Convenient Synthesis of Novel 2-Substituted Imidazopyrazinone Derivatives

Abstract Starting from commercially available piperazine-2-carboxylic acid, a series of novel 2-aryl and 2-benzyl substituted imidazopyrazinone were prepared. The intermediates 5a–g were obtained through facile Buchwald–Hartwig coupling reaction, and the effects of catalyst, base, and solvent on the coupling reaction were investigated. The optimal reaction conditions for the coupling reaction were PdCl2(dppf)/NaO-t-Bu/toluene.