CN114315556B

CN114315556B - Preparation method of aromatic acid

Info

Publication number: CN114315556B
Application number: CN202111620201.8A
Authority: CN
Inventors: 李俊; 付晓静; 陈睿; 韩玉婵; 韩琪
Original assignee: Shanghai Institute of Technology
Current assignee: Shanghai Institute of Technology
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-03-31
Anticipated expiration: 2041-12-28
Also published as: CN114315556A

Abstract

The invention relates to a preparation method of aromatic acid, which takes alkaline resin as a catalyst and oxygen as an oxidant to oxidize aromatic aldehyde into the aromatic acid. Compared with the prior art, the method has the advantages of mild reaction conditions, few byproducts, high yield of target products, easy separation and recycling of the catalyst, environment friendliness and the like, and accords with the green development concept.

Description

Preparation method of aromatic acid

Technical Field

The invention relates to the technical field of heterogeneous catalytic reaction, in particular to a preparation method of aromatic acid.

Background

Aromatic acid compounds are important organic chemical raw materials, and main structural units of the aromatic acid compounds are commonly used in pesticides and medicines. The aromatic carboxylic acid can be made into ester, amide, acid anhydride, halide, etc., and has wide application.

The preparation of corresponding carboxylic acid by aldehyde oxidation is a main production process for preparing organic acid at present, and a reaction system takes metal salt as a catalyst (mostly salts of manganese, iron, cobalt, nickel, ruthenium, rhodium, palladium, copper and the like), such as acetate or naphthenate. In patent CN200510054082.9, propionic acid is prepared by oxidizing propionaldehyde with propionate or acetate or naphthenate as a catalyst. For another example, in the device for producing acetic acid by oxidizing acetaldehyde, manganese acetate is used as a catalyst to timely decompose peracetic acid generated during the oxidation of acetaldehyde. At the same time, the metal salt can promote the generation of free radicals and accelerate the initiation reaction of the chain, the reaction time is obviously shortened, but the reaction is difficult to control along with the rapid progress of the exothermic reaction, the selectivity is reduced along with the reaction, and the defects of low atom economy, more byproducts, serious environmental pollution and the like are caused. In recent years, there have also been many researchers designing transition metal ions as heterogeneous systems for the oxidation of aldehydes. In patent CN112657510A, pd-Co/C or Pd-Cu/C is used as a catalyst to oxidize aldehyde into acid, but inorganic alkali liquor is required to be added in a reaction system as a cocatalyst, so that the subsequent treatment difficulty is increased.

Disclosure of Invention

The invention aims to provide a method for preparing aromatic acid by oxidizing aromatic aldehyde.

The purpose of the invention can be realized by the following technical scheme: a process for preparing aromatic acid features that the basic resin is used as catalyst and oxygen is used as oxidant to oxidize aromatic aldehyde into aromatic acid.

Preferably, the preparation method comprises mixing and heating aromatic aldehyde, solvent and alkaline resin, carrying out oxidation reaction in an oxygen atmosphere, and separating the alkaline resin and the solvent after the reaction is finished to obtain the aromatic acid.

Further preferably, the preparation method specifically comprises the following steps:

(1) Mixing and heating aromatic aldehyde, a solvent and alkaline resin, and adding the mixture into a reaction kettle;

(2) Replacing air in the kettle with oxygen;

(3) Starting magnetic stirring, and heating the reaction mixed solution to a target temperature;

(4) Further charging oxygen to set pressure, and starting timing reaction to set reaction time;

(5) After the reaction is finished, cooling the reaction mixture to room temperature;

(6) The resin catalyst is separated by filtration and the solvent is then removed from the reaction mixture by evaporation to give the aromatic acid.

Preferably, the solvent is one or more of acetonitrile, water, dichloroethane and octane.

More preferably, the solvent is a mixture of two of acetonitrile, water, dichloroethane and octane which are mixed according to a volume ratio of 1:1.

Preferably, the molar ratio of the aromatic aldehyde to the solvent to the basic resin is 1 (4-20) to (0.03-0.15).

Preferably, the target temperature in the step (3) is 30-80 ℃, the reaction time in the step (4) is 30-60 min, and the set pressure is 0.1-2 MPa.

Preferably, the basic resin is a D201 strongly basic anion exchange resin.

Preferably, the basic resin is soaked with sodium hydroxide solution before use, filtered and washed to neutrality.

Further preferably, the alkaline resin is soaked in 2% sodium hydroxide solution for 24 hours before use, and then is filtered and washed to be neutral by deionized water for later use.

Preferably, the aromatic aldehyde comprises benzaldehyde, phenylacetaldehyde, p-tolualdehyde, 4-isopropylbenzaldehyde or 2,4,6-trimethylbenzaldehyde.

Compared with the prior art, the invention has the following advantages:

1. the preparation method has mild reaction conditions, environment-friendly technical process and high yield of target products;

2. the invention reacts for 30-60 min at 30-80 ℃ to obtain the aromatic acid with high yield;

3. the catalyst, namely the basic resin D201, is cheap and easy to obtain, is easy to separate and recycle, and has stable performance under the operating condition of the process;

4. the method has the advantages of few byproducts, high product purity, high yield and good economic benefit;

5. the method has the advantages of simple process, high safety and small environmental pollution, and accords with the green development concept.

Detailed Description

The following examples are given to illustrate the present invention, and the following examples are carried out on the premise of the technical solution of the present invention, and give detailed embodiments and specific procedures, but the scope of the present invention is not limited to the following examples.

Example 1

A preparation method of aromatic acid comprises the steps of firstly adding 0.04mol of reaction substrate benzaldehyde, 20ml of solvent and 0.6g of D-201 resin into a reaction kettle, heating reaction mixed liquid to 45 ℃, replacing air in the kettle by using oxygen, further filling oxygen to 0.6MPa, reacting for 40min, cooling the reaction kettle to room temperature, and evaporating the solvent to obtain the target product benzoic acid. The results are shown in the following table.

Example 2

A preparation method of aromatic acid comprises the steps of firstly adding 0.04mol of benzaldehyde as a reaction substrate, 20ml of acetonitrile and 0.6g of D-201 resin into a reaction kettle, heating a reaction mixed solution to 48 ℃, replacing air in the kettle by using oxygen, further filling oxygen to 0.6MPa, reacting for 40min, cooling the reaction kettle to room temperature, and evaporating to remove a solvent to obtain a target benzoic acid with the yield of 83%.

Example 3

A preparation method of aromatic acid comprises the steps of firstly adding 0.04mol of benzaldehyde as a reaction substrate, 20ml of acetonitrile and 0.6g of D-201 resin into a reaction kettle, heating a reaction mixed solution to 45 ℃, replacing air in the kettle by using oxygen, further filling oxygen to 0.8MPa, reacting for 40min, cooling the reaction kettle to room temperature, and evaporating a solvent to obtain a target product, namely benzoic acid, wherein the yield is 89%.

Example 4

A preparation method of aromatic acid comprises the steps of firstly adding 0.04mol of benzaldehyde as a reaction substrate, 20ml of acetonitrile and 0.6g of D-201 resin into a reaction kettle, heating a reaction mixed solution to 48 ℃, replacing air in the kettle by using oxygen, further filling oxygen to 1.0MPa, reacting for 40min, cooling the reaction kettle to room temperature, and evaporating a solvent to obtain a target product, namely benzoic acid, wherein the yield is 87%.

Example 5

A preparation method of aromatic acid comprises the steps of firstly adding 0.04mol of reaction substrate aromatic aldehyde, 20ml of acetonitrile and 0.6g of D-201 resin into a reaction kettle, heating reaction mixed liquid to 48 ℃, replacing air in the kettle by using oxygen, further filling oxygen to 0.6MPa, reacting for 40min, cooling the reaction kettle to room temperature, and evaporating off a solvent to obtain a target product aromatic acid, wherein the results are shown in the table below.

Example 6

A preparation method of aromatic acid comprises the steps of firstly adding 0.04mol of reaction substrate 4-isopropyl benzaldehyde, 20ml of dichloroethane and 0.6g of D-201 resin into a reaction kettle, heating reaction mixed liquid to 45 ℃, replacing air in the kettle by using oxygen, further filling oxygen to 2MPa, reacting for 40min, cooling the reaction kettle to room temperature, and evaporating off a solvent to obtain a target product aromatic acid, wherein the yield is 54%.

Example 7

A preparation method of aromatic acid comprises the steps of firstly adding 0.04mol of benzaldehyde as a reaction substrate, 20ml of octane and 0.6g of D-201 resin into a reaction kettle, heating a reaction mixed solution to 45 ℃, replacing air in the kettle by using oxygen, further filling oxygen to 0.6MPa, reacting for 40min, cooling the reaction kettle to room temperature, and evaporating a solvent to obtain the target aromatic acid with the yield of 65%.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. A preparation method of aromatic acid is characterized in that basic resin is used as a catalyst, oxygen is used as an oxidant, and aromatic aldehyde is oxidized into aromatic acid;

the basic resin is D201 strong-base anion exchange resin.

2. The method according to claim 1, wherein the aromatic acid is obtained by mixing and heating an aromatic aldehyde, a solvent and a basic resin, performing an oxidation reaction in an oxygen atmosphere, and separating the basic resin and the solvent after the reaction.

3. The method for preparing an aromatic acid according to claim 2, comprising the steps of:

(2) Replacing air in the kettle with oxygen;

(3) Starting magnetic stirring, and heating the reaction mixed solution;

(4) Further charging oxygen for oxidation reaction;

4. The method according to claim 2 or 3, wherein the solvent is a mixture of one or more of acetonitrile, water, dichloroethane, and octane.

5. The method as claimed in claim 4, wherein the solvent is a mixture of two of acetonitrile, water, dichloroethane and octane in a volume ratio of 1:1.

6. The method according to claim 2 or 3, wherein the molar ratio of the aromatic aldehyde to the solvent to the basic resin is 1 (4) - (20) to (0.03) - (0.15).

7. The method for producing an aromatic acid according to claim 2 or 3, wherein the oxidation reaction temperature is from 30 to 80 ℃, the time is from 30 to 60min, and the pressure is from 0.1 to 2MPa.

8. The method of claim 1, wherein the basic resin is soaked in sodium hydroxide solution before use, filtered and washed to neutrality.

9. The method according to claim 1, wherein the aromatic aldehyde is selected from the group consisting of benzaldehyde, phenylacetaldehyde, p-tolualdehyde, 4-isopropylbenzaldehyde, and 2,4,6-trimethylbenzaldehyde.