Azabenzomorphane and Related Compounds. IX. A Synthesis of 3-Benzyl-3, 4, 5, 6-tetrahydro-2H-1, 5-methanobenzo[d][1, 3]diazocine. (Studies on the Synthesis of Heterocyclic Compounds. CXLI.)

Abstract

In order to test the analgesic action of azabenzomorphane derivatives, 3-benzyl-3, 4, 5, 6-tetrahydro-2H-1, 5-methanobenzo[d] [1, 3] diazocine (Ixa) and its 2-phenyl derivative (IXb) were synthesized by cyclization of 3-(N-benzylaminomethyl)-1, 2, 3, 4-tetrahydroquinoline (VI) with paraformaldehyde and benzaldehyde. Both compounds were found to be extremely labile against acid. Methods for synthesis of VI, which was used as a key intermediate, were also examined using 3-cyanoquinoline (II) as a starting material according to two procedures, that is, a) reduction of 3-benzylcarbamoylquinoline (IV) and b) reductive benzylation of 3-aminomethyl-1, 2, 3, 4-tetrahydroquinoline with benzaldehyde in the presence of hydrogen and platinum oxide.