2522 Vol, 32 (1984) [Chemi Pharmi Bull} 32( 7 )2522—2529(1984) Antivertigo Agents. ... Division, Nippon Kayaku Ca,“ Shimo, Kilo-kn, Tokyo 115, Japan and Pharmaceutical Institute, Tohoku ... 5,6,7,8-tetrahydro-1,6-naphthyridine (4c) were synthesized by chemical modification of ...