2-(4'-Benzyl-piperazino)-5-oxo-6-carbethoxy-8-ethyl-5,8-dihydro-pyrido(2,3-d)pyrimidine → Ethyl 8-Ethyl-5-oxo-2-(piperazin-1-yl)-5,8-dihydropyrido[2,3-d]pyrimidine-6-carboxylate (Pipemidic Acid Ethyl Ester)

Participants

Reaction Steps

A solution of 3.0 g of ethyl 2-(4-benzyl-1-piperazinyl)-5,8-dihydro-8-ethyl-5-oxopyrido[2,3-d]-pyrimidine-6-carboxylate in 100 ml of ethanol was allowed to consume an equivalent amount of hydrogen over 1.5 g of 10% palladium-on-carbon under hydrogen atmosphere. The reaction mixture was filtered to remove the catalyst, and the filtrate was concentrated to give a solid which was collected and recrystallized from acetone. There is obtained 2.5 g of the product, m.p. 156° - 158°C.

Provenance & Evidence