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

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.

1. temperaturethe mixture was refluxed for 4 h
2. filtrationwas filtered through diatomaceous earth
3. concentrationthe filtrate was concentrated to small volume under vacuum
4. dissolutionThe residue was dissolved in TFA (90 ml)
5. temperaturethe solution was heated at 120° C. for 20 h
6. concentrationThen it was concentrated to small volume under vacuum
7. extractionIt was then extracted with EE
8. dry with materialThe organic phase was dried over Na2SO4
9. filtrationfiltered
10. concentrationconcentrated to small volume under vacuum

ORD record

ord-055e0f0688014304a95189636568386f

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08367700B2