Isopropenyl chloroformate → 1-Methylethenyl N-[3-(2-fluorophenyl)-1-methyl-1H-pyrazol-5-yl]carbamate

Participants

Reaction Steps

To a biphasic solution of 3-(2-fluorophenyl)-1-methyl-1H-pyrazol-5-amine (1.19 g, 6.22 mmol) in ethyl acetate (30 mL) and NaHCO3 solution (30 mL) was added isopropenylchloroformate (1.28 g, 10.6 mmol) and mixture was stirred at RT for 24 h. Both layers were separated; the aqueous layer was extracted with ethyl acetate (1×30 mL) and the combined organic layers were washed with brine, dried (Na2SO4) and concentrated to afford crude product which was purified by chromatography (ethyl acetate/hexane) to afford prop-1-en-2-yl 3-(2-fluorophenyl)-1-methyl-1H-pyrazol-5-ylcarbamate (1.15 g, 82% yield) as a pasty mass. 1H NMR (400 MHz, DMSO-d6): δ 10.09 (brs, 1H), 7.90 (td, J=8.0 Hz, 1.6 Hz, 1H), 7.38-7.22 (m, 3H), 6.54 (d, J=3.6 Hz, 1H), 4.79-4.77 (m, 2H), 3.76 (s, 3H), 1.96 (s, 3H); MS (ESI) m/z: 276.0 (M+H+).

Provenance & Evidence