Synthesis of Benzylisoquinoline Derivatives

Department of Chemistry, Meerut College, Meerut-250 001

Manuscript received 12 July 1982, revised 30 April 1983, accepted 27 October 1983

4-Benzyloxy-3-methoxyphenethylamine (1) on formylation with ethyl formate gave N-formyI-7-benzyloxy-6-methoxyphenethylamine (2) which on Bischeler-Napieralski cyclizatlon with phosphorusoxychloride followed by methylation with methyl iodide furnished 7-benzyloxy-6-methoxy-3,4-dihydroisoquinoline methiodide (4). The base catalysed condensation of 4 with 2-methoxy-6-nitrotoluene (5) afforded 7-benzyloxy-6- metboxy-1-(2.nitro-6-methoxybenzyl)-1,2,3,4-tetrahydro-2-methylisoquinoline (6). On hydrogenation with zinc and sulphuric acid, 6 gave 7-benzyloxy-6-methoxy-1-(2-amino-6- methoxybenzyl)-1,2,3,4-tetrahydro-2-methylisoquinoline (7). Pschorr cyclization of 7 furnished three compounds, 1-benzyloxy-2,8-dimethoxyaporphine (8), 1-hydroxy-2,8- dimethoxyaporphine (9) and 7-benzyloxy-6-methoxy-1-(2-methoxybenzyl)-1,2,3,4-tetra­hydro-2-methylisoguinoline (l0).