1 Key Laboratory of Radiopharmaceuticals, Ministry of Education, Department of Chemistry, Beijing Normal University, Xin Jie Kou Wai Street 19, 100875 Beijing, People's Republic of China.
All non-H atoms of the title compound, C(8)H(4)Cl(2)N(4), are essentially coplanar, with an r.m.s. deviation of 0.011 Å. In the crystal, weak C-H⋯N hydrogen bonds link the mol-ecules into infinite sheets parallel to the bc plane.