反应详情

A mixture of ethyl 3-(6-methoxy-3-pyridyl)propionate (32.74 g) and ethyl formate (17.22 g) was added dropwise over 1.5 hours to a stirred suspension of sodium hydride in oil (50%. 9.38 g) in 1,2-dimethoxyethane (50 ml) cooled to -2°, allowed to stand overnight at room temperature and was poured on to ice. The mixture was extracted with ether (discarded), and the aqueous phase was adjusted to pH 5 with 2 N sulphuric acid. An oil was precipitated and crystallised on standing to give ethyl 2-formyl-3-(6-methoxy-3-pyridyl)propionate (25.9 g, 70%) m.p. 91.5°-94°. A sample recrystallised from aqueous ethanol had m.p. 93°-94°.

1. temperaturecooled to -2°
2. additionwas poured on to ice
3. extractionThe mixture was extracted with ether (discarded)
4. customAn oil was precipitated
5. customcrystallised