tert-Butyl methyl ether → Ethyl (3-benzyl-2,4-dioxo-2,3,4,5,7,8-hexahydro-1H-pyrido[4,3-d]pyrimidin-6-yl)(2-chlorophenyl)acetate hydrochloride

Participants

Reaction Steps

A mixture of 77.2 g of 3-benzyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione, 63 g of ethyldiisopropylamine and 126 g of ethyl chloro(2-chlorophenyl)-acetate (89% pure according to GC) in 1700 ml of dimethylformamide was stirred for 48 h at room temperature. It was concentrated under reduced pressure and the residue was worked up by extraction with dichloromethane and water. The dichloromethane phases were combined, dried and concentrated. The residue was diluted with 50 ml of dichloromethane, 1.3 equivalents of a solution of hydrochloric acid in ether were added dropwise at room temperature, with stirring, and 700 ml of tert-butyl methyl ether were added slowly. This initially gave an oil, which solidified gradually to a white mass. This ethyl (3-benzyl-2,4-dioxo-2,3,4,5,7,8-hexahydro-1H-pyrido[4,3-d]pyrimidin-6-yl)(2-chlorophenyl)acetate hydrochloride was purified by recrystallization from dichloromethane/diethyl ether.

Provenance & Evidence