3,3′-(Ethane-1,2-diyl)bis(6-meth­oxy-3,4-dihydro-2H-1,3-benzoxazine) mono­hydrate

The asymmetric unit of the title compound, C₂₀H₂₄N₂O₄·H₂O, contains one half-organic mol­ecule (an inversion centre generates the other half of the mol­ecule) and a half-mol­ecule of water (the O atom has site symmetry 2). The near planarity of the fused-benzene ring is illustrated by the very small deviations of all the atoms from the plane [largest deviation = 0.0092 (11) Å. The six-membered N,O-containing ring adopts a half-chair conformation. The observed N—CH₂ and CH₂—O bond lengths can be correlated to the manifestation of an anomeric effect in the N—CH₂—O unit. In the crystal, the mol­ecules are connected into zigzag chains parallel to [001] through O—H...N hydrogen bonds formed between the oxazinic N atom and the solvent water mol­ecule. The chains are consolidated by C—H...O inter­actions.

4,4′-Dimethyl-2,2′-[imidazolidine-1,3-diylbis(methyl­ene)]diphenol

The imidazolidine ring in the title compound, C₁₉H₂₄N₂O₂, adopts a twist conformation and its mean plane (r.m.s. deviation = 0.19 Å) makes dihedral angles of 72.38 (9) and 71.64 (9)° with the two pendant aromatic rings. The dihedral angle between the phenyl rings is 55.94 (8)°. The mol­ecular structure shows the presence of two intra­molecular O—H...N hydrogen bonds between the phenolic hydroxyl groups and N atoms with graph-set motif S(6). In the crystal, C—H...O hydrogen bonds lead to the formation of chains along the b-axis direction.