Hydrochloric Acid → 3-chloro-1-methyl-1H-pyrazole-4-carboxylic acid

Participants

Reaction Steps

A mixture of 23.9 g (127 mmol) of ethyl 3-chloro-1-methylpyrazole-4-carboxylate and 10.4 g (260 mmol) of sodium hydroxide in 130 mL of water was prepared and was heated at reflux for 3 hr. The solution that formed was cooled to about 0° C. and neutralized to pH 6.5 with concentrated hydrochloric acid with stirring and the precipitate that formed was recovered by filtration, washed with water, and dried under reduced pressure to obtain 18.1 g (89 percent of theory) of the title compound as a white solid melting at 211°-213° C. (d).

Provenance & Evidence