| 摘要 |
NEW MATERIAL:3,4'-Dimethyl-biphenyl-4,3'-dicarboxylic acid dialkyl ester and 4,4'-dimethyl-biphenyl-3,3'-dicarboxylic acid dialkyl ester. USE:Production raw material for monomer component for the production of various monomers and 3,4,3',4'-substitution compound of corresponding dimethylbiphenyldicarboxylic acids or their acid halides. PREPARATION:The objective 3,4,3',4,-substitution compound of dimethyl- biphenyldicarboxylic acid dialkyl ester of formula [R1 and R4 are CH3 or COOR5 (R5 is alkyl); R1 and R2, and R3 and R4 are different substituents] can be selectively produced by the oxidative coupling of an o-toluic acid alkyl ester with O2 in the presence of a palladium salt and 1,10-phenanthroline and/or alpha,alpha'- bipyridine (0.9-4mol based on 1mol of the Pd salt) or in the presence of a Pd salt and a chelate compound of 1,10-phenanthroline and/or alpha,alpha'-bipyridine. |
