A series of newly disubstituted (compounds 4a,b) and trisubstituted 1,3,4-thiadiazines 5a-l with various substituents was prepared utilizing different thiosemicarbazides and 3-α-bromoacetylcoumarins as starting compounds. The structures of the synthesized 1,3,4-thiadiazines are elucidated and confirmed utilizing the corresponding analytical and spectroscopic data. All of the new thiadiazine der...