THE SYNTHESIS OF QUINAZOLON-1,3,4-OXADIAZOLE ANALOGUES AND STUDIES OF THEIR ANTIMICROBIAL AND ANTIOXIDANT ACTIVITYAbstract
A series of conjugation of two heterocycles 1, 3, 4-oxadiazole and quinazolone were synthesized and screened for antimicrobial as well as antioxidant activity. Compound4-(4-oxo-2-phenyl-quinazoline-3(4H)-yl)-benzohydrazide 3 on cyclization with different aromatic acids in the presence of phosphoryl chloride (POCl3) give different 1, 3, 4-oxadiazole derivatives. Similarly, compound 3 on reaction with carbon disulphide (CS2) gives substituted oxadiazole thione which on reaction with different halides in the presence of dimethylformamide (DMF) give oxadiazole thiones analogs 6a-6c. Structural assignments of these compounds have been made by elemental analysis, UV, IR, 1H NMR, and mass spectral data. Synthesized analogs were screened for in-vitro growth inhibition activity against different strains of bacteria and fungi and compared with standard drugs ciprofloxacin and fluconazole. Compounds 4e and 4f have good activity against bacteria. All compounds have moderate activity against fungi. These compounds were screened for antioxidant activity by using radical scavenging DPPH assay by using ascorbic acid as a standard drug. Compounds 4e, 6a to 6c have good antioxidant activity.
V. S. Kulkarni *, D. S. Chavan and G. P. S. Kumar
Department of Pharmaceutical Chemistry, Indira Institute of Pharmacy, Sadavali (Devrukh), Ratnagiri, Maharashtra, India.
11 July 2018
18 February 2019
20 February 2019
01 March 2019