Synthesis and evaluation of novel carbazole derivatives as free radical scavengers

A series of carbazole conjugated with different aminophenols and substituted aminophenols were synthesized by base catalyzed condensation reaction. The key intermediate 1-(9H-carbazol-9-yl)-2-chloroethanone, was obtained by Nacylation of carbazole with chloroacetyl chloride. The newly synthesized compounds were characterized by spectral and elemental analysis data and studied for their radical scavenging activity using 2, 2-diphenyl-1- picrylhydrazyl (DPPH) assay. Butylated hydroxy anisole (BHA) was used as a reference antioxidant compound and the comparative study with newly synthesized compounds was also done. Among the analogues, 1-(9H-carbazole-9-yl)-2-(4- hydroxy-3-rnethoxyphenylamino)ethanone, bearing electron donating methoxy substituent in the phenolic moiety, showed predominant activity.