5,6,7-Trichloro-2-meth-oxy-8-hy-droxy-quinoline.

In the title compound, C(10)H(6)Cl(3)NO(2), a mean plane fitted through all non-H atoms has an r.m.s. deviation of 0.035 Å. In the crystal, adjacent mol-ecules are connected by O-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distance = 3.650 (1) Å], resulting in an infinite chain which propagates in the b-axis direction.