Synthesis of novel 1,2,3,4‐tetrahydrobenzo[<i>c</i>]‐1,5‐naphthyridines from pyrrolo[1,2‐<i>b</i>]isoquinolines

Abstract

Abstract 1,2,3,4‐Tetrahydrobenzo[ c ]‐1,5‐naphthyridine ( 5a ) was prepared by a novel synthetic route involving the rearrangement of (±)‐( Z )‐1,10a‐dihydropyrrolo[1,2‐ b ]isoquinoline‐3,10(2 H ,5 H )‐dione oxime to afford 1,4‐dihydrobenzo[ c ]‐1,5‐naphthyridin‐2(3 H )‐one, which was reduced to 5a. The cholinomimetic activity observed with 5a prompted the synthesis and biological evaluation of additional analogues.