Ethyl 1-(2-hy-droxy-eth-yl)-2-(4-meth-oxy-phen-yl)-1H-benzimidazole-5-carboxyl-ate monohydrate.

In the title mol-ecule, C(19)H(20)N(2)O(4)·H(2)O, the benzimidazole ring system is essentially planar [maximum deviation = 0.013 (11) Å] and is inclined to the 4-meth-oxy-phenyl ring by 30.98 (5)°. In the crystal, O-H⋯O and O-H⋯N hydrogen bonds involving the water mol-ecule link neighbouring mol-ecules, forming a two-dimensional network lying parallel to the bc plane. There are also C-H⋯π and π-π inter-actions present. The latter involve inversion-related benzimidazole rings with centroid-centroid distances of 3.5552 (8) and 3.7466 (8) Å.