1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → tert-butyl 3-(4-(2-chloro-3-fluorophenyl)piperidine-1-carbonyl)-6,7-dihydro-1Hpyrazolo[4,3-c]pyridine-5(4H)-carboxylate

Participants

Reaction Steps

To a solution of 4-(2-chloro-3-fluorophenyl)piperidine hydrochloride (14, 90 mg, 0.36 mmol), 5-(tert-butoxycarbonyl)-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine-3-carboxylic acid (96 mg, 0.36 mmol), and diisopropylethylamine (0.19 mL, 1.08 mmol) in DMF (7.8 mL) was added EDCI (83 mg, 0.43 mmol) and HOBt (58 mg, 0.43 mmol). The resulting solution was stirred at ambient temperature for 24 h. The reaction mixture was diluted with H2O (30 mL), and the resulting precipitate was collected by filtration. The obtained solids were chromatographed over silica gel (Isco CombiFlash Rf unit, 12 g Redisep column, 0% to 5% CH3OH in CH2Cl2 with 0.1% NH4OH in CH2Cl2) to provide tert-butyl 3-(4-(2-chloro-3-fluorophenyl)piperidine-1-carbonyl)-6,7-dihydro-1Hpyrazolo[4,3-c]pyridine-5(4H)-carboxylate (41) as a white foam (139 mg, 82%): 1H NMR (500 MHz, DMSO-d6) δ 13.11-12.91 (m, 1H), 7.39-7.32 (m, 1H), 7.30-7.22 (m, 2H), 5.28-5.13 (m, 1H), 4.75-4.60 (m, 1H), 4.49-4.36 (m, 2H), 3.65-3.53 (m, 2H), 3.33-3.25 (m, 1H, overlaps with H2O), 3.24-3.08 (m, 1H), 2.91-276 (m, 1H), 2.67 (t, J=5.5 Hz, 2H), 1.91-1.75 (m, 2H), 1.67-1.50 (m, 2H), 1.41 (s, 9H); ESI MS m/z 463 [M+H]+.

Provenance & Evidence