| abstract |
The invention relates to a method of preparing 2- andn4-hydroxymandelic acid by condensing glyoxylic acid withnphenol. The glyoxylic acid is reacted with phenol, afternwhich the formed reaction mixture or the phenol, the 2- andn4-hydroxymandelic acid respectively are elution-separated inna column comprising an anion exchange resin, wherein firstnthe excess phenol is separated, followed by the separation ofnthe 4-hydroxymandelic acid and finally the 2-hydroxymandelicnacid, both in the form of acid and salt, depending on theneluent used. |