ANTIFERROELECTRIC LIQUID CRYSTAL COMPOUND EXCELLENT IN DEPENDENCE OF RESPONSE SPEED ON TEMPERATURE

摘要

PROBLEM TO BE SOLVED: To obtain a new antiferroelectric liquid crystal compound free of possibility of showing defects, such as uneven display or the like, when working as a display and excellent in dependence of response speed on temperature by adequately positioning the fluorine-modified site in the main skeleton in the antiferroelectric liquid crystal compound. SOLUTION: This antiferroelectric liquid crystal compound is shown by formula I (R<1> is a 6-16C alkyl; R<2> is a 2-10C alkyl; Cf is CH3 or CF3 ; and *is optically active carbon), e.g. 4- 1-(trifluoromethyl) pentyloxycarbonyl} phenyl-4'-decyl-3'-fluorobiphenyl-4-carboxylate. It has an index of temperature dependence of response timeτ<=1.7. 1-Bromo-3-fluoro-4-iodobenzene as the starting compound is treated in two or more stages of reaction to produce a compound shown by formula II, which is chlorinated and then reacted with 1-(trifluoromethyl) pentyl-4-hydroxybenzoate in a nitrogen atmosphere, to produce the objective compound after it is separated and purified.