| 摘要 |
NEW MATERIAL:A compound shown by formula I (one of R<1> and R<2> is 4-18C alkyl containing methyl branch and the other is 2-18C alkyl; X is F, C1 or CN). EXAMPLE:Optically active (S)-3-fluoro-4-(7''-methylnonyloxy)-4'-decylbiphenyl. USE:A low-viscosity component for covering a low-temperature range of chiral smectic liquid crystal composition useful as an optical switch element taking advantage of ferroelectric liquid crystal. PREPARATION:A compound shown by formula 1 is methyletherified and treated with Mg to give a compound shown by formula 3, which is reacted with Mg to give a compound shown by formula 3, which is reacted with cyclohexanone to give a compound shown by formula 4. Then this compound shown by formula 4 is dehydrogenated to give a compound shown by formula 5 and subjected to Friedel-Crafts reaction in the presence of AlCl3 catalyst to give a compound shown by formula 6. Further this compound reduced, an alkyl group is introduced to the resulting compound and the compound is treated with HBr to give a compound shown by formula 8, which is etherified by the well-known method to give a compound shown by formula I (X is Cl or Br).
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