Diethyl (ethoxymethylene)malonate → HCID 178469683, compound

Participants

Reaction Steps

266 g. of 2-aminobenzimidazole (2 mol.) and 432 g. of ethoxymethylene malonic acid diethyl ester are heated with stirring in 3 liters of DMF at 80° for three hours. The solution is cooled to room temperature and then filtered off and the crystalline 4-hydroxypyrimido[1,2-a]-benzimidazole-3-carboxylic acid, ethyl ester is recrystallized from acetic acid, yield 490 g. (95%); m.p. 309°-310°.

Provenance & Evidence