Chlorodifluoromethane → 4-(5-Difluoromethoxy-3-trifluoromethyl-pyrazol-1-yl)-benzoic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-(5-hydroxy-3-trifluoromethyl-pyrazol-1-yl)-benzoic acid ethyl ester (1 g, 3.3 mmol), difluorochloromethane (3 g, 34 mmol) and potassium carbonate (0.5 g, 3.6 mmol) in DMF (9 mL) was stirred in a sealed tube at −78° C. for 3 minutes and then at 100° C. for 12 hours. The mixture was cooled to −78° C. and the precipitate was removed by filtration and washed with DMF (3×1 mL). The filtrate and washings were poured into cold water (200 mL). The resulting suspension was transferred into a centrifuge tube and the contents were centrifuged at room temperature for 10 minutes and filtered to give 4-(5-difluoromethoxy-3-trifluoromethyl-pyrazol-1-yl)-benzoic acid ethyl ester (1.1 g, 94% yield) as a yellow solid.

Provenance & Evidence