PURPOSE: To obtain a new compound having an extremely large optical anisotropy value, a wide liquid crystal temperature range, a low viscosity, excellent compatibility with other liquid crystal materials sufficiently stable under ordinary working environmental conditions.
CONSTITUTION: This compound is shown by formula I (R1 and R2 are each 1-10C alkyl or alkyelne; rings A and B are each 1,4-cyclohexylene or 1,4 phenylene) such as 1,6-di(trans-4-propylcyclohexyl)-1,5-hexadien-3-yne. The compound, for example, is obtained by coupling an acetylene derivative of formula II with a halogenated vinyl derivative of formula III in the presence of a transition metal complex catalyst such as dichlorobistriphenylphosphinepalladium in a solvent. Diethylamine is preferable as the solvent and the reaction temperature is 120°C to the boiling point of the solvent. The compound of formula II, for example, is obtained from a halogenated vinyl derivative such as (trans-4- propylcyclohexyl)-2-bromoethylene.
MATSUI SHUICHI
MIYAZAWA KAZUTOSHI
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