Synthesis of novel bicycloalkane ring-fused pyridines via Michael addition reaction of a,ß-Unsaturated Nitriles

Camphorylidene(cyano)thioacetamide (3) and camphorylidenemalononitrile (9) were easily prepared by the reaction of (+)-camphor (1) with cyanothioacetamide (2) and malononitrile (8), respectively, under solid-liquid phase-transfer catalyzed conditions. The reaction of the arylidene derivatives of malononitrile, cyanothioacetamide and cyanoacetamide with 3 and 9 leads to condensed 2-thioxo- and 2-oxo-pyridine derivatives. Treatment of the latter compounds with P4S10 causes transformation into the corresponding pyridinethiones.