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Method for preparing 2-bromo-fluorobenzyl bromide

A technology of fluorobromobenzyl and fluorotoluene, which is applied in the field of bromination reaction to prepare 2-bromo-6-fluorobromobenzyl, can solve the problems of benzoyl peroxide introducing impurities, low yield, expensive reagents, etc., to reduce production Cost, high yield, and safety-enhancing effects

Inactive Publication Date: 2011-05-25
CHANGZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The present invention overcomes the problems of relatively expensive reagent price, low yield and impurities introduced by benzoyl peroxide in the above method

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] In a 150ml four-neck flask equipped with a stirring, thermometer and reflux condensing device, add 1.89g (0.01mol) of 2-bromo-6-fluorotoluene, 2.03g (0.01mol) of hydrobromic acid with a mass fraction of 40%, 30ml Dichloromethane was heated to reflux under the irradiation of a 1000W iodine-tungsten lamp. Slowly add 1.13g (0.01mol) of hydrogen peroxide with a mass fraction of 30%, and the dropping speed should be such that the red color fades. After reacting for 10 h, GC detected that the reaction of raw materials was complete, and the solution was light yellow. After cooling, the reaction solution was washed with 20 ml of saturated sodium sulfite solution, washed with water, the organic layer was dried with anhydrous sodium sulfate, filtered, and the solvent was evaporated from the filtrate under reduced pressure. Silica gel column chromatography (eluent: petroleum ether (60-90°C)) yielded 2.34 g of 2-bromo-6-fluorobenzyl bromide with a purity of 99.4% (GC) and a yield ...

Embodiment 2

[0023] With the technological operation step of embodiment 1, different conditions are:

[0024] 3.03g (0.015mol) of hydrobromic acid with a mass fraction of 40%, 2.27g (0.02mol) of hydrogen peroxide with a mass fraction of 30%, and 30ml of ethyl acetate were reacted for 18 hours to obtain 2.1g of 2-bromo-6-fluorobenzyl bromide, The purity is 99.2%, and the yield is 78.4%.

Embodiment 3

[0026] With the technological operation step of embodiment 1, different conditions are:

[0027] 3.03g (0.015mol) of hydrobromic acid with a mass fraction of 40%, 3.92g (0.035mol) of hydrogen peroxide with a mass fraction of 30%, and 30ml of chloroform were reacted for 6 hours to obtain 2.31g of 2-bromo-6-fluorobenzyl bromide with a purity of 99.6 %, yield 85.6%.

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PUM

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Abstract

The invention relates to the field of organic synthesis, in particular to a method for preparing 2-bromo-fluorobenzyl bromide, which comprises the following steps: (1) in the presence of an organic or inorganic solvent, adding a 2-bromo-6-fluorotoluene compound and 40-mass-percent hydrobromic acid and dripping 30-mass-percent hydrogen peroxide under a lighting condition, and reacting for 6 to 24 hours, wherein the molar ratio of 2-bromo-6-fluorotoluene to HBr is 1:(1-3.5) and the molar ratio of the 2-bromo-6-fluorotoluene to H2O2 is 1:(1-3.5); and (2) washing the reaction solution with saturated sodium sulfite solution and water, drying the reaction solution with anhydrous sodium sulfate, evaporating solvent under a reduced pressure, and obtaining the 2-bromo-6-fluorotoluene compound by silica gel column chromatography. In the method, the hydrobromic acid and hydrogen peroxide are used in place of the traditional N-bromosuccinimide brominating agent, so the production cost is reduced; and lighting is used in place of a benzoyl peroxide initiator, so method has the advantages of mild reaction conditions, high product purity, high yield and the like.

Description

technical field [0001] The invention relates to the field of organic synthesis, in particular to a method for preparing 2-bromo-6-fluorobenzyl bromide through bromination reaction. The invention provides a simple and economical method for preparing 2-bromo-6-fluorobenzyl bromide. Background technique [0002] 2-Bromo-6-fluorobenzyl bromide is an important pharmaceutical intermediate. In the patent WO2007031828A2, Fluoxetine was synthesized from 2-bromo-6-fluorobenzyl bromide. The trade name is “Bioyoujie” Or "Prozac" (Prozac), is a drug developed by Eli Lilly and Company for the treatment of adult depression, obsessive-compulsive disorder and bulimia nervosa; patent WO2005059107A2 uses 2-bromo-6-fluorobenzyl bromide Piperidine derivatives synthesized as raw materials can be used to inhibit HIV virus; gram crown acid sodium synthesized from 2-bromo-6-fluorobenzyl bromide in patent WO03066620A1 can be used to treat angina pectoris, unstable sore throat and other diseases; pat...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C25/13C07C17/14
Inventor 方永勤李江河郭丽婷
Owner CHANGZHOU UNIV
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