| 摘要 |
PROBLEM TO BE SOLVED: To obtain a biphenyl derivative expressed by specific formula, having activity to give liquid crystal molecule stable orientation, thus useful as e.g. a surface modifier for the oriented films for liquid crystal display elements. SOLUTION: This biphenyl derivative is expressed by the formula [e.g. 4-(4'- cyanobiphenyl)butanal], and is obtained, pref. for example, by the following process: biphenyl as the starting material is reacted with a dicarboxylic acid anhydride to form a 4-substituted biphenyl compound, which is, in turn, subject twice to dehydration reaction under basic condition to substitute a hydrogen atom for the oxygen atom in the carbonyl group, followed by introducing a halogen atom into the 4'-site of the biphenyl along with protecting the terminal hydroxyl group under acidic condition, and then substituting a cyano group for the halogen atom on the 4'-site of the biphenyl using a metal cyanide and deprotecting the terminal hydroxyl group to effect oxidation into the aimed aldehyde. |
