METHOD FOR SYNTHESIS OF p-TERPHENYL-2',5'-DICARBOXYLIC ACID Russian patent published in 2011 - IPC C07C63/331 C07C51/265 C07C51/43 C07C51/42 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for synthesis of p-terphenyl-2',5'-dicarboxylic acid through akylation of p-xylene with a cyclohexanol alkylation agent in the presence of a catalyst - sulphuric acid and then dehydrogenation of the obtained 2,5-dicyclohexyl-p-xylene in liquid phase at atmospheric pressure and temperature 260-290°C on aluminium-palladium catalysts, with extraction of 2',5'-dimethyl-p-terphenyl during cooling and then its oxidation with oxygen in a solution of glacial acetic acid at high temperature in the presence of a dissolved cobalt-manganese-bromine catalyst and extraction of p-terphenyl-2',5'-dicarboxylic acid crystals from the reaction mixture after cooling, where alkylation is carried out in molar ratio of p-xylene, cyclohexanol and sulphuric acid equal to 2-5:2-5:2-4 and temperature 0-5°C while adding the first half of cyclohexanol and raising temperature to 10-20°C until the end of the alkylation process, and oxidation of 2',5'-dimethyl-p-terphenyl is carried out at 105-110°C.

EFFECT: method enables to increase output of the said product by several times.

3 ex