Methanol → 4-chloro-1-(difluoromethyl)-1H-pyrazole-3-carboxylic acid

Participants

Reaction Steps

A solution of 4-chloro-1-difluoromethyl-1H-pyrazole-3-carboxylic acid methyl ester (540 mg, 2.6 mmole) in THF (18 ml) was treated at 23° C. with a solution of lithium hydroxide (135 mg, 5.6 mmole) in a 1:1-mixture of water and methanol (12 ml). After 1 hour the reaction was complete, and the solvents were evaporated at reduced pressure. The residue was partitioned between 2 M aqueous HCl and AcOEt, the organic layer was dried, evaporated, the residue was triturated with pentane and the solid was dried to give the title compound (477 mg) as a white solid. MS: m/z=195.0 [M−H]−.

Provenance & Evidence