| Abstract: | When 7-aroylalkyl-8-bromo-3-methyl- and 1,3-dimethylxanthines are boiled with an excess of thioglycolic acid, a reductive dehalogenation takes place, while reaction with an equimolar amount of thioglycolic acid in DMFA leads to 7-aroylalkyl-3-methyl- and 1,3-dimethylxanthinyl-8-thioacetic acids. Cyclization of the latter with acetic anhydride in the presence of anhydrous sodium acetate results in the formation of 3-aryl-1,4-dihydro-9-methyl- and-7,9-dimethylthiazino[3,2-f]xanthine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 967–970, July, 1990. |
