Ammonia → 7-(3,4-Dimethoxyphenyl)-9-methyl-pyrido[3',2':4,5]thieno[3,2-d]pyrimidine-2,4-dione

Participants

Reaction Steps

3.0 g (8.7 mmol) 3-amino-6-(3,4-dimethoxyphenyl)-4-methyl-thieno[2,3-b]pyridine-2-carboxamide is suspended in 100 ml absolute dioxane. Then, 1.1 ml (8.7 mmol) chloroformic acid trichloromethylester (diphosgene) is added and refluxed for 3 h. Following cooling, the precipitate is sucked off and then suspended in 50 ml water. The suspension is adjusted to pH 8 using concentrated ammonia solution and the precipitate is sucked off, washed with some water, suck dried and in vacuo at 50° C. 3.08 g (96%) 7-(3,4-dimethoxyphenyl)-9-methyl-pyrido[3′,2′:4,5]thieno[3,2-d]pyrimidine-2,4-dione is obtained.

Provenance & Evidence