Reaktion #792161

Reaktionsgleichung

hexachloroethane

N-dimethylsulfamoylpyrazole

n-butyllithium

→

title product

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

Lösungsmittel

tetrahydrofuran

hexane

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONUpon completion of the addition the reaction mixture
2. 2
   Temperaturwas maintained at ˜78° C. for an additional 45 minutes
3. 3
   TemperaturThe reaction mixture was maintained for an hour at ˜78° C.
4. 4
   Temperaturwarmed to ˜20° C.
5. 5
   Sonstigequenched with water (1 L)
6. 6
   ExtraktionThe reaction mixture was extracted with methylene chloride (4×500 mL)
7. 7
   Trocknenthe organic extracts were dried over magnesium sulfate
8. 8
   Einengenconcentrated
9. 9
   SonstigeThe crude product was further purified by chromatography on silica gel

Vorschrift

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).

Quelle