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Preparation method of 5-bromo-2-chlorobenzoic acid

A technology of chlorobenzoic acid and bromine, applied in the field of preparation of 5-bromo-2-chlorobenzoic acid, can solve problems such as low yield, and achieve the effects of high yield, short steps and low cost

Inactive Publication Date: 2019-12-20
吕东
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0009] Literature (Amalendu B.Gopal Ch.etc.Bromination of halobenzenes and halobenzoic acids.J Indian Chem.Soc.1980,57(6),640~642.) discloses the use of potassium bromate and bromide respectively as raw materials with 2-chlorobenzoic acid The sodium system carries out bromination to prepare 5-bromo-2-chlorobenzoic acid (the preparation process is shown in formula IV), but the yield of this method is low, only 40%;

Method used

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  • Preparation method of 5-bromo-2-chlorobenzoic acid

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preparation example Construction

[0030] The invention provides a kind of preparation method of 5-bromo-2-chlorobenzoic acid, comprises the following steps:

[0031] Mix 2-chlorobenzoic acid, bromine, catalyst and organic solvent for bromination reaction to obtain 5-bromo-2-chlorobenzoic acid.

[0032] In the present invention, unless otherwise specified, all raw materials are commercially available products well known to those skilled in the art.

[0033] In the present invention, the catalyst is preferably a Lewis acid, more preferably aluminum ferric chloride, ferric chloride, ferric tribromide, boron trifluoride, zinc chloride, niobium pentachloride and trifluoromethanesulfonate One or more of acid salts; when the catalyst is two or more of the above-mentioned specific selections, the present invention does not have any special restrictions on the proportioning of the specific substances.

[0034] In the present invention, the molar ratio of the 2-chlorobenzoic acid, bromine and catalyst is preferably 1:(...

Embodiment 1

[0049]Mix 93.6kg 2-chlorobenzoic acid and 750kg dichloromethane, add aluminum trichloride (162kg, each batch of 32.4kg) in 5 times under the condition of stirring, continue to stir for 30 minutes until aluminum trichloride is fully Dissolve, add 105.6kg bromine dropwise at 25°C for 30 minutes, react at room temperature for 48 hours, monitor the reaction by HPLC, terminate the reaction when the 2-chlorobenzoic acid content in the reaction solution is less than 0.5%;

[0050] Mix 200kg of dilute hydrochloric acid with a mass concentration of 30% and 400kg of deionized water, stir and cool down to -10°C, press the product system obtained after the bromination reaction into it for quenching, control the temperature below 0°C, and quench After completion, dichloromethane was removed by distillation under reduced pressure (stop when the internal temperature was 40°C), 600kg of toluene was added, the temperature was raised to 70-75°C to completely dissolve, the temperature was maintai...

Embodiment 2

[0053] Mix 46.8kg 2-chlorobenzoic acid and 375kg chloroform, add aluminum trichloride (81kg, each batch of 16.2kg) in 5 times under the condition of stirring, continue to stir for 30 minutes until aluminum trichloride is fully Dissolve, add 52.8kg bromine dropwise at 25°C for 30 minutes, react at room temperature for 48 hours, detect the reaction by HPLC, stop the reaction when the 2-chlorobenzoic acid content in the reaction solution is less than 0.5%;

[0054] Mix 100kg of dilute hydrochloric acid with a mass concentration of 30% and 200kg of deionized water, stir and cool down to -10°C, press the product system obtained after the bromination reaction into it for quenching, control the temperature below 0°C, and quench After completion, dichloromethane was removed by distillation under reduced pressure (stop when the internal temperature was 50°C), 300kg of toluene was added, the temperature was raised to 70-75°C until it was completely dissolved, and the temperature was main...

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Abstract

The invention relates to the technical field of preparation of 5-bromo-2-chlorobenzoic acid, and in particular relates to a preparation method of the 5-bromo-2-chlorobenzoic acid. The preparation method of the 5-bromo-2-chlorobenzoic acid provided by the invention comprises the following steps: mixing 2-chlorobenzoic acid, bromine, a catalyst and an organic solvent, and performing a bromination reaction to obtain the 5-bromo-2-chlorobenzoic acid. The preparation method provided by the invention has short steps, mild reaction conditions, low costs, a high yield, and high purity of the product;and at the same time, according to the description of embodiments, the purity by HPLC of the 5-bromo-2-chlorobenzoic acid prepared by using the preparation method is >=99.5%, and the molar yield is >=80.9%.

Description

technical field [0001] The invention relates to the technical field of preparation of 5-bromo-2-chlorobenzoic acid, in particular to a preparation method of 5-bromo-2-chlorobenzoic acid. Background technique [0002] Both empagliflozin and dapagliflozin are a type 2 sodium glucose cotransporter (SGLT-2), which are new drugs for the treatment of diabetes. Compared with traditional hypoglycemic drugs, SGLT-2 inhibitors will not cause adverse reactions such as hypoglycemia and weight gain, and can even prevent the decline of pancreatic β-cell function, making diabetes easier to control. And it does not need to be administered by injection, will not cause serious gastrointestinal reactions, and improves the compliance of the drug users. Both have been marketed in Europe and the United States, and have become the drug of choice for diabetic patients, while 5-bromo-2-chlorobenzoic acid is the starting material for the synthetic drug empagliflozin or dapagliflozin, and its structu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/363C07C63/70
CPCC07C51/363C07C63/70
Inventor 吕东梁建明
Owner 吕东
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