1,2,3,4-Tetrahydroisoquinoline → 3,4-Dihydroisoquinoline

Participants

Reaction Steps

To a solution of 26.67 g (0.2 mol) of 1,2,3,4-tetrahydroisoquinoline in methylene chloride (300 ml) was added N-bromosuccinimide (39.2 g) under ice-cooling over 20 minutes. After stirring for 40 minutes, 30% sodium hydroxide aqueous solution (130 ml) was added to the reaction mixture. The organic layer was washed with water, extracted with 10% hydrochloric acid (200 ml), and the aqueous layer was washed with methylene chloride. The aqueous layer was basified with an aqueous ammonia, extracted with methylene chloride. The extract was dried over magnesium sulfate and then evaporated. The resulting residue was distilled (about 16 mm-Hg, 120 degrees), to give 21.5 g of the title compound as an oil.

Provenance & Evidence