Abstract Readily accessible 5-acetyl-4-hydroxy-3, 6-dihydro-2 H-1, 3-thiazine-2, 6-dione reacts with substituted hydrazines and carboxylic acid hydrazides under mild conditions to give the corresponding hydrazones. Under severe conditions (heating in boiling dimethylformamide) the reaction is accompanied by extrusion of COS with formation of substituted 1-amino-6-methyluracils. Reactions of 5-acetyl-4-hydroxy-3, 6-dihydro-2 H-1, 3 ...
