Simple and efficient heterocyclization method for synthesis of new 1,5-tetra alkyl-phenyl-1H-pyrimido[4,5-e][1,3,4]thiadiazine-3,7-diamine derivatives

New 1,5-tetra alkyl methyl- phenyl-1H-pyrimido[4,5-e][1,3,4]thiadiazine-3,7-diamine were synthesized via the cyclo condensation of 2-(5-bromo-2-chloro-6-methylpyrimidin-4-yl)-2-methylhydrazine with phenylthioisothiocyanate and further replacement of chlorine atom on the seven number position of pyrimido[4, 5- e][1, 3, 4]thiadiazin by appropriate secondary amines in simple and efficient methods.