Synthesis and Antimicrobial Activity of Polyfunctionally Substituted Heterocyclic Compounds Derived from 5-Cinnamoylamino-2-Cyanomethyl-1,3,4-Thiadiazole

Cinnamoyl isothiocyanate 1 was reacted with 2-cyanoethanoic acid hydrazide 2 to afford 1-cyanoacetyl-4-substituted thiosemicarbazide 3, which on treatment with a mixture of glacial acetic acid and acetic anhydride gave the desired 5-cinnamoylamino-2-cyanomethyl-1,3,4-thiadiazole 4. Compound 4 was subjected to react with aromatic aldehydes, phenylisothiocyanate, carbon disulphide, and arylidene malononitrile to give coumarin 5, thiazolidines 8,9, and 1,3,4-thiadiazolo[3,2-a]pyridine 13 derivatives. The structures of all synthesized compounds were ascertained by spectral and analytical data. Antimicrobial activity of some of prepared compounds was investigated, and compounds 7, 8 were found to exhibit the highest strength.