Application of phosphate compound in preparation of nitrophenylboronic acid

A technology of nitrophenylboronic acid and compounds, applied in the field of organic synthesis, can solve the problems of harsh reaction conditions, low reaction yield, poor product uniformity, etc., and achieve easy control of the reaction, high yield and purity, high yield and The effect of purity

Pending Publication Date: 2020-12-08
商河知济新材料技术中心
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Problems solved by technology

This method uses excessive nitric acid (the molar weight of nitric acid is 3 times that of phenylboronic acid), resulting in very cumbersome post-treatment steps, and the overall reaction time is long, and the yield is low, only 42%, which is not conducive to industrial production
[0005] (2) World patent WO2011132865A1 discloses a method for preparing o-nitrophenylboronic acid. Dissolve 1-iodo-2-nitrobenzene in tetrahydrofuran, cool to -78°C, slowly add phenylmagnesium chloride and stir to mix, then add boric acid Trimethyl ester, after warming up to room temperature, fully stirred, and finally added hydrochloric acid to terminate the reaction, the molar yield was 89%, but this method needs to be reacted at an extremely low temperature, resulting in harsh reaction conditions and many isomers, Product uniformity difference
This method also uses an excessive amount of fuming nitric acid, which also leads to very cumbersome post-treatment, and also produces more isomers, which is also not suitable for industrial production
[0007] (4) English literature Journal of Organic Chemistry; vol.79; nb.21; (2014); 10568-10580, which discloses a method for preparing o-nitrophenylboronic acid, which combines 2-nitroaniline and tetrahydroxydiboron Mix in water, add hydrogen chloride, sodium nitrite, and sodium acetate in order to react to obtain the product, and the final reaction molar yield is only 28%. The reaction yield of this method is low, and the raw material price is relatively expensive, so it is not suitable for industrial production
The molar amount of nitric acid in this method is also much greater than that of phenylboronic acid, which will lead to cumbersome post-treatment, and there is an excessive amount of nitric acid in the waste liquid, which is extremely troublesome to handle and extremely harmful to the environment.
In addition, this application omits the reaction or treatment time of each step in the embodiment, in fact, concentrated nitric acid and water release heat, because there is a large amount of nitric acid in the system, therefore, in the process of dropping concentrated nitric acid, in order to keep the system Low temperature, concentrated nitric acid cannot be dripped too fast, and it takes a lot of time to absorb the released heat. In addition, there is a large amount of nitric acid in the system during post-treatment, and nitric acid is very soluble in water, so , will cause great trouble to the post-processing, and it will also take a lot of time
Therefore, the overall energy consumption of this method is relatively large and time-consuming, which is also not conducive to large-scale reactions.

Method used

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preparation example Construction

[0025] According to the preparation method of nitrophenylboronic acid described in the present invention, preferably, the phosphate compound is selected from binaphthol phosphate.

[0026] According to the preparation method of nitrophenylboronic acid of the present invention, the protective gas is nitrogen or argon.

[0027] According to the preparation method of nitrophenylboronic acid of the present invention, the protective gas is preferably nitrogen.

[0028] According to the preparation method of nitrophenylboronic acid described in the present invention, described organic solvent is selected from acetic anhydride, formic acetic anhydride or propionic anhydride.

[0029] According to the preparation method of nitrophenylboronic acid of the present invention, the organic solvent is preferably acetic anhydride.

[0030] According to the preparation method of nitrophenylboronic acid described in the present invention, the molar amount of the fuming nitric acid is not great...

Embodiment 1

[0036] Under nitrogen atmosphere, add 1mol phenylboronic acid and 1.2L acetic anhydride into the reaction vessel, stir until uniform, control the temperature of the system at 0°C, then add 1g of catalyst binaphthol phosphate, continue stirring for 2min, and then slowly add Add 51 g (0.8 mol) of fuming nitric acid dropwise for 30 minutes. After the dropwise addition, keep the above temperature and continue the reaction for 1 hour until the reaction ends. Add 500 g of ice water to the system, continue stirring for 5 minutes until the system is uniform, and concentrate under reduced pressure. , when the volume is reduced to one-third, add 200g of ice water again, continue to stir until the system is uniform, then let it stand, the system is layered, the solid is filtered, washed with ice water, and vacuum-dried to obtain 130g of o-nitrophenylboronic acid , yield 97.4% (calculated as fuming nitric acid), purity 99.8%.

Embodiment 2

[0038] Under nitrogen atmosphere, add 1mol phenylboronic acid and 1.2L acetic anhydride into the reaction vessel, stir until uniform, control the temperature of the system at 10°C, then add 5g of catalyst binaphthol phosphate, continue stirring for 1min, and then slowly add Add 51 g (0.8 mol) of fuming nitric acid dropwise for 20 minutes. After the dropwise addition, keep the above temperature and continue the reaction for 40 minutes until the reaction ends. Add 500 g of ice water to the system, continue stirring for 10 minutes until the system is uniform, and concentrate under reduced pressure. , when the volume is reduced to one-third, add 200g of ice water again, continue to stir until the system is uniform, then let it stand, the system is layered, the solid is filtered, washed with ice water, and vacuum-dried to obtain o-nitrophenylboronic acid 130.4 g, yield 97.7% (based on fuming nitric acid), purity 99.7%.

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Abstract

The application of the phosphate compound in preparation of nitrophenylboronic acid is characterized by comprising the following steps: adding phenylboronic acid and an organic solvent into a reactioncontainer in a protective gas atmosphere, uniformly stirring the reactants, controlling the temperature of the system to be 0-25 DEG C, adding a catalyst phosphate compound, continuously stirring for1-2 minutes, and slowly dropwise adding fuming nitric acid into the system; then keeping the temperature, continuously reacting for 0.5-1 h until the reaction is finished, adding ice water into the system, continuously stirring the system for 5-10 min until the system is uniform, carrying out reduced pressure concentration, adding ice water again when the volume is reduced to 1/3, continuously stirring the system until the system is uniform; performing standing treatment, layering the system, filtering out the solid, washing the solid with ice water, and carrying out vacuum drying to obtain o-nitrophenylboronic acid. By using the phosphate catalyst, the nitrophenylboronic acid is easier to control in the preparation process. The preparation is mild in reaction, simple in post-treatment, high in yield and purity, capable of guaranteeing large-batch production, high in yield and purity and more suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of organic synthesis, in particular to a preparation method of nitrophenylboronic acid, more specifically to a preparation method of o-nitrophenylboronic acid. Background technique [0002] O-nitrophenylboronic acid is an important chemical intermediate, an important raw material for the synthesis of organic light-emitting diodes, and an important intermediate for the synthesis of many pharmaceutical compounds. [0003] The preparation method of reporting nitrophenylboronic acid in the prior art mainly contains following several kinds: [0004] (1) Chinese patent CN 103214489A discloses a method for preparing o-nitrophenylboronic acid. In the acetic anhydride solution of phenylboronic acid, fuming nitric acid containing a small amount of urea is added dropwise to react at low temperature. After the reaction is completed, crushed Ice, concentrated under reduced pressure, added water, then concentrated under reduced pr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07F5/02B01J31/02
CPCC07F5/025B01J31/0258
Inventor 卢正祥
Owner 商河知济新材料技术中心
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