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P-bromomethyl phenylacetic acid preparation method

A technology of bromomethylphenylacetic acid and methylphenylacetic acid, which is applied in the field of preparation of fine chemical intermediates and p-bromomethylphenylacetic acid, can solve the problems of difficult scale-up production and low yield, and achieve high yield and convenient The effect of preparation

Inactive Publication Date: 2017-06-30
SHANGHAI INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] Aiming at the above-mentioned technical problems in the prior art, the invention provides a kind of preparation method of p-bromomethyl phenylacetic acid, the preparation method of described this p-bromomethyl phenylacetic acid solves the problem of p-bromomethyl phenylacetic acid in the prior art. The technical problem that the yield of phenylacetic acid is low in the preparation process and it is difficult to scale up the production

Method used

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Examples

Experimental program
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Effect test

Embodiment 1

[0019] Put the raw material p-tolueneacetic acid (24 grams) in 250 ml of three ports, add 80 ml of chlorobenzene, add 30 grams of NBS, 0.6 grams of azobisisobutyronitrile, and heat to 85 ° C under mechanical stirring, the reaction starts Afterwards, the temperature will be automatically raised to 110°C, the reaction will be controlled at 90 to 110°C, and the reaction will be kept in this temperature range for 4 hours, monitored by TLC plate, and the reaction is complete. After cooling, a solid was precipitated. After filtration, the filter cake was washed with water and dried as much as possible by suction. Then the obtained white solid weighed 33.0 g after drying, the yield was 90%, and the HPLC purity was 98.7%.

[0020] 1 HNMR (DMSO-d6,300 MHz) δ: 12.2(s,1H),7.18-7.23(m,4H),4.69(s,2H),3.57(s,2H).

Embodiment 2

[0022] Put the raw material p-tolueneacetic acid (24 grams) in 250 ml of three mouths, add 90 ml of dichlorobenzene, add 30 grams of NBS, 0.6 grams of azobisisobutyronitrile, and heat at 85 ° C under mechanical stirring, and react After initiation, the temperature will be automatically raised to 115°C, the reaction will be controlled at 90 to 115°C, and the reaction will be kept in this temperature range for 5 hours, monitored by TLC plate, and the reaction is complete. After cooling, a solid was precipitated. After filtration, the filter cake was washed with water and dried as much as possible by suction. Then the obtained white solid weighed 32.3 g after drying, the yield was 88.1%, and the HPLC purity was 98.3%.

[0023] 1 HNMR (DMSO-d6,300 MHz) δ: 12.2(s,1H),7.18-7.23(m,4H),4.69(s,2H),3.57(s,2H).

Embodiment 3

[0025] Put the raw material p-tolueneacetic acid (24g) in a 250ml three-port, add 75ml of chlorobenzene, add 30g of NBS, 0.5g of benzoyl peroxide, heat to 85°C under mechanical stirring, After initiation under irradiation, the temperature will automatically rise to 110°C, the reaction will be controlled at 90 to 110°C, and the reaction will be kept in this temperature range for 8 hours, monitored by TLC plate, and the reaction is complete. After cooling, a solid was precipitated. After filtration, the filter cake was washed with water and dried as much as possible by suction. Then the obtained white solid weighed 33.7 g after drying, the yield was 91.9%, and the HPLC purity was 99.2%.

[0026] 1 HNMR (DMSO-d6,300 MHz) δ: 12.2(s,1H),7.18-7.23(m,4H),4.69(s,2H),3.57(s,2H).

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Abstract

The present invention provides a p-bromomethyl phenylacetic acid preparation method, which comprises: dissolving p-methyl phenylacetic acid in a high boiling point solvent, wherein the solvent is benzene, chlorobenzene or dichlorobenzene; adding a brominating agent and a catalyst, wherein the brominating agent is bromine or bromosuccinimide, the catalyst is azobisisobutyronitrile or benzoyl peroxide, and a molar ratio of the p-methyl phenylacetic acid to the brominating agent is 1:0.8-2.0; heating to a temperature of 80-130 DEG C, carrying out a reaction for 6-12 h through the initiation with incandescent light irradiation, and cooling; and filtering, and carrying out water washing to obtain the p-bromomethyl phenylacetic acid. According to the present invention, the high boiling point reaction solvent is used, a lot of the generated heat can be taken away by the high boiling point solvent through the circulation after the reaction is initiated by the illumination, the product p-bromomethyl phenylacetic acid is precipitated from the solvent after the cooling, and the water washing and the drying are performed to obtain the product, wherein the HPLC purity of the product is greater than 98.5%, and the yield is up to 90%.

Description

technical field [0001] The invention belongs to the field of chemical industry and relates to a fine chemical intermediate, in particular to a preparation method of p-bromomethylphenylacetic acid. Background technique [0002] p-Bromomethylphenylacetic acid is a common intermediate in organic synthesis, widely used in the synthesis of pesticides, pharmaceuticals and intermediates. Its structure is as follows: [0003] [0004] According to literature reports, patents CN101386590 and WO2001019939 both use carbon tetrachloride as the reaction solvent, bromosuccinimide as the brominated reagent, AIBN as the initiator, and heat and reflux the reaction. The synthesis yield is only 72%; Literature EuropeanJournal of Organic Chemistry, (18), 4135-4146, 2006 then uses bromine as bromine reagent, carbon tetrachloride as solvent, heating and reflux reaction, and its yield is only 62%; And, this reaction is free radical reaction , Exothermic heat is severe in the reaction process...

Claims

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Application Information

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IPC IPC(8): C07C51/363C07C57/30
CPCC07C51/363C07C57/30
Inventor 吴岳林马建江何慧红陆芳柳
Owner SHANGHAI INST OF TECH
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