2-[(5-Chloro-2-oxidobenzyl­idene)aza­nium­yl]-2-methyl­propane-1,3-diol

The title compound, C(11)H(14)ClNO(3), was prepared by the condensation of equimolar quanti­ties of 5-chloro­salicyl­aldehyde and 2-amino-2-methyl­propane-1,3-diol in methanol. In the crystal, it exists in the zwitterionic form, with nominal proton transfer from the phenol group to the imine N atom. This results in the formation of an intra­molecular N—H⋯O hydrogen bond, which generates an S(6) ring. Inter­molecular O—H⋯O hydrogen bonds arise from the hy­droxy groups, forming (001) sheets.