| 摘要 |
NEW MATERIAL:The compound of formula I or formula II (A is alkyl or acyl). EXAMPLE:2-(4-Alkoxyphenylazo)phenanthrene. USE:A liquid crystal display element. It has excellent liquid crystal properties. It exhibits a nematic liquid crystal phase at a relatively high temperature range, and is useful as a liquid crystal display element for high-temperature use. PREPARATION:The compound of formula I can be prepared by reacting 2-(4- hydroxyphenylazo)phenanthrene of formula III with an alkyl halide, acyl halide or acid anhydride, etc. As an alternative method, the compound of formula II is prepared by (1) reducing the compound of formula III with hydrated hydrazine and palladium carbon in ethanol, (2) subjecting to the diazo-coupling with phenol, and (3) reacting the product with an alkyl halide, acyl halide or acid anhydride, etc.
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