Ring transformation of pyrimidines to pyridines. Synthesis of 4‐alkylaminopyridin‐2‐ones by alkaline hydrolysis of 6‐(2‐dimethylaminovinyl)uracils

Abstract Alkaline hydrolysis of 1,3‐disubstituted 6‐(2‐dimethylaminovinyl)uracils 2 induced a novel ring transformation giving 4‐alkylaminopyridin‐2‐ones 3 via ring‐opening and ring‐closure processes. The 4‐methylamino‐3‐nitropyridin‐2‐one (3a) thus obtained was employed for the synthesis of 3‐deazahypoxanthine derivative 8. 4‐Alkylamino‐3‐cyanopyridin‐2‐ones 11, ricinine analogs, were also prepared by the reaction of 4‐chloro‐3‐cyano‐1‐methylpyridin‐2‐one (10) with amines.