* 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.
Stage #1: at 20℃; for 1 h; Stage #2: With hydrogen bromide; copper(I) bromide In water at 20℃; for 13.5 h;
To concentrated sulfuric acid (25 mL) was added sodium nitrite (3.20 g) portionwise at 5 °C, and the mixture was stirred at room temperature for 0.5 h. The mixture was cooled down to 5 °C, and then acetic acid (40 mL) was added dropwise to the mixture. The mixture was stirred at 5 °C for 5 min. To the mixture was added 4-amino-3,5-difluorobenzonitrile (8, 6.50 g) portionwise, and then the mixture was stirred at room temperature for 1 h. The mixture was transferred into a dropping funnel, and was added dropwise to a solution of copper(I) bromide (9.07 g) in 47 wt percent hydrobromic acid (25 mL) over 0.5 h. The mixture was stirred at room temperature for 13 h. Water (300 mL) was added to the mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, and then dried. The desiccant was removed by filtration and the filtrate was evaporated in vacuo. The resulting residue was purified by silica gel column chromatography (hexane-ethyl acetate) to obtain 9g (5.00 g, 54percent) as a white solid: 1H NMR (DMSO-d6) δ 7.98 (2H, d, J = 6.3 Hz); EI-MS m/z 217, 219 [(M)+].
Reference：
[1] Bioorganic and Medicinal Chemistry, 2012, vol. 20, # 17, p. 5235 - 5246
[2] Patent: WO2018/75871, 2018, A1, . Location in patent: Page/Page column 68
2
[ 110301-23-0 ]
[ 123688-59-5 ]
Reference：
[1] Patent: US5354502, 1994, A,
3
[ 110301-23-0 ]
[ 7787-70-4 ]
[ 123688-59-5 ]
Reference：
[1] Patent: US5200110, 1993, A,
[2] Patent: US5030382, 1991, A,
[3] Patent: US4883609, 1989, A,
4
[ 67567-26-4 ]
[ 110301-23-0 ]
Yield
Reaction Conditions
Operation in experiment
86%
for 1.5 h; Reflux
A mixture suspension of 4-bromo-2,6-difluoroaniline (7, 25.85 g) and copper(I) cyanide (16.70 g) in NMP (60 mL) was stirred at reflux temperature for 1.5 h and then cooled down to room temperature. To the mixture was added 1,2-diaminoethane (23 mL) and the mixture was poured into water (150 mL). The mixture was extracted with ethyl acetate and the organic layer was washed with 10 wt percent 1,2-diaminoethane solution in water and water, and then dried. The desiccant was removed by filtration and the filtrate was evaporated in vacuo. The resulting residue was purified by silica gel column chromatography (hexane-ethyl acetate) to obtain 8 (16.54 g, 86percent) as a pale yellow solid: 1H NMR (DMSO-d6) δ 6.36 (2H, s), 7.50 (2H, dd, J = 2.7, 6.7 Hz); EI-MS m/z 154 [(M)+].
Reference：
[1] Journal of Materials Chemistry C, 2016, vol. 4, # 23, p. 5326 - 5333
[2] Bioorganic and Medicinal Chemistry, 2012, vol. 20, # 17, p. 5235 - 5246
[3] Journal of the American Chemical Society, 2012, vol. 134, # 51, p. 20597 - 20600
[4] ACS Medicinal Chemistry Letters, 2018, vol. 9, # 3, p. 250 - 255
[5] Patent: WO2018/136935, 2018, A1, . Location in patent: Paragraph 00407
5
[ 141743-49-9 ]
[ 544-92-3 ]
[ 110301-23-0 ]
Yield
Reaction Conditions
Operation in experiment
66%
for 2 h; Heating / reflux
A mixture of the solid and CuCN in DMF was heated with reflux for 2 days and then filtered through celite. The filtrate was dissolved in methylene chloride and water, and the aqueous phase was extracted with methylene chloride. The combined organic layer was washed with brine, dried over anhyd. MgSO4, filtered, and concentrated under reduced pressure. The crude residue was column-chromatographed (hexane/ethylacetate = 4/1) to yield a yellow solid (1.03g, 66percent).1HNMR (300MHz, CDC13): 7.15 (dd, 2H, J= 2.4 and 6.0 Hz), 4.28 (bs, 2H).
4-amino-3,5-difluorobenzonitrile (354.3 mg, 2.3 mmol) was suspended in 1M aqueous sodium hydroxide (12 mL) and the resulting suspension was heated at 110 °C for 16 h. After cooling, the mixture was washed with ether. The aqueous phase was acidified to pH = 2 with 10percent KHS04/Na2S04 buffer and extracted with EtOAc (2X). The combined EtOAc extracts were washed with water, and then brine, dried over anhydrous sodium sulfate and concentrated in vacuo to provide 4-amino-3,5-difluorobenzoic acid (335 mg, 84percent yield) as a yellow solid. 1H NMR (300 MHz, Chloroform-d) δ 7.66 - 7.58 (m, 2H).
Reference：
[1] Journal of Materials Chemistry C, 2016, vol. 4, # 23, p. 5326 - 5333
[2] ACS Medicinal Chemistry Letters, 2018, vol. 9, # 3, p. 250 - 255
[3] Patent: WO2018/136935, 2018, A1, . Location in patent: Paragraph 00408
[4] Bioconjugate Chemistry, 2018, vol. 29, # 2, p. 324 - 334
[5] Journal of the American Chemical Society, 2012, vol. 134, # 51, p. 20597 - 20600
The benzaldehyde used as starting material was prepared as follows; To a stirred solution of <strong>[110301-23-0]4-amino-3,5-difluorobenzonitrile</strong> (2.Og, 12.98mmol) in toluene (16ml) was added dropwise DIBAL (1.5M in toluene) at O0C. The reaction mixture was warmed to RT and stirring continued for 2h. The reaction was quenched by dropwise addition to 10% aq citric acid (10ml). EtOAc (50ml) and saturated aq potassium sodium tartrate (Rochelle's salt) (30ml) were added and the mixture was vigorously stirred for 20min. The organic layer was isolated and washed with water (10ml), dried (Na2SO4), filtered and concentrated to dryness to give a pale yellow solid (1.9g, 93%). LCMS purity 92%, m/z 158 [M+H]+.
(ii) Preparation of 4-cyano-2,6-difluoraniline A 22.6 g quantity (0.11 mole) of the above bromo compound was treated with 11.7 g (0.13 mole) cuprous cyanide in 17 ml dimethylformamide by the method of Friedman and Schechter, J. Org. Chem., 26, 2522 (1961), and employing the ethylenediamine-sodium cyanide complex-decomposition procedure in this reference [25 ml ethylenediamine and 20 ml 10% aqueous sodium cyanide] to give 4.3 g (26%) of 4-cyano-2,6-difluoroaniline, crystallized from ether-hexane, m.p.: 110-111 C. (soften 107 C.).
Step 3 21 g of 4-bromo-2,6-difluoroaniline, 11 g of copper (I) cyanide, and 70 ml of N-methyl-2-pyrrolidone were placed in a flask for three hours to form a reaction mixture. The reaction mixture was poured into a solution of 41 g of iron (III) chloride mixed with 13 ml of concentrated hydrochloric acid and 50 ml of water. The mixture was extracted with chloroform and washed with water and 10% potassium hydroxide and the chloroform was removed by distillation. The residue was distilled under reduced pressure (bp 90 to 110 C. at 4 mmHg) and recrystallized with a mixture of hexane and chloroform to yield 8.9 g of 4-cyano-2,6-difluoroaniline.
By following the procedures of Example 2A and substituting for 3-nitroaniline with the following: ... 3,5-dibromoaniline, 2,4,6-trifluoro-3-ethylaniline, 2,4-dimethyl-3-methylcarbonylaniline, 2,6-difluoro-4-propylaniline, 2,6-difluoro-4-cyanoaniline, and 3,5-dimethylthioaniline;
3
[ 110301-23-0 ]
[ 7787-70-4 ]
[ 123688-59-5 ]
Yield
Reaction Conditions
Operation in experiment
With sulfuric acid; sodium nitrite; In methanol; hydrogen bromide; acetic acid; acetone;
Step 9 While stirring 420 cm3 of concentrated sulfuric acid on an ice water bath, 54 g (0.78 mol) of finely pulverized NaNO2 was added at a rate which maintained the temperature below 40 C. The mixture was stirred on a warm water bath at 50 C. until the crystals were completely dissolved. The solution was stirred on an ice water bath and 700 cm3 of glacial acetic acid was added drop-wise. 108 g (0.70 mol) of 4-amino-3,5-difluorobenzonitrile was added at a rate which maintained the temperature at 20-25 C. and the mixture was stirred at that temperature until the crystals were completely dissolved to form the corresponding diazonium salt. An aqueous solution of the diazonium salt was added drop-wise for 2 hours to a solution of 143 g (1.0 mol) of copper (I) bromide dissolved in 420 cm3 of 47% hydrobromic acid while stirring on an ice water bath. The resulting solution was stirred for one hour on an ice water bath and allowed to sit overnight at room temperature. The product was filtered, washed with glacial acetic acid and recrystallized from a solvent mixture of acetone and methanol to yield 98 g (0.45 mol) of 4-bromo-3,5-difluorobenzonitrile.
With hydrogen bromide; acetic acid; sodium nitrite; In methanol; water; acetone;
Step 3 24 g of sodium nitrite was added to 180 ml of concentrated sulfuric acid cooled to a temperature of at least 10 C. 38 ml of acetic acid was added to the mixture. 53 g of 4-cyano-2,6difluoroaniline was added gradually to keep the temperature of the solution between about 20and 25 C. The mixture was stirred at 20-25 C. for one hour. A solution was prepared by dissolving 60 g of copper (I) bromide in 180 ml of an aqueous 48% solution of hydrobromic acid. The mixture was added drop-wise to the solution and the solution was stirred at room temperature for 15 hours. Water was added to the solution, and the solution was extracted with chloroform and washed with water. The chloroform in the aqueous layer was distilled off and the residue was recrystallized from a solution mixture of methanol and acetone, to yield 25 g of 2-bromo-5-cyano-1,3-difluorobenzene.
With sulfuric acid; acetic acid; In concentrated hydrobromic acid; water;
Step 4 4 g of sodium nitride was added to 30 ml of concentrated sulfuric acid and chilled to a temperature of 10 C. and 38 ml of acetic acid was added thereto. 8.9 ml of 4-cyano-2,6-difluoroaniline was added gradually to maintain the solution at a temperature of 20 to 25 C. The reaction mixture was added dropwise to a solution a 10 g of copper (I) bromide dissolved in 30 ml of concentrated hydrobromic acid. After the dropwise addition was completed, the reaction mixture was stirred for one and one half hours at room temperature. Water was added to the reaction mixture, the reaction mixture was extracted with chloroform and washed with water. The organic layer was removed by distillation, and the residue was recrystallized with a mixture of methanol and acetone to yield 6.6 g of 2-bromo-5-cyano-1,3-difluorobenzene.
Step 2-2. 340 g (1.63 mol) of 4-bromo-2,6-difluoroaniline, 223 g (2.5 mol) of CuCN and 800 cm3 of NMP were refluxed for 1.5 hours on a mantle heater. The reaction solution was cooled to room temperature, and after adding 300 cm3 of EDA, it was poured into 2,000 cm3 of water, extracted with hexane, and washed with an aqueous EDA solution and ice. The hexane was removed, and the residue was distilled under reduced pressure (b. p. 143 C./6mmHg) to obtain 108 g (0.7 mol) of 4-amino-3,5-difluorobenzonitrile.
With sodium nitrite;copper(I) bromide; In hydrogen bromide; acetic acid;
Step 2-3. While stirring 420 cm3 of concentrated H2 SO4 on an ice water bath, 54 g (0.78 mol) of pulverized NaNO2 was added at a rate that maintained a temperature under 40 C., and after the addition it was stirred in a hot water bath at 50 C. until the crystals dissolved completely. While stirring this solution on an ice water bath, 700 cm3 of glacial acetic acid was added dropwise, then 108 g (0.7 mol) of 4-amino-3,5-difluorobenzonitrile was added at a rate maintaining the temperature at 20-25 C., and after the addition was completed it was stirred at this temperature until the crystals were completely dissolved to prepare a diazonium salt solution. A solution with 143 g (1.0 mol) of CuBr dissolved in 420 cm3 of 47% HBr was stirred in an ice water bath while the previously prepared diazonium salt solution was added dropwise for 2 hours, and after the dropping was completed, it was stirred on an ice water bath for 1 hour and at room temperature overnight. The crystals formed were filtered, and after washing the crystals in glacial acetic acid, they were recrystallized from a mixture of acetone and methanol to obtain 98 g (0.44 mol) of 4-bromo-3,5-difluorobenzonitrile.
In N,N-dimethyl-formamide; for 2h;Heating / reflux;
A mixture of the solid and CuCN in DMF was heated with reflux for 2 days and then filtered through celite. The filtrate was dissolved in methylene chloride and water, and the aqueous phase was extracted with methylene chloride. The combined organic layer was washed with brine, dried over anhyd. MgSO4, filtered, and concentrated under reduced pressure. The crude residue was column-chromatographed (hexane/ethylacetate = 4/1) to yield a yellow solid (1.03g, 66%).1HNMR (300MHz, CDC13): 7.15 (dd, 2H, J= 2.4 and 6.0 Hz), 4.28 (bs, 2H).
Step 2: N-(4-Cyano-2,6-difluoro-phenyl)-methanesulfonamide;To a ice-cooled solution of <strong>[110301-23-0]4-amino-3,5-difluoro-benzonitrile</strong> (1.03g,6.68mmol) in methylene chloride was added pyridine (1.5mL) followed by methanesulfonyl chloride (1.5mL). The mixture was warmed up to room temperature and then heated at 50 0C ovenight. The reaction was quenched with water, and the reaction solution was extracted with methylene chloride, washed with water and brine, dried over anhyd. MgSO4; filtered and concentrated under reduced pressure. The resulting residue was treated with IN NaOH/MeOH/THF (1/2/1) for 2 hrs, and then EPO <DP n="80"/>neutralized by adding IN HCl. After evaporating methanol, water was added to the residue. The resulting mixture was extracted with EtOAc, and the combined organic layer was washed with brine, dried over anhyd. MgS 04, filtered, and concentrated under reduced pressure. The crude residue was column-chromatographed (hexane/ethylacetate = 1/1) to yield a white solid (780mg, 69%).1HNMR (300MHz, CDC13): 7.33 (d, 2H, J = 7.2 Hz), 6.50 (bs, IH), 3.33 (s, 3H).
With 1-methyl-pyrrolidin-2-one; hydrogenchloride; potassium hydroxide; In hexane; chloroform; water;
Step 2 132 g of 4-bromo-2,6-difluoroaniline, 70 g of copper (I) cyanide and 444 ml of N-methylpyrrolidone were mixed in a flask and refluxed for 3 hours. The reaction solution was poured into a solution including 266 g of iron (III) chloride, 85 ml of concentrated hydrochloric acid and 315 ml of water. The solution was extracted with chloroform and washed with water and an aqueous 10% solution of potassium hydroxide. The chloroform was distilled off. The residue was distillated under a reduced pressure (bp: 90-110 C./4 mmHg) and recrystallized from a solvent mixture of hexane and chloroform, to yield 56 g of 4-cyano-2,6-difluoroaniline.
To concentrated sulfuric acid (25 mL) was added sodium nitrite (3.20 g) portionwise at 5 C, and the mixture was stirred at room temperature for 0.5 h. The mixture was cooled down to 5 C, and then acetic acid (40 mL) was added dropwise to the mixture. The mixture was stirred at 5 C for 5 min. To the mixture was added 4-amino-3,5-difluorobenzonitrile (8, 6.50 g) portionwise, and then the mixture was stirred at room temperature for 1 h. The mixture was transferred into a dropping funnel, and was added dropwise to a solution of copper(I) bromide (9.07 g) in 47 wt % hydrobromic acid (25 mL) over 0.5 h. The mixture was stirred at room temperature for 13 h. Water (300 mL) was added to the mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with brine, and then dried. The desiccant was removed by filtration and the filtrate was evaporated in vacuo. The resulting residue was purified by silica gel column chromatography (hexane-ethyl acetate) to obtain 9g (5.00 g, 54%) as a white solid: 1H NMR (DMSO-d6) delta 7.98 (2H, d, J = 6.3 Hz); EI-MS m/z 217, 219 [(M)+].
NaN02 (1.60 g, 23.20 mmol) was added portion wise at 5C to a solution of H2SO4 (0309) (12.50 mL, 98 %), and the mixture was stirred at 15C for 0.5 hour. The mixture was cooled to 5C and AcOH (20.00 mL) was added dropwise. The mixture was stirred at 5C for 5 min. 3.25 g Compound BD6-1 (i.e., 4-amino-3,5-difluorobenzonitrile) was added portionwise and the mixture was stirred at 15C for 1 hour. The mixture was transferred into a dropping funnel and then added dropwise to a solution of CuBr (4.54 g, 31.64 mmol) in HBr (12.50 mL, 47 %) over 0.5 hour. The mixture was then stirred at 15C for 12 hour. TLC showed the reaction had completed. The reaction mixture was diluted by addition H20 (150 mL) and extracted with EtOAc (20 mL * 3). The combined extracted organic layers were washed with brine (20 mL * 3), dried over Na2SC>4, filtered and concentrated under reduced pressure to yield a residue. The residue was purified by column chromatography (S1O2, petroleum etherethyl acetate mixture in a ratio of 1:0 to 10: 1) to afford Compound BD6-2 (2.30 g, crude) as a white solid.
A mixture suspension of 4-bromo-2,6-difluoroaniline (7, 25.85 g) and copper(I) cyanide (16.70 g) in NMP (60 mL) was stirred at reflux temperature for 1.5 h and then cooled down to room temperature. To the mixture was added 1,2-diaminoethane (23 mL) and the mixture was poured into water (150 mL). The mixture was extracted with ethyl acetate and the organic layer was washed with 10 wt % 1,2-diaminoethane solution in water and water, and then dried. The desiccant was removed by filtration and the filtrate was evaporated in vacuo. The resulting residue was purified by silica gel column chromatography (hexane-ethyl acetate) to obtain 8 (16.54 g, 86%) as a pale yellow solid: 1H NMR (DMSO-d6) delta 6.36 (2H, s), 7.50 (2H, dd, J = 2.7, 6.7 Hz); EI-MS m/z 154 [(M)+].
70%
In 1-methyl-pyrrolidin-2-one; at 202℃; for 1.5h;
CuCN (1.29 g, 14.42 mmol) was added into a solution of 6 (2 g, 9.61 mmol) in 6 mL of NMP. The mixturewas refluxed for 1.5 h. Upon cooling to rt, 50 mL of NH4OH aq. sat. were added and the mixture wasextracted with toluene (3 × 20 mL). The pooled organic layers were washed with NaCl aq. sat. (2 × 30 mL),dried over Na2SO4 and evaporated at reduced pressure. The resulting brown residue was purified by columnchromatography [SiO2, hexane/DCM (1:1, v/v)] to afford 7 (1.04 g, 70%) as a white solid
51%
In N,N-dimethyl-formamide; at 120℃; for 24h;
4-Bromo-2,6-difluoroaniline (5.00 g, 24.0 mmol, 1.00 equiv) and copper(I) cyanide (6.45 g, 72.0 mmol, 3.00 equiv) were suspended in 50 mL DMF and heated at 120 C for 24 h. After cooling to room temperature, the mixture was poured into an aqueous solution of ammonia (12%, v%, 250 mL). The mixture was then filtered and the precipitate was washed with EtOAc (500 mL). The organic phases were combined and washed with the ammonia solution (500 mL), distilled water (500 mL), brine (500 mL) and dried over anhydrous MgSO4. Solvents were removed under reduced pressure. The crude was purified by flash column chromatography (CH2Cl2/n-pentane, 2:1, v/v) to yield the desired compound (1.88 g, 12.2 mmol, 51%) as a white solid.
In N,N-dimethyl-formamide; at 160℃; for 18h;Inert atmosphere;
To 4-bromo-2,6-difluoroaniline (1.0 g, 4.81 mmol) and copper (I) cyanide (1.28 g, 14.3 mmol) was added DMF (10 mL) under nitrogen and the resulting mixture was heated at 160 C for 18 h. After 18 h, the mixture was cooled, poured onto a 12% aqueous ammonia solution and extracted with EtOAc (2X). The combined organic extract was washed with water. The organic phase was combined with a little water and was filtered through celite to remove suspended solids. The organic phase was then separated from the water, then washed with brine, dried over anhydrous sodium sulfate and concentrated under reduced pressure. Purification by flash chromatography (12% EtOAc/ hexanes eluent) provided 4-amino-3,5-difluorobenzonitrile as a white solid. 1H NMR (300 MHz, Chloroform-d) delta 7.19 - 7.14 (m, 2H), 4.29 (br. s, 2H).
4-amino-3,5-difluorobenzonitrile (354.3 mg, 2.3 mmol) was suspended in 1M aqueous sodium hydroxide (12 mL) and the resulting suspension was heated at 110 C for 16 h. After cooling, the mixture was washed with ether. The aqueous phase was acidified to pH = 2 with 10% KHS04/Na2S04 buffer and extracted with EtOAc (2X). The combined EtOAc extracts were washed with water, and then brine, dried over anhydrous sodium sulfate and concentrated in vacuo to provide 4-amino-3,5-difluorobenzoic acid (335 mg, 84% yield) as a yellow solid. 1H NMR (300 MHz, Chloroform-d) delta 7.66 - 7.58 (m, 2H).
83%
With sodium hydroxide; In water; at 100℃;
4-Amino-3,5-difluorobenzonitrile (1.00 g, 6.49 mmol, 1.00 equiv) was suspended in 1 M NaOH aqueous solution (80 mL) and heated to reflux for 4 h. The reaction mixture was cooled to room temperature and acidified with 1 M HCl aqueous solution (50 mL). The resulting precipitate was filtered, washed with distilled water (200 mL) and dried to yield the desired product (0.93 g, 5.39 mmol, 83%) as a white solid. The characterization is in agreement with the literature.[2]
71.4%
With sodium hydroxide; for 18h;Reflux;
Step S2: 25 g of 2,6-difluoro-4-cyanoaniline is dissolved in 800 mL of 1 M sodium hydroxide solution.After refluxing for 18 h, the reaction was completed by TLC thin layer chromatography and cooled to room temperature.Adjust the system to pH=8 with 1N hydrochloric acid, precipitate a large amount of solid, and filter by suction.The solid was dissolved in 500 mL of ethyl acetate and dried over anhydrous sodium sulfate (20 g).The product was concentrated to give a pale yellow solid (20.2 g).The yield was 71.4%.
In N,N-dimethyl-formamide; for 20h;Inert atmosphere; Reflux;
Step S1: 100 g of 2,6-difluoro-4-bromoaniline is added to 1000 mL of N,N-dimethylformamide under nitrogen protection.Further, 128 g of cuprous cyanide was added and refluxed for 20 hours. The reaction was completed by TLC and cooled to room temperature.Pour into 15% ammonia solution 3L to ensure the solution is alkaline, and extract 1L*3 with ethyl acetate.The organic phase was washed with saturated brine (500 mL*3), and dried over anhydrous sodium sulfate (100 g).The crude product was dissolved in 1 L of dichloromethane, and then 150 g of 100-200 mesh silica gel was added, and after mixing,The dichloromethane was spun off and the resulting mixture was chromatographed on a 200-300 mesh silica gel column.The eluent was petroleum ether: ethyl acetate = 10:1 to 3:1 to give the product 2,6-difluoro-4-cyanoaniline 60 g of a yellow solid.The yield was 81%.
(E)-4-(4-((4-(((2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)methyl)carbamoyl)-2,6-difluorophenyl)diazenyl)-3,5-difluorophenyl)-N,N,N-trimethylbutan-1-aminium trifluoroacetate[ No CAS ]
4-cyano-2,6-difluorobenzenediazonium tetrafluoroborate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
54%
In ethyl acetate; at -10℃; for 1h;Inert atmosphere;
7 (2.03 g, 13.17 mmol) was dissolved in 20 mL of EtOAc and cooled to -10 C with a salt/ice bath. NOBF4(1.54 g, 13.17 mmol) was added in small portions and the reaction mixture was stirred at this temperatureunder Ar. After 1 h, the resulting suspension was filtered over a glass filter and the collected solid waswashed with Et2O (2 × 40 mL) and dried under vacuum to afford 8 (1.8 g, 54%) as a white powder
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