反应详情

The sodium salt of 3-(hydroxymethylene)-tetrahydropyran-2-one (25 g, 0.17 mol) and 2-methoxyaniline hydrochloride (32 g, 0.2 mol) in ethanol (750 ml) were warmed to 70° C. with stirring for 2 hours, then filtered hot. After evaporation of the ethanol, the crude product was taken up in dichloromethane, washed with dilute hydrochloric acid, dried and evaporated. Trituration with ether gave 3-(2-methoxyphenylaminomethylene)tetrahydropyran-2-one (21.5 g, 55%) as a mixture of E and Z isomers, m.p. 85°-100°.

1. filtrationfiltered hot
2. customAfter evaporation of the ethanol
3. washwashed with dilute hydrochloric acid
4. customdried
5. customevaporated