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-butyl-lithium (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 methylene chloride (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 methylene chloride as eluent to afford 160 g of the title product compound as a yellow oil.

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 methylene chloride (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-608618a1e2a1418e960fcf32652ae234

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07875634B2