2-(3-Chloro-1,2-dihydro-pyrazin-2-yl-idene)malononitrile.

In the crystal structure of the title compound, C(7)H(3)ClN(4), neighbouring mol-ecules are linked via pairs of N-H⋯N hydrogen bonds into inversion dimers, thereby forming an R(2) (2)(12) ring motif. With respective average deviations from planarity of 0.009 (1) and 0.006 (1) Å, the pyrazine skeleton and the malononitrile fragment are oriented at an angle of 6.0 (1)° with respect to each other. The mean planes of the pyrazine ring lie either parallel or are inclined at an angle of 68.5 (1)° in the crystal structure.