反应详情

To a stirred, cooled suspension of 50% sodium hydride in oil (5.73 g) in dimethoxyethane (50 ml) was added dropwise over 50 minutes a mixture of ethyl β-[N-(2-dimethylaminoethyl)- 2-oxo-4-pyridyl]propionate (25.43 g) and ethyl formate (10.60 g). The reaction temperature was maintained below 3° C., and then was allowed to warm to room temperature overnight. The reaction mixture was poured on to ice and the resultant brown solution was extracted with petroleum ether (40°-60°) (80 ml) and diethyl ether (3×60 ml). The combined organic extracts were washed with water (20 ml). The combined aqueous solution and aqueous washings were taken to pH 5 with glacial acetic acid, the solvent volume was halved by evaporation under reduced pressure and taken to pH 8 with sodium bicarbonate solution. The solvents were removed by thorough evaporation under reduced pressure and the residue taken up in hot isopropanol-acetone, filtered over diatomaceous earth and evaporated under reduced pressure to yield an oil which was washed with petroleum ether (40°-60°) to afford as a brown oil, ethyl α-formyl-β-(N-(2-dimethylaminoethyl)-2-oxo-4-pyridyl]propionate (25.05 g).

1. temperatureTo a stirred, cooled
2. additionwas added dropwise over 50 minutes
3. temperatureThe reaction temperature was maintained below 3° C.
4. additionThe reaction mixture was poured on to ice
5. extractionthe resultant brown solution was extracted with petroleum ether (40°-60°) (80 ml) and diethyl ether (3×60 ml)
6. washThe combined organic extracts were washed with water (20 ml)
7. customthe solvent volume was halved by evaporation under reduced pressure
8. customThe solvents were removed by thorough evaporation under reduced pressure
9. filtrationfiltered over diatomaceous earth
10. customevaporated under reduced pressure
11. customto yield an oil which
12. washwas washed with petroleum ether (40°-60°)