反应详情

Part A. To lithium 1-tert-butoxy-4-(2-furyl)-1,4-dioxo-2-buten-2-olate (13 g, 54 mmol; Example 74, Part A) was added 2-fluoro-5-hydrazinobenzonitrile hydrochloride (10 g, 54 mmol) and 250 mL of glacial acetic acid. The resulting orange mixture was maintained at rt for 20 h and then concentrated to dryness. The resulting residue was taken up in 30% chloroform in hexanes and filtered to afford tert-butyl 1-(3-cyano-4-fluorophenyl)-5-(2-furyl)-1H-pyrazole-3-carboxylate (18 g, 95%) as a light brown solid. LC/MS (ESI+): 354.2 (M+H)+. 1H NMR (CDCl3) δ 7.64–7.78(m, 3H), 7.42 (s, 1H), 7.05 (s, 1H), 6.45 (s, 1H), 6.30 (s, 1H), 1.61 (s, 9H) Part B. To the product from Part A (10 g, 28 mmol) was added 125 mL of dichloromethane and 125 mL of trifluoroacetic acid. The resulting black solution was maintained at rt under nitrogen for 2 h and was then concentrated to dryness. The resulting solid was triturated with ethyl acetate and then dried in a vacuum oven for 4 h to afford 1-(3-cyano-4-fluorophenyl)-5-(2-furyl)-1H-pyrazole-3-carboxylic acid (5.3 g, 63%) as a light brown solid. LC/MS (ESI+): 298.1 (M+H)+. 1H NMR (CD3OD) δ 7.90(m, 1H), 7.75 (m, 1H), 7.51 (s, 1H), 7.46 (t, 1H), 6.98 (s, 1H), 6.47 (m, 1H), 6.35 (m, 1H). Part C. To the product (4.1 g, 14 mmol) from Part B was added 23 mL of dichloromethane and 2.0 M oxalyl chloride (10 mL, 21 mmol) in dichloromethane. After dropwise addition of N,N-dimethylformamide (10 drops), the brown mixture became a clear solution over a period of 30 min. The solution was concentrated; the resulting residue was redissolved in 100 mL of dichloromethane, and 0.5 M ammonia in dioxane (110 mL, 55 mmol) was added via cannula. After 30 min, the resulting suspension was concentrated and poured into water. The aqueous layer was washed with ethyl acetate (3×70 mL), and the combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, and concentrated. The resulting residue was dissolved in 10 mL of dichloromethane and 50 mL of hexanes were added. The resulting suspension was filtered, and the filter cake was washed with 50 mL of hexanes, and dried in a vacuum oven to afford 1-(3-cyano-4-fluorophenyl)-5-(2-furyl)-1H-pyrazole-3-carboxamide (2.5 g, 62%) as a brown solid. LC/MS (ESI+): 297.1 (M+H)+. 1H NMR (CDCl3) δ 7.75(m, 1H), 7.64 (m, 1H), 7.42 (s, 1H), 7.33 (t, 1H), 7.16 (s, 1H), 6.79 (br s, 1H), 6.46(m, 1H), 6.36 (m, 1H), 5.50 (br s, 1H). Part D. To the product (2.5 g, 8.3 mmol) from Part C was added water (51 mL), 5% aqueous sodium dihydrogenphosphate (35 mL), and tert-butanol (51 mL). The resulting mixture was warmed to 60° C., and potassium permanganate (8.0 g, 51 mmol) was added over a period of 10 min. After an additional 10 min, the resulting purple slurry was cooled to 0° C., and the reaction was quenched by the addition of 200 mL of saturated aqueous sodium bisulfite. The resulting mixture was filtered, washed with 300 mL of water, and the filtrate was acidified with concentrated hydrogen chloride. The aqueous layer was extracted with ethyl acetate (6×100 mL) and the combined organic layers were washed with saturated aqueous sodium chloride, dried over sodium sulfate, and filtered. Concentration afforded 3-(aminocarbonyl)-1-(3-cyano-4-fluorophenyl)-1H-pyrazole-5-carboxylic acid (1.6 g, 71%) as a yellow solid. LC/MS (ESI+): 275.1 (M+H)+. 1H NMR (CD3OD) δ 8.03 (m, 1H), 7.90 (m, 1H), 7.5 (t, 1H), 7.44 (s, 1H). Part E. Sodium cyanoborohydride (1.54 g, 25 mmol) was added in one portion to a stirring orange solution of 5-iodo-1H-indole (6.0 g, 25 mmol) in glacial acetic acid (350 mL). After 24 h, the orange solution was concentrated. To the resulting red residue was added tetrahydrofuran (250 mL) and di-tert-butyl dicarbonate (16 g, 74 mmol) followed by saturated aqueous sodium bicarbonate (20 mL). The resulting mixture was stirred for 24 h and was then poured into aqueous 1N hydrogen chloride (70 mL). The layers were separated, and the aqueous layer was washed with ethyl acetate (3×50 mL). The combined organic layers were washed with saturated aqueous sodium chloride (50 mL), dried over sodium sulfate and concentrated. The resulting residue was dissolved in THF (100 mL), and benzyl amine (6 mL, 55 mol) was added. The resulting solution was stirred for 1.5 h and was then poured into 1N hydrogen chloride (70 mL). The layers were separated and the aqueous layer was washed with ethyl acetate (3×50 mL). The combined organic layers were washed with saturated aqueous sodium chloride (50 mL), dried over sodium sulfate, and concentrated. Purification of the resulting residue by flash column chromatography (5% ethyl acetate in hexanes) afforded tert-butyl 5-iodo-1-indolinecarboxylate (3.9 g, 45%) as a white solid. LC/MS (ESI+): 346.1 (M+H)+. 1H NMR (CDCl3) δ 7.43 (m, 1H), 7.15 (m, 1H), 6.89 (dt, 1H), 3.96 (m, 2H), 3.08 (t, 1H), 3.05 (t, 1H) 1H), 1.55 (s, 9H). Part F. To the product (1.65 g, 4.8 mmol) from Part E was added dimethylsulfoxide (59 mL), 2-hydroxypyridine (910 mg, 9.6 mmol), and potassium carbonate (2.6 g, 19 mmol). The resulting mixture was degassed (alternate vacuum & nitrogen; three times), and copper(I) iodide (910 mg, 4.8 mmol) was added in one portion. The now light green mixture was again degassed (vac/N2) and warmed to 122° C. After 3 h, the mixture was cooled and poured into saturated aqueous ammonium hydroxide (100 mL) and ethyl acetate (200 mL). The layers were separated, and the aqueous layer was washed with one 50 mL-portion of ethyl acetate. The combined organic layers were then washed with water (2×50 mL), saturated aqueous sodium chloride, and dried over sodium sulfate. The organic layers were concentrated, and the resulting oil was purified by flash column chromatography (10–100% ethyl acetate in hexanes) to afford tert-butyl 5-(2-oxo-1(2H)-pyridinyl)-1-indolinecarboxylate (660 mg, 44%) as a yellow solid. LC/MS (ESI+): 313.2 (M+H)+. 1H NMR (CDCl3) δ 7.41 (dd, 1H), 7.34 (dd, 1H), 7.25 (s, 1H), 7.18 (d, 1H), 6.73 (d, 1H), 6.23 (t, 1H), 4.08 (br s, 2H), 3.16 (t, 2H), 1.68 (s, 9H). Part G. To the product (610 mg, 2.0 mmol) from Part F was added dichloromethane (6 mL) and trifluoroacetic acid (6 mL). After 20 min, the reaction was concentrated to dryness and treated with saturated aqueous sodium bicarbonate (15 mL). The layers were separated, and the aqueous layer was washed with dichloromethane (2×50 mL). The organic layers were dried over sodium sulfate and concentrated to afford 1-(2,3-dihydro-1H-indol-5-yl)-2(1H)pyridinone (410 mg, 99%). LC/MS (ESI+): 213.1 (M+H)+. 1H NMR (CDCl3) δ 7.55–8.09 (br m, 1H), 7.30–7.40 (m, 2H), 7.14 (s, 1H), 6.95 (d, 1H), 6.66 (d, 1H), 6.64 (d, 1H), 6.19 (dt, 1H), 3.62 (t, 2H), 3.08 (t, 2H). Part H. To the product from Part G (274 mg, 1.30 mmol) was added 3-(aminocarbonyl)-1-(3-cyano-4-fluorophenyl)-1H-pyrazole-5-carboxylic acid (390 mg, 1.4 mmol), followed by pyridine (11 mL) and N,N-dimethylformamide (4.0 mL). Then 1,3-diisopropylcarbodiimide (0.242 mL, 1.6 mmol) was added, and the resulting solution was stirred for 14 h. The red mixture was poured into 1N aqueous hydrochloric acid (70 mL) and washed with ethyl acetate (60 mL). The organic layer was washed with 1N aqueous hydrochloric acid (3×25 mL), saturated aqueous sodium chloride, and dried over sodium sulfate. Concentration of the organic layers and purification of the resulting residue by radial chromatography (5% methyl alcohol in dichloromethane) afforded partially pure 1-(3-cyano-4-fluorophenyl)-5-{[5-(2-oxo-1(2H)-pyridinyl)-2,3-dihydro-1H-indol-1-yl]carbonyl}-1H-pyrazole-3-carboxamide (620 mg, 62%) as a red oil (LC/MS (ESI+): 469.0 (M+H)+). This material was dissolved in N,N-dimethylformamide (10 mL), and potassium carbonate (910 mg, 6.6 mmol) and water (3.0 mL) were added. Acetohydroxamic acid (110 mg, 1.5 mmol) was added in one portion, and the resulting yellow mixture was warmed to 50° C. After 1.5 h, the reaction was cooled to rt, concentrated, and diluted with ethyl acetate (10 mL). Filtration afforded 1-(3-amino-1,2-benzisoxazol-5-yl)-5-{[5-(2-oxo-1(2H)-pyridinyl)-2,3-dihydro-1H-indol-1-yl]carbonyl}-1H-pyrazole-3-carboxamide (100 mg, 16%) as a white solid. LC/MS (ESI+): 482.1 (M+H)+. 1H NMR (d6-DMSO) δ 8.09(s, 1H), 8.01 (d, 1H), 7.85 (s, 1H), 7.68 (m, 1H), 7.46–7.62 (m, 3H), 7.38 (d, 2H), 7.18 (br d, 1H), 6.58 (s, 1H), 6.46 (d, 1H), 6.29 (t, 1H), 4.34 (br t, 2H), 3.22 (br t, 2H).

1. concentrationconcentrated to dryness
2. filtrationfiltered