Homolytic acylation of methyl 3-amino-2-pyrazinecarboxylates 1a-c under  standard Minisci conditions affords the corresponding 5- or 6-monoacylated  pyrazines 3a-d or 4a,b in reasonable yields. With 1a, complete  selectivity in favor of the 5-acyl products is observed.
                                    在标准Minisci条件下,对1a-c的甲基3-
氨基-2-
吡唑-
羧酸酯进行同裂解酰化反应,得到了相应的5-或6-单酰化
吡唑化合物3a-d或4a,b,并获得了合理的产率。对于1a,观察到对5-酰化产物的完全选择性。