Ortho­rhom­bic polymorph of 4-[(1H-benzimidazol-1-yl)meth­yl]benzoic acid

We reported recently the first polymorph of the title compound [Kuai & Cheng (2011a ▶). Acta Cryst., E67, o2787]. A second polymorph of the title compound, C(15)H(12)N(2)O(2), was unexpectedly obtained by the hydro­thermal reaction of the title compound with manganese chloride in the presence of potassium hydroxide at 413 K. The benzimidazole ring system is almost planar, with a maximum deviation from the mean plane of 0.015 (2) Å. The benzimidazole and benzene rings are inclined at a dihedral angle of 79.00 (1)°. In the crystal, adjacent mol­ecules are connected through O—H⋯N hydrogen bonds into a one-dimensional chain along the [001] direction.