反应详情

A solution of 1-methyl-4-nitro-1H-pyrazole-3-carboxylic acid (500 mg, 2.92 mmol) in DMF (5 ml) under inert gas atmosphere was treated with TBTU (1030 mg, 3.2 mmol), dimethylamine hydrochloride (262 mg, 3.2 mmol) and N,N-diisopropylethylamine (2.0 ml, 11.7 mmol) and stirring was continued for 4 h. All volatiles were removed and the crude product was extracted with water and ethyl acetate. The organic phase was washed with sodium bicarbonate and the aqueous phases were back-extracted with ethyl acetate and dichloromethane. The combined organic phases were dried and the solvent was evaporated. The product was obtained after purification by silica gel chromatography using a dichloromethane/methanol gradient as white solid (230 mg, 40%).

1. customAll volatiles were removed
2. extractionthe crude product was extracted with water and ethyl acetate
3. washThe organic phase was washed with sodium bicarbonate
4. extractionthe aqueous phases were back-extracted with ethyl acetate and dichloromethane
5. customThe combined organic phases were dried
6. customthe solvent was evaporated
7. customThe product was obtained
8. customafter purification by silica gel chromatography