Hexachloroethane → 3-Chloro-N,N-dimethyl-1H-pyrazole-1-sulfonamide

Participants

Reaction Conditions

Reaction Steps

To a solution of N-dimethylsulfamoylpyrazole (188.0 g, 1.07 mol) in dry tetrahydrofuran (1500 mL) at −78° C. was added dropwise a solution of 2.5 M n-butyllithium (472 mL, 1.18 mol) in hexane while maintaining the temperature below −65° C. Upon completion of the addition the reaction mixture was maintained at −78° C. for an additional 45 minutes, after which time a solution of hexachloroethane (279 g, 1.18 mol) in tetrahydrofuran (120 mL) was added dropwise. The reaction mixture was maintained for an hour at −78° C., warmed to −20° C. and then quenched with water (1 L). The reaction mixture was extracted with dichloromethane (4×500 mL); the organic extracts were dried over magnesium sulfate and concentrated. The crude product was further purified by chromatography on silica gel using dichloromethane as eluent to afford the title compound as a yellow oil (160 g).

Provenance & Evidence