| abstract |
PURPOSE: The dehalogenation of a halogenated substituted phenylacetic acid gives a phenylacetic acid used as a modifier for antibiotics or synthetic intermediate for anti-inflammatory analgesic in high yield with industrial advantage from the view point of the price of the starting materials as well. n CONSTITUTION: The catalytic hydrogenolysis of halogenated substituted phenylacetic acid of formula I (X is halogen; R 1 , R 2 are H, lower alkyl; R 3 is H, lower alkyl, hydroxyl), preferable 3-chloro-4-hydroxy-phenylacetic acid, is conducted in a solvent mainly consisting of water, lower alcohol or their mixture in the presence of a strong acid such as sulfuric acid to cause the dehalogenation and form a phenylacetic acid of formula II, preferably 4-hydroxyphenylacetic acid. Since the compound of formula I is readily derived through mandelic acid derivative from glyoxylic acid and o-chlorophenol, the present process is superior to existing processes from view point of the costs of the starting material as well. n COPYRIGHT: (C)1981,JPO&Japio |