title: A new polymorph of 1-({[1,3-dihy-droxy-2-(hy-droxy-meth-yl)propan-2-yl]iminio}meth-yl)naphthalen-2-olate.
abstract: The title compound, C15H17NO4, containing two mol-ecules in the asymmetric unit is a polymorph of the crystal structure published by Martínez et al. [(2011). Eur. J. Org. Chem. pp. 3137-3145] which at 120 K is monoclinic with one mol-ecule in the asymmetric unit. Both mol-ecules in the title compound are in the trans form. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds connect mol-ecules, forming a two-dimensional network parallel to (001).
authors.affiliation: School of Chinese Materia Medica, Shanxi University of Traditional Chinese Medicine, Taiyuan 030024, People's Republic of China.
authors.forename: Ailing
authors.initials: A
authors.lastname: Guo
authors.affiliation: School of Chinese Materia Medica, Shanxi University of Traditional Chinese Medicine, Taiyuan 030024, People's Republic of China.
authors.forename: Shurong
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Chinese Materia Medica, Shanxi University of Traditional Chinese Medicine, Taiyuan 030024, People's Republic of China.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Taiyuan Normal University, Taiyuan 030031, People's Republic of China.
authors.forename: Ruitao
authors.initials: R
authors.lastname: Zhu
keywords: 2-hy­droxy-1-naphthaldehyde; N—H⋯O hydrogen bonding; O—H⋯O hydrogen bonding; Schiff base; crystal structure