FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to the improved method for preparing p-hydroxymandelic compounds by condensation in an aqueous medium, in the presence of an alkaline agent, aromatic compound comprising at least one hydroxyl group and having free para-position with glyoxylic acid. Method involves condensation of hydroxyl-containing aromatic compound corresponding to the formula (I):
wherein: para-position is free; x means a whole number from 0 to 4; R means: hydrocarbon group with 1-20 carbon atoms taken among the following groups: alkyl, alkoxyl, hydroxyalkyl, cycloalkyl, aryl, phenoxy-group, alkoxyalkyl, fluoroalkyl, hydroxyalkoxyalkylene; hydroxyl group; group -CHO; acyl group having from 2 to 6 carbon atoms; halogen atom; two groups R bound with two adjacent carbon atoms can form benzene cycle in common with these carbon atoms; with glyoxylic acid in the presence of compound having at least two carboxyl groups and corresponding to the formula (II): HOOC-R1-COOH (II) wherein R1 means a valence bond or hydrocarbon radical comprising from 1 to 40 carbon atoms that can be saturated or unsaturated, linear or branched acyclic aliphatic radical; mono- or polycyclic, carbocyclic saturated, unsaturated or aromatic radical; mono- or polycyclic, heterocyclic, saturated, unsaturated or aromatic radical.
EFFECT: improved preparing method.
33 cl, 2 tbl, 11 ex
