Mannich reaction in the synthesis of n,s-containing heterocycles. 13. one-pot method for preparing pyrimido[4,3-b]-[1,3,5]thiadiazines by reaction of aldehydes, cyanothioacetamide, formaldehyde, and primary amines

摘要

Successive reaction of cyanothioacetamide with aliphatic or aromatic aldehydes, formaldehyde, and primary amines gives the corresponding 3,7-disubstituted 3,4,7,8-tetrahydro-2H,6H-pyrimido-[4,3-b][1,3,5]thiadiazine-9- carbonitriles.