| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compound capable of giving a liquid crystal composition which lowers threshold voltage by employing an ester compound of a substituted benzoic acid. SOLUTION: There is provided an ester compound of formula I. In formula I, R is an alkyl and A is phenyl or cyclohexyl. A liquid crystal composition can be obtained by incorporating at least one ester compound of formula I. The compounded amount of the ester compound of formula I in the liquid crystal composition is 1-50 wt.%, desirably 3-20 wt.%, through depending on the kinds of other liquid crystal compounds, their compounding ratios or the like. This liquid crystal composition has a high nematic isotropic phase transition temperature (N-1 point) and a large birefringence. A liquid crystal display device is obtained by loading this liquid crystal composition. The ester compound of formula I can be prepared, for example, by reacting a hydroxybenzoic acid with a compound of the formula: R-A-COCl obtained by the reaction of a halogenating agent with a compound of the formula: R-A-COOH and subsequently converting the resultant compound of formula II into an acid chloride of formula III followed by the reaction thereof with a compound of formula IV.
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