Hexachloroethane → HCID 59589496, compound

Participants

Reaction Steps

Under a nitrogen atmosphere, a solution of N,N-dimethyl-1H-pyrazole-1-sulfonamide (5.0 g, 28 mmol) (i.e. the product of Example 12, Step A) in tetrahydrofuran (50 mL) was cooled to −78° C. and then treated with n-butyllithium (2 M solution in cyclohexane, 15.0 mL, 30 mmol) dropwise. The reaction mixture formed a thick precipitate, and stirring was continued for 30 minutes after the addition. To the stirred suspension, a solution of hexachloroethane (7.1 g, 30 mmol) in tetrahydrofuran (20 mL) was added dropwise. After 30 minutes the resulting clear solution was warmed to ambient temperature and quenched with the addition of water (70 mL). The reaction mixture was extracted with dichloromethane and dried over MgSO4. The reaction mixture was filtered and concentrated under reduced pressure. The crude product was purified by silica gel chromatography (50% hexanes in dichloromethane as eluant) to give 1.71 g of 5-chloro-N,N-dimethyl-1H-pyrazole-1-sulfonamide. The 5-chloro-N,N-dimethyl-1H-pyrazole-1-sulfonamide was heated to 110° C. for 12 h with a catalytic amount of pyrazole to isomerize to the title compound.

Provenance & Evidence