(E)-4-Allyl-2-[(2-hydroxy­phen­yl)iminiometh­yl]-6-methoxy­phenolate

The title compound, C(17)H(17)NO(3), crystallizes in a zwitterionic form with cationic iminium and anionic enolate groups. The zwitterion exists in a trans configuration about the C=N bond. The dihedral angle between the two benzene rings is 13.42 (7)°. The meth­oxy group is almost coplanar [C—O—C—C = 2.1 (2)°] with the attached ring whereas the allyl unit is oriented at a dihedral angle of 67.9 (1)°. An intra­molecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, the mol­ecules are linked into zigzag chains along [010] by O—H⋯O hydrogen bonds. In addition, weak C—H⋯π inter­actions are observed.