... 3-dichloro- 5,6-dicyanopyrazine, various nucleophiles such as amines, enamines and thiocarbonyl compounds could be used to synthesize many types of pyrazine heterocycles [2]. Cyanoaromatics and ... 2] D. Hou, A. Oshida and M. Matsuoka, I. Heterocyclic Chem., 30 ... 4] J. B. Kim ...