Indole → 1-Octyl-1H-indole

Participants

Reaction Steps

A mixture of indole (1) (0.03 mole, 3.51 g), potassium hydroxide (0.03 mole, 1.97 g) powdered in a mortar, and 18-crown-6 ether (0.001 mole, 250 mg) in benzene (20 cm3) is heated under reflux with vigorous stirring for two hours. A solution of octylbromide (2a), (0.04 mole, 7.72 g) in benzene (10 cm3) is added and reflux is maintained for an additional four hours. The reaction is monitored by TLC and the reaction mixture is filtered on Celite. Evaporation of the solvent yields an orange liquid which is purified by distillation in vacuo. The colourless liquid distilled at 154-156° C. and 1.5 mmHg pressure is shown by 1H nmr to be pure 1-octylindole (3a) (4.98 g, 0.0217 mole, 72% yield).

Provenance & Evidence