Synthesis and antimicrobial activity of new 4-thiazolidinone derivatives containing 2-amino-6-ethoxybenzothiazole

A novel series of Schiff bases 5a–j and 4-thiazolidinones 6a–j have been prepared from the building blocks 2-chloro pyridine-3-carboxylic acid [1] and 2-amino-6-ethoxy-benzothiazole [2]. All of the synthesized compounds have been confirmed by elemental analyses, IR, ¹H NMR and ¹³C NMR spectral data. These newly synthesized compounds were screened for their antimicrobial activity. Variable and modest activity was observed against the investigated strains of bacteria and fungi, however, compound 6h revealed significant antibacterial activity against Escherichia coli. Compounds 1, 2, 3, 5c, 5g and 5h, on the other hand, revealed potent antifungal activity against Candida albicans compared to the reference drug greseofulvin