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Eine neue Synthese von 8‐Hydroxy‐2‐methyl‐1,2,3,4‐tetrahydroisochinolin
Author(s) -
Gray Robert W.,
Dreiding Andréa S.
Publication year - 1980
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19800630131
Subject(s) - chemistry , formylation , tetrahydroisoquinoline , aldehyde , methylamine , methylation , ammonia , hydrolysis , methyl group , liquid ammonia , double bond , medicinal chemistry , stereochemistry , organic chemistry , group (periodic table) , catalysis , biochemistry , gene
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 .