Bromine → 8-Bromothiopyrano[3,2-b]indol-4(5H)-one

Participants

Reaction Steps

A solution of 8.04 g (0.04 mole) of thiopyrano[3,2-b]indol-4(5H)-one in 200 ml of acetic acid is treated dropwise with stirring at room temperature with 8.0 g (9.5 mole) of bromine. An immediate heavy precipitate formed. The mixture is concentrated to dryness and the solid residue suspended in 20 ml of pyridine and stirred for 10 minutes at 95°. The reaction mixture is poured onto ice, the solid is filtered and recrystallized from dimethylformamide, mp 334°-337°C.

Provenance & Evidence