Abstract: | The cyclocondensation of 4,6-dichloro-2-methylthiopyridine-5-carbaldehyde and heterocyclic thiones such as 1,2,4-triazole-5-thione, imidazolidine-2-thione, imidazole-2-thione, and 4,5-diphenylimidazole-2-thione in dimethylformamide gave tricyclic heterocycles containing a pyrimido[5,4-e][1,3]thiazine fragment. The reaction of 6-chloro-8-methylthio-5H-pyrimido[5,4-e][1,2,4]triazolo[5,1-b][1,3]thiazin-5-ol with diethylamine, pyrrolidine, and morpholine gave the corresponding 6-dialkylaminopyrimidotriazolothiazines.Vilnius University, 2006 Vilnius, Lithuania; e-mail: sigitas.tumkevicius@chf.vu.lt. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 854–856, June, 2000. |