Several 4-arylidene-2-phenyl-1-(2,4,5-trichlorophenyl)-1H-imidazol-5(4H)-ones (4a-q), N-(4-benzylidene-5-oxo-2-phenyl-4,5-dihydroimidazol-1-yl)-4-chlorobenzamides (5a-o) and N-(4-benzylidene-5-oxo-2-phenyl-4,5-dihydroimidazol-1-yl)-2,4-dichlorobenzamides (6a-m) were prepared. All newly synthesized compounds have been tested for their antibacterial activity against gram (+)ve and gram (−)ve bacteria and also on different strains of fungi. Introduction of OH, OCH3, NO2, Cl and Br groups to the heterocyclic frame work enhanced antibacterial and antifungal activities.

Ring closure reactions O 0130Synthesis and QSAR Studies of Thiosemicarbazides, 1,2,4-Triazoles, 1,3,4-Thiadiazoles and 1,3,4-Oxadiazoles Derivatives as Potential Antibacterial Agents. -A series of title compounds of type (I)-(V) is prepared and screened for antibacterial activities. The results are discussed on the basis of QSAR calculations. -(DESAI*, N. C.; BHAVSAR, A. M.; SHAH, M. D.; SAXENA, A. K.; Indian J. Chem., Sect. B: Org. Chem. Incl. Med. Chem. 47 (2008) 4, 579-585; Med. Chem. Div., Dep. Chem., Bhavnagar Univ., Bhavnagar 364 002, India; Eng.) -M. Bohle 33-036

Ring closure reactions O 0130Synthesis and QSAR Studies of 4-Oxo-thiazolidines and 2-Oxo-azetidines as Potential Antibacterial Agents. -Compared to the standard drug ciprofloxacin, products of type (III) and (V) exhibit moderate to good activity against Gram-positive and Gram-negative bacteria. -(DESAI*, N. C.; SHAH, M. D.; BHAVSAR, A. M.; SAXENA, A. K.; Indian J.