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

Participants

Reaction Steps

30.0 g of 1,2,3,4-tetrahydroisoquinoline and 15.0 g of sulphur powder in 200 ml of toluene are refluxed for 6 hours. After cooling the precipitating sulphur is filtered off, the filtrate is extracted with 200 ml of 5% hydrochloric acid. The aqueous solution is made alkaline with 40% sodium hydroxide to pH=10, then extracted with 250 ml of chloroform. The chloroform extract is dried with sodium sulfate and evaporated in vacuo. As residue 28.5 g of 3,4-dihydroisoquinoline are obtained.

Provenance & Evidence