Experimental

R factor = 0.049; wR factor = 0.148; data-to-parameter ratio = 19.1. In the title compound, C18H23N5, the imidazole ring makes a dihedral angles of 3.96 (8) and 19.02 (8), respectively, with the pyrazine and benzene rings while the dihedral angle between the pyrazine and benzene rings is 16.96 (7). In the crystal, molecules are linked via N—H N hydrogen bonds, forming chains along [010]. These chains are linked by C— H N hydrogen bonds, forming two-dimensional networks lying parallel to (001). Related literature For applications of the pyrazine ring system in drug devel-opment, see: Du et al. (2009); Dubinina et al. (2006); Ellsworth et al. (2007); Mukaiyama et al. (2007). For ongoing structural studies of heterocyclic N-containing derivatives, see: Nasir et al. (2010). For background to the fluorescence properties of compounds related to the title compound, see: Kawai et al. (2001); Abdullah (2005). For general background to the use of imidazole derivatives as drugs, see: Dooley et al. (1992); Jackson et al. (2000); Banfi et al. (2006). For a related structure, see: Ouzidan et al. (2011)