SYNTHESIS AND APPLICATION OF SOME NEW S-(SUBSTITUTED)-THIOQUINOLINE AND THIENOQUINOLINE DERIVATIVES AS ANTIMICROBIAL AGENTS

Ethyl (4-aryl-3-cyano-5,6,7,8-tetrahydro-2-quinolinylthio) acetate (IIa, IIb) were prepared and reacted with hydrazine hydrate to give hydrazides IIIa, IIIb which underwent cyclization into thienoquinoline derivatives IVa, IVb. Reaction of IIIa, IIIb with phenyl isocyanate yielded semicarbazides Va, Vb. Similarly, IIIa, IIIb and IVb were interacted with methyl/phenyl isothiocyanates affording the corresponding thiosemicarbazide derivatives VIa-VId and XIVa, XIVb respectively. On the other hand, condensation of IIIb with acetylacetone gave the pyrazole VII which upon treatment with ethoxide furnished VIII. Also, IIIa, IIIb and IVa, IVb reacted with aromatic aldehydes to afford hydrazones IXa-IXf and XIa-XIf respectively. Cyclodehydration of IXd-IXf with thioglycolic acid furnished 4-thiazolidinone derivatives Xa-Xc. Moreover, IVb was reacted with formic acid/acetic anhydride to give XII and XIII. Diazotization of IVb gave azide XV which underwent Curtius rearrangement into XVI. The structures of all newly synthesized compounds were confirmed by elemental analyses and spectral data. Also, the most of these compounds were tested in vitro for their antimicrobial activities against some Gram-positive and Gram-negative bacteria.