1,2,3,4-Tetrahydroisoquinoline → HCID 14405661, compound

Participants

Reaction Conditions

Reaction Steps

251 ml (594 mmol) of trimethylaluminium (at a concentration of 25% in hexane) are introduced under an argon atmosphere into 400 ml of toluene. The solution is cooled in an ice bath and 81.5 g (612 mmol) of 1,2,3,4-tetrahydroisoquinoline, dissolved in 200 ml of toluene, are added. The mixture is heated to approximately 50° C. and 95 g (384 mmol) of ethyl 1-phenylmethyl-4-piperidinecarboxylate, dissolved in 400 ml of toluene, are added. The mixture is heated under reflux for 2 h, approximately 250 ml of solvent being removed by means of a Dean and Stark apparatus. The mixture is cooled in an ice bath and hydrolysed by slowly adding 250 ml of water, and the insoluble material is filtered off, it being rinsed with ethyl acetate. The filtrate is washed three times with water, the organic phase dried over sodium sulphate, the solvent evaporated off and the residue recrystallized in cyclohexane. 116.6 g of product are obtained. Melting point: 98°-100° C.

Provenance & Evidence