THE SYNTHESIS OF 2-ARYLMETHYLTETRAHYDROISOQUINOLINES FROM BIS(AMINOL) ETHERS INVOLVING 2 IMINIUM SALT INTERMEDIATES

The bis(aminol) ether derived from 3,4-dimethoxy-b-phenylethylamine, methanol, and formaldehyde reacts with trichloromethylsilane to afford an equilibrium mixture of N-chloromethyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline and its related iminium chloride. Interaction with electron rich aromatic compounds afford good yields of N-arylmethyl derivatives, including sendaverine methyl ether. Reactions of the bis(aminol) ether in the presence of the aromatic substrate allows the formation of the N-arylmethyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline derivatives in a one pot reaction.