Lithium Hydroxide → 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylic acid

Participants

Reaction Steps

To a suspension of ethyl 5-amino-1-(4-fluorophenyl)-1H-pyrazole-4-carboxylate (12.1 g, 48.5 mmol) in ethanol (250 ml) was added a solution of lithium hydroxide (5.8 g, 242 mmol) in water (100 ml). The mixture was stirred at reflux for 2.5 hours. It was allowed to cool and concentrated to 50% of its volume before 5M hydrochloric acid (47 ml) was added. After stirring for 15 minutes, the resulting white solid was filtered off and further 5M hydrochloric acid (3 ml) was added to the filtrate and the resulting solid was filtered and the combined solids were washed with water and diethyl ether and then dried under vacuum to give the title compound (10.27 g).

Provenance & Evidence