On Catalytic Reduction of 1, 2, 3, 4-Tetrahydroacridine

Abstract

Catalytic reduction of 1, 2, 3, 4-tetrahydroacridine (I) in methanol at ordinary temperature and pressure, with palladium-platinum-carbon as a catalyst, results in smooth progress of the reaction to form 1, 2, 3, 4, 4a, 9, 9a, 10-octahydroacridine (II). Similarly, 1, 2, 3, 4, 4a, 9, 9a, 10-octahydro-4-acridinol (IX) is formed from 1, 2, 3, 4-tetrahydro-4-acridinol (VIII) and methyl 1, 2, 3, 4, 4a, 9, 9a, 10-octahydro-9-acridinecarboxylate (XI) from methyl 1, 2, 3, 4-tetrahydro-9-acridinecarboxylate (X). Quinoline (IV), quinaldine (V), 2-ethyl-3-methylquinoline (VI), and 7, 8, 9, 10-tetrahydrophenanthridine (VII) are not reduced under these conditions. The reduction does not progress by the use of palladium-carbon or Raney nickel in place of palladium-platinum-carbon, and the reaction is markedly retarded by the use of platinum-carbon. There should be stereoisomers of II, IX, and XI, but no examinations were made on this point. The compound (II) obtained by this reaction melted at 70° and its N-acetylated compound showed m.p. 136°, which are assumed to correspond to one of the two stereoisomers separated from (II) synthesized by Perkin, et al. through a different route; the one of m.p. 82° and its N-acetylated compound of m.p. 86°, and the other of m.p. 72° and its N-acetylated compound of m.p. 136°.