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

Temperature

-78 °C

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).

1. temperaturewhile maintaining the temperature below −65° C
2. additionUpon completion of the addition the reaction mixture
3. temperatureThe reaction mixture was maintained for an hour at −78° C.
4. temperaturewarmed to −20° C.
5. customquenched with water (1 L)
6. extractionThe reaction mixture was extracted with dichloromethane (4×500 mL)
7. dry with materialthe organic extracts were dried over magnesium sulfate
8. concentrationconcentrated
9. customThe crude product was further purified by chromatography on silica gel

ORD record

ord-42ea870a19f1496eb148bf24d7894486

Source dataset

uspto-grants-2008_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07339057B2