反应详情

温度

-78 °C

1-Dimethylsulfamoyl-1H-pyrazole-3-carboxylic acid methyl ester (4 g, 17.15 mmol) and N,O-dimethylhydroxylamine hydrochloride (2.18 g, 22.29 mmol) were slurried in DCM (20 mL). The mixture was flushed with nitrogen and cooled to −78° C. Then a solution of isopropylmagnesium chloride (2M in THF) (24.01 mL, 48.02 mmol) was added dropwise. When the addition was completed the mixture was allowed to warm to room temperature and stirred overnight. The mixture was quenched with NH4Cl (aq. sat. solution) and the product was 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 100/0). The desired fractions were collected and concentrated in vacuo to yield 1-dimethylsulfamoyl-1H-pyrazole-3-carboxylic acid methoxy-methyl-amide (3.2 g, 71% yield) as a pale yellow oil.

1. customThe mixture was flushed with nitrogen
2. additionWhen the addition
3. temperatureto warm to room temperature
4. customThe mixture was quenched with NH4Cl (aq. sat. solution)
5. extractionthe product was extracted with AcOEt
6. customThe organic layer was separated
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. customthe solvents evaporated in vacuo
10. customThe crude product was purified by flash column chromatography (silica gel; AcOEt in DCM 0/100 to 100/0)
11. customThe desired fractions were collected
12. concentrationconcentrated in vacuo