NEW MATERIAL:A compound shown by formula I (R1 and R2 are 1-7C straight- chain alkyl; (n) is 2-7; group shown by formula IV is cyclohexane ring of trans- configuration). USE:An electro-optical display material. The liquid crystal compound having high nematic phase-isotropic liquid phase transition temperature, low anisotropy ( n) of refractive index of liquid crystal material to be packed into a cell, and excellent solubility in widely used nematic mixed liquid crystal, is useful for a material of liquid crystal display cell having excellent high-temperature driving characteristics and sight characteristics. PREPARATION:A compound shown by formula II is made to react with a compound shown by formula III in a toluene solvent in the presence of a base such as pyridine as a catalyst, the reaction mixture is mixed with 9% hydrochloric acid, extracted, washed with water, dried, then the solvent is distilled away under reduced pressure and the reaction product is recrystallized from an alcoholic solvent such as ethanol and purified to give a compound shown by formula I.
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