Hydrogen Bromide → HCID 22406909, compound

Participants

Reaction Steps

A mixture of 6,7-dimethoxy-1-[1-(2-naphthyl)cyclobutyl]-1,2,3,4-tetrahydroisoquinoline (4.74 g prepared as described in Example RB20), 37-40% aqueous formaldehyde solution (5.1 ml), acetonitrile (120 ml) and sodium cyanoborohydride (1.3 g) was stirred at ambient temperature for 15 minutes. The mixture was neutralised by addition of glacial acetic acid and stirred for 45 minutes. The mixture was concentrated by evaporation and basified with 2N aqueous potassium hydroxide solution. The resulting mixture was extracted with ether. The extracts were washed with aqueous potassium hydroxide solution and extracted with aqueous hydrochloric acid. The acid extract was basified and extracted with ether. The ether extract yielded a residue, a portion (3.86 g) of which was mixed with 48% aqueous hydrobromic acid (40 ml) and glacial acetic acid (40 ml) and heated at 100° C. for two days. The solvent was removed by evaporation and the residue dried by azeotropic distillation with propan-2-ol. The residue was washed with ether and decolourised with charcoal in propan-2-ol. The mixture was filtered and yielded 6,7-dihydroxy-2-methyl-1-[1-(2-naphthyl)cyclobutyl]-1,2,3,4-tetrahydroisoquinoline 1.1 hydrobromide (m.p. 150°-153° C.) which was dried in vacuo.

Provenance & Evidence