Synthetic utility of 4-acetyl-3-arylsydnones: Synthesis,spectral characterisation and antimicrobial activity of 3-aryl-4-[(2′,3′-dihydrospiro-1′,4′-benzodiazepine-5′,[3″-3″H]-2″-oxindol]-(1″H))-7′-yl] sydnones

3-Aryl-4-[3′-hydroxy-2'oxo)-3′-indol]acetylsydnones IIa–n have been synthesised from 4-acetyl-3-arylsdnones Ia–n and isatin. These β-hydroxy derivatives were readily converted into the corresponding α, β-unsaturated ketones IIIa–n which were further condensed with 1,2-phenylenediamine to give the 3-aryl-4-[2′,3′-dihydrospiro-1′,4′-benzodiazepine-5′,3″-[3″H]-2″-oxindol-)1″H))-7′-yl]sydnones IVa–n. All the compounds have been evaluated for their in vitro growth inhibitory activity against few microbes.