Synthesis of 1-(Indol-2-yl)-phenoxazine hybrids from quinacetophenone precursors and their biological evaluation as DNA intercalating agents

An operationally simple reaction between quinacetophenone and aniline derivatives in the presence of triethylamine at room temperature afforded 1-(indol-2-yl)-phenoxazine hybrids in good yields. This unique transformation proceeds via sequential aza-Michael attack and imine formation to yield 1-(indol-2-yl)-phenoxazine hybrids. The most plausible reaction mechanism was established based on the mechanistic studies carried out with Mass spectrometry. The synthesized molecules were subjected to in-vitro anti-proliferative evaluation on various cancer cell lines by MTT assay where compound 8 was found to display signifiacnt IC50 value of 3.71 ± 0.57 μM on A-549 cell line. The ability of compound 8 to intercalate DNA was also confirmed by DNA Nanodrop method and viscosity experimental studies. [Display omitted] •An operationally simple reaction between quinacetophenone and aniline derivatives to afforded 1-(indol-2-yl)-phenoxazine hybrids in good yields is presented.•The most plausible reaction mechanism was established based on the mechanistic studies carried out with Mass spectrometry.•MTT assay reveals compound 8 to display significant IC50 value of 3.71 ± 0.57 μM on A-549 cell line.•The ability of 8 to intercalate DNA was also confirmed by DNA Nanodrop method and viscosity experiments.