3,3'-Diindolylmethane → Indolo(3,2-b)carbazole

Participants

Reaction Steps

In a 2000-ml three-necked flask that had been deaerated and filled with nitrogen were placed 50.69 g (0.2058 mole) of 3,3′-methylenediindole and 30.55 g (0.2061 mole) of triethyl orthoformate, then 640 g of methanol was added, and the mixture was stirred. To the mixture was added dropwise 5.0 g (0.0515 mole) of concentrated sulfuric over 3 minutes and the mixture was heated under reflux for 1 hour. The mixture was cooled to room temperature and the reddish brown crystals formed were collected by filtration and reslurried twice with 500 ml of methanol. The solvent was distilled off under reduced pressure and 36.81 g of solid C or indolo[3,2-b]carbazole (0.1438 mole, 69.9% yield) was obtained as a reddish brown powder.

Provenance & Evidence