Studies on the Syntheses of Analgesics. LV. Synthesis of 4a-(3-Substituted phenyl) 1, 2-disubstituted Decahydrocinnoline Derivatives (2) (Studies on the Syntheses of Heterocyclic Compounds. CMLV)

Abstract

With the expectation of the synthesis of the compounds having both agonist and antagonist properties, novel decahydrocinnoline derivatives (IIa-i), (IIIa-g) and (IVa-f) were synthesized as analgetics. In order to prepare N-2-propenyl derivatives, the reduction of N-acryloyl compounds (IIf) and (IIg) with various reducing agents (lithium aluminum hydride, sodium borohydride and sodium bis (2-methoxyethoxy) aluminum hydride was examined. In addition, it was found that N-acryloyl derivative (IIf) cyclized to give 2, 3, 4, 5, 6, 6a, 7, 8, 9, 10, 10a, 11-dodecahydro-1H-pyrazolo [1, 2-a] cinnoline derivative (VII) by heating with phosphorus pentasulfide and potassium sulfide in xylene. Among these decahydrocinnoline derivatives (IVa), (IVb) and (IVc) were found to have a potent analgesic effect with antagonistic effect for morphine analgesia.