Chlorosuccinimide → ethyl 4-chloro-5-methyl-1H-pyrazole-3-carboxylate

Participants

Reaction Steps

A mixture of 5-methyl-1H-pyrazole-3-carboxylic acid ethyl ester (4.45 g, 28.9 mmol) and N-chlorosuccinimide (5.01 g, 37.5 mmol) in dimethylformamide (60 mL) was stirred for 24 hours at ambient temperature. The reaction was then concentrated down and purified by eluting through a silica gel column with a 0 to 100% ethyl acetate/heptane gradient to afford the title compound (5.2 g, 96% yield) as a white solid. MS (ESI) [m/e, (M+H)+]=189.3. 1H NMR (400 MHz, chloroform-d) δ ppm 9.39 (br. s., 1H), 4.44 (q, J=7.1 Hz, 2H), 2.35 (s, 3H), 1.43 (t, J=7.1 Hz, 3H).

Provenance & Evidence