1964 年 84 巻 5 号 p. 412-415
Michael condensation of 1 mole of 6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinolineacetonitrile (III) and 2 moles of acrylonitrile by heating in a sealed tube at 110° for 6 hours afforded a small amount of condensate (VII) of nitrite (III) with 1 mole of acrylonitrile besides γ-cyano-γ-(2-cyanoethyl)-6, 7-dimethoxy-3, 4-dihydro-1-isoquinolinebutyronitrile (VI). Cyclization of this condensate (VII) by refluxing with sodium ethoxide for 30 minutes gave the amidine (VIII). Hydrolysis of this amidine to the lactam (IX), its derivation to thiolactam (X) by the usual method, and desulfurization reaction with Raney nickel afforded XI. Catalytic reduction of XI over platinum dioxide in the presence of hydrochloric acid unexpectedly caused the liberation of nitrile to form 9, 10-dimethoxy-1, 2, 3, 4, 6, 7-hexahydro-11bH-benzo[a]quinolizine (XII), whose infrared absorption spectrum agreed completely with that of the authentic specimen synthesized by another route.