ESTER OF 2-CYANO-4-HALOGENOPHENOL

摘要

NEW MATERIAL:The compound of formula I (R is 1-15C alkyl; the rings A and B are group of formula II or formula III; X is F or Cl. EXAMPLE:4-Pentylterphenyl-4''-carboxylic acid 2-cyano-4-fluorophenyl ester. USE:A liquid crystal substance having negative dielectric anisotropy and high clear point. It can be used as a guest-hose display element by mixing with other nematic liquid crystals. When combined with a liquid crystal having positive dielectric anisotropy, it can be used as a double-frequency display element. PREPARATION:The compound of formula I can be prepared by reacting 4-alkylterphenyl-4''-carboxylic acid of formula IV with thionyl chloride, and reacting the resultant acid chloride with 2-cyano-4-halogenophenol in the presence of pyridine.