Investigations on the synthesis and properties of new derivatives of methyl 3H-2-imino-7-methyl-4-oxopyrido [3,2-e]-1,3-thiazine-5-carboxylate.

Condensation of dimethyl 2-chloro-6-methylpyridine-3,4-dicarboxylate with thiourea and its N-substituted derivatives is described. It has been found that depending on the kind of substituents in the starting thiourea derivatives, pyrido [3,2-e]-1,3-thiazine or pyrido [2,3-d] pyrimidine derivatives were formed.