Synthesis and antimicrobial studies of some new Substituted 3-arylidene-2-methylpyrazolo[5,1-b]quinazolin-9(3H)-ones

Ravi R Vidule and S G Shirodka

Abstract

Synthesis of substituted 3-arylidene-2-methylpyrazolo[5,1-b]quinazolin-9(3H)-ones [4a-t] is attempted by the condensation of aromatic aldehydes [3a-d] with 2-methylpyrazolo[5,1-b]quinazolin-9(4H)-ones [2a-e] in the presence of piperdine. 2a-e were obtained by azeotropic distillation of 3-methyl-1H-pyrazol-5(4H)-one and 1Hbenzo[ d][1,3]oxazine-2,4-diones [1a-e]. The structures of synthesized compounds are confirmed by IR and 1HNMR, 13CNMR and mass spectral studies. Further, they were screened in vitro for antibacterial activity against Escherichia coli and Salmonella typhi. Antifungal activity is evaluated against Aspergillus niger and Penicillium chrysogenum using Paper disc diffusion method. Some of the compounds were found to exhibit promising antibacterial and antifungal activities.