The preparation of Benzoic acid, 4-[4-[(1-oxo-2-propenyl)oxy]butoxy]-, 2-Methyl-1,4-phenylene ester is as follows:2-methylhydroquinone 3.0 g (24.2 mmol), 4-[3-(acryloyloxy)butoxy]benzoic acid 14.7 g (55.6 mmol), 4-dimethylaminopyridine (DMAP) 0.18 g (1.5 mmol) ) And 0.14 g (1.4 mmol) of 35% hydrochloric acid were added to 39 mL of tetrahydrofuran (THF) and stirred, and 7.0 g (55.6 mmol) of N,N-diisopropylcarbodiimide (DIC) was added dropwise to the solution. After completion of dropping, the mixture was stirred at 40° C. for 5 hours to obtain a reaction solution. The reaction solution was filtered to remove insoluble matter. A part of the solvent of the filtrate from which the insoluble matter was removed was distilled off to obtain 15 mL of a solution. 60 mL of methanol was added dropwise to 15 mL of the obtained solution to crystallize the polymerizable liquid crystal compound, and then the mixture was stirred under cooling. The obtained precipitate (crystal) is collected by filtration, and the collected precipitate (crystal) is dried to give 2-methyl-1,4-phenylene=bis{4-[3-(acryloyloxy)butoxy]. Benzoate} was obtained with a yield of 94% (14.0 g, 22.8 mmol). The purity of the obtained 2-methyl-1,4-phenylene=bis{4-[3-(acryloyloxy)butoxy]benzoate} was 97.8%. In addition, the content of N,N-diisopropylurea as a by-product contained in the finally obtained 2-methyl-1,4-phenylene bis{4-[3-(acryloyloxy)butoxy]benzoate} , 0.01% by mass relative to the yield, which was sufficiently reduced.
