Synthesis and properties of new 3-acyl- and 3-carbamoyl derivatives of esters of 3H-2-imino-7-methyl-4-oxopyrido[3,2-e]-1,3-thiazine-5- and -6-carboxylic acids.

It was stated that esters of 3H-2-imino-7-methyl-4-oxopyrido[3,2-e]-1,3-thiazine-5- and -6-carboxylic acids react with acyl anhydrides and chlorides giving 3-acyl derivatives. Reaction of the above mentioned esters with isocyanates affords the corresponding 3-carbamoyl derivatives.