Studies with Alkylheterocycles: Novel Synthesis of Functionally Substituted Isoquinoline and Pyridopyridines Derivatives

Abstract
Several isoquinolines were prepared via reacting pyridine 4 with cinnamonitriles 5a‐c or 5d‐f. Treating 4 with elemental sulphur yielded thienopyridine 9. 9 reacts with acrylonitrile to give isoquinoline 12. 12 was also prepared from 4 and methylenemalononitrile. Condensation of 4 with aromatic aldehydes gave the arylidine 13. 13 afforded the pyridine 14 and 15 on treating it with NH4OH and AcOH/HCl, respectively.