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

Participants

Reaction Steps

A solution of 5-chloro-N,N-dimethyl-3-(trifluoromethyl)-1H-pyrazole-1-sulfonamide (i.e. the product of Example 10, Step B) (4.38 g, 15.8 mmol) and trifluoroacetic acid (2.7 mL, 35 mmol) was stirred at 0° C. for 1.5 h. The reaction mixture was diluted with water (15 mL), and sodium carbonate was added to raise the pH to 12. The solution was extracted with diethyl ether, dried (MgSO4), and concentrated under reduced pressure to give 2.1 g of the title compound. This compound was of sufficient purity to use in subsequent reactions.

Provenance & Evidence