p-Toluenesulfonic acid → 4-Chloro-3-[4-chloro-3-(1,3-dithian-2-yl)-phenyl]-5-difluoromethoxy-1-methyl-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

0.5 g (4.6 mmol) of 1,3-propanedithiol was added to a solution of 1.7 g (4.6 mmol) of 4-chloro-3-[4-chloro-3-(dimethoxymethyl)phenyl]-5-difluoromethoxy-1-methyl-1H-pyrazole in 50 ml of toluene. The mixture was heated to 60-70° C. and then a spatula-tipful of p-toluenesulfonic acid was added. The reaction mixture was stirred at reflux temperature for 3 hours and then cooled and diluted with 50 ml of toluene. The organic phase was washed with 10% strength by weight sodium hydrogen carbonate solution and water and then dried over magnesium sulfate and concentrated. The crude product thus obtained was purified by chromatography on silica gel (eluent: hexane/ethyl acetate=4:1). Yield: 1.8 g.

Provenance & Evidence