Diazabenzo[a]phenoxazone sulphonamides: synthesis, in-silico and in-vitro antimicrobial studies

AbstractThe syntheses of new sulphonamide derivatives of 8,10-diazabenzo[a]phenoxazones are reported. The condensation of 4,5-diamino-6-hydroxy-2-mercaptopyrimidine and 2,3-dichloro-1,4-naphthoquinone in a basic medium gave the key functional intermediate, 11-amino-6-chloro-9-mercapto-8,10-diazabenzo[a]phenoxazin-5-one. The conversion of the later compound to its sulphonamide derivatives was achieved via nickel catalyzed cross-coupling Buchwald-Hartwig protocol. Reaction between 11-amino-6-chloro-9-mercapto-8,10-diazabenzo[a]phenoxazin-5-one and various aryl sulphonamides and sulphonyl chlorides furnished eight new mono sulphonamide substituted diazaphenoxazone compounds. Subsequent coupling of mono sulphonamide substituted diazaphenoxazone compounds5a-d with four different arylsulphonyl chlorides under similar reaction conditions gave the disubstituted derivatives8a-d. The products were isolated in 74 – 88% yields and characterized by means of Uv-visible, FT-IR,1H-NMR,13C-NMR, and Mass spectroscopy. The synthesized compounds were screened for antimicrobial activity against bacterial strains:Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhi andKlebsiella pneumonia, and fungal strains, Aspergillus niger, and Candida albican, using agar-well diffusion method. The activities of the compounds were compared with that of colymycin, which is a strong antibacterial, and antifungal drug, Most of the compounds showed appreciable antimicrobial activities com...

Source: Medicinal Chemistry Research - October 10, 2018 Category: Chemistry Source Type: research