Studies on cerebral protective agents. X. Synthesis and evaluation of anticonvulsant activities for novel 4,5,6,7-tetrahydrothieno[3,3-c]pyridines and related compounds.

Novel 4,5,6,7-tetrahydrothieno[3,2-c]pyridines, 1-thienyl-1,2,3,4-tetrahydroisoquinolines and related compounds, in which the benzene rings of (+)-1 (FR115427) were replaced with heteroaromatic rings such as thiophene, furan, benzothiophene and indole, were synthesized and evaluated for anticonvulsant activity against i.c.v. N-methyl-D-aspartate (NMDA)-induced seizures in mice. Among these compounds, (+)-4-methyl-4-phenyl-4,5,6,7-tetrahydrothieno[3,2-c]pyridine hydrochloride ((+)-2a), (+)-4-methyl-4-(2-thienyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridine hydrochloride ((+)-2g), and (-)1-methyl-2-(2-thienyl)-1,2,3,4-tetrahydroisoquinoline hydrochloride ((-)-3a) showed significant anticonvulsant activity. The structure-activity relationships with regard to the anticonvulsant activity of this series of compounds are discussed.