D. S. Kashdan, J. Schwartz, H. Rapoport
Jun 1, 1982
Citations
0
Influential Citations
32
Citations
Journal
Journal of Organic Chemistry
Abstract
Several aspects of 1,2,3,4-tetrahydroisoquinoline synthesis have been examined. An improved synthesis of 2-(m-methoxyphenyl)ethylamine (4) is reported. m-Anisaldehyde (5) was treated with potassium cyanide and ethyl chloroformate to yield O-(ethoxycarbonyl)-3-methoxymandelonitrile (7). Hydrogenation afforded 2-(mmethoxypheny1)ethyline (4) in 87 % yield overall. Some observations have been made regarding the reduction of 3,4-dihydroisoquinolines derived from the Bischler-Napieralski reaction. Amides 3a and 3c were cyclized with phosphorus oxychloride, followed by reduction to the corresponding tetrahydroisoquinolines la and IC. It was shown that la and IC were contaminated with 4% of 2a and 3% of 2c, respectively. Both 2a and 2c were independently synthesized by routes with general applicability to 8-alkoxy-1,2,3,4-tetrahydroisoquinolines.