Efficient Halogenation of 2-Aminopyrazine

Abstract

2-Aminopyrazine was halogenated with NIS, NCS, and NBS under different reaction conditions. Chlorination and bromination were achieved with good yields by using acetonitrile as the solvent. However, iodination was only obtained in poor yields. Undoubtedly, the best conditions for both mono-and dihalogenation were the use of NBS, acetonitrile, and microwave assistance for short periods. 3,5-Dibromo-2-Aminopyrazine is an excellent functionalized starting material for the synthesis of nitrogen heterocycles.