Method for preparing epsilon-caprolactone through solvent-free cyclohexanone-benzaldehyde oxidation

Abstract

The invention belongs to the technical field of epsilon-caprolactone preparation, and discloses a method for preparing epsilon-caprolactone through solvent-free cyclohexanone-benzaldehyde oxidation. The method comprises the steps: adding a catalyst into a mixture of cyclohexanone and a co-oxidant, taking oxygen as an oxidant, and carrying out stirring reaction under the conditions that the pressure is 0.1-10 MPa and the temperature is 25-150 DEG C, so as to obtain epsilon-caprolactone, wherein the co-oxidant is benzaldehyde, and the catalyst is a nitrogen-doped carbon nanotube. The method disclosed by the invention is simple, and the process flow of solvent separation in the industry is removed by taking cheap and readily available oxygen as an oxidant under a solvent-free condition, so that the process energy consumption is reduced; and the epsilon-caprolactone is high in selectivity and high in yield.

Description

technical field

[0001] The invention relates to the field of preparation of ε-caprolactone, in particular to a method for preparing ε-caprolactone by oxidation of anhydrous cyclohexanone-benzaldehyde. Background technique

[0002] ε-caprolactone is a chemical with huge market demand. Its polymer polyε-caprolactone has excellent biocompatibility and good biodegradability. It is used in automobiles, home appliances, medicine, packaging materials, etc. Wide range of applications in various fields. Due to the complex production process of ε-caprolactone monomer, only a few domestic enterprises can produce it, making ε-caprolactone in short supply in the market. Therefore, it is of great significance to find a green and cost-effective synthetic route to produce ε-caprolactone.

[0003] At present, the synthesis method of ε-caprolactone is mainly based on the Baeyer-Villiger (B-V) oxidation of cyclohexanone. For a long time, peroxyacid and hydrogen peroxide were used as oxidant...

Examples

Embodiment 1～6

[0022] Solvent system: 1.306g of o-dichlorobenzene (internal standard), 0.4907g of cyclohexanone, 2.1224g of benzaldehyde, 100mg of nitrogen-doped carbon nanotubes and 17.5ml of the solvent in Table 1 were added to the autoclave.

[0023] Solvent-free system: Add 1.306g o-dichlorobenzene (internal standard), 8.5732g cyclohexanone, 9.3201g benzaldehyde, and 100mg nitrogen-doped carbon nanotubes into the autoclave.

[0024] Both systems were stirred at a stirring rate of 1500rpm and heated to 85°C. Oxygen at a pressure of 1MPa was introduced, and timing was started. After 2 hours of reaction, the reaction vessel was cooled to 15°C in ice water, and the liquid-solid phase mixture was filtered to obtain a solid catalyst. And the liquid phase mixture containing unreacted reactant and reaction product, the liquid phase mixture is diluted 10 times with dichloroethane. GC detection results are shown in Table 1.

[0025] Table 1 has solvent B-V reaction performance contrast

[0026] ...

Embodiment 7

[0029] 1.306g of o-dichlorobenzene (internal standard), 13.68g of cyclohexanone, 14.976g of benzaldehyde and 100mg of nitrogen-doped carbon nanotubes with a nitrogen content of 5.25 at.% were added to the autoclave. Stir at a stirring rate of 1500 rpm and heat to 85° C., feed oxygen at a pressure of 1 MPa, and start timing. After reacting for 2 hours, cool the reactor to 15°C in ice water, filter the liquid-solid phase mixture to obtain a solid catalyst and a liquid phase mixture containing unreacted reactants and reaction products, and dilute the liquid phase mixture 10 times with dichloroethane . GC detection results: the conversion rate of cyclohexanone was 13.12%, the selectivity of ε-caprolactone was 91.4%, the conversion rate of benzaldehyde was 66.28%, the selectivity of benzoic acid was 100%, and the absolute production amount of ε-caprolactone was 16.7 mmol.

Embodiment 8

[0031] Add 1.306g o-dichlorobenzene (internal standard), 13.68g cyclohexanone, 14.976g benzaldehyde and 5mg nitrogen-doped carbon nanotubes (5.25at.% nitrogen content) into the autoclave and stir at a stirring rate of 2000rpm And heated to 85 ℃, through the oxygen pressure of 1MPa, start timing. After reacting for 2 hours, cool the reactor to 15°C in ice water, filter the liquid-solid phase mixture to obtain a solid catalyst and a liquid phase mixture containing unreacted reactants and reaction products, and dilute the liquid phase mixture 10 times with dichloroethane . GC detection results: the conversion rate of cyclohexanone is 15.22%, the selectivity of ε-caprolactone is 92.4%, the conversion rate of benzaldehyde is 69.28%, the selectivity of benzoic acid is 100%, and the absolute production amount of ε-caprolactone is 18.1 mmol.

technical field

[0001] The invention relates to the field of preparation of ε-caprolactone, in particular to a method for preparing ε-caprolactone by oxidation of anhydrous cyclohexanone-benzaldehyde. Background technique

[0002] ε-caprolactone is a chemical with huge market demand. Its polymer polyε-caprolactone has excellent biocompatibility and good biodegradability. It is used in automobiles, home appliances, medicine, packaging materials, etc. Wide range of applications in various fields. Due to the complex production process of ε-caprolactone monomer, only a few domestic enterprises can produce it, making ε-caprolactone in short supply in the market. Therefore, it is of great significance to find a green and cost-effective synthetic route to produce ε-caprolactone.

[0003] At present, the synthesis method of ε-caprolactone is mainly based on the Baeyer-Villiger (B-V) oxidation of cyclohexanone. For a long time, peroxyacid and hydrogen peroxide were used as oxidant...

Examples

Embodiment 1～6

[0022] Solvent system: 1.306g of o-dichlorobenzene (internal standard), 0.4907g of cyclohexanone, 2.1224g of benzaldehyde, 100mg of nitrogen-doped carbon nanotubes and 17.5ml of the solvent in Table 1 were added to the autoclave.

[0023] Solvent-free system: Add 1.306g o-dichlorobenzene (internal standard), 8.5732g cyclohexanone, 9.3201g benzaldehyde, and 100mg nitrogen-doped carbon nanotubes into the autoclave.

[0024] Both systems were stirred at a stirring rate of 1500rpm and heated to 85°C. Oxygen at a pressure of 1MPa was introduced, and timing was started. After 2 hours of reaction, the reaction vessel was cooled to 15°C in ice water, and the liquid-solid phase mixture was filtered to obtain a solid catalyst. And the liquid phase mixture containing unreacted reactant and reaction product, the liquid phase mixture is diluted 10 times with dichloroethane. GC detection results are shown in Table 1.

[0025] Table 1 has solvent B-V reaction performance contrast

[0026] ...

Embodiment 7

[0029] 1.306g of o-dichlorobenzene (internal standard), 13.68g of cyclohexanone, 14.976g of benzaldehyde and 100mg of nitrogen-doped carbon nanotubes with a nitrogen content of 5.25 at.% were added to the autoclave. Stir at a stirring rate of 1500 rpm and heat to 85° C., feed oxygen at a pressure of 1 MPa, and start timing. After reacting for 2 hours, cool the reactor to 15°C in ice water, filter the liquid-solid phase mixture to obtain a solid catalyst and a liquid phase mixture containing unreacted reactants and reaction products, and dilute the liquid phase mixture 10 times with dichloroethane . GC detection results: the conversion rate of cyclohexanone was 13.12%, the selectivity of ε-caprolactone was 91.4%, the conversion rate of benzaldehyde was 66.28%, the selectivity of benzoic acid was 100%, and the absolute production amount of ε-caprolactone was 16.7 mmol.

Embodiment 8

[0031] Add 1.306g o-dichlorobenzene (internal standard), 13.68g cyclohexanone, 14.976g benzaldehyde and 5mg nitrogen-doped carbon nanotubes (5.25at.% nitrogen content) into the autoclave and stir at a stirring rate of 2000rpm And heated to 85 ℃, through the oxygen pressure of 1MPa, start timing. After reacting for 2 hours, cool the reactor to 15°C in ice water, filter the liquid-solid phase mixture to obtain a solid catalyst and a liquid phase mixture containing unreacted reactants and reaction products, and dilute the liquid phase mixture 10 times with dichloroethane . GC detection results: the conversion rate of cyclohexanone is 15.22%, the selectivity of ε-caprolactone is 92.4%, the conversion rate of benzaldehyde is 69.28%, the selectivity of benzoic acid is 100%, and the absolute production amount of ε-caprolactone is 18.1 mmol.

Images