The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 1995
Filed:
May. 19, 1994
Jean-Claude Vallejos, Paris, FR;
Yani Christidis, Paris, FR;
Societe Francaise Hoechst, Puteaux, FR;
Abstract
Preparation process for a hydroxyphenylacetic acid of formula (I): ##STR1## where R.dbd.H, alkyl or alkoxyl as well as its salts, in which the corresponding free or salified hydroxymandelic acid of formula (II): ##STR2## in which R has the meaning given previously and M.dbd.H, K or an ammonium group is reacted in an aqueous medium, at a temperature greater than or equal to 50.degree. C., with formic acid in the presence of catalytic quantities of an oxygenated derivative of sulphur having a degree of oxidation from 2 to 4, in order to obtain the hydroxyphenylacetic acid of formula (I) which is isolated or, if desired, is salified according to the usual methods and the hydroxyphenylacetic acid thus obtained.