Method for cycloaddition of dimethyl muconate

Patent metadata

Field	Value
Publication number	US-10913702-B2
Application number	US-201816771999-A
Country	US
Kind code	B2
Filing date	Dec 14, 2018
Priority date	Jan 15, 2018
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A method for cycloaddition of dimethyl muconate is disclosed. According to the method, a direct transferring of a solid phase trans,trans-dimehtyl muconate into a reactor pre-filled with ethylene gas increases the efficiency of the reaction and suppress side reactions resulting an improvements in yield and purity. Furthermore, the method is capable of obtaining a high yield of dimethylcyclohex-2-en-1,4-dicarboxylate at a lower cost, and therefore is also useful for the mass synthesis of dimethyl terephthalate.

First claim

The invention claimed is:

1. A process for cycloaddition of dimethyl muconate, which comprises:
(1) preparing a reactor filled with ethylene gas; and
(2) introducing a compound of the following Formula 1 in a solid phase to the reactor and carrying out a cycloaddition reaction to obtain a compound of the following Formula 2

2. The process for cycloaddition of dimethyl muconate of claim 1 , wherein the reactor in step (1) has an internal pressure of 140 bar or more.

3. The process for cycloaddition of dimethyl muconate of claim 1 , wherein the reactor in step (1) has an internal temperature of 170 to 250° C.

4. The process for cycloaddition of dimethyl muconate of claim 1 , wherein in step (2), the compound of Formula 1 is divided into two or more and then introduced into the reactor.

5. The process for cycloaddition of dimethyl muconate of claim 4 , wherein the cycloaddition reaction is carried out for 1 to 6 hours at the time of each divided introduction.

6. The process for cycloaddition of dimethyl muconate of claim 1 , wherein the reactor in step (1) is filled with a solvent for the cycloaddition reaction of the compound of Formula 1.

7. The process for cycloaddition of dimethyl muconate of claim 6 , wherein the total amount of the compound of Formula 1 divided and introduced into the reactor is 1.0 to 3.0 moles based on 1 liter of the solvent, and the yield of the cycloaddition reaction is 85% or more.

8. The process for cycloaddition of dimethyl muconate of claim 6 , wherein in step (2), the compound of Formula 1 is divided into two or more and then introduced into the reactor; and
the amount of the compound of Formula 1 introduced into the reactor at each time is 0.1 to 0.5 mole based on 1 liter of the solvent.

9. The process for cycloaddition of dimethyl muconate of claim 8 , wherein the total amount of the compound of Formula 1 divided and introduced into the reactor is 1.0 to 3.0 moles based on 1 liter of the solvent.

10. The process for cycloaddition of dimethyl muconate of claim 6 , wherein the solvent is selected from the group consisting of meta-xylene, tetrahydrofuran, ethyl acetate, dimethyl ethylene glycol, N-methyl pyrrolidone, dimethylsulfoxide, and mixtures thereof.

11. The process for cycloaddition of dimethyl muconate of claim 1 , wherein the reactor in step (1) is filled with a solvent for the cycloaddition reaction of the compound of Formula 1 and has an internal pressure of 140 bar or more and an internal temperature of 170 to 250° C.; and
in step (2), the compound of Formula 1 is divided into two or more and then introduced into the reactor, wherein the amount of the compound of Formula 1 introduced into the reactor at each time is 0.1 to 0.5 mole based on 1 liter of the solvent, the total amount of the compound of Formula 1 divided and introduced into the reactor is 1.0 to 3.0 moles based on 1 liter of the solvent, and the cycloaddition reaction is carried out for 1 to 6 hours at the time of each divided introduction.

12. A process for preparing dimethyl terephthalate, which comprises:
(1) preparing a reactor filled with ethylene gas;
(2) introducing a compound of the following Formula 1 in a solid phase to the reactor and carrying out a cycloaddition reaction to obtain a compound of the following Formula 2; and
(3) obtaining dimethyl terephthalate from the compound of Formula 2 through an aromatization reaction

Assignees

• Sk Chemicals Co Ltd

Inventors

• Park Jae Kyun
• Park Jeong Ho
• Chae Hee-Il

Classifications

• C07C69/82

  Terephthalic acid esters · CPC title

• C07C69/75

  of acids with a six-membered ring · CPC title

• C07C67/62

  Use of additives, e.g. for stabilisation · CPC title

• C07C67/347 Primary

  by addition to unsaturated carbon-to-carbon bonds · CPC title

• C07C67/317 Primary

  by splitting-off hydrogen or functional groups; by hydrogenolysis of functional groups · CPC title