3,6-dibenzyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione → 3-benzyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione

Participants

Reaction Steps

A solution of 70 g of 3,6-dibenzyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione in 1.5 1 of glacial acetic acid was debenzylated in the 6-position by hydrogenolysis on 10 g of 10% palladium/activated charcoal at 70° C. and a hydrogen pressure of 3.5 bar. After the catalyst had been filtered off, the filtrate was concentrated under reduced pressure, the residual oil was taken up with 500 ml of water and the pH was adjusted to 8 with conc. sodium carbonate solution, with stirring, to give 46 g of a white precipitate of 3-benzyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione.

Provenance & Evidence