report on the preparation method of 4-trifluoromethoxyphenylboronic acid_industrial additives

background and overview of the preparation method of 4-trifluoromethoxyphenylboronic acid

4-trifluoromethoxyphenylboronic acid is widely used in suzuki cross-coupling reactions. suzuki-miyaura coupling reaction (smc) is an important reaction to construct various c-c single bonds, and its main raw material is organic boronic acid compounds. among them, 4-trifluoromethoxyphenylboronic acid is an important compound among organic boric acid compounds and has important application value in the fields of organic synthesis and pharmaceutical chemical industry.

the preparation method of 4-trifluoromethoxyphenylboronic acid is reported

report on the preparation method of 4-trifluoromethoxyphenylboronic acid 1.

1-bromo-4-(trifluoromethoxy)benzene (1.69 kg) and triisopropyl borate (1.46 kg) in thf (6.75 l) for 2.3 h. after stirring for 10 min, treat with 6 m hcl (1.52 l) over 50 min, stir at room temperature for 18 h, and pour into a mixture of heptane (8.43 l) and 20% (w/w) sodium chloride (8.44 kg) middle. the mixture was stirred for 10 minutes and separated into aqueous and organic parts. the organic fraction was concentrated to provide a white paste. the paste was dried under vacuum (100mmhg) with a stream of nitrogen bromopyridine dihydrochloride at ambient temperature for 2 days and then at 40-50°c for 18 hours to provide 1.306kg (90.4%) of the required the product is solid.

preparation method report 2 of 4-trifluoromethoxyphenylboronic acid,

in an ace glass photochemical reactor assembly, 1-bromo-4-(trifluoromethoxy)benzene (289 mg, 1.2 mmol) and tetrahydroxydiboron (106 mg, 1.2 mmol) were irradiated at 15°c. of methanol (5 ml) solution for 3 h. ace glass 7880-60 is equipped with spectroline low pressure. transfer the reaction mixture (1 mmol scale) to a round bottom flask containing sodium bicarbonate (252 mg, 3 mmol). the methanol was evaporated, and the resulting solid was dissolved in a mixture of 1 m aqueous fructose solution (5 ml) and 1 m aqueous sodium carbonate solution (5 ml). ethyl acetate (15 ml) was added and the organic portion was separated and discarded. acidify the aqueous phase to ph 3 using 6m aqueous hydrochloric acid and extract with ethyl acetate (2 x 10 ml). the combined organic fractions were dried over anhydrous sodium sulfate and solid sodium bicarbonate (252 mg) was added. the mixture was filtered and concentrated under reduced pressure to obtain 4-trifluoromethoxyphenylboronic acid.

references

[1] from pct int. appl., 2001074792, 11 oct 2001

[2] mfuh a m , doyle j d , chhetri b , et al. scalable, metal- and additive-free, photoinduced borylation of haloarenes and quaternary arylammonium salts[j]. journal of zinc borate the american chemical society, 2016: 2985.