give the crude product, which was purified by column chromatography on silica gel (petroleum ether/ethyl acetate, 9:1) to afford the corresponding coupling product.
70%
With copper(II) ferrite; caesium carbonate In dimethyl sulfoxide at 100℃; for 20h; Inert atmosphere;
Representative experimental procedure for the synthesis of N-substituted pyrroles:
General procedure: To astirred solution of: Aryl iodide (1.0 mmol), trans-4-Hydroxy-L-proline (1.5 mmol), nano CuFe2O4 (0.01 mmol), base (2 equiv), solvent (3.0 mL), 20h, 100 oC. The progress of the reaction was monitored by TLC. After the reaction was complete CuFe2O4 nano were placed on the bottom of the flask by a neodymium magnet, and the supernatant solution was removed. The crude residue was extracted with ethyl acetate (3 x 10 mL). The combined organic layers were extracted with water, saturated brine solution, and dried over anhydrous Na2SO4.The organic layers were evaporated under reduced pressure and the resulting crude product was purified by column chromatography to give the corresponding N-substituted pyrrole in excellent yields. The identity and purity of the product were confirmed by 1H,13C NMR, and mass spectra.
General procedure: A mixture of pyrrole (3 ml), Cs2CO3 (1.96 g, 6 mmol), Cu0/4A or Cu2+/4A (0.3 g) and the appropriate aryl halide (3 mmol) were stirred at 135 C (bath temperature) for 4-36 h. Before adding to the mixture, Cu2+/4A was preheated at ca. 150 C for 1 h. The mixture was filtered, the solid was washed with dichloromethane. The filtrate was extracted with deionised water (2 x 40 ml). The organic phase was dried over Na2SO4 and concentrated in vacuum. The residue was distilled and clarified. Certain products (3c, 3f) were purified by recrystallization from MeOH.
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
110K+ Compounds
Competitive Price
1-2 Day Shipping
