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Preparation method of p-alkyl catechol

A technology of alkyl catechol and catechol, which is applied in the field of preparation of p-alkyl catechol, can solve problems such as poor selectivity, equipment corrosion, poor product quality and yield, and achieve good product quality , Less by-products, high activity effect

Active Publication Date: 2012-05-23
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method has poor selectivity, more by-products 3-TBC and 3,5-DTBC, poor product quality and yield
[0005] CN101012155A has reported that adopting the composite of concentrated sulfuric acid and p-toluenesulfonic acid as catalyst, pyrocatechol and isobutylene as raw material synthesis technique, this technique omits neutralization, washing and separation treatment, direct rectification obtains product, but with Acid high-temperature distillation is very corrosive to equipment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0016] The preparation method of the supported heteropolyacid catalyst of the present invention is as follows: fully mixing the heteropolyacid solution and the carrier to form a sol, and then drying, calcining and pulverizing the sol. The heteropolyacid solution is a solution of heteropolyacid in polar solvents such as water, alcohol, aldehyde, ketone, ether, etc., and the solvent is preferably methanol, ethanol or water. The concentration of the heteropolyacid solution is preferably 0.01 to 0.5 g / ml. The drying temperature is preferably 80-120°C, the drying time is preferably 2-5 hours, the calcination temperature is preferably 250-350°C, and the calcination time is preferably 2-5 hours.

[0017] The synthesis reaction of the present invention is preferably carried out under nitrogen protection. Before the reaction, the catechol is heated and melted in a nitrogen environment, raised to the reaction temperature under stirring conditions, and an alkylating agent is added for re...

example 1

[0022] (1) Preparation of catalyst

[0023] Mix phosphotungstic acid and ethanol to make a solution with a concentration of 0.2g / ml, take 80ml of phosphotungstic acid solution and 24.0g of SiO 2 Mix evenly to form a sol, dry at 120°C for 4 hours, bake at 300°C for 4 hours, and pulverize to obtain a supported catalyst A, which contains 40% by mass of phosphotungstic acid.

[0024] (2) Preparation of p-tert-butylcatechol

[0025] Add 165.2g (1.5mol) of catechol, 33.0g of catalyst A in a four-necked flask with a mechanical stirrer, a thermometer, an air inlet conduit and a liquid-sealed condenser connected, and feed N 2 Gas, replace the air in the reaction system, then heat and melt catechol, raise the temperature to 130°C under stirring, feed isobutene gas, adjust the ventilation speed of isobutene, control the pressure of the reaction system to 0.1015MPa, and feed 84.0 MPa within 3 hours g (1.5 mol) of isobutene, after ventilation is completed, continue to react at this tempe...

example 2

[0027] Add 165.2g (1.5mol) of catechol, 25.5g of Catalyst A into a four-neck flask with mechanical stirring, thermometer, dropping funnel, water separator and a condenser connected to a liquid seal, and feed into N 2 Gas, replace the air in the reaction system, then heat and melt catechol, raise the temperature to 120°C under stirring, add methyl tert-butyl ether liquid dropwise, adjust the dropping speed, control the reaction system pressure to 0.1015MPa, within 3 hours Add 110.2 g (1.25 mol) of methyl tert-butyl ether dropwise. After the addition is complete, react at this temperature for 1.5 hours, cool down to 90° C. within 15 minutes, continue to react for 1.5 hours, and stop the reaction. The methanol by-product produced by the reaction is separated from the water separator, and the reaction mixture is directly rectified to obtain the raw material catechol, the middle distillate, the p-tert-butyl catechol product and the rectification residue including the catalyst. The ...

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Abstract

The invention relates to a preparation method of p-alkyl catechol; the method comprises the step of carrying out alkylation reaction on catechol and alkylating agent in the presence of a supported heteropoly acid catalyst, wherein the supported heteropoly acid catalyst comprises 20-70% of heteropoly acid and 30-80% of carrier by mass, the carrier is selected from silicon dioxide, activated carbon or HZSM-5 zeolite, and the alkylating agent is olefin with C4-C6 or ether with C5-C8. The catalyst used in the method has the advantages of high activity, good selectivity, good product quality and high yield.

Description

technical field [0001] The invention relates to a preparation method of p-alkylcatechol. Background technique [0002] 4-tert-butylcatechol (4-TBC for short) is a white or light yellow crystal, mainly used as a high-efficiency polymerization inhibitor in the polymer industry, and can be applied to styrene, butadiene, chloroprene, acrylic acid and its esters Distillation and storage and transportation of monomers such as At 60°C, its polymerization inhibition effect is 25 times higher than that of hydroquinone. It can also be used as an antioxidant for oil, rubber, nylon and other polymers, lubricating oil and other oils, and can also be used as a stabilizer for soil, pesticides and various organic compounds. [0003] At present, the main method of synthesizing 4-TBC is that catechol reacts with alkylating agents such as tert-butanol or isobutene under the catalysis of liquid strong acid, and undergoes layering, neutralization, washing, water separation, drying and rectific...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C39/08C07C37/14C07C37/16
Inventor 韩恒文段庆华李勇黄作鑫
Owner CHINA PETROLEUM & CHEM CORP