Trifluoroacetic acid → Picolinamide hydrochloride

Participants

Reaction Steps

N-(4-Chloro-5-(trifluoromethyl)-1H-pyrrolo[2,3-b]pyridin-3-yl)picolinamide (280 mg, 0.81 mmol), (R)-tert-butyl piperidin-3-ylcarbamate (490 mg, 2.42 mmol) and DIEA (0.28 mL, 1.61 mmol) in NMP (2 mL) were stirred at 156° C. (bath) for 10 hours. Ethyl acetate (20 mL) was added, the organic layer was washed with water (10 mL), brine (10 mL) and dried over sodium sulfate. After removal of the solvent, the residue was purified by C-18 reverse phase flash chromatography (Biotage SP4 unit, C-18 25M column, 40-80% CH3CN/water gradient; 30 CV) to give a solid. This solid was dissolved in DCM (3 mL), and TFA (0.5 mL) was added. The mixture was stirred at room temperature for 1 hour. The solvent was removed. The residue was dissolved in DCM (1 mL), and 2N HCl in ether (3 mL) was added. The solid formed was collected by filtration to give (R)-N-(4-(3-aminopiperidin-1-yl)-5-(trifluoromethyl)-1H-pyrrolo [2, 3-1)]pyridin-3-yl)picolinamide hydrochloride (195 mg, 47% yield) as a solid. 1H NMR (400 MHz, D2O) δ 8.40 (m, 1H), 8.37 (s, 1H), 7.86 (s, 1H), 7.81 (m, 2H), 7.44 (m, 1H), 3.68 (m, 1H), 3.36 (m, 1H), 2.99 (m, 1H), 2.93 (m, 1H), 2.53 (m, 1H), 2.05 (m, 1H), 1.87 (m, 1H), 1.66 (m, 1H), 1.42 (m, 1H); LCMS (APCI+) m/z 405 (M+H)+.

Provenance & Evidence