CN113248367A

CN113248367A - Method for realizing continuous production of acyl chloride compound by catalysis of immobilized organic base

Info

Publication number: CN113248367A
Application number: CN202110550537.5A
Authority: CN
Inventors: 周建成; 邢舒雅; 李乃旭; 李美娟; 刘珺
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2021-05-20
Filing date: 2021-05-20
Publication date: 2021-08-13
Anticipated expiration: 2041-05-20
Also published as: CN113248367B

Abstract

The invention discloses a method for realizing continuous production of acyl chloride compounds by catalysis of immobilized organic base, belonging to the technical field of organic chemical industry, wherein a glass microchannel reactor is treated by amino, pyridine, acetamide and nicotinamide organic base silane coupling agents, and an immobilized organic base catalyst is used; 3,5, 5-trimethylhexanoic acid, adipic acid, trimethylacetic acid, benzoic acid and terephthalic acid are taken as raw materials, and acyl chlorination reaction is carried out through a fixed bed microchannel to generate corresponding 3,5, 5-trimethylhexanoyl chloride, adipoyl chloride, trimethylacetyl chloride, benzoyl chloride and terephthaloyl chloride; the solvent is one or more of toluene, dichloromethane, dichloroethane, cyclohexane and tetrahydrofuran; the material molar ratio is the number of carboxylic acid groups: the solid phosgene is 3: 1-1.5; the reaction temperature is 30-150 ℃, the total material feeding speed is 5-40 mL/min, and the reaction time is 2-16 min. The method for producing 3,5, 5-trimethyl hexanoyl chloride, benzoyl chloride and adipoyl chloride realizes the reutilization of the catalyst, has high product purity and safe production process, and reduces the environmental pollution.

Description

Method for realizing continuous production of acyl chloride compound by catalysis of immobilized organic base

Technical Field

The invention belongs to the technical field of organic chemical industry, and particularly relates to a method for realizing continuous production of acyl chloride compounds by catalysis of immobilized organic base.

Background

Most of compounds containing acyl chloride groups in molecules are medicines or medical intermediates or basic raw materials for synthesizing medicines. The chlorination reaction of carboxylic acid compounds has important significance in actual production, and the ester compounds are produced by using acyl chloride to replace corresponding carboxylic acid and alcohol, so that the production cost can be reduced, the product quality can be improved, and the environmental pollution can be reduced.

Acyl chloride is used as a reactant and is matched with other raw materials for reaction, and various chemical intermediates or products with novel structures and excellent performance can be synthesized by modifying various substituent groups and utilizing the splicing principle of an active structure and carrying out high-molecular polymerization, so that the acyl chloride has increasingly wide application in the aspects of medicines, pesticides, resource environments and the like.

Currently, the most important method for obtaining acyl chloride is to synthesize acyl chloride by using carboxylic acid and acylating agent. The phosphorus trichloride method is convenient for preparing low-boiling-point acyl chloride by using carboxylic acid and an acyl chlorination reagent; the phosphorus pentachloride method is convenient for preparing acyl chloride with high boiling point, has narrow application range and less application in laboratories and industries; the industrial production of the thionyl chloride method and the phosgene method is earlier, but the problems of environmental protection, operation and the like exist, and an ideal substitute is urgently needed to be found.

In addition, because organic base is often added in a small amount in a reaction system as a catalyst, the organic base in the product acyl chloride is often not subjected to separation post-treatment, which brings impurities to the acyl chloride system, and thus affects the purity of the product.

Disclosure of Invention

The technical problem is as follows: the invention provides a method for realizing continuous production of acyl chloride compounds by catalysis of immobilized organic base, which realizes the reutilization of catalyst and solves the problems of low purity caused by difficult recovery of catalyst and separation of organic base in the product acyl chloride.

The technical scheme is as follows: in order to achieve the purpose, the method for realizing the continuous production of the acyl chloride compound by the catalysis of the immobilized organic base comprises the following steps:

1) introducing a tetrahydrofuran solution of KH-550 (amino functional group silane) containing organic base catalyst groups/synthesized organic base silane coupling agent into a microchannel reactor at 140-150 ℃, introducing nitrogen into the microchannel after the channel is filled with the solution, evacuating the solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with the organic base catalyst groups on the inner wall of the channel;

2) dissolving organic acid in a solvent to obtain a reaction solution a;

3) dissolving solid phosgene in a solvent to obtain a reaction solution b; the molar ratio of the organic acid to the solid phosgene is the number of carboxyl groups: the solid phosgene is 3: 1-3: 1.5;

4) respectively introducing the reaction liquid a obtained in the step 2) and the reaction liquid b obtained in the step 3) into a microchannel reactor through a feed pump to obtain a mixed liquid c;

5) rectifying the mixed liquid c obtained in the step 4) to obtain the acyl chloride compound.

Further, in the step 1), the synthetic organic base silane coupling agent is obtained by the following steps:

immersing magnesium powder in tetrahydrofuran, and slowly dripping magnesium powder according to the molar ratio of 1: 1 in tetrahydrofuran solution of an organic base; wherein the organic base is selected from bromopyridine, bromoacetamide, 5-bromonicotinamide; the reaction produces a grignard reagent, the grignard reagent produced is reacted with a compound in a molar ratio of 1: 3-chloropropyltriethoxysilane of 1 to obtain the synthetic organic alkali silane coupling agent.

Further, in the step 2), the organic acid is any one of 3,5, 5-trimethylhexanoic acid, adipic acid, trimethylacetic acid, benzoic acid and terephthalic acid; in the step 6), the mixed solution c is rectified to obtain 3,5, 5-trimethyl hexanoyl chloride, adipoyl chloride, trimethyl acetyl chloride, benzoyl chloride and terephthaloyl chloride.

Further, in the step 3), the molar ratio of the organic acid to the solid phosgene is the number of carboxyl groups: and the solid phosgene is 3: 1.2-3: 1.4.

Further, in the step 1), the feeding speed of the micro-channel reactor is 1-5 mL/min, and after the channel is filled with the solution, the feeding is closed and kept for 5-10 min.

Further, in the step 4), the feeding rate of the feeding pump is controlled to be 5-40 mL/min, and the mixture stays in the microchannel reactor for 4-8 min at the reaction temperature of 40-90 ℃ to perform acyl chlorination reaction, so as to obtain a mixed solution c.

Further, in the step 2) and the step 3), the solvent is one or more of toluene, dichloromethane, dichloroethane, cyclohexane and tetrahydrofuran.

Further, in the step 1), when KH-550 is adopted, the structure of the organic base silane coupling agent is as follows:

the R group is amino;

when a synthetic organobase silane coupling agent is employed, the synthetic organobase silane coupling agent has the following structure:

r is selected from

From left to right are: a pyridine group, an acetamide group, a nicotinamide group.

Has the advantages that: compared with the prior art, the invention has the following advantages:

1. the organic base catalyst is immobilized on the wall of the microchannel by using the silane coupling agent to form the catalytic fixed bed, so that the utilization rate of the catalyst is greatly improved, and the problems of difficult catalyst recovery and low product purity are solved;

2. the operation is simple, the mass transfer and heat transfer of the reaction are greatly improved by using the microchannel reactor, the energy utilization rate is improved, the yield is improved, the continuous production is realized by the continuous flow reaction, the product quality control is good, and the repeatability is good;

3. the invention has high safety, and the closed reaction in the microchannel reactor effectively prevents the safety problems of leakage of a small amount of possible phosgene or corrosive products and the like, and ensures the safety of the production process;

4. the solid phosgene used as the acyl chlorination reagent has good acyl chlorination effect, and generates carbon dioxide and hydrogen chloride gas through acyl chlorination reaction, so that compared with the traditional acyl chlorination reagent, the acyl chlorination reagent does not generate polluting acidic gas and heavy polluting wastewater; the invention has safe production process, no harmful gas and greatly reduced environmental pollution.

Drawings

FIG. 1 is a schematic cross-sectional view of an organic base catalyzed fixed bed microchannel treated with a pyridine silane coupling agent;

FIG. 2 is a nuclear magnetic hydrogen spectrum of 3,5, 5-trimethylhexanoyl chloride.

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

A method for realizing continuous production of acyl chloride compounds by catalysis of immobilized organic base comprises the following steps:

1) introducing a tetrahydrofuran solution of a KH-550/synthesized organic base silane coupling agent into a microchannel reactor at 140-150 ℃, introducing nitrogen into a microchannel after the microchannel is filled with the solution, emptying the solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with an organic base catalyst on the inner wall of the channel;

2) dissolving organic acid in a solvent to obtain a reaction solution a;

In the step 1), the synthesized organic alkali silane coupling agent is obtained through the following steps:

immersing magnesium powder in tetrahydrofuran, and slowly dripping magnesium powder according to the molar ratio of 1: 1 in tetrahydrofuran solution of an organic base; wherein the organic base is selected from bromopyridine, bromoacetamide, 5-bromonicotinamide; reacting to form a grignard reagent, the formed grignard reagent being present in a molar ratio of 1: 3-chloropropyltriethoxysilane of 1 to obtain the synthetic organic alkali silane coupling agent.

In the step 2), the organic acid is any one of 3,5, 5-trimethylhexanoic acid, adipic acid, trimethylacetic acid, benzoic acid and terephthalic acid; and 6), rectifying the mixed solution c to obtain 3,5, 5-trimethyl hexanoyl chloride, adipoyl chloride, trimethyl acetyl chloride, benzoyl chloride and terephthaloyl chloride.

In the step 3), the molar ratio of the organic acid to the solid phosgene is the number of carboxyl groups: and the solid phosgene is 3: 1.2-3: 1.4.

In the step 1), the feeding speed of the microchannel reactor is 1-5 mL/min, and after the channel is filled with the solution, the feeding is closed and kept for 5-10 min.

In the step 4), the feeding speed of the feeding pump is controlled to be 5-40 mL/min, and the mixture stays in the microchannel reactor for 4-8 min at the reaction temperature of 40-90 ℃ to carry out acyl chlorination reaction, so that a mixed solution c is obtained.

In the step 2) and the step 3), the solvent is one or more of toluene, dichloromethane, dichloroethane, cyclohexane and tetrahydrofuran.

In step 1), when KH-550 is used, the structure of the organic base silane coupling agent is as follows:

the R group is amino;

r is selected from

Example 1

The invention relates to a method for synthesizing 3,5, 5-trimethyl hexanoyl chloride by using immobilized organic base catalysis, which comprises the following steps:

1) preparing 10g of KH-550 silane coupling agent into 100mL of tetrahydrofuran solution;

2) introducing the KH-550 solution into a microchannel reactor at 140 ℃ at a feeding speed of 1mL/min, after the channel is filled with the solution, closing the feeding and keeping for 5min, introducing nitrogen into the microchannel, emptying the coupling agent solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with an amino catalyst on the inner wall of the channel;

3) dissolving 61.3g of 3,5, 5-trimethylhexanoic acid in a solvent of tetrahydrofuran to obtain a reaction solution a;

4) dissolving 50.0g of solid phosgene in tetrahydrofuran solvent, wherein the molar ratio of 3,5, 5-trimethylhexanoic acid to the solid phosgene is 3:1.3, so as to obtain reaction liquid b;

5) respectively introducing the reaction liquid a obtained in the step 3) and the reaction liquid b obtained in the step 4) into a microchannel reactor through a feeding pump at a feeding rate of 10mL/min, and staying for 8min in the microchannel reactor at a reaction temperature of 55 ℃ to obtain a mixed liquid c;

6) rectifying the mixed solution c obtained in the step 5) to obtain the 3,5, 5-trimethyl hexanoyl chloride.

The product yield of the 3,5, 5-trimethyl hexanoyl chloride prepared by the method is 98.12% and the purity reaches 99.8%.

Example 2

2) introducing the KH-550 solution into a microchannel reactor at 140 ℃ at a feeding speed of 5mL/min, after the channel is filled with the solution, closing the feeding and keeping for 10min, introducing nitrogen into the microchannel, emptying the coupling agent solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with an amino catalyst on the inner wall of the channel;

3) dissolving 95.9g of 3,5, 5-trimethylhexanoic acid in a composite solvent of dichloromethane and toluene to obtain a reaction solution a;

4) dissolving 60.0g of solid phosgene in a composite solvent of dichloromethane and toluene to obtain a reaction solution b, wherein the molar ratio of 3,5, 5-trimethylhexanoic acid to the solid phosgene is 3: 1;

5) respectively introducing the reaction liquid a obtained in the step 3) and the reaction liquid b obtained in the step 4) into a microchannel reactor through a feeding pump at a feeding rate of 5mL/min, and staying in the microchannel reactor for 16min at a reaction temperature of 30 ℃ to obtain a mixed liquid c;

The product yield of the 3,5, 5-trimethyl hexanoyl chloride prepared by the method is 90.63 percent and the purity reaches 99.5 percent.

Example 3

The invention relates to a method for synthesizing trimethylacetyl chloride by using immobilized organic base catalysis, which comprises the following steps:

1) 2.4g of magnesium powder is immersed in 25mL of tetrahydrofuran, and 50mL of 0.5mol/L bromopyridine tetrahydrofuran solution is slowly dropped to react to generate the Grignard reagent. Slowly dripping 50 mL0.5mol/L3-chloropropyltriethoxysilane in an ice bath to react to obtain an aminosilane coupling agent;

2) introducing a 3-pyridylpropyltriethoxysilane solution into a microchannel reactor at 150 ℃ at a feeding speed of 1mL/min, closing feeding and keeping for 5min after a channel is filled with the solution, introducing nitrogen into the microchannel, emptying a coupling agent solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with an amino catalyst on the inner wall of the channel;

3) dissolving 30.9g of trimethylacetic acid in a solvent of cyclohexane to obtain a reaction solution a;

4) dissolving 60.0g of solid phosgene in cyclohexane solvent, wherein the molar ratio of trimethyl acetic acid to the solid phosgene is 3:1.5, and obtaining reaction liquid b;

5) respectively introducing the reaction liquid a obtained in the step 3) and the reaction liquid b obtained in the step 4) into a microchannel reactor through a feeding pump at a feeding rate of 10mL/min, and staying for 8min in the microchannel reactor at a reaction temperature of 90 ℃ to obtain a mixed liquid c;

6) rectifying the mixed solution c obtained in the step 5) to obtain the trimethylacetyl chloride.

The yield of the benzoyl chloride prepared by the method is 92.62 percent and the purity reaches 99.1 percent.

Example 4

The invention discloses a method for synthesizing adipoyl chloride by using immobilized organic base catalysis, which comprises the following steps:

1) 2.4g of magnesium powder is immersed in 25mL of tetrahydrofuran, and 50mL of 0.5mol/L bromoacetamide tetrahydrofuran solution is slowly dropped to react to generate the Grignard reagent. Slowly dripping 50 mL0.5mol/L3-chloropropyltriethoxysilane in an ice bath to react to obtain an acetamide silane coupling agent;

2) introducing a 3-acetamidopropyltriethoxysilane solution into a microchannel reactor at 150 ℃ at a feeding speed of 1mL/min, after the channel is filled with the solution, closing the feeding and keeping for 5min, introducing nitrogen into the microchannel, emptying the coupling agent solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with an acetamide catalyst on the inner wall of the channel;

3) dissolving 74.0g of adipic acid in tetrahydrofuran solvent to obtain reaction liquid a;

4) 60.0g of phosgene in solid form was dissolved in tetrahydrofuran solvent, and the molar ratio of adipic acid to phosgene in question was the number of carboxyl groups, since adipic acid has two carboxyl groups: obtaining reaction liquid b by using solid phosgene as 3: 1.5;

5) respectively introducing the reaction liquid a obtained in the step 3) and the reaction liquid b obtained in the step 4) into a microchannel reactor through a feeding pump at a feeding rate of 40mL/min, and staying in the microchannel reactor for 2min at a reaction temperature of 150 ℃ to obtain a mixed liquid c;

6) rectifying the mixed solution c obtained in the step 5) to obtain adipoyl chloride.

The product yield of adipoyl chloride prepared by the method is 85.59 percent and the purity reaches 98.9 percent.

Example 5

The invention relates to a method for synthesizing benzoyl chloride by using immobilized organic base catalysis, which comprises the following steps:

1) 2.4g of magnesium powder is immersed in 25mL of tetrahydrofuran, and 50mL of 0.5mol/L bromoacetamide tetrahydrofuran solution is slowly dropped to react to generate the Grignard reagent. Slowly dripping 50 mL0.5mol/L3-chloropropyltriethoxysilane in an ice bath to react to obtain a nicotinamide silane coupling agent;

3) dissolving 61.7g of benzoic acid in a solvent of toluene to obtain a reaction solution a;

4) dissolving 60.0g of solid phosgene in a solvent toluene, wherein the molar ratio of benzoic acid to the solid phosgene is 3:1.2, so as to obtain a reaction liquid b;

5) respectively introducing the reaction liquid a obtained in the step 3) and the reaction liquid b obtained in the step 4) into a microchannel reactor through a feeding pump at a feeding rate of 20mL/min, and staying for 4min in the microchannel reactor at a reaction temperature of 90 ℃ to obtain a mixed liquid c;

6) rectifying the mixed solution c obtained in the step 5) to obtain the benzoyl chloride.

The yield of the benzoyl chloride prepared by the method is 89.85% and the purity reaches 98.7%.

Example 6

The invention relates to a method for synthesizing terephthaloyl chloride by using immobilized organic base as a catalyst, which comprises the following steps:

1) 2.4g of magnesium powder is immersed in 25mL of tetrahydrofuran, and 50mL of 0.5 mol/L3-bromonicotinamide tetrahydrofuran solution is slowly dropped to react to generate the Grignard reagent. Slowly dripping 50 mL0.5mol/L3-chloropropyltriethoxysilane in an ice bath to react to obtain a nicotinamide silane coupling agent;

2) introducing a 3-nicotinamide propyltriethoxysilane solution into a microchannel reactor at a feeding speed of 1mL/min at 150 ℃, closing feeding and keeping for 5min after a channel is filled with the solution, introducing nitrogen into the microchannel, emptying a coupling agent solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with a nicotinamide catalyst on the inner wall of the channel;

3) dissolving 76.3g of terephthalic acid in a composite solvent of solvents of toluene, cyclohexane and dichloroethane to obtain a reaction liquid a;

4) 60.0g of solid phosgene is dissolved in a composite solvent of solvents toluene, cyclohexane and dichloroethane, and because terephthalic acid has two carboxyl groups, the molar ratio of the terephthalic acid to the solid phosgene is the number of the carboxyl groups: obtaining reaction liquid b by using solid phosgene as 3: 1;

5) respectively introducing the reaction liquid a obtained in the step 3) and the reaction liquid b obtained in the step 4) into a microchannel reactor through a feeding pump at a feeding rate of 40mL/min, and staying for 2min in the microchannel reactor at a reaction temperature of 110 ℃ to obtain a mixed liquid c;

6) rectifying the mixed solution c obtained in the step 5) to obtain the terephthaloyl chloride.

The product yield of the terephthaloyl chloride prepared by the above method is 85.34% and the purity is 99.8%.

Claims

1. A method for realizing continuous production of acyl chloride compounds by catalysis of immobilized organic base is characterized by comprising the following steps:

1) introducing a tetrahydrofuran solution of KH-550/synthesized organic base silane coupling agent containing organic base catalyst groups into a microchannel reactor at 140-150 ℃, introducing nitrogen into the microchannel after the channel is filled with the solution, emptying the solution, and naturally cooling to normal temperature to obtain a catalytic fixed bed microchannel with the organic base catalyst groups on the inner wall of the channel;

2) dissolving organic acid in a solvent to obtain a reaction solution a;

2. The method for realizing the continuous production of the acyl chloride compound catalyzed by the organic base supported on the carrier according to claim 1, wherein in the step 1), the synthetic organic base silane coupling agent is obtained by the following steps:

3. The method for continuous production of acyl chloride compound catalyzed by organic base supported on the carrier of claim 1, wherein in the step 2), the organic acid is any one of 3,5, 5-trimethylhexanoic acid, adipic acid, trimethylacetic acid, benzoic acid and terephthalic acid; in the step 6), the mixed solution c is rectified to obtain 3,5, 5-trimethyl hexanoyl chloride, adipoyl chloride, trimethyl acetyl chloride, benzoyl chloride and terephthaloyl chloride.

4. The method for realizing the continuous production of the acyl chloride compound under the catalysis of the immobilized organic base according to claim 1, wherein in the step 3), the molar ratio of the organic acid to the solid phosgene is the number of carboxyl groups: and the solid phosgene is 3: 1.2-3: 1.4.

5. The method for realizing the continuous production of the acyl chloride compound under the catalysis of the immobilized organic base according to claim 1, wherein in the step 1), the feeding speed of the microchannel reactor is 1-5 mL/min, and after the channels are filled with the solution, the feeding is stopped and kept for 5-10 min.

6. The method for realizing the continuous production of the acyl chloride compound under the catalysis of the immobilized organic base according to claim 1, wherein in the step 4), the feeding rate of the feeding pump is controlled to be 5-40 mL/min, and the acyl chloride compound stays in the microchannel reactor for 4-8 min at the reaction temperature of 40-90 ℃ to perform the acyl chlorination reaction, so as to obtain the mixed solution c.

7. The method for realizing the continuous production of the acyl chloride compound under the catalysis of the immobilized organic base according to claim 1, wherein in the step 2) and the step 3), the solvent is one or more of toluene, dichloromethane, dichloroethane, cyclohexane and tetrahydrofuran.

8. The method for realizing the continuous production of the acyl chloride compound catalyzed by the immobilized organic base according to claim 1, wherein in the step 1), when KH-550 is adopted, the structure of the organic base silane coupling agent is as follows:

the R group is amino;

r is selected from