2

3

4-trifluoroiodobenzene is prepared with 2

3

4-trifluorophenylamine by sandmeyer reaction. 4-(2

3

4-Trifluorophenyl)-2-methylbut-3-yn-2-ol is prepared with 2

3

4-trifluoroiodo benzene and 2-methyl-3-butyn-2-ol.2

3

4-trifluorophenylacetylene is prepared with 4-(2

3

4-trifluo -rophenyl)-2-methylbut-3-yn-2-ol and potassium hydroxide in paraffin oil. Six derivatives of 2

3

4-trifluorotolanes are prepared with 2

3

4 -trifluorophenylacetylene and six derivatives of iodobenzene by Sonogashira reactions. These compounds not only have large optical anisotropy(

n

).but also have wider nematic phase temperature range by a series photo electricity test and DSC analysis.