The first syntheses of antiviral, cytotoxic 6-cyano-5-methoxy- and-12-methyundolo[2,3-a]carbazoles, and related indolo[2,3-a]carbazoles from indigo

Article abstract of DOI:10.3987/com-97-7848

The first simple total syntheses of 6-cyano-5-methoxy- (1a) and -12-methylindolo[2,3-a]carbazolc (1b) are attained from indigo (2) in only five and six steps, respectively. Preparations of 5-hydroxy- (13), 5-bromoindolo[2,3-a]carbazole (14), and a novel spiro compound (7) are also included.