反应详情

A mixture of (-)-1-[1-(2-bromophenyl)cyclobutyl]-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (1.85 g) [liberated from the dibenzoyl-(L)-tartrate salt (3.7 g)], acetonitrile (60 ml), 37-40% aqueous formaldehyde solution (1.8 ml) and sodium cyanoborohydride (0.46 g) was stirred for 15 minutes, then neutralised with glacial acetic acid and stirred for a further 45 minutes. The mixture was concentrated by evaporation and basified to pH 12 with dilute aqueous sodium hydroxide solution. The mixture was extracted with ethyl acetate, the extract yielding a gum which was purified via flash chromatography using a 1:2 mixture of ethyl acetate and petroleum ether as eluant to give (-)-1-[1-(2-bromophenyl)cyclobutyl]-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline, which had a specific optical rotation αD of -33.6°. Yield 1.6 g.

1. stirringstirred for a further 45 minutes
2. concentrationThe mixture was concentrated by evaporation
3. extractionThe mixture was extracted with ethyl acetate
4. customthe extract yielding a gum which
5. customwas purified via flash chromatography
6. additiona 1:2 mixture of ethyl acetate and petroleum ether as eluant