Diisopropylethylamine → 3,3-difluoro-1-(1-methyl-4-nitro-1H-pyrazol-5-yl)piperidine

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-chloro-1-methyl-4-nitro-1H-pyrazole (0.1 g, 4.5 mmol), 3,3-difluoropiperidine hydrochloride (0.14 g, 0.93 mmol) and DIPEA (0.5 mL, 2.8 mmol) in EtOH (3 mL) was heated at 130° C. in a microwave for 1 hr. Additional DIPEA (0.5 mL, 2.8 mmol) and 3,3-difluoropiperidine hydrochloride (0.29 g, 1.8 mmol) were added and the mixture was heated at 130° C. in a microwave for 2 hr. The solvent was removed under reduced pressure and the crude product was purified via silica gel column chromatography (0-60% EtOAc/isohexane) to yield 3,3-difluoro-1-(1-methyl-4-nitro-1H-pyrazol-5-yl)piperidine as a yellow oil (127 mg, 83%). 1H NMR (400 MHz, CDCl3) δ 8.04 (s, 1H), 3.80 (s, 3H), 3.41-3.29 (m, 2H), 3.26-3.04 (m, 2H), 2.17-2.03 (m, 2H), 1.97-1.88 (m, 2H).

Provenance & Evidence