Preparation method of 2-(4-alkylphenyl) propanoic acid

A technology of alkylphenyl and alkylbenzene, applied in the field of synthesis of 2-propionic acid, achieving the effects of low production cost, low reaction conditions, and short synthesis steps

Inactive Publication Date: 2011-09-28
SHANGHAI QIBAO HIGH SCHOOL
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Problems solved by technology

However, the carbonylation reaction needs to be completed under high pressure, and the noble metal palladium is used as the re

Method used

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  • Preparation method of 2-(4-alkylphenyl) propanoic acid
  • Preparation method of 2-(4-alkylphenyl) propanoic acid
  • Preparation method of 2-(4-alkylphenyl) propanoic acid

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Embodiment 12

[0026] The preparation of embodiment 12-ethyl chloropropionate

[0027] Mix 10.9 g of 2-chloropropionic acid, 10 ml of absolute ethanol and 0.2 g of 98% concentrated sulfuric acid, add 10 ml of toluene to carry water, and reflux for 2 hours under a water bath condition of 80-100 ° C. Add 20% sodium hydroxide solution to the reacted mixed solution to adjust the pH value to 9, separate with a separatory funnel to obtain a toluene layer, dry the product with anhydrous sodium sulfate, and rotary evaporate to obtain ethyl 2-chloropropionate.

Embodiment 22

[0028] The synthesis of embodiment 22-(p-methylphenyl) ethyl propionate

[0029] Place 0.1mol of ethyl 2-chloropropionate, 60ml of toluene and 2 grams of anhydrous aluminum chloride in a three-necked flask, and a low-temperature circulation pump (using absolute ethanol as a refrigerant in laboratory conditions) controls the temperature at 0°C, mechanically The reaction was stirred for 24 hours. Friedel-Crafts reaction of ethyl 2-chloropropionate with toluene produces ethyl 2-(p-methylphenyl)propionate.

Embodiment 32

[0030] The preparation of embodiment 32-(p-methylphenyl) propionic acid

[0031] Add 10% dilute hydrochloric acid to the product of Example 2 and heat to 80° C. to hydrolyze the ester, and recover ethanol by distillation. After 20 minutes of reaction, add water to destroy the unfinished aluminum chloride. The toluene layer was obtained by liquid separation, and the obtained mixture was evaporated to toluene to obtain the product 2-(p-methylphenyl)propionic acid.

[0032] The prepared sample was submitted for inspection, and the relative molecular mass of the determined sample was 164.1, which was consistent with the relative molecular mass of 2-(p-methylphenyl)propionic acid. The GCMS spectrum is shown in (a) and (b) of Figure 1, and the hydrogen nuclear magnetic resonance spectrum ( figure 2 ) shows that there are 5 groups of peaks, the integral values ​​are 1.00, 4.14, 0.96, 2.92, 3.19 respectively, and the ratio is close to 1:4:1:3:3, which is consistent with the molecula...

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Abstract

The invention discloses a synthesis method of 2-(4-alkylphenyl) propionic acid, which comprises the following steps of: carrying out Friedel-Crafts reaction between ethyl 2-chloro-propionate and alkyl benzene with anhydrous aluminum chloride as a catalyst to obtain an intermediate product ethyl 2-(4-alkylphenyl) propionate; and hydrolyzing the intermediate product to obtain 2-(4-alkylphenyl) propionic acid. The invention has the advantages of short synthesis step, low reaction condition, and no need for high temperature or high pressure; the atom utilization rate is high, and the invention can lower energy consumption and reduce waste discharge, meeting the requirement of green chemistry on chemical production; and inexpensive common anhydrous aluminum chloride is used as a catalyst, thus lowering the production cost; moreover, the anhydrous aluminum chloride is especially suitable for producing brufen.

Description

technical field [0001] The invention relates to the fields of pharmaceutical chemistry and organic chemistry synthesis, in particular to a synthesis method of 2-(4-alkylphenyl)propionic acid. Background technique [0002] Ibuprofen (Ibuprofen), namely 2-(4-isobutylphenyl) propionic acid, or 2-(p-isobutylphenyl) propionic acid, is a non-steroidal anti-inflammatory and analgesic drug with excellent and reliable performance. Called "Super Aspirin". Compared with aspirin, it has almost the same efficacy, but wins in gastrointestinal tolerance. The common painkiller "Fenbid" uses ibuprofen as an active ingredient, which has the effect of relieving moderate joint and muscle pain and reducing fever caused by colds. [0003] The Friedel-Crafts reaction is used in important steps of the current industrial synthesis of 2-(4-alkylphenyl)propionic acid, especially ibuprofen. Friedel-Crafts reaction (Friedel-Crafts reaction) is a type of electrophilic substitution reaction that occurs...

Claims

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Application Information

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IPC IPC(8): C07C57/30C07C51/09
Inventor 黎良枝徐奕婧段李平姚轩宇
Owner SHANGHAI QIBAO HIGH SCHOOL
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