METHOD OF HYDROLYSIS OF DIMETHYL SUCCINYL SUCCINATE

Abstract

A method of hydrolysis of dimethyl succinyl succinate includes: adding DMSS and water to a reactor, and stirring; adding a phase transfer catalyst to the reactor, and heating; and adding an acid and a transition metal salt to the reactor for hydrolysis of DMSS. The acid is sulfuric acid, hydrochloric acid or nitric acid, and the W ion concentration of the mixture in the reactor is 0.2-12 mol/L. The transition metal salt is a nitrate, sulfate, or chloride of copper, nickel, zinc or manganese, or a combination thereof; and the metal ion concentration of the mixture in the reactor is 0.01-0.1 mol/L.

Claims

1. A method of hydrolysis of dimethyl succinyl succinate (DMSS), the method comprising: 1) adding DMSS and water to a reactor, and stirring; 2) adding a phase transfer catalyst to the reactor, and heating; and 3) adding an acid and a transition metal salt to the reactor for hydrolysis of DMSS; wherein the acid is sulfuric acid, hydrochloric acid or nitric acid, and a H.sup.+ ion concentration of a mixture in the reactor is 0.2-12 mol/L; and the transition metal salt is a nitrate, sulfate, or chloride of copper, nickel, zinc or manganese, or a combination thereof; and a metal ion concentration of the mixture in the reactor is 0.01-0.1 mol/L.

2. The method of claim 1, wherein in 1), an addition amount of the water is 5-20 times that of DMSS by weight.

3. The method of claim 1, wherein in 2), the phase transfer catalyst is dodecyl benzene sulfonic acid, sodium dodecyl benzene sulfonate, polyethylene glycol, dodecyl trimethyl ammonium chloride or tetrabutyl ammonium bromide.

4. The method of claim 1, wherein an addition amount of the phase transfer catalyst accounts for 0.01-0.1 wt. % that of the water.

5. The method of claim 1, wherein the mixture in the reactor is heated to 60-100° C., and then the acid and the transition metal salt are added to the reactor.

Description

DETAILED DESCRIPTION

[0020] To further illustrate, embodiments detailing a method of hydrolysis of dimethyl succinyl succinate are described below. It should be noted that the following embodiments are intended to describe and not to limit the disclosure.

[0021] A method of hydrolysis of dimethyl succinyl succinate (DMSS) comprises:

[0022] 1. adding DMSS and water to a reactor, and stirring, where the addition amount of the water is 5-20 times that of DMSS by weight;

[0023] 2. adding a phase transfer catalyst to the reactor, and heating; and

[0024] 3. adding an acid and a transition metal salt to the reactor for hydrolysis of DMSS when the mixture in the reactor is heated to 60-100° C.

[0025] The phase transfer catalyst is dodecyl benzene sulfonic acid, sodium dodecyl benzene sulfonate, polyethylene glycol, dodecyl trimethyl ammonium chloride or tetrabutyl ammonium bromide. The addition amount of the phase transfer catalyst accounts for 0.01-0.1 wt. % that of the water.

[0026] The acid is sulfuric acid, hydrochloric acid or nitric acid, and a H.sup.+ ion concentration of a mixture in the reactor is 0.2-12 mol/L.

[0027] The transition metal salt is a nitrate, sulfate, or chloride of copper, nickel, zinc or manganese, or a combination thereof; and the metal ion concentration of the mixture in the reactor is 0.01-0.1 mol/L.

Example 1

[0028] 200 g of DMSS and 1 L of water were mixed and stirred. 0.1 g of dodecyl benzene sulfonic acid was added to the mixture, and heated to 60° C. Thereafter, 10 g of concentrated sulfuric acid and 2.4 g of copper nitrate trihydrate were added to the mixture. 60 hours later, an orange clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 90.5%.

Example 2

[0029] 200 g of DMSS and 1 L of water were mixed and stirred. 0.3 g of sodium dodecyl benzene sulfonate was added to the mixture, and heated to 70° C. Thereafter, 25 g of concentrated sulfuric acid and 6.8 g of zinc chloride were added to the mixture. 50 hours later, a faint yellow clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 95.1%.

Example 3

[0030] 200 g of DMSS and 1 L of water were mixed and stirred. 1.0 g of polyethylene glycol was added to the mixture, and heated to 80° C. Thereafter, 156 g of concentrated sulfuric acid and 26.3 g of nickel sulfate hexahydrate were added to the mixture. 35 hours later, a faint yellow clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 98.3%.

Example 4

[0031] 200 g of DMSS and 1 L of water were mixed and stirred. 0.5 g of dodecyl benzene sulfonic acid was added to the mixture, and heated to 100° C. Thereafter, 792 g of concentrated sulfuric acid and 23.9 g of 50% manganese nitrate aqueous solution were added to the mixture. 4 hours later, a brown clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 90.2%.

Example 5

[0032] 200 g of DMSS and 2 L of water were mixed and stirred. 1 g of dodecyl trimethyl ammonium chloride was added to the mixture, and heated to 80° C. Thereafter, 503 g of concentrated sulfuric acid and 32.7 g of zinc nitrate hexahydrate were added to the mixture. 24 hours later, a faint yellow clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 98.5%.

Example 6

[0033] 200 g of DMSS and 4 L of water were mixed and stirred. 2 g of dodecyl trimethyl ammonium chloride was added to the mixture, and heated to 80° C. Thereafter, 1000 g of concentrated sulfuric acid and 55.6 g of zinc nitrate hexahydrate were added to the mixture. 18 hours later, a faint yellow clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 98.0%.

Example 7

[0034] 200 g of DMSS and 2 L of water were mixed and stirred. 1 g of tetrabutyl ammonium bromide was added to the mixture, and heated to 80° C. Thereafter, 793 g of concentrated hydrochloric acid and 39.6 g of zinc nitrate hexahydrate were added to the mixture. 40 hours later, a faint yellow clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 94.5%.

Example 8

[0035] 200 g of DMSS and 2 L of water were mixed and stirred. 1 g of dodecyl trimethyl ammonium chloride was added to the mixture, and heated to 80° C. Thereafter, 703 g of concentrated nitric acid and 36.5 g of zinc nitrate hexahydrate were added to the mixture. 40 hours later, a faint yellow clear solution was obtained. Chromatographic analysis showed, the conversion rate of DMSs was 100% and the selectivity of 1,4-cyclohexanedione was 94.6%.

[0036] It will be obvious to those skilled in the art that changes and modifications may be made, and therefore, the aim in the appended claims is to cover all such changes and modifications.