| 摘要 |
NEW MATERIAL:The compound of formula I (R1 is 1-10C alkyl; R2 is 1-10C alkyl or alkoxy). EXAMPLE:2-Propoxy-6-(trans-5-butyl-1,3-dioxan-2-yl)naphthalene. USE:A liquid crystal composition. When a small amount of the compound is added to a conventional liquid crystal composition, the upper limit of the working temperature range of the liquid crystal display element containing said liquid crystal composition can be raised, and the driving voltage of the element can be lowered. PREPARATION:The compound of formula I can be produced by reacting the 2- alkyl-1,3-propanediol of formula II with the 6-substituted-2-naphthaldehyde of formula III in toluene in the presence of p-toluenesulfonic acid as the catalyst, and separating and purifying the resultant 5-alkyl-2-(6-substituted-2-naphthyl)-1,3- dioxane of formula IV by recrystallization.
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