CN110386868A

CN110386868A - The preparation method of one kind 2,4,6- trimethylbenzoic acid

Info

Publication number: CN110386868A
Application number: CN201810366146.6A
Authority: CN
Inventors: 孙建; 郑康健
Original assignee: Tianjin Mo Sen Science And Technology Ltd
Current assignee: Tianjin Mo Sen Science And Technology Ltd
Priority date: 2018-04-23
Filing date: 2018-04-23
Publication date: 2019-10-29

Abstract

The present invention provides a kind of preparation method of 2,4,6- trimethylbenzoic acids, comprising the following steps: step (1): Friedel-Crafts reaction: with 1,3,5- trimethylbenzene for raw material, carrying out Friedel-Crafts reaction with trichloro-acetic chloride under the effect of the catalyst；Step (2): hydrolysis: product obtained in step (1) hydrolyzes in acid condition obtains 2,4,6- trimethylbenzoic acids, the present invention has reaction conversion ratio high, small, the advantages that yield and purity of product improve is polluted, industrialized production is suitable for.

Description

The preparation method of one kind 2,4,6- trimethylbenzoic acid

Technical field

The invention belongs to technical field of organic chemistry, more particularly, to a kind of preparation side of 2,4,6- trimethylbenzoic acids Method.

Background technique

UV i.e. UV ultraviolet light solidification, be using in UV ultraviolet light, shortwave (300-800 nanometers) solidify, In Under UV radiation, photoinitiator in liquid UV material is stimulated to become free radical or cation, contains active function groups to cause High molecular material (resin) aggregate into insoluble (not melting) solid paint film process, phosphinoxides initiator such as TPO/819/ TPO-L etc. is widely used in the industries such as the cured ink of UV, coating, and 2,4,6- trimethylbenzoic acids are as production TPO/819/ The primary raw material of TPO-L only has the production of 1-2 family at home, the first technique used is reacted using CO 2 high pressure, existed Conversion per pass is low, byproduct mostly with seriously polluted problem；Second of technique uses the carbon tetrachloride of state control as master Raw material is wanted, yield is low, is difficult to be suitble to industrialized production.

Summary of the invention

The problem to be solved in the present invention is to provide a kind of preparation methods of 2,4,6- trimethylbenzoic acids, using 1,3,5- tri- Methylbenzene is raw material, carries out Friedel-Crafts reaction with trichloro-acetic chloride under the catalytic action of lewis acid or solid super-strong acid, obtains Product hydrolyze obtain 2,4,6- trimethylbenzoic acids in acid condition, high conversion rate, product purity is high, and pollution is small, holds It is easy to realize industrial production.

In order to solve the above technical problems, the technical solution adopted by the present invention is that: the system of one kind 2,4,6- trimethylbenzoic acid Preparation Method, comprising the following steps:

Step (1): Friedel-Crafts reaction: with 1,3,5- trimethylbenzene be raw material, under the effect of the catalyst with trichloro-acetic chloride Carry out Friedel-Crafts reaction, reaction equation are as follows:

Step (2): hydrolysis: product obtained in step (1) hydrolyzes in acid condition obtains 2,4,6- trimethyls Benzoic acid, reaction equation are as follows:

Further, the catalyst in step (1) is lewis acid or solid super-strong acid.

Further, the lewis acid includes alchlor, ferric trichloride or zinc dichloride.

Further, the reaction temperature of step (1) is -20 DEG C -50 DEG C.

Further, the reaction temperature of step (1) is 0 DEG C -30 DEG C.

Further, the weight feed ratio in step (1) between 1,3,5- trimethylbenzenes, trichloro-acetic chloride and catalyst is 0.8-20:1-3:1-2。

Compared with prior art, the present invention has the advantage that is with beneficial effect:

The present invention shortens the manufacturing cycle of product, only using the preparation method of 2,4,6- completely new trimethylbenzoic acids Final products can be obtained by Friedel-Crafts reaction and two step of hydrolysis, realize reaction conversion ratio height, pollute small, the receipts of product Rate and purity improve, and are suitable for industrialized production.

Specific embodiment

It elaborates below to a specific embodiment of the invention.

The preparation method of one kind 2,4,6- trimethylbenzoic acid, comprising the following steps:

Further, the catalyst in step (1) is lewis acid or solid super-strong acid, and wherein lewis acid includes trichlorine Change aluminium, ferric trichloride or zinc dichloride.

Further, the reaction temperature of step (1) be -20 DEG C -50 DEG C, it is preferred that the reaction temperature of step (1) be 0 DEG C - It 30 DEG C, can guarantee the adequacy of material reaction in this temperature range, effectively reduce the generation of by-product.

Further, the weight feed ratio in step (1) between 1,3,5- trimethylbenzenes, trichloro-acetic chloride and catalyst is 0.8-20:1-3:1-2, by experimental verification, in the range of this feed ratio, the purity of obtained final products is higher.

Embodiment 1

1,3, the 5- anhydrous tri-chlorinations of trimethylbenzene 500g and 150g are put under nitrogen protection into the four-hole boiling flask of 1000mL Aluminium is opened and stirs and cool to 0-5 DEG C, and 180g trichloro-acetic chloride is slowly added dropwise and keeps temperature lower than 10 DEG C, after being added dropwise After the reaction was continued 2 hours plus the hydrolysis of the ice water of the dilute hydrochloric acid containing 1000ml, standing separate organic layer, are evaporated under reduced pressure out unreacted 1, 3,5- trimethylbenzene recycleds obtain 2,4,6- trimethylbenzoic acid 156g products, purity 98.6%, yield 95%.

Embodiment 2

1,3, the 5- anhydrous tri-chlorinations of trimethylbenzene 500g and 135g are put under nitrogen protection into the four-hole boiling flask of 1000mL Aluminium is opened and stirs and cool to 0-5 DEG C, and 180g trichloro-acetic chloride is slowly added dropwise and keeps temperature lower than 5 DEG C, is added dropwise subsequent After continuous reaction 2 hours plus the ice water hydrolysis of the dilute hydrochloric acid containing 1000ml, standing separate organic layer, are evaporated under reduced pressure out unreacted 1,3, 5- trimethylbenzene recycled obtains 2,4,6- trimethylbenzoic acid 148g products, purity 98.1%, yield 90%.

Embodiment 3

1,3, the 5- anhydrous tri-chlorinations of trimethylbenzene 500g and 140g are put under nitrogen protection into the four-hole boiling flask of 1000mL Aluminium is opened and stirs and cool to 0-5 DEG C, and 190g trichloro-acetic chloride is slowly added dropwise and keeps temperature lower than 20 DEG C, after being added dropwise After the reaction was continued 2 hours plus the hydrolysis of the ice water of the dilute hydrochloric acid containing 1000ml, standing separate organic layer, are evaporated under reduced pressure out unreacted 1, 3,5- trimethylbenzene recycleds obtain 2,4,6- trimethylbenzoic acid 160g products, purity 98.3%, yield 93%.

The present invention by the preparation methods of 2,4,6- completely new trimethylbenzoic acids, and combine to reaction temperature, feed ratio, The adjustment of the response parameters such as catalyst type, by embodiment 1,2 and 3, it can be seen that finally obtained product purity reaches 98% or more, product yield has reached unexpected technical effect, while the by-product generated using the method 90% or more Product are few, and environmental pollution is small, are suitable for industrialized production.

One embodiment of the present invention has been described in detail above, but the content is only preferable implementation of the invention Example, should not be considered as limiting the scope of the invention.It is all according to all the changes and improvements made by the present patent application range Deng should still be within the scope of the patent of the present invention.

Claims

1. one kind 2,4, the preparation method of 6- trimethylbenzoic acid, it is characterised in that: the following steps are included:

Step (1): it Friedel-Crafts reaction: with 1,3,5- trimethylbenzene for raw material, is carried out under the effect of the catalyst with trichloro-acetic chloride Friedel-Crafts reaction, reaction equation are as follows:

Step (2): hydrolysis: product obtained in step (1) hydrolyzes in acid condition obtains 2,4,6- trimethylbenzene first Acid, reaction equation are as follows:

2. according to claim 1 a kind of 2, the preparation method of 4,6- trimethylbenzoic acids, it is characterised in that: step (1) In catalyst be lewis acid or solid super-strong acid.

3. according to claim 2 a kind of 2, the preparation method of 4,6- trimethylbenzoic acids, it is characterised in that: the Louis This acid includes alchlor, ferric trichloride or zinc dichloride.

4. according to claim 1 a kind of 2, the preparation method of 4,6- trimethylbenzoic acids, it is characterised in that: step (1) Reaction temperature be -20 DEG C -50 DEG C.

5. according to claim 4 a kind of 2, the preparation method of 4,6- trimethylbenzoic acids, it is characterised in that: step (1) Reaction temperature be 0 DEG C -30 DEG C.

6. according to claim 1 a kind of 2, the preparation method of 4,6- trimethylbenzoic acids, it is characterised in that: step (1) In weight feed ratio between 1,3,5- trimethylbenzenes, trichloro-acetic chloride and catalyst be 0.8-20:1-3:1-2.