Substituent-Directing Effects in the Homolytic Acylation of Pyrazine Derivatives

Article abstract of DOI:10.1021/jo00264a026

The homolytic acylation of various monosubstituted pyrazines was studied for a wide spectrum of substituents.Methoxy and chloro substituents were found to direct ortho substitution, thus giving the corresponding 2,3-disubstituted pyrazines.Acetyl, carbethoxy, and carboxamide groups were found to direct para substitution, thus leading to the corresponding 2,5-disubstituted pyrazines.These selectivities result from the combination of the inductive and resonance effects of the substituents.The synthetic potential of the acylation reaction is demonstrated in the preparation of some novel pyrazine flavorants.