Synthesis and characterization of new compounds derived from 2-hydrazinobenzothiazole and evaluated their antibacterial activity

A series of new benzothiazole hydrazide derivatives starting from 2-mercaptobenzothiazole have been synthesized. 2-hydrazinobenzothiazole [M1] was prepared by refluxing of a mixture of hydrazine hydrate. H2O (80%) with 2-mercaptobenzothiazole. The reaction of the compound [M1] with the synthesized esters and amino esters [M2-M7 afforded benzothiazole hydrazide derivatives [M8-M13]. Compounds [M2-M7] were prepared from the reaction of different amino acids and carboxylic acids with absolute ethanol in presence of concentrated sulfuric acid. The structures of all synthesized compounds were established on the basis of FT-IR and some of them by 1H-NMR. The synthesized compounds have been evaluated for antimicrobial activity against Gram-positive and Gram-negative bacteria. Among thirteen synthesized compounds, in which four compounds (M8-M12) exhibited promising antibacterial activity. (paper)