Classical and microwave assisted synthesis of new 4-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-ylazo)-N-(2-substituted-4-oxo-4H-quinazolin-3-yl)benzenesulfonamide derivatives and their antimicrobial activities

A simple and efficient methodology was developed for the synthesis of new 4-(3,5-dimethyl-1-phenyl-1H-pyrazol-4-ylazo)-N-(2-substituted-4-oxo-4H-quinazolin-3-yl)benzenesulfonamide derivatives 10a-10j in good amount of yields. They have been prepared using 2-acetamidobenzoic acid derivatives 2a-2j via intermediates benzenesulfonamide substituted quinazolinone derivatives 8a-8j, and its corresponding hydrazono derivatives 9a-9j. Entitled compounds (10a-10j) were also obtained using microwave heating in good amount of yields. The structures of all the new compounds have been evaluated on the basis of elemental analysis, FT-IR, 1H and 13C NMR spectral studies. Entitle compounds have been screened for their in vitro antimicrobial activities and all these compounds displayed excellent to moderate activities, which were found to be significantly potent against bacteria compared to fungal.