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Method for synthesizing m-hydroxybenzaldehyde

A technology of hydroxybenzaldehyde and m-hydroxybenzoyl chloride, which is applied in the field of synthesizing m-hydroxybenzaldehyde, can solve the problems of large amount of waste water and salt, prominent environmental protection problems, and high environmental pressure, and achieve high product yield and equipment occupancy The effect of small size and fewer production steps

Inactive Publication Date: 2018-01-23
BEIJING RISUN TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This route needs to use relatively expensive stannous chloride as a reducing agent, diazotization requires low temperature, and hydrolysis will produce a large amount of acidic wastewater, which contains a large amount of waste salt, and the environmental protection problem is prominent.
Another route is the route that m-cresol is hydrolyzed to make m-hydroxybenzaldehyde after phenolic hydroxyl protection, chlorination or bromination, and this route has more by-products, and yield only has 20-30%, and needs to use chlorine, liquid Hazardous chemicals such as bromine lead to serious corrosion of equipment, a large amount of waste water and salt, and huge pressure on environmental protection

Method used

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  • Method for synthesizing m-hydroxybenzaldehyde
  • Method for synthesizing m-hydroxybenzaldehyde
  • Method for synthesizing m-hydroxybenzaldehyde

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Step (1) acid chloride:

[0030] Add 100 grams of m-hydroxybenzoic acid, 600 milliliters of toluene and 1 milliliter of N,N-dimethylformamide into the reaction flask, raise the temperature to 110°C, start to add 115 grams of thionyl chloride dropwise, and complete the addition within 1-3 hours. After adding and keeping warm, HPLC monitors the reaction process until there is no m-hydroxybenzoic acid, and the reaction is stopped to obtain m-hydroxybenzoyl chloride solution.

[0031] Step (2) hydrogenation reduction:

[0032] Add the m-hydroxybenzoyl chloride solution obtained in the previous step into the autoclave, add 20 grams of palladium carbon catalyst and 0.01 gram of poisoning agent quinoline / sulfur, add 150 grams of triethylamine, heat up to 120 ° C, and feed hydrogen until the pressure is 0.6MPa, start the reaction, during which hydrogen is constantly replenished to maintain the pressure in the reactor, react until the liquid phase monitors that there is no raw ...

Embodiment 2

[0035] Step (1) acid chloride:

[0036] Add 100 grams of m-hydroxybenzoic acid, 600 milliliters of xylene and 1 milliliter of N,N-dimethylformamide into the reaction flask, raise the temperature to 110°C, start adding 122 grams of oxalyl chloride dropwise, and finish adding in 1-3 hours. Complete heat preservation, HPLC monitors the reaction process until there is no m-hydroxybenzoic acid, stop the reaction, and obtain m-hydroxybenzoyl chloride solution.

[0037] Step (2) hydrogenation reduction:

[0038] Add the m-hydroxybenzoyl chloride solution obtained in the previous step into the autoclave, add 20 grams of palladium / barium sulfate catalyst, add 120 grams of sodium acetate, raise the temperature to 110 ° C, pass hydrogen to the pressure of 0.8 MPa, and start the reaction. Supplement hydrogen to maintain the pressure in the reactor until there is no raw material peak in the liquid phase monitoring, that is, the end of the reaction is reached, the reaction is stopped, the ...

Embodiment 3

[0041] Step (1) acid chloride:

[0042] Add 100 grams of m-hydroxybenzoic acid, 800 milliliters of dichloroethane and 1 milliliter of N,N-dimethylformamide into the reaction flask, raise the temperature to 110°C, and start adding 155 grams of phosphorus oxychloride dropwise for 1-3 hours After the addition is completed, keep warm after the addition, and monitor the reaction process by HPLC until there is no m-hydroxybenzoic acid, then stop the reaction to obtain m-hydroxybenzoyl chloride solution.

[0043] Step (2) hydrogenation reduction:

[0044] Add the m-hydroxybenzoyl chloride solution obtained in the previous step into the autoclave, add 5 grams of palladium / calcium carbonate catalyst, raise the temperature to 80°C, and let the hydrogen flow until the pressure is 0.4MPa to start the reaction. When there is no raw material peak, the end of the reaction is reached, the reaction is stopped, the reaction solution is filtered, and the filtrate is distilled under reduced pressu...

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Abstract

The invention provides a method for synthesizing m-hydroxybenzaldehyde. The method comprises, in sequence, (1) taking m-hydroxybenzoic acid as a raw material, taking N,N-dimethylformamide or N,N-dimethyl acetamide as a catalyst, and in the presence of a chloroformylation agent, carrying out a chloroformylation reaction according to the equation 1 to generate m-benzoyl chloride; and (2) in the presence of hydrogen and a catalyst, carrying out a hydrogenation reduction reaction to the m-benzoyl chloride according to the equation 2 to generate m-hydroxybenzaldehyde. The method is mild in condition, less in steps, and high in synthetic yield, and produces no waste water in the production process. Compared with a traditional method, the method is green and eco-friendly, and is energy saving andefficient, the occupation amount of equipment is small, and the quality of the product is improved.

Description

technical field [0001] The invention relates to a method for synthesizing m-hydroxybenzaldehyde, in particular to a method for synthesizing m-hydroxybenzaldehyde by using m-hydroxybenzoic acid as a raw material through steps such as acyl chloride and reduction. Background technique [0002] m-Hydroxybenzaldehyde is an important organic raw material and intermediate in the field of medicine and chemical industry. It is mainly used in the production of roxatidine, phenylephrine hydrochloride and quinine, etc., and is widely used. [0003] There are two conventional production routes of m-hydroxybenzaldehyde at present, one is to adopt m-nitrobenzaldehyde as a reactant, through reduction, diazotization and hydrolysis to obtain m-hydroxybenzaldehyde. This route needs to use relatively expensive stannous chloride as a reducing agent, diazotization requires low temperature, and hydrolysis will produce a large amount of acidic wastewater, which contains a large amount of waste salt...

Claims

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Application Information

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IPC IPC(8): C07C45/41C07C47/565
Inventor 张英伟赵会娟潘小君张敏生
Owner BEIJING RISUN TECH CO LTD
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