Background and overview of preparation and application examples of 3,4,5-trifluorobenzeneboronic acid
3,4,5-Trifluorobenzeneboronic acid is a fluorine-containing phenylboronic acid. Fluorine-containing phenylboronic acid is a kind of organic synthesis, pharmaceutical, and chemical intermediates that are relatively stable in the air, insensitive to moisture, can be stored for a long time, and have high reactivity. The Suzuki coupling reaction of fluorobenzene boric acid and sodium carbonate halogenated aromatic hydrocarbons has good position selectivity and stereoselectivity. Various chemical functional groups do not change during the reaction. The reaction conditions are mild and the yield is high. It is the best way to form C—C important way to key. Fluorine-containing phenylboronic acid has a very important application in organic synthesis reactions such as the formation of C—O bonds, C—N bonds, and C—S bonds. Fluorine-containing phenylboronic acid is a fluorine-containing monosubstituted phenylboronic acid derivative. Since the atomic radii of fluorine atoms and hydrogen atoms are similar, when the hydrogen atoms in the molecule are replaced by fluorine, it will not cause significant changes in the three-dimensional configuration of the molecule. . However, because the fluorine atom has strong electron withdrawal, it often causes great changes in the electronic properties of the original molecule. As a result, fluorine-containing phenylboronic acid has good stability and large dielectric anisotropy. In recent years, it has been widely used in organic synthesis and Biomedicine, pesticides and materials science all play a very important role, especially in liquid crystal display materials.
Preparation and application examples of 3,4,5-trifluorobenzeneboronic acid
A glass three-neck reaction bottle is equipped with mechanical stirring, a thermometer, and a constant pressure dropping funnel. Add the solvent tetrahydrofuran and the raw material 3,4,5-trifluorobromobenzene, replace it with nitrogen, and drop 1.1 molar equivalent of Isopropyl magnesium chloride solution, react for 1 hour after the dropwise addition, and use boric acid gas chromatography to detect the completion of the reaction of the raw material 3,4,5-trifluorobenzene. Then add 1.2 molar equivalents of trimethyl borate dropwise at 5-10°C, react for 2 hours, and perform post-treatment. After the post-treatment, a certain amount of water is added to terminate the reaction, the pH value of the system is adjusted to acidic with acid, the organic phase is separated, the solvent is removed by distillation under reduced pressure, and the product 3,4,5-trifluorobenzene boric acid is obtained after recrystallization, with a purity greater than 99.5 %, relevant impurities are less than 200PPM.
Preparation and application examples of 3,4,5-trifluorobenzeneboronic acid
CN201110369051.8 provides a preparation method of 3,4,5-trifluorophenol, which includes the following steps: using water as a solvent, oxidizing 3,4,5-trifluorophenylboronic acid and hydrogen peroxide reaction; the temperature of the reaction is 20°C~100°C. The preparation method of the present invention is simple in process, low in cost, environmentally friendly and more suitable for industrialized safe production.
References
[1][Chinese invention] CN201510482058.9 A preparation method of 3,4,5-trifluorobenzene boric acid
[2] Preparation method of CN201110369051.83,4,5-trifluorophenol
[3][Chinese invention] CN201510406439.9 A high-performance liquid chromatography detection method for 3,4,5-trifluorobenzene boric acid
