Synthese einiger 8‐substituierter 2‐Methyl‐1,2,3,4‐tetrahydroisochinoline

Synthesis of Some 8‐Substituted 2‐Methyl‐1,2,3,4‐tetrahydroisoquinolines A general route to 8‐substituted tetrahydroisoquinolines is exemplified by the preparation of the 2‐methyl‐1,2,3,4‐tetrahydroisoquinolin‐8‐ol (11), the ‐8‐carbaldehyde oxime (12) and the ‐8‐carbonitrile (13). It involves the conversion of isoquinoline (1) by partially modified Steps 1, 2, 3, and 5 (see the Scheme) into the 5‐bromo‐8‐nitro derivative 5, reduction of the latter to the 8‐amino derivative 8 and replacement of the NH2‐group with an appropriate substituent by a Sandmeyer‐like reaction. The selective reductions of the N‐containing ring in 6 (Steps 5, 6, and 8) and of the NO2‐group in 5 (Steps 4 and 7) were also studied.