An expeditious synthesis and anticancer activity of novel 4-(3′-indolyl)oxazoles

A series of 4-(3′-indolyl)oxazole congeners have been synthesized and studied for their cytotoxicity against six cancer cell lines. Reaction of 3-acetyl-1′-benzenesulfonylindole with [hydroxy(tosyloxy)iodo]benzene afforded pure 3-tosyloxyacetyl-1′-benzenesulfonylindole. Microwave-accelerated neat reaction of 3-tosyloxyacetyl-1-benzenesulfonylindole with amides resulted in the exclusive formation of 4-(1′-benzenesulfonylindol-3′-yl)-2-substituted oxazoles (4) in very good yield. Treatment of 4 with aqueous sodium hydroxide under refluxing conditions afforded pure 4-(3′-indolyl)-2-substituted oxazoles (5) in excellent yield. The 4-(3′-indolyl)oxazoles 5d and 11 were found to be most cytotoxic and selective against various cancer cell lines. Compounds 5g, 5j and 5l showed moderate anticancer activity.

Graphical abstractA novel series of 4-(3′-indolyl)oxazoles have been synthesized and evaluated for their cytotoxicity.Figure optionsDownload full-size imageDownload as PowerPoint slide