反应详情

温度

0 °C

Sodium hydride (1.57 g, 41.03 mmol) was added to a solution of 1H-pyrazole-3-carboxylic acid methyl ester (3.45 g, 27.36 mmol) in THF (20 mL) at 0° C. The mixture was stirred at 0° C. for 30 minutes. Then dimethylsulfamoyl chloride (4.41 mL, 41.03 mmol) was added and the mixture was allowed to warm to room temperature and stirred for 18 hours. The mixture was diluted with water and the product extracted with AcOEt. The organic layer was separated, dried (MgSO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica gel; AcOEt in DCM 0/100 to 10/90). The desired fractions were collected and concentrated in vacuo to yield 1-dimethylsulfamoyl-1H-pyrazole-3-carboxylic acid methyl ester (4.8 g, 75% yield) as a colourless oil.

1. temperatureto warm to room temperature
2. stirringstirred for 18 hours
3. extractionthe product extracted with AcOEt
4. customThe organic layer was separated
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. customthe solvents evaporated in vacuo
8. customThe crude product was purified by flash column chromatography (silica gel; AcOEt in DCM 0/100 to 10/90)
9. customThe desired fractions were collected
10. concentrationconcentrated in vacuo