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

Temperatur

-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 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 the title product 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 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-Eintrag

ord-8f699849a5c84fca8d42d8812131cebc

Quelldatensatz

uspto-grants-2016_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US09445593B1