An Expedient One-Pot Synthetic Protocol to the Preparation Of Isoxazolo and Pyrazolo Annulated Analogues of Benzoxazepino Condensed Carbazoles and Azacarbazoles of Medicinal Interest

A facile one-pot synthetic protocol for the preparation of isoxazolo and pyrazolo annulated analogues of the benzoxazepine condensed carbazoles and azacarbazoles from the corresponding enolic ethers, α, β-unsaturated ketones, oxoketene dithioacetals and dimethylaminomethylene ketones derived from benzoxazepino condensed oxocarbazoles and oxoazacarbazoles has been described. Compounds were realized from the Japp-Klingemann reaction of the diazonium salt of 2-aminodibenzo [b,f] [1,4]oxazepine with 2-hydroxymethylideno cyclohexanone and N-benzyl-3-hydroxymethylidenopiperidin-4-one followed by Fischer indolization of the obtained hydrazone with kent’s acid. The synthesized heterocyclic compounds were characterized by IR, NMR and MS spectral data and in vitro antimicrobial activity of the synthesized compounds was screened against the standard bacterial and fungal strains. Some of these benzoxazepine derivatives have been found to display excellent antimicrobial activity against bacteria and fungi