反应详情

To a solution of ethyl 5-aminopyrazole-3-carboxylate (5.00 g, 26.1 mmol) and ethyl hydrogen malonate (3.62 g, 27.4 mmol) in pyridine (130 mL) was added N,N′-diisopropylcarbodiimide (4.28 g, 33.9 mmol) at 0° C. After being stirred at same temperature, the reaction mixture was poured into water. The mixture was extracted with ethyl acetate and the organic layer was washed with saturated brine, dried over sodium sulfate, filtrated and concentrated in vacuo. The crude was purified by silica gel column chromatography (chloroform to chloroform:methanol=19:1) and triturated with diisopropyl ether to give ethyl 5-[(3-ethoxy-3-oxopropanoyl)amino]-1H-pyrazole-3-carboxylate. MS (APCI): m/z 270 (M+H).

1. extractionThe mixture was extracted with ethyl acetate
2. washthe organic layer was washed with saturated brine
3. dry with materialdried over sodium sulfate
4. filtrationfiltrated
5. concentrationconcentrated in vacuo
6. customThe crude was purified by silica gel column chromatography (chloroform to chloroform:methanol=19:1)
7. customtriturated with diisopropyl ether