Studies on pyrazine. 23 ^†. Homolytic acylation of 2-amino-3-cyanopyrazine and the related compounds with α-keto acids: A synthesis of 5-acyl-3-aminopyrazinecarboxylic acid derivatives

Homolytic acylation of 2-amino-3-cyanopyrazine (1) with α-keto acids led to the formation of 6-acylated compounds in 74-85% yields. Methyl 3-aminopyrazinecarboxylate (2) and 3-aminopyrazinecarboxamide (3) were also acylated under the same conditions although in lower yields. The observed reactivity of acylation is explained by comparison with the homolytic reactions of related pyrazines.