An Efficient One Pot Synthesis and Biological Activities of 6H-Indolo[2,3-b]quinoxalines Promoted by Palladium Acetate as Catalyst

A multi-component one pot protocol for the synthesis of quinoxalines derivatives by condensation reaction of substituted isatin with substituted o-phenylene diamine in presence palladium acetate as catalyst in strong base such as triphenylphosphine under conventional method has been reported. The molecular structures of the newly synthesized compounds were characterized by elemental analyses, IR, 1H NMR, 13C NMR and LCMS spectral data. The presented method is mild, inexpensive, highly atom economy and easy work up to give the products in good to excellent yields. All the synthesized compounds were also evaluated for in vitro antibacterial assay against Gram-negative (Escherichia coli and Staphylococcus aureus), Gram-positive (Salmonella typhi and Bacillus subtilis) and fungi (Aspergillus niger and Candida albicans) pathogenic bacteria in comparison to the standards streptomycin and fluconazole.