| 摘要 |
NEW MATERIAL:The pyrazine derivative of formula I (R<1> is 1-12C aliphatic alkyl; R<2> is 1-20C alphatic alkyl or alkoxy, or Br). EXAMPLE:2-(n-Pentyl)-5-(4-n-butoxyphenyl) pyrazine. USE:A liquid crystal compound having high physical, chemical and electrical stability, and excellent voltage-transmission characteristics. It has high compatibility with other liquid crystal compounds, and gives a liquid crystal mixture having steep voltage-transmission characteristics. Accordingly, the compound is useful as a component of a liquid crystal composition exhibiting various characteristics required in time-shared driving. PREPARATION:The compound of formula I can be prepared by reacting the compound of formula II (X is halogen or ArSO2O; Ar is aryl) with the Grignard reagent of formula R<1>MgY (Y is halogen) in the presence of a transition metal halide and/or a quaternary ammonium salt.
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