Benzaldehyde → 4-Methyl-1-phenyl-1,2,3,4-tetrahydroisoquinoline

Participants

Reaction Steps

4 Å molecular sieve (10 g) was added to a solution of 1.06 g (10.0 mmol) of benzaldehyde and 1.35 g (10.0 mmol) of 2-phenylpropylamine in toluene (45 ml) and the mixture was refluxed for 4 h. After cooling to RT the mixture was filtered through diatomaceous earth and the filtrate was concentrated to small volume under vacuum. The residue was dissolved in TFA (90 ml) and the solution was heated at 120° C. for 20 h. Then it was concentrated to small volume under vacuum and made alkaline with a 2N aqueous NaOH solution. It was then extracted with EE. The organic phase was dried over Na2SO4, filtered and concentrated to small volume under vacuum. Column chromatography (hexane/EE 7:3) of the residue produced 1.74 g (7.8 mmol, 78%) of 4-methyl-1-phenyl-1,2,3,4-tetrahydroisoquinoline.

Provenance & Evidence