Diphenyl Ether → 2,4-Diamino-5-methyl-6-(2,5-dimethoxybenzyl)-7-oxo-7,8-dihydropyrido[2,3-d]pyrimidine

Participants

Reaction Steps

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) were 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.

Provenance & Evidence