title: 4-[(4-Diethyl-amino-2-hydroxy-benzyl-idene)ammonio]-3-methyl-benzene-sulfonate.
abstract: In the zwitterionic title compound, C(18)H(22)N(2)O(4)S, the dihedral angle between the aromatic rings is 16.39 (11)° and an intra-molecular N-H⋯O hydrogen bond occurs. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming chains propagating in [01].
authors.forename: Xi-Shi
authors.initials: XS
authors.lastname: Tai
authors.forename: Zeng-Bing
authors.initials: ZB
authors.lastname: Zhao