Réaction #792161

Équation de réaction

hexachloroethane

N-dimethylsulfamoylpyrazole

n-butyllithium

→

title product

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

Solvants

tetrahydrofuran

hexane

tetrahydrofuran

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONUpon completion of the addition the reaction mixture
2. 2
   Températurewas maintained at ˜78° C. for an additional 45 minutes
3. 3
   TempératureThe reaction mixture was maintained for an hour at ˜78° C.
4. 4
   Températurewarmed to ˜20° C.
5. 5
   Autrequenched with water (1 L)
6. 6
   ExtractionThe reaction mixture was extracted with methylene chloride (4×500 mL)
7. 7
   Séchagethe organic extracts were dried over magnesium sulfate
8. 8
   Concentrationconcentrated
9. 9
   AutreThe crude product was further purified by chromatography on silica gel

Mode opératoire

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).

Source