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Updated: Jun 1, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
2-[(E)-(3-Carb-oxy-4-hy-droxy-phen-yl)iminiometh-yl]-4-chloro-phenolate
Abstract:
The title Schiff base compound, C(14)H(10)ClNO(4), has been synthesized by the reaction of 5-amino-2-hy-droxy-benzoic acid and 5-chloro-2-hy-droxy-benzaldehyde. The mol-ecule is a zwitterion in the crystal, with the phenolic hy-droxy group deprotonated and the imine N atom protonated. It adopts an E configuration about the central C=N double bond. The dihedral angle between the two benzene rings is 3.83 (7)°. Intra-molecular N-H⋯O and O-H⋯O hydrogen bonding generates S(6) ring motifs. In the crystal, mol-ecules are connected by inter-molecular O-H⋯O and C-H⋯Cl hydrogen bonds, forming a supra-molecular chain.
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