Hexachloroethane → 5-chloro-N,N-dimethyl-3-(trifluoromethyl)-1H-pyrazole-1-sulfonamide

Participants

Reaction Steps

A stirred solution of N,N-dimethyl-3-(trifluoromethyl)-1H-pyrazole-1-sulfonamide (i.e. the product of Example 10, Step A) (4.0 g, 16 mmol) in tetrahydrofuran (25 mL) was cooled to −78° C., and then treated dropwise with 2 M n-butyllithium in cyclohexane (8.6 mL, 17.2 mmol). The reaction mixture was stirred for a further 30 minutes, and then a solution of hexachloroethane (4.2 g, 18 mmol) in tetrahydrofuran (15 mL) was added dropwise. The reaction mixture was stirred for 1 h, warmed to room temperature, and quenched with water (50 mL). The resulting solution was extracted with dichloromethane, dried (MgSO4), and concentrated under reduced pressure to give 4.38 g of title compound. This compound was of sufficient purity to use in subsequent reactions.

Provenance & Evidence