Synthesizing method for phenylacetic acid

A synthesis method and technology of phenylacetic acid, applied in the preparation of carboxylic acid esters/lactones, organic chemistry, etc., can solve the problems of harsh conditions for synthesizing phenylmalonic acid, increased equipment for reaction pressure conditions, and low production costs of products, and achieve Avoid the effects of high equipment withstand voltage requirements, enhanced environmental friendliness, and high conversion rate

Active Publication Date: 2019-04-05
TAIXING LINGFEI CHEM TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Considering factors such as source of raw materials, reliability of synthesis technology and production cost, the methods commonly used in industrialization to synthesize phenylacetic acid mainly include the hydrolysis reaction of benzyl nitrile, the catalytic carbonylation reaction of benzyl chloride and the catalytic thermal decarboxylation of phenylmalonic acid. The advantages of these three synthetic methods are that the raw materials are easy to obtain, the conversion rate of the reactant and the yield of the product are high, and the production cost is relatively low. The disadvantage is that the first route uses highly toxic hydrogen cyanide as a raw material for synthesis However, there are doubts about the possible residual hydrogen cyanide in the product. In addition to using highly toxic carbon monoxide, which causes hemoglobin to lose its oxygen-carrying capacity, the second route is used as a raw material. The high-pressure condition of not less than 5 MPa during the reaction also increases operational risks. , the conditions for the synthesis of phenylmalonic acid in the third route are harsh and the yield is not high, and the atom utilization rate of the subsequent decarboxylation reaction is low
[0003] Phenylacetic acid is an important intermediate of medicines and pesticides. However, in the existing synthesis methods of phenylacetic acid with industrial value, either highly toxic raw materials are selected to cause doubts about possible residues of highly toxic chemicals, or extremely high reaction pressure is selected. Conditions increase the demand for equipment to withstand high pressure and at the same time increase the unsafe factors of the production process, or the selected synthesis method has low atom utilization, so a new green and safe synthesis method for the production of phenylacetic acid is developed to become a pharmaceutical intermediate and An important research direction of pesticide intermediates

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] Add 1740g of benzene with a moisture content of less than 0.05% and 116g of glycolide into a reaction kettle equipped with heating, condensation, stirring and temperature control devices, stir and mix evenly, and then add 290g of anhydrous aluminum trichloride in batches into the system and stir to disperse evenly; raise the temperature of the system to 80°C, and continue the reaction for 3 h under constant stirring; Dissolve the newly formed precipitate; after standing and stratifying, the benzene layer is rotated and evaporated to recover benzene, and the product after recovering benzene is vacuum-dried to obtain 271g of crude phenylacetic acid; the crude phenylacetic acid is decompressed at 2 mmHg with warm water at 50°C as the cooling medium After distillation, 261.4 g of phenylacetic acid with a purity of 99.8% was obtained.

Embodiment 2

[0022] Add 2430g of benzene with a moisture content of less than 0.05% and 116g of glycolide into a reaction kettle equipped with heating, condensation, stirring and temperature control devices, stir and mix evenly, and then add 310g of anhydrous aluminum trichloride in batches into the system and stir to disperse evenly; raise the temperature of the system to 70°C, and continue the reaction for 4 h under constant stirring; The resulting precipitate was dissolved; after standing and stratifying, the benzene layer was rotated and evaporated to recover benzene, and the product after recovering benzene was vacuum-dried to obtain 274g of crude phenylacetic acid; the crude phenylacetic acid was distilled under reduced pressure at 2 mmHg with warm water at 50°C as the cooling medium 263.8 g of phenylacetic acid with a purity of 99.7% was obtained.

Embodiment 3

[0024] Add 2550g of benzene with a moisture content of less than 0.05% and 318g of anhydrous aluminum trichloride into a reaction kettle equipped with heating, condensation, stirring and temperature control devices, stir and mix evenly, and then add 116g of glycolide in batches into the system and stir to disperse evenly; raise the temperature of the system to 45°C, and continue to react for 16 h under constant stirring; The resulting precipitate was dissolved; after standing and stratifying, the benzene layer was rotary evaporated to recover benzene, and after the recovery of benzene, 272g of crude phenylacetic acid was obtained by vacuum drying; the crude phenylacetic acid was obtained by distillation under reduced pressure at 2 mmHg with warm water at 50°C as the cooling medium 261.0 g of phenylacetic acid with a purity of 99.5%.

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PUM

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Abstract

The invention discloses a synthesizing method for phenylacetic acid. The synthesizing method comprises the following steps: enabling benzene and glycolide or oligoglycolic acid in the mass ratio of (25 to 5) to 1 to react for 1 to 24 hours at the temperature of 35 to 80 DEG C under the catalysis of Lewis acid with the amount-of-substance of 1.0 to 1.3 times that of oxyacetyl; performing quenchingreaction by using water, adding an inorganic strong acid for acidifying, performing oil-water phase stratifying, removing a solvent by distilling, and drying to obtain the phenylacetic acid product. According to the synthesizing method, highly toxic chemicals, such as hydrogen cyanide and carbon monoxide, are not selected and used so as to eliminate product safety concerns caused by micro-raw material residue or trace raw material residue; extremely high reactive pressure conditions are also not adopted, so that high-pressure reaction equipment is not required to be used; therefore, the safetyin a production process is improved; meanwhile, the raw materials used in the synthesizing method is high in biodegradability, green and safe; and synthesized reaction atoms have high economical efficiency and good economical efficiency.

Description

technical field [0001] The invention relates to a synthesis method of phenylacetic acid, that is, the selective Friedel-Crafts alkylation reaction of benzene and glycolide or oligoglycolic acid to synthesize phenylacetic acid, which belongs to the technical field of organic compound synthesis. Background technique [0002] Phenylacetic acid is a synthetic hypnotic drug luminal, anticonvulsant drug mesurin, cardiovascular drug methimazole, antirheumatic drug methamphetamine, appetite suppressant drug benzfetamine, antiarrhythmic drug lorcainide, hypolipidemic drug An important intermediate of atorvastatin, the anticholinergic drug atropine, and the hormone testosterone nandrolone phenylacetate, and an important substrate for the production of penicillin by fermentation, as well as the synthetic insecticide Daofengsan, the fungicide benalaxyl, and the herbicide triclosan An important intermediate of phenylacetic acid. Natural phenylacetic acid exists in cocoa, coffee and stra...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C51/09C07C57/32
CPCC07C51/09C07C57/32
Inventor 胡学一方云张磊
Owner TAIXING LINGFEI CHEM TECH CO LTD
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