4-[Difluoro(3,4,5-trifluorophenoxy)methyl]-2',3,5-trifluoro-4''-pentyl-1,1':4',1''-terphenyl

4-[Difluoro(3,4,5-trifluorophenoxy)methyl]-2',3,5-trifluoro-4''-pentyl-1,1':4',1''-terphenyl can be used as a liquid crystal monomer.

The preparation of 4-[Difluoro(3,4,5-trifluorophenoxy)methyl]-2',3,5-trifluoro-4''-pentyl-1,1':4',1''-terphenyl is as follows:10.0 g (29.0 mmol) of 5-[4-chloro-2,6-difluorophenyl)difluoromethoxy]-1,2,3-trifluorobenzene and 8.47 g (29.6 mmol, 1.02 equivalent amount) of 4'-pentyl-3-fluoro-4-biphenylboronic acid were placed in a 300-ml SUS autoclave, after which 467 mg (0.05 equivalent amount) of TBAB, 16.6 mg (0.0012 equivalent amount) of 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (purchased from Johnson Matthey Japan Inc.), and 49.4 mg (0.0004 equivalent amount) of 5% palladium carbon were placed in the autoclave. The autoclave was subsequently sealed, and the atmosphere therein was replaced with nitrogen. Thereafter, 30 ml of deaerated water and 10 ml of deaerated DMAc was added thereto, and 4.5 g (1.5 equivalent amount) of triethylamine was further added thereto, followed by stirring at the reaction liquid temperature of 99°C for 4 hours. The mixture was stirred at room temperature for 20 minutes, and 50 ml of toluene and 30 ml of water were added to the reaction mixture, followed by additional stirring for 15 minutes. The reaction yield was 97.7% (quantified by 19F NMR). The organic layer was subjected to suction filtration (using Celite), the filtrate was concentrated, and then the residue was purified using column chromatography. The crude substance thus obtained was recrystallized with a mixed solvent of denatured ethanol and heptane, thereby obtaining 4-[difluoro-(3,4,5-trifluoro-phenoxy)-methyl]-2',3,5-trifluoro-4"-pentyl-[1,1';4',1"]terphenyl in the form of a white solid. Amount obtained: 14.8 g (isolation yield 93.0%, purity 99.9%).