Trifluoroacetic acid → HCID 135409736, compound

Temperature

45 °C

4-Dimethylaminopyridine (102 mg, 0.835 mmol) was added to a mixture of 5-methoxy-pyrrolo[3,2-b]pyridine (4.50 g, 30.4 mmol, prepared according to procedures described in Liebigs Ann. Chem. 1988, 203-208), di-tert-butyl dicarbonate (10.7 g, 49.0 mmol), and anhydrous dichloromethane (100 mL) at room temperature with stirring. The resulting solution was stirred at room temperature overnight. The reaction was washed with water (75 mL) and brine (75 mL) successively, dried over magnesium sulfate, and concentrated under reduced pressure to an amber oil. The crude product was chromatographed on silica, eluting first with dichloromethane and then 10% ethyl acetate/dichloromethane to give 5-methoxy-pyrrolo[3,2-b]pyridine-1-carboxylic acid tert-butyl ester [7.06 g, 94%, Intermediate (60)] as a viscous amber oil. TLC Rƒ0.27 (silica, dichloromethane); LC/MS: 249.1 (M+H), RT=3.60 minutes); 1H NMR [300 Mhz, (CD3)2SO]: δ 8.21 (d, J=9 Hz, 1H), 7.85 (d, J=4Hz, 1H), 6.76 (d, J=9 Hz, 1H), 6.70 (d, J=4 Hz, 1 H), 3.89 (s, 3H), 1.63 (s, 9H). Step 2. A solution of tert-butyllithium (15.0 mL, of a 1.5 M solution in pentane, 22.5 mmol) was added in portions to a solution of 5-methoxy-pyrrolo[3,2-b]pyridine-1-carboxylic acid tert-butyl ester [4.66 g, 18.8 mmol, Intermediate (60)] in anhydrous tetrahydrofuran (85 mL) under nitrogen at −78° C. over 4 minutes. The resulting red reaction was stirred at −78° C. for 41 minutes. Triisopropyl borate (8.70 mL, 37.7 mmol) was added over 2 minutes and the red-brown reaction stirred at −78° C. for 20 minutes. The reaction was warmed to 0° C., stirred for 2.5 hours, and then water (50 mL) was added. After stirring at room temperature for 1 hour, the solvent was removed under reduced pressure. The aqueous mixture was basified with 5 N aqueous sodium hydroxide to pH 14. The mixture was extracted twice with ethyl acetate (30 mL). The aqueous layer was cooled to 0° C., acidified with 10% aqueous KHSO4 to pH 4, and the resulting slurry aged at 0° C. for 15 minutes. The solid was collected, washed with water, and dried to yield 5-methoxy-1H-indole-2-boronic acid 1-carboxylic acid tert-butyl ester [2.48 g, 45%, Intermediate (61)] as a white powder. LC/MS: 293.16 (M+H), RT=2.43 minutes; 1H NMR [300 Mhz, (CD3)2SO]: δ 8.28 (s, 2H), 8.23 (d, J=9 Hz, 1H), 6.70 (d, J=9 Hz, 1H), 6.58 (s, 1 H), 3.87 (s, 3H), 1.60 (s, 9H). Step 3. A mixture of 5-methoxy-1H-indole-2-boronic acid 1-carboxylic acid tert-butyl ester [600 mg, 2.05 mmol, Intermediate (61)], 3-iodo-thieno[3,2-c]pyrazole-1-carboxylic acid tert-butyl ester [600 g, 1.71 mmol, Example 5B], cesium carbonate (2.23 g, 6.84 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) complex with dichloromethane (1:1) (93 mg, 0.114 mmol), 1,4-dioxane (12 mL), and water (3.0 mL) was purged with nitrogen and then heated at 90° C. with stirring under nitrogen. After 105 minutes, the reaction was cooled to room temperature, diluted with ethyl acetate (50 mL), and washed twice with water (25 mL) and brine (25 mL) successively. The organic layer was dried over magnesium sulfate and the solvent was removed under reduced pressure to give a brown foam The crude product was chromatographed on silica, eluting first with 5% ethyl acetate/dichloromethane and then 10% ethyl acetate/dichloromethane to give 2-(1-tert-butoxycarbonyl-1H-thieno[3,2-c]pyrazol-3-yl)-5-methoxy-pyrrolo[3,2-b]pyridine-1-carboxylic acid tert-butyl ester [470 mg (58%, Intermediate (62)] as a tan foam. TLC Rƒ0.46 (silica, 10% ethyl acetate/dichloromethane); LC/MS: 471.19 (M+H), RT=4.02 minutes; 1H NMR [300 Mhz, (CD3)2SO]: δ 8.32 (d, J=9 Hz, 1H), 8.00 (d, J=5 Hz, 1H), 7.36 (d, J=5 Hz, 1H), 7.07 (s, 1 H), 6.88 (d, J=9 Hz, 1H), 3.92 (s, 3H), 1.65 (s, 9H), 1.33 (s, 9H). Step 4. To a solution of 2-(1-tert-butoxycarbonyl-1H-thieno[3,2-c]pyrazol-3-yl)-5-methoxy-pyrrolo[3,2-b]pyridine-1-carboxylic acid tert-butyl ester [250 mg, 0.531 mmol, Intermediate (62)], anisole (1.0 mL), and dichloromethane (1.0 mL) at ambient temperature was added trifluoroacetic acid (1.0 mL) and the resulting solution heated at 45° C. After 1 hour, the green reaction solution was cooled to ambient temperature, basified with 5% aqueous potassium carbonate (30 mL), and the resulting mixture extracted twice with ethyl acetate (20 mL). The combined extracts were washed with water (20 mL) and brine (20 mL) successively, dried over magnesium sulfate, and concentrated in vacuo to an oily mixture. Trituration with ether/heptane (1:1) provided 5-methoxy-2-(1H-thieno[3,2-c]pyrazol-3-yl)-1H-pyrrolo[3,2-b]pyridine [107 mg, 74%, Example 60] as a tan powder. TLC Rƒ0.52 (silica, ethyl acetate); mp: 234-236° C.; LC/MS: 271.02 (M+H), RT=2.03 minutes; 1H NMR [300 Mhz, (CD3)2SO]: δ 13.32 (br s 1H), 11.67 (br s, 1H), 7.74 (d, J=5 Hz, 1H), 7.66 (d, J=9 Hz, 1H), 7.18 (d, J=5 Hz, 1H), 6.58-6.53 (m, 2H), 3.85 (s, 3H).

1. temperaturethe green reaction solution was cooled to ambient temperature
2. extractionthe resulting mixture extracted twice with ethyl acetate (20 mL)
3. washThe combined extracts were washed with water (20 mL) and brine (20 mL) successively
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated in vacuo to an oily mixture

ORD record

ord-59df419ca92f42eebf140a8422c37c52

Source dataset

uspto-grants-2009_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07518000B2