反应详情

Sodium hydride (60% dispersion in mineral oil, 0.52 g, 13.0 mmol) was added, at 0° C., to a mixture of 3-amino-1H-pyrazole-4-carboxylic acid ethyl ester (0.9 g, 5.8 mmol) and 3-dimethylamino-2-formyl-acrylonitrile (0.72 g, 5.8 mmol) in anhydrous tetrahydrofuran (30 mL) and the reaction mixture was stirred overnight while warming up to room temperature. Ice-water was added and the resulting mixture was partitioned between water and ethyl acetate; the organic layer was separated and the aqueous layer was extracted 3 times with ethyl acetate. The combined organic extracts were washed with brine, dried over anhydrous sodium sulfate, filtered and evaporated. The yellow crude residue was purified twice on a silica gel plug (EtOAc/hexane) to afford 0.4 g (32% yield) of 6-cyano-pyrazolo[1,5-a]pyrimidine-3-carboxylic acid ethyl ester.

1. customthe resulting mixture was partitioned between water and ethyl acetate
2. customthe organic layer was separated
3. extractionthe aqueous layer was extracted 3 times with ethyl acetate
4. washThe combined organic extracts were washed with brine
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. customevaporated
8. customThe yellow crude residue was purified twice on a silica gel plug (EtOAc/hexane)