Phosgene → N-(1-methyl-1H-indazol-4-yl)-4-[4-(trifluoromethyl)-2-pyridinyl]-1-piperazinecarboxamide

Participants

Reaction Steps

1-Methyl-1H-indazol-4-amine (560 mg, 3.81 mmol) in toluene (20 mL) was treated with 20% phosgene solution (2.5 mL) and refluxed overnight. The mixture was allowed to cool to ambient temperature and was concentrated under reduced pressure. The residue was taken up in THF (20 mL) and treated with diisopropylamine (5 mL) and 1-[4-(trifluoromethyl)-2-pyridinyl]piperazine (450 mg, 1.95 mmol). The mixture was refluxed overnight, allowed to cool to ambient temperature, and concentrated under reduced pressure. The residue was purified by flash chromatography (97:3 CH2Cl2:CH3OH to 95:5 CH2Cl2:CH3OH) to provide the title compound. The corresponding hydrochloride salt was prepared by treatment with methanolic HCl. 1H NMR (300 MHz, d6-DMSO) δ 8.78 (s, 1H), 8.44 (m, 1H), 8.07 (d, J=1.0 Hz, 1H), 7.83 (m, 1H), 7.19-7.31 (m, 3H), 7.02 (d, 9.2 Hz, 1H), 4.00 (s, 3H), 3.74 (m, 4H), 3.63 (m, 4H); MS (ESI+) m/z 405 (M+H)+.

Provenance & Evidence