Hydrochloric Acid → 3-cyclopropyl-5-(difluoromethyl)-1H-pyrazole

Participants

Reaction Steps

Intermediate 62 (390 mg, 2.4 mmol) dissolved in ethanol (2 ml), added hydrazine hydrate (0.13 ml, 2.65 mmol) and HCl (0.18 ml). This mixture was refluxed for 3 h. After 3 h, ethanol was removed on rotavapour and work up (H2O/AcOEt) afforded the title compound (290 mg) which was used in the next step without further purification. 1H-NMR (δ ppm, CDCl3, 400 MHz): 12.96 (s, 1H), 6.84 (t, J 54.8, 1H), 6.15 (s, 1H), 1.95-1.87 (m, 1H), 0.99-0.91 (m, 2H), 0.74-0.66 (m, 2H).

Provenance & Evidence