Sodium Hydroxide → 1-Methyl-1H-pyrazole-4-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester (300 mg, 1.95 mmol) in ethanol cooled to 0° C. was treated with a 1N aqueous sodium hydroxide solution. The reaction was then warmed to 25° C. and was stirred at 25° C. for 18 h. At this time, the reaction was concentrated in vacuo and acidified to pH=2 with a 1N aqueous hydrochloric acid solution. This solution was extracted with ethyl acetate (3×50 mL). The organics were washed with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered, and dried in vacuo to afford 1-methyl-1H-pyrazole-4-carboxylic acid (193 mg, 78.5%) as a white solid: LR-MS for C5H6N2O2 (M−H)+ at m/z=125.

Provenance & Evidence