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Preparation method for tert-butyl substituted hydroxybenzoate

A technology of hydroxybenzoate and hydroxybenzoate, applied in the field of preparation of tert-butyl substituted hydroxybenzoate, can solve the problem of low yield of hydroxybenzoate and halogenated hydrocarbon esterification, tert-butyl Solve the problems of butyl leaving and other problems, and achieve the effects of easy purification, reduction of by-products and high yield

Active Publication Date: 2020-03-06
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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  • Preparation method for tert-butyl substituted hydroxybenzoate
  • Preparation method for tert-butyl substituted hydroxybenzoate
  • Preparation method for tert-butyl substituted hydroxybenzoate

Examples

Experimental program
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Effect test

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 for a tert-butyl substituted hydroxybenzoate, belongs to the field of fine chemical engineering, and aims to solve the problem of leave of t-butyl in the dehydration and esterification reaction process of a sulfonate catalyst. The method includes the following steps: A, adding a halogenated hydrocarbon and a quaternary amine salt catalyst into intermediate tert-butyl substituted hydroxybenzoate obtained after a Kolbe-Schmitt reaction under the condition that N,N-dimethylformamide is used as a solvent, and performing a reaction at a certain temperature to obtain an ester, wherein the hydroxybenzoate is converted into hydroxybenzoate through LC detection; and B, after the reaction is completed, adding a 10% dilute hydrochloric acid aqueous solution, performing acidification, performing extraction on the product by using toluene, combining organic phases, adding clay, performing reflux for decoloration and impurity removal, performing reduced-pressure distillation to remove the solvent, adding methanol, performing crystallization to obtain a crude product, and performing methanol recrystallization on the crude product to obtain the qualified product. The method uses the Kolbe-Schmitt reaction intermediate to prepare the t-butyl substituted hydroxybenzoate in a one-pot process, and the product has high purity and a 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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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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