Base‐ and acid‐catalyzed condensation reactions of reissert compounds with vinylpyridines

The hydrochloric acid‐catalyzed condensation of 2‐ p ‐anisoyl‐1,2‐dihydroisoquinaldonitrile ( 3 ) with 2‐vinylpyridine gave 2‐(1‐isoquinolyl)‐3‐(2‐pyridyl)‐5‐ p ‐anisylpyrrole ( 4 ), and the corresponding reaction of 3 with 4‐vinylpyridine afforded 2‐(1‐isoquinolyl)‐3‐(4‐pyridyl)‐5‐ p ‐anisylpyrrole (5). The condensation of the lithium salt of 3 with 4‐vinylpyridine gave α‐(4‐pyridyl)‐β‐(1‐iso‐quinolyl)‐ p ‐methoxypropiophenone ( 10 ), which was cyclized to 2‐(4‐pyridyl)‐3‐ p ‐anisylpyrrolo‐[2,1‐ a ]isoquinoline (7) by the action of concentrated hydrochloric acid. 2‐(4‐Pyridyl)‐3‐phenyl‐pyrrolo[2,1‐ a ]isoquinoline ( 6 ) and 2‐(2‐pyridyl)‐3‐ p ‐anisylpyrrolo[2,1‐ a ]isoquinoline ( 8 ) were prepared by analogous sequences of reactions.