Preparation method of DL-mandelic acid

A technology of mandelic acid and sodium mandelic, applied in the directions of carboxylate preparation, carboxylate preparation, separation/purification of carboxylic acid compounds, etc., can solve problems such as harm to human health, cumbersome reaction steps, reduction of final product yield and the like , to achieve the effect of low toxicity and simple operation steps

Active Publication Date: 2018-01-12
鼎盛同创(宁夏)环保新材料科技发展有限公司
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Mandelic acid is a very important pharmaceutical intermediate. The application number is CN201710322156. The invention patent application titled "A method for preparing mandelic acid using benzaldehyde and chloroform" discloses a method for preparing almonds with benzaldehyde and chloroform as raw materials. The method of acid, the main problems that this method exists are as follows: the one, reaction step is loaded down with trivial details, and the amount of adding reactant in chemical experiment can inevitably have error, and the error in multi-step operation process can be amplified, causes the generation rate of final product Reduce; the 2nd, in the catalyst that this method uses, benzyl chloride belongs to carcinogen, and triethylamine is inflammable and explosive and has strong pungent smell, and trichloroethane has narcotic effect, and promptly there is pollution in the method for preparing mandelic acid Hazards to the environment and to human health

Method used

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preparation example Construction

[0012] A kind of preparation method of (DL)-mandelic acid, take benzaldehyde, chloroform, sodium hydroxide as raw material, take β-cyclodextrin as catalyst preparation (DL)-mandelic acid, comprise the following steps:

[0013] S1. Add benzaldehyde, chloroform, and β-cyclodextrin to the reaction vessel. The molar ratio of benzaldehyde to chloroform is 1:1 to 3, and the amount of β-cyclodextrin accounts for 1% to 9% of the amount of benzaldehyde. The temperature in the reaction vessel is raised to 40°C to 65°C, and stirring is carried out while the temperature is rising, so that the reactants are fully mixed, and then fully utilize the hydrophobic cavity structure possessed by β-cyclodextrin to clathrate benzaldehyde, Add dropwise concentration to the reaction vessel and be the sodium hydroxide solution of 30%~60%, so that chloroform forms dichlorocarbene under the effect of sodium hydroxide, dichlorocarbene and benzaldehyde react to form mandelic acid sodium salt, the reaction t...

Embodiment 1

[0019] S1. Add 10ml of benzaldehyde, 20ml of chloroform and 4.54g of β-cyclodextrin into a 100ml three-necked flask, raise the temperature in the reaction vessel to 55°C, and stir while raising the temperature so that the reactants are fully mixed , and then make full use of the hydrophobic cavity structure of β-cyclodextrin to clathrate benzaldehyde, and add 20ml of 50% sodium hydroxide solution dropwise to the reaction vessel, so that chloroform can react with sodium hydroxide Dichlorocarbene is formed under the following conditions, and dichlorocarbene reacts with benzaldehyde to form mandelic acid sodium salt. The reaction temperature is maintained at 60° C., and the reaction time is 4 hours. The reaction product is solid mandelic acid sodium salt. Add 300 ml of mandelic acid to the reaction vessel Water completely dissolves the solid mandelic acid sodium salt to obtain a mixed solution. Add 30ml of ethyl acetate to the mixed solution and stir evenly to remove the unreacted...

Embodiment 2

[0024] A preparation method for (DL)-mandelic acid, comprising the following steps:

[0025]S1. Add 5ml of benzaldehyde, 10ml of chloroform and 2.5g of β-cyclodextrin into a 50ml three-necked flask, raise the temperature in the reaction vessel to 50°C, and stir while raising the temperature so that the reactants are fully mixed , and then make full use of the hydrophobic cavity structure possessed by β-cyclodextrin to clathrate benzaldehyde, add 11ml of sodium hydroxide solution with a concentration of 50% to the reaction vessel, so that the effect of chloroform on sodium hydroxide Dichlorocarbene is formed under the following conditions, and dichlorocarbene reacts with benzaldehyde to form mandelic acid sodium salt. The reaction temperature is maintained at 50°C, and the reaction time is 5h. The reaction product is solid mandelic acid sodium salt. Add 200ml Water completely dissolves the solid mandelic acid sodium salt to obtain a mixed solution. Add 20ml of ethyl acetate to ...

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Abstract

A preparation method of DL-mandelic acid comprises: using benzaldehyde, chloroform and sodium hydroxide as materials and beta-cyclodextrin as a catalyst, including the cyclodextrin via hydrophobic cavity structure that the beta-cyclodextrin has, forming dichlorocarbene by the chloroform under the action of the sodium hydroxide, allowing the dichlorocarbene and benzaldehyde to react to form sodiummandelate, forming mandelic acid by the sodium mandelate under acidifying action of sodium hydroxide, extracting the generated mandelic acid via ethyl acetate, recrystallizing via distilled water so as to obtain DL-mandelic acid of high purity. The preparation method of the invention has simple operation steps; all the benzaldehyde, sodium hydroxide, dilute hydrochloric acid, beta-cyclodextrin andethyl acetate used in the preparation process are nontoxic, and the chloroform has low toxicity and causes little harm to the environment and human bodies; in addition, the beta-cyclodextrin and ethyl acetate do not engage in reaction and are reusable.

Description

technical field [0001] The invention relates to the technical field of preparation and purification methods of chiral drugs, in particular to a preparation method of (DL)-mandelic acid. Background technique [0002] Mandelic acid is a very important pharmaceutical intermediate. The application number is CN201710322156. The invention patent application titled "A method for preparing mandelic acid using benzaldehyde and chloroform" discloses a method for preparing almonds with benzaldehyde and chloroform as raw materials. The method of acid, the main problems that this method exists are as follows: the one, reaction step is loaded down with trivial details, and the amount of adding reactant in chemical experiment can inevitably have error, and the error in multi-step operation process can be amplified, causes the generation rate of final product Reduce; the 2nd, in the catalyst that this method uses, benzyl chloride belongs to carcinogen, and triethylamine is inflammable and e...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C07C59/50C07C51/41C07C51/02C07C51/48
Inventor田秉仁王志忠褚慧敏
Owner鼎盛同创(宁夏)环保新材料科技发展有限公司