Method for preparing fluoride-bearing phenyloboric acid

A technology of fluorine-containing benzene boronic acid, bromobenzene: magnesium: borate ester, applied in the field of preparation of fluorine-containing benzene boronic acid, can solve the problems of harsh conditions, large operation energy consumption, large operation danger, etc., and achieves low water solubility, The effect of good purity and shortened reaction time

Inactive Publication Date: 2010-03-17
ZHEJIANG UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

4) Using m-fluorochlorobenzene derivatives as raw materials, Grignard reagents were prepared in tetrahydrofuran, reacted with lithium reagents at a low temperature of -70°C, and then reacted with trimethyl borate. The main disadvantage of this method ...

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  • Method for preparing fluoride-bearing phenyloboric acid
  • Method for preparing fluoride-bearing phenyloboric acid
  • Method for preparing fluoride-bearing phenyloboric acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] The molar ratio of 3-fluorobromobenzene:magnesium:trimethyl borate is 1.0:1.1:1.5. The total mass amount of the solvent 2-methyltetrahydrofuran is 7 times the mass of 3-fluorobromobenzene.

[0040] Add magnesium chips 2.6g (0.11mol) and 1-2 grains of iodine, 2-methyltetrahydrofuran 30g, N 2Protected at 40°C, a small amount of 17.5 g (0.10 mol) of 3-fluorobromobenzene in 22.5 g of 2-methyltetrahydrofuran solution was added dropwise, and after stirring to initiate the reaction, the remaining 3-fluorobromobenzene solution was added dropwise. After the dropwise addition, react at this temperature for 3 hours to obtain a solution of 3-fluorophenylmagnesium bromide in 2-methyltetrahydrofuran.

[0041] Take another 500mL four-necked bottle, add trimethyl borate 15.6g (0.153mol) and 2-tetrahydrofuran 90.0g, N 2 Cool to -20°C under protection, add the above-mentioned Grignard reagent solution dropwise, and keep warm for 3 hours after the dropwise addition. At this temperature...

Embodiment 2

[0049] The molar ratio of 3-fluorobromobenzene:magnesium:trimethyl borate is 1.0:1.05:1.5. The total mass amount of the solvent 2-methyltetrahydrofuran is 7 times the mass of 3-fluorobromobenzene.

[0050] Add 2.5g (0.105mol) of magnesium chips and 1 to 2 grains of iodine, 18.5g of 2-methyltetrahydrofuran, and N 2 Protected at 45°C, a small amount of 17.5 g (0.10 mol) of 3-fluorobromobenzene in 52 g of 2-methyltetrahydrofuran solution was added dropwise, and after stirring to initiate the reaction, the remaining 3-fluorobromobenzene solution was added dropwise. After the dropwise addition, react at this temperature for 2.5 hours to obtain a solution of 3-fluorophenylmagnesium bromide in 2-methyltetrahydrofuran.

[0051] Take another 500mL four-neck bottle, add 15.6g (0.15mol) of trimethyl borate and 52.0g of 2-methyltetrahydrofuran, N 2 Cool to -35°C under protection, add the above-mentioned Grignard reagent solution dropwise, and keep warm for 3 hours after the dropwise add...

Embodiment 3

[0053] The molar ratio of 3-fluorobromobenzene:magnesium:trimethyl borate is 1.0:1.1:1.5. The total mass amount of the solvent 2-methyltetrahydrofuran is 6 times the mass of 3-fluorobromobenzene.

[0054] Add magnesium chips 2.6g (0.11mol) and 1-2 grains of iodine, 18g 2-methyltetrahydrofuran, N 2 At 50°C, a small amount of 17.5 g (0.10 mol) of 3-fluorobromobenzene and 43 g of 2-methyltetrahydrofuran solution was added dropwise, and after stirring to initiate the reaction, the remaining 3-fluorobromobenzene solution was added dropwise. After the dropwise addition, react at this temperature for 4 hours to obtain a solution of 3-fluorophenylmagnesium bromide in 2-methyltetrahydrofuran.

[0055] Take another 500mL four-neck bottle, add trimethyl borate 15.6g (0.15mol) and 2-methyltetrahydrofuran 44g, N 2 Cool to -15°C under protection, add the above-mentioned Grignard reagent solution dropwise, and keep warm for 2 hours after the dropwise addition. At this temperature, add 100...

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Abstract

The invention discloses a method for preparing fluoride-bearing phenyloboric acid with a structure shown in (I). The method is characterized in that by taking tetrahydro-2-methylfuran as solvent, fluoride-bearing bromobenzene shown in (II) and magnesium react for 1-8 hours at the temperature of 10-80 DEG C so as to obtain Grignard reagent; and the Grignard reagent and boric acid ester react in thetetrahydro-2-methylfuran for 0.5-8 hours at the temperature of -45-15 DEG C and then carry out hydrolysis in an acid condition, an organic layer is used for solvent recovery so as to obtain a crude product, and the fluoride-bearing phenyloboric acid is obtained after recrystallization of the crude product. The method utilizes the green organic solvent, i.e. tetrahydro-2-methylfuran, to replace tetrahydrofuran, aether and other conventional organic solvents to synthesize the fluoride-bearing phenyloboric acid, the process is simple and safe, and the obtained product realizes high yield and good purity. As the tetrahydro-2-methylfuran has high recovery rate and can be recycled, the production cost of the fluoride-bearing phenyloboric acid is greatly reduced, and great industrialization prospect can be born.

Description

(1) Technical field [0001] The invention relates to a preparation method of fluorine-containing phenylboronic acid, including the preparation methods of 3-fluorophenylboronic acid and 3,4,5-trifluorophenylboronic acid. (2) Background technology [0002] 3-fluorophenylboronic acid and 3,4,5-trifluorophenylboronic acid are important pharmaceutical and chemical intermediates, which are widely used in organic and pharmaceutical synthesis. In addition to its important application in the Suzuki coupling reaction, there are other applications: for example, it is used as a catalyst to catalyze the condensation reaction of carboxylic acid and amine, and catalyze the reduction of carboxylic acid to alcohol; -Conjugate addition reaction to synthesize β-aryl substituted carbonyl compounds, etc. Most of these reactions use relatively non-toxic and cheap common reagents, the reaction conditions are mild, the yield is high, and the stereoselectivity is good. In recent years, with the con...

Claims

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Application Information

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IPC IPC(8): C07F5/02
Inventor 俞传明苏为科金蓓蓓叶海伟何人宝王莺妹
Owner ZHEJIANG UNIV OF TECH
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