1,2,3-Trifluoro-4-nitrobenzene → 5-cyclopropyl-N-(2,3-difluoro-6-nitrophenyl)-1H-pyrazol-3-amine

Participants

Reaction Conditions

Reaction Steps

To a solution of 1,2,3-trifluoro-4-nitrobenzene (3.2 g, 18 mmol) and DIEA (4.2 ml, 24 mmol) in dry THF (20 ml) was added dropwise a solution of 5-cyclopropyl-1H-pyrazol-3-amine (2.0 g, 16 mmol) in THF (5 ml) at 0° C. After addition, the reaction mixture was stirred at 25° C. for 21 hours. The solvent was removed under reduced pressure and the resulted residue was purified by column chromatography (hexane:EtOAc=5:2). Recrystallization from EtOAc (10 ml) and hexanes (˜100 ml) gave the title compound as red crystals (1.5 g, 33%). NMR (400 MHz) 11.90 (s, 1H), 8.78 (s, 1H), 7.86 (t, J=7.6 Hz, 1H), 7.08 (q, J=8.7 Hz, 1H), 5.60 (s, 1H), 1.83 (m, 1H), 0.89 (m, 2H), 0.65 (m, 2H). MS: Calcd.: 280; Found: [M+H]+ 281.

Provenance & Evidence