Morpholine-4-nitro-phenol (1/2).

In the title adduct, 2C6H5NO3·C4H9NO, the morpholine ring adopts a chair conformation. The dihedral angle between the two nitro-phenol rings is 69.47 (9)°. The nitro groups attached to the benzene rings make dihedral angles of 3.37 (16) and 3.14 (13)° in the two mol-ecules of nitro-phenol. The crystal structure is stabilized by N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds and further consolidated by C-H⋯O inter-actions, resulting in a three-dimensional network.