Synthesis of some new quinolone hybrid compounds and evaluation of the antimicrobial activities

In this study, the synthesis of a series of new antibacterial compounds containing quinolone and thiazolidinone units together has been planned. For this purpose, the basic skeleton of the quinolone has been synthesized from the cyclization reaction of m-bromoaniline with diethyl(ethoxymethylene)malonate and diphenylether, respectively. To combine the quinolone ring with the thiazolidinone ring, the obtained quinolone has been converted to the N-alkylated derivatives followed by the conversion to the corresponding hydrazides by the treatment with hydrazine hydrate. The treatment of the hydrazides with several isothiocyanates has afforded the corresponding carbothioamides, which has been converted to the corresponding quinolone-thiazolidinone hybrid compounds via the cyclization with ethyl bromoacetate. In the present study, besides conventional heating, microwave and ultrasonic irradiation methods have also been used as energy sources. The structures of all the new synthesized compounds have been illuminated utilizing FT-IR, NMR, and mass spectroscopic techniques. Their antibacterial properties have been evaluated in KTU Faculty of Medicine, Department of Microbiology, by Prof. Dr. Ali Osman Kılıç and his team. Keywords: Quinolone ring, thiazole ring, microwave, ultrasonic irradiation, antimicrobial activity.