Abstract
4'-Carbamoyl-1, 4'-bipiperidine 1 was dehydrogenated on Pd-C to give 2-oxo-2, 3, 5, 6, 7, 8-hexahydroimidazo [1, 2-α] pyridine-3-spiro-4'-piperidine 2, which was reduced to 2-oxo-1, 2, 3, 5, 6, 7, 8, 8a-octahydroimidazo [1, 2-α] pyridine-3-spiro-4'-piperidine 3 with NaBH4. The iminodibenzyl and similar derivatives of 2 and 3 were synthesized and evaluated by using antiapomorphine test in mice. The derivatives of 3 had more potent antagonistic activity than those of 2 and the order of potency of 3 was : chloriminodibenzyl > chlordibenzocycloheptene > iminodibenzyl > iminostilbene > fluorene. Further chemical modification of the most active chloriminodibenzyl derivative 8, such as the substitution of Cl atom to Br atom, N-methylation on amine moiety, the replacement of imidazopyridine ring to imidazopyrrole ring, did not give any positive effect. Therefore, 8 may have potential usefulness as an antipsychotic drug.
