A second monoclinic polymorph of 2-amino-4,6-dichloro-pyrimidine.

The title chloro-substituted 2-amino-pyrimidine, C(4)H(3)Cl(2)N(3), is a second monoclinic polymorph of this compound which crystallizes in the space group C2/c. The structure was previously reported [Clews & Cochran (1948 ▶). Acta Cryst. 1, 4-11] in the space group P21/a. There are two crystallographically independent mol-ecules in the asymmetric unit and each mol-ecule is planar. The dihedral angle between the two pyrimidine rings is 30.71 (12)°. In the crystal structure, mol-ecules are linked via N-H⋯N inter-molecular hydrogen bonds, forming infinite one-dimensional chains along the a axis. These hydrogen bonds generate R(2) (2)(8) ring motifs. The chains are stacked along the b axis.