The methylation of the 1-(4-benzyloxybenzyl)-6,7-dimethoxy-3,4-dihydroisoquinoline (I) with methyl iodide gives the isoquinolinium salt (II), which is reduced with potassium borohydride to afford 1-(4-benzyloxybenzyl)-6,7-dimethoxy-2-methyl-3,4-dihydroisoquinoline (III). The treatment of (III) with HCl yields the phenol (IV), which is finally alkylated with 2-(4-nitrophenoxy)ethanol.