| 摘要 |
PURPOSE:To provide a novel compound which is useful as a polymer modifier by oxidative coupling reaction of an alkyl toluate in the presence of palladium salt, copper salt and beta-diketone in the reaction mixture. CONSTITUTION:4,5'-Dimethylbiphenyl-2,3'-dicarboxylic dialkyl ester of formula I (R is alkyl), for example, dimethyl 4,5-dimethylbiphenyl-2,3'-dicarboxylate. The compound of formula I is obtained in high yield by effecting oxidative coupling reaction of alkyl toluate of formula II (methyl is substituted in the meta or ortho position to -COOR group) in an oxygen atmosphere at 50 to 300 deg.C in the presence of a palladium salt, 0.5 to 10-time molar amount of a copper salt based on the palladium salt and 0.5 to 5-time molar amount of beta-diketone based on the total amount of the salts. |
