Trifluoroacetic acid → 5-chloro-3-(trifluoromethyl)-1H-pyrazole

Participants

Reaction Conditions

Reaction Steps

In a round bottom flask with magnetic stirrer, 5-chloro-N,N-dimethyl-3-(trifluoromethyl)-1H-pyrazole-1-sulfonamide (4.38 g, 15.8 mmol) (i.e. the product of Example 13, Step B) was cooled to 0° C. and treated with trifluoroacetic acid (2.7 mL, 35 mmol). The reaction mixture was stirred at 0° C. for 1.5 h. The resulting solution was diluted with water (15 mL) and basified with sodium carbonate to pH 12. The reaction mixture was extracted with diethyl ether. The extract was dried over MgSO4 and concentrated under reduced pressure giving 2.1 g of the title compound. This compound was of sufficient purity to use in subsequent reactions.

Provenance & Evidence