Mesomorphic Properties of 4-Benzoylaminobenzonitrile Derivatives Having an Electron-withdrawing Group with Hydrogen Bonding Ability

4-Benzoylaminobenzonitrile derivatives having an electron-withdrawing group with hydrogen bonding ability such as a formyl or a nitro group at the C-3 position of the benzonitrile moiety were synthesized. They had the higher transition temperatures than the parent compound. It is explained by the intramolecular hydrogen bonding between the lateral group at C-3 and the amide proton to prohibit the free rotation around the N-benzonitrile bond, which made molecules flat to increase transition temperatures.