Preparation of 1,4-Bis-[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene(RM257)

1,4-Bis-[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene (RM257) is an important organic intermediate to synthetize. The homeotropic alignment liquid crystal film.

1,4-Bis-[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene can be prepared according to the reported literatures[1-2].

Method 1

The acid (54 g, 204 mmol) and the phenol (6.8 g, 17.7 mmol) were mixed with ethyl acetate (50 mL), THF (45 mL) and diisopropylethylamine (41.8 mL). The obtained solution was added dropwise to an ethyl acetate solution of methanesulfonyl chloride (25.5 g, 223 mmol), slowly under cooling on ice. The feed ratio by mole of the acid and the phenol was 92:8. Next, the mixture was stirred for one hour under cooling on ice, an ethyl acetate solution (13.5 g, 109 mmol) was added dropwise under cooling on ice, N-methylimidazole (0.5 g) was further added, and thereto triethylamine (33.7 mL) was slowly added dropwise under cooling on ice. The mixture was then stirred for two hours while keeping the reaction temperature at 20° C., water (140 mL) was added for extraction into an organic layer, and the organic layer was washed with a 2percent aqueous hydrochloric acid solution and a 10 percent brine in this order. A portion of the organic layer was sampled and subjected to HPLC analysis, and production ratio of the acid and the phenol was estimated based on the ratio of peak areas. The production ratio by mole was found to be 88:12. Next, the organic layer was filtered under suction, methanol/water was added to the filtrate so as to allow crystal to deposit, and the resultant crystal was collected by filtration, to thereby obtain a liquid crystal composition containing the compounds (yield=60 g). The obtained liquid crystal composition was sampled and subjected to HPLC analysis, and compositional ratio of the compounds was estimated based on the ratio of peak areas. The compositional ratio by mass was found to be 87:113. The liquid crystal composition was found to show a nematic-Iso phase transition temperature of 140° C. Note that the production ratio and the compositional ratio of the compounds were estimated using standard curves determined based on the ratio of peak areas in HPLC analyses, using standard samples of separately synthesized the compounds.

Method 2

Stirrer, was added methanesulfonyl chloride 5.00 g (43.6 mmol) and tetrahydrofuran 10mL the reactor having a thermometer and two dropping device. Ice-cold while each by dropping a tetrahydrofuran solution 30 mL of formula tetrahydrofuran solution 60mL and triethylamine 5.25g of the phenol represented by the compound 12.9g (44.1 mmol) of (51.9 mmol) from device (equation (solution of the compound represented by I-3-1)) :( triethylamine solution) = 2: were added dropwise simultaneously with one of the drip rate. After stirring for 1 hour while cooling with ice, it was added 4-dimethylaminopyridine 2.64 g (21.6 mmol) and 2- (4-hydroxyphenyl) ethanol 2.69 g (19.4 mmol).With ice-cooling was added dropwise triethylamine 5.25g (51.9 mmol).After stirring for 7 hours, the solvent was distilled off and treated added for liquid separation dichloromethane and 5percent hydrochloric acid. After the organic layer was washed with brine neutralization, and purified by column chromatography (silica gel) and reprecipitated (dichloromethane / methanol) to give the compound 12.2g of formula (I-3).82 percent yield, had a purity of 99.63 percent.

References

1. Fujifilm Corporation. Katoh S, Matsuyama H, Yoshikawa M. Liquid crystal composition, method for manufacturing the same, and film. US9464228[P], 2016, B2, Page column 49-52. 
2.DIC Corporation. Horiguchi M, Aoki Y, Hayashi M, Kusumoto T. Compound (by machine translation). JP5988087[P], 2016, B2, Paragraph 0054; 0060; 0062.