A Convenient Synthesis of Novel Pyrido(1′,2′:1,2)imidazo[5,4‐d]‐1,2,3‐triazinones from Imidazo[1,2‐a]pyridines.

Abstract

A Convenient Synthesis of Novel Pyrido(1',2':1,2)imidazo[5,4-d]-1,2,3-triazinones from Imidazo[1,2-a]pyridines. -In view of compounds possessing potential affinity of binding to dopaminergic and adrenergic receptors, the imidazopyridine nucleus is a suitable synthon for the construction of a rigid geometry tri-heterocycle system containing a 1,2,3-triazine ring. Thus, nitro ester (I) is treated with ammonia or primary amines (II) to afford amides (III). The reaction time of this step can be essentially shortened by using IR radiation. Reduction of the nitro substituent in (III) followed by performing diazotation on (IV) furnish the pyridoimidazotriazinones (V). -(ZAMORA*, H. S.; RIZO, B.; CAMPOS, E.; JIMENEZ, R.; REYES, A.; J.