Study on the Synthesis and Antimicrobial Assay of Some Novel 4-Thiazolidinone Derivatives Possessing Benzofuran, Quinoline and Pyrazole Moieties

Simple, easy and convenient syntheses of six novel 4-thiazolidinone derivatives (3a-f) bearing
benzofuran, quinoline and pyrazole moieties have been described in this article. In the first step, six
different carbohydrazides (2a-f) were synthesized by reacting 5-(benzofuran-2-yl)-1-phenyl-1Hpyrazole-
3-carbohydrazide (2) with six different 2-(p-tolyloxy)quinoline-3-carbaldehyde (1a-f).
Similarly, in second step, 5-(benzofuran-2-yl)-N’-(2-(2- (p-tolyloxy) substituted quinolin-3-yl)-4-
oxothiazolidin-3-yl)-1-phenyl-1H-pyrazole-3-carboxamide (3a-f) was prepared in excellent yield
through the interaction of 2a-f with thioglycolic acid in presence of anhydrous zinc chloride. Structural
identifications of products 2a and 3a are reported on the basis of IR, 1H NMR, 13C NMR and Mass
spectra and the analytical data obtained confirms the structure of title compounds. Further, these new
products have been assayed for their antimicrobial screening against S. aureus and E. coli as the two
selected bacterial strains and two fungi such as C. albicans and A. niger using paper disc diffusion
method. Antimicrobial screening revealed that the compounds are good antibacterial agents but found
to be inactive against fungi. In conclusion we have reported the synthesis of some new 4-
thiazolidinone derivatives bearing benzofuran, quinoline and pyrazole moieties in good yield and
characterized by elemental and spectral studies such as IR, 1H NMR and mass spectra. Antimicrobial
assay of these synthesized compounds showed better activities for bacteria but were inactive against
selected fungi.