Eine neue Synthese von 8-Hydroxy-2-methyl-1,2,3,4-tetrahydroisochinolin

A new Synthesis of 8-Hydroxy-2-methyl-1,2,3,4-tetrahydroisoquinoline Vilsmeier formylation of N-2-(3,5-dimethoxyphenyl)ethyl]-trifluoroacetamide ( 5 ) yielded the aldehyde 6 , which under mild basic conditions was hydrolyzed to 7 and cyclized to 6,8-dimethoxy-3,4-dihydroisoquinoline ( 3 ). Methylation of 3 and reduction of the double bond in 10 afforded 6,8-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline ( 11 ). The methoxyl group at C(6) was selectively demethylated and the free hydroxyl group in 12 was phosphorylated to give 13 . Reduction of the latter with potassium in liquid ammonia yielded 8-methoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline ( 2 ), which was demethylated to the title compound 1 .