As the model substance of bis-benzyl-tetrahydroisoquinoline-type bases with biphenyl structure in the molecule, dl-2-methoxy-4′, 5-bis[2-methyl-6, 7-dimethoxy-1, 2, 3, 4-tetrahydro-1-isoquinolyl)-1-methyl]biphenyl (XVI) was synthesized from 3, 4-dimethoxyphenethylamine and 2-methoxy-4′, 5′-biphenyldiacetic acid (XII) through the diacetamide (XIII) and bis (3, 4-dihydroisoquinoline) compound (XIV), by the route shown in Charts 1 and 2.
