Procerss Study Of0-Hydrophenylacetic Acid

Hydroxyphenylglycine is an important pharmaceutical intermediate, which commonly used as side chain of β-lactam antibiotics and used as medicine intermediate of the production of semi-synthetic penicillins and cephalosporins. The preparation process of hydroxyphenylglycine hydroxyl Deng salt will produce a byproduct o-hydroxymandelic acid, which can be converted into another important intermediate o-hydroxyphenyl acetic acid. O-hydroxyphenyl acetic acid is an important intermediate synthesis of azoxystrobin. Thus, the research of synthesis of o-hydroxyphenyl acetic acid has a very important significance for cost savings and avoids resource waste, but also can produce another important drug intermediate o-hydroxyphenyl acetic acid.The paper will explore a synthetic method which is simple, low cost and easy to implement industrial production. The main research was that o-hydroxy mandelic acid or its sodium salt as raw materials was reduced to o-hydroxyphenyl acetic acid. Refer to the literatures for the reduction of hydroxy mandelic acid to obtain p-hydroxyphenylacetic acid, o-hydroxy mandelic acid can be reduced to o-hydroxyphenylacetic acid adopting the same method. The appropriate synthesis method was obtained by comparing the advantages or shortcomings of different reduction methods, which was catalytic hydrogenation at atmospheric or high pressure to synthesis o-hydroxyphenylacetic acid using Raney nickel as catalyst. The appropriate condition of atmospheric hydrogenation was that the reaction temperature is80℃,the mass ratio of catalyst to raw meterial is2to1, the ratio of the reaction solvent distilled water to raw meterial is10(V/W). And the yield can reach88%. High-pressure hydrogenation show that the reaction temperature, pressure, amount of catalyst has great impact on the reaction, and the suitable temperature is95℃, pressure is0.2-0.14MPa, the mass ratio of Raney Ni to the raw material is two times. Alcohol as the reaction solvent, the reaction can hardly be carried out. Concentration of the reaction solution has little effect on the reaction. In addition, the catalyst and the reaction mother liquor and can be recycled, which can get the cost savings and reduce the processing of catalyst and wastewater with environmentally benefits.