Nitrogen → 1-Methyl-1H-pyrazole-3-sulfonyl chloride

The N-methylpyrazole sulfonyl chloride was prepared by adding N-methylpyrazole to chilled (0° C.) chlorosulfonic acid. The reaction mixture was allowed to warm to room temperature and then heated to 100° C. overnight under a stream of N2. The reaction mixture was then cooled to room temperature and chilled to 0° C. To this solution was added thionyl chloride (2.5 eq.) and the reaction was stirred at room temperature for 30 min., then warmed to 70° C. for two hours. The reaction was cooled to room temperature and then chilled in an ice bath. Water and ice were slowly added to the reaction mixture to precipitate a white solid which was collected by filtration. The desired sulfonyl chloride was washed with cold water and hexane.

1. temperatureThe reaction mixture was then cooled to room temperature
2. temperaturechilled to 0° C
3. temperaturewarmed to 70° C. for two hours
4. temperatureThe reaction was cooled to room temperature
5. temperaturechilled in an ice bath
6. customto precipitate a white solid which
7. filtrationwas collected by filtration
8. washThe desired sulfonyl chloride was washed with cold water and hexane

ORD record

ord-d2d036e95cfa4b08a790535de7ba9f10

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06525026B2