反应详情

2-n-Propoxybenzamidine hydrochloride (12.0 g., 0.0558 mole) was added to a stirred, cooled (ice-water) solution of sodium (2.57 g., 0.112 g-atom) in ethanol (50 ml.). To this cooled, stirred solution was added a solution of diethyl ethoxymethylenemalonate (12.1 g., 0.0558 mole) in ethanol (50 ml.) during 10 minutes. The mixture was heated under reflux for 2.5 hours. The cooled solution was poured onto ice and acidified with 6N hydrochloric acid. The precipitated ethyl 1,6-dihydro-6-oxo-2-(2-n-propoxyphenyl)pyrimidine-5-carboxylate (16.2 g., 96% yield) had m.p. 111°-113°. Two recrystallizations from cyclohexane gave title product with m.p. 112°-113°.

1. temperatureThe mixture was heated
2. temperatureunder reflux for 2.5 hours
3. additionThe cooled solution was poured onto ice