A SEPARATION OF 2-HYDROXYMANDELIC AND 4-HYDROXYMANDELIC ACID

Citation
Aj. Hoefnagel et al., A SEPARATION OF 2-HYDROXYMANDELIC AND 4-HYDROXYMANDELIC ACID, Recueil des travaux chimiques des Pays-Bas, 115(7-8), 1996, pp. 353
Citations number
13
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry
ISSN journal
0165-0513
Volume
115
Issue
7-8
Year of publication
1996
Database
ISI
SICI code
0165-0513(1996)115:7-8<353:ASO2A4>2.0.ZU;2-7
Abstract
Hydroxyalkylation of phenol with glyoxylic acid, catalyzed by Al-III r esults, under neutral aqueous conditions, in ortho-rich mixtures of hy droxymandelic acids. Para-rich mixtures of hydroxymandelic acids are o btained by Zn-II catalysis under slightly alkaline conditions. A new s eparation method of these mixtures into the pure alkali salts of 2- an d 4-hydroxymandelic acid is presented. Formation of a complex between the alkali ion and three co-operating oxygen atoms of 2-hydroxymandela te explains the excellent solubility of the ortho isomer in acetone, e nabling extraction of this isomer selectively from mixtures of alkali salts of 2- and 4-hydroxymandelic acid.