反应详情

A mixture of ethyl α-(2,5-dimethoxybenzyl)acetoacetate (21.2 g), 2,4,6-triaminopyrimidine (10 g) and diphenyl ether (100 ml) was heated at 190°-230° C. for 1.5 hours in an apparatus fitted with a Dean-Stark trap and water-ethanol (4 ml) was collected. Methanol (200 ml) and ethanol (50 ml) was added to the cooled reaction mixture. The resulting solid was collected by filtration and treated with boiling water (1 l) to give 2,4-diamino-5-methyl-6-(2,5-dimethoxybenzyl)-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidine (17 g), m.p. 325°-326° C.

1. temperaturewas heated at 190°-230° C. for 1.5 hours in an apparatus
2. customwas collected
3. additionMethanol (200 ml) and ethanol (50 ml) was added to the cooled reaction mixture
4. filtrationThe resulting solid was collected by filtration
5. additiontreated with boiling water (1 l)