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A kind of preparation method of tert-butyl substituted hydroxybenzoate

A technology of hydroxybenzoate and hydroxybenzoate, which is applied in the field of preparation of tert-butyl substituted hydroxybenzoate, and can solve the problem of tert-butyl leaving, esterification of hydroxybenzoate and halogenated hydrocarbon Low yield and other problems, to achieve the effect of reducing by-products, easy purification and high yield

Active Publication Date: 2022-05-13
GANSU RES INSTION OF CHEM IND GRICI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] The present invention aims at providing a kind of preparation method of tert-butyl substituted hydroxybenzoic acid ester, to solve the leaving problem of tert-butyl group in the dehydration esterification reaction process of sulfonate catalyst
[0011] In order to solve the problem of tert-butyl removal by catalytic reflux and water separation method at present, and the low yield of esterification of hydroxybenzoate and halogenated hydrocarbon, the present invention utilizes the Kolbe-Schmidt reaction intermediate One-pot method prepares tert-butyl substituted hydroxybenzoate, and its reaction process and mechanism are as follows:

Method used

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  • A kind of preparation method of tert-butyl substituted hydroxybenzoate
  • A kind of preparation method of tert-butyl substituted hydroxybenzoate
  • A kind of preparation method of tert-butyl substituted hydroxybenzoate

Examples

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Embodiment 1

[0030] Embodiment 1: Preparation of n-hexadecyl 5-tert-butyl-2-hydroxybenzoate

[0031] Add 172 grams of 4-tert-butylphenol sodium salt to 342 grams of N,N dimethylformamide, pass through carbon dioxide, react completely at 0.7 MPa, cool down to 15°C, add 13.0 grams of tetrabutylammonium fluoride, slowly drop Add 287 grams of hexadecane chloride, drop it in about 20 minutes, then raise the temperature to 70°C and react for 10 hours until the HPLC detection of 5-tert-butyl-2-hydroxybenzoic acid is less than 1%, and the reaction solvent is recovered by distillation under reduced pressure. The system is viscous, then add 10% hydrochloric acid to adjust the pH to neutral, extract three times with toluene, combine the organic phase and add catalytic amount of white clay to reflux for 2 hours to decolorize, evaporate a large amount of toluene until the system is viscous, add 5 times the volume of methanol and slowly cool down to Crystallize at 10°C, filter the crystals and recrystal...

Embodiment 2

[0032] Embodiment 2: Preparation of n-hexadecyl 5-tert-butyl-2-hydroxybenzoate

[0033] 172 grams of 4-tert-butylphenol sodium salt are introduced into 342 grams of N,N dimethylformamide with carbon dioxide, the reaction is complete at 0.7MPa, the temperature is lowered to 15°C, 13.0 grams of tetrabutylammonium bromide is added, slowly drop Add 287 grams of hexadecane chloride, drop it in about 20 minutes, then raise the temperature to 70°C and react for 10 hours until the HPLC detection of 5-tert-butyl-2-hydroxybenzoic acid is less than 1%, and the reaction solvent is recovered by distillation under reduced pressure. The system is viscous, then add 10% hydrochloric acid to adjust the pH to neutral, extract three times with toluene, combine the organic phase and add catalytic amount of white clay to reflux for 2 hours to decolorize, evaporate a large amount of toluene until the system is viscous, add 5 times the volume of methanol and slowly cool down to Crystallize at 10°C, f...

Embodiment 3

[0034] Embodiment 3: Preparation of n-hexadecyl 5-tert-butyl-2-hydroxybenzoate

[0035]172 grams of 4-tert-butylphenol sodium salt are introduced into 342 grams of N,N dimethylformamide with carbon dioxide, and the reaction is complete under a pressure of 0.7MPa. The temperature is lowered to 15°C, and 26.0 grams of tetrabutylammonium bromide is added, slowly Add 310 grams of hexadecane chloride dropwise, and the dropwise addition is completed in about 20 minutes, then raise the temperature to 75°C and react for 10 hours until the HPLC detection of 5-tert-butyl-2-hydroxybenzoic acid is less than 1%, and the reaction solvent is recovered by distillation under reduced pressure When the system is viscous, add 10% hydrochloric acid to adjust the pH to neutral, extract three times with toluene, combine the organic phase and add a catalytic amount of white clay to reflux for 2 hours to decolorize, evaporate a large amount of toluene until the system is viscous, then add 5 times the v...

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Abstract

The invention discloses a preparation method of tert-butyl substituted hydroxybenzoate, which belongs to the field of fine chemical industry and aims to solve the problem of leaving tert-butyl group in the dehydration esterification reaction process of sulfonate catalyst. The method comprises the following steps: A, using the intermediate tert-butyl substituted hydroxybenzoate after the Kolbe-Kolbe-Schmidt reaction under the condition that N,N dimethylformamide is used as a solvent, The ester can be obtained by adding a halogenated hydrocarbon and a quaternary ammonium salt catalyst to react at a certain temperature, and the hydroxybenzoate is completely converted into a hydroxybenzoate by LC detection. B. After the reaction, add 10% dilute hydrochloric acid aqueous solution to acidify, then extract the product with toluene, combine the organic phase and add clay to reflux for decolorization and removal of impurities, add methanol to crystallize the crude product after removing the solvent under reduced pressure, and obtain a qualified product through methanol recrystallization. The invention utilizes the one-pot method of the Kolbe-Schmidt reaction intermediate to prepare tert-butyl substituted hydroxybenzoate, and the product has high purity and high yield.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a preparation method of tert-butyl substituted hydroxybenzoate. Background technique [0002] Tert-butyl substituted hydroxybenzoate is an important pharmaceutical intermediate and light stabilizer for rubber and plastics. Its main structural formula is as follows: [0003] [0004] It can be widely used in the preparation of salicylic acid ultraviolet absorbers (UV2908), and can also be added to color developing solutions, paints, cosmetics and herbicides. [0005] At present, the preparation of tert-butyl-substituted hydroxybenzoate at home and abroad is to prepare the corresponding hydroxybenzoic acid through the Kolbe-Schmitt reaction, and then prepare the corresponding ester by reacting with alcohol. There are two common methods, the first is tert-butyl substituted hydroxybenzoic acid and alcohol under the catalysis of acid (p-toluenesulfonic acid, sulfuric acid...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C67/11C07C67/52C07C69/84C07C51/15C07C51/02C07C65/05
CPCC07C67/11C07C67/52C07C51/15C07C51/02C07C65/05C07C69/84
Inventor 刘荣王永胜韩正支曹碧霞
Owner GANSU RES INSTION OF CHEM IND GRICI
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