Reactions of 2‐Methylchromones with Cyanoacetamides and Ethyl Cyanoacetate. Synthesis of 6‐(2‐Hydroxyaryl)‐4‐methyl‐2‐oxo‐1,2‐dihydropyridine‐3‐carbonitriles and 7‐Hydroxy‐6‐imino‐9‐methyl‐6H‐benzo[c]chromene‐8‐carbonitriles

Abstract

Although 2‐methylchromones react with cyanoacetamide and N‐methyl cyanoacetamide in the presence of sodium ethoxide in refluxing ethanol to produce 6‐(2‐hydroxyaryl)‐4‐methyl‐2‐oxo‐1,2‐dihydropyridine‐3‐carbonitriles, their reactions with ethyl cyanoacetate under the same conditions took an entirely different course and gave 7‐hydroxy‐6‐imino‐9‐methyl‐6H‐benzo[c]chromene‐8‐carbonitriles.