Dimethylformamide → 5-Chloro-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

DMF (9.5 mL, 0.12 mol) was stirred over ice bath and phosphoryl chloride (24.0 mL, 0.257 mol) was added dropwise. To the solution was added 3-(difluoromethyl)-1-methyl-1H-pyrazol-5(4H)-one (5.51 g, 0.0372 mol) portion wise and the mixture was heated at 120° C. for 40 minutes. The reaction mixture was cooled, and the phosphoryl chloride was quenched by adding small chunks of ice slowly with stirring. The mixture was then extracted with ethyl acetate three times and combined organic layer was washed with water and brine, dried over MgSO4 and evaporated to give 5-chloro-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carbaldehyde (5.66 g, 78.2%) as a dark orange/brown solid. This material was used without further purification for the next reaction.

Provenance & Evidence