CN111718249A - Method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis - Google Patents
Method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis Download PDFInfo
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- CN111718249A CN111718249A CN202010585034.7A CN202010585034A CN111718249A CN 111718249 A CN111718249 A CN 111718249A CN 202010585034 A CN202010585034 A CN 202010585034A CN 111718249 A CN111718249 A CN 111718249A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/42—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by hydrolysis
- C07C45/43—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by hydrolysis of >CX2 groups, X being halogen
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
- B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
- B01J31/20—Carbonyls
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
- C07C17/10—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms
- C07C17/14—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms in the side-chain of aromatic compounds
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
- B01J2531/02—Compositional aspects of complexes used, e.g. polynuclearity
- B01J2531/0213—Complexes without C-metal linkages
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
- B01J2531/20—Complexes comprising metals of Group II (IIA or IIB) as the central metal
- B01J2531/26—Zinc
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Abstract
The invention discloses a method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis, which comprises the steps of heating 2, 6-dichlorobenzaldehydes to 120-160 ℃, adding a pi complex formed by 0.05-6 wt% of metal salt and benzaldehyde or benzaldehyde derivatives as a catalyst, slowly dropwise adding water with the same molar weight as the 2, 6-dichlorobenzaldehydes, stopping reaction when the content of the 2, 6-dichlorobenzaldehydes is lower than 0.05wt%, obtaining a 2, 6-dichlorobenzaldehydes crude product, and refining to obtain the 2, 6-dichlorobenzaldehydes. The method takes 2, 6-dichlorobenzyl as a raw material, uses a catalyst which is a pi complex formed by metal salt and benzaldehyde, increases the solubility of the reaction raw material 2, 6-dichlorobenzyl, forms a homogeneous reaction system, has small usage amount, can initiate hydrolysis reaction at lower temperature, and has stable reaction. The method has the advantages of mild reaction conditions, high yield, less side reactions and environmental friendliness.
Description
Technical Field
The invention belongs to the technical field of chemical synthesis, and particularly relates to a method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis.
Background
The 2, 6-dichlorobenzaldehyde is an important intermediate in the synthetic process of the benzoylurea insecticides, is used for synthesizing the next intermediate 2, 6-dichlorobenzaldehyde oxime, and finally obtains pesticide varieties such as hexaflumuron, diflubenzuron, chlorfluazuron, lufenuron and the like. For synthetic dyes, also as fungicides and for the production of the herbicide 2, 6-dichlorobenzonitrile; used for producing acid mordant blanched B; can also be used for preparing diclofenac sodium in the pharmaceutical industry. In the prior art, the synthesis of 2, 6-dichlorobenzaldehyde mainly comprises the following methods: 1. taking p-nitrotoluene as an initial raw material, firstly obtaining 2, 6-dichlorotoluene, and then directly oxidizing the 2, 6-dichlorotoluene to obtain 2, 6-dichlorobenzaldehyde; 2. 2, 6-dichlorotoluene and potassium permanganate are mixed in concentrated sulfuric acid and react in one step to obtain 2, 6-dichlorobenzaldehyde, but the problems of acid liquor reuse and three-waste treatment exist, and a large amount of expensive manganese salt is consumed; 3. or chloridized to obtain 2, 6-dichlorobenzyl and then synthesized into 2, 6-dichlorobenzaldehyde. Although one-step side chain chlorination reaction is added in the method, the reaction is easy to carry out, and the yield is high; 4. alternatively, 2, 6-dichlorobenzyl may be heated in a medium of an aromatic sulfonic acid in the presence of a catalyst to produce 2, 6-dichlorobenzaldehyde.
Chinese patent CN103396301B discloses a method for preparing 2, 6-dichlorobenzaldehyde, under the action of phosphorus pentachloride and light, 2, 6-dichlorotoluene is chloridized to generate 2, 6-dichlorobenzyl, formic acid and zinc chloride are added into the 2, 6-dichlorobenzyl, and the 2, 6-dichlorobenzaldehyde is generated by hydrolysis under the condition of heating and refluxing water vapor, although the method is simple to operate, formic acid is added in the hydrolysis process, and the mass ratio of the 2, 6-dichlorobenzyl to the formic acid is 100:20-300, so that a large amount of formic acid is consumed, and environmental pressure is also caused. Chinese patent CN 102875342a discloses a continuous flow method for preparing benzaldehyde by benzyl dichloride hydrolysis, which, although the use of a corning micro-channel continuous flow reactor shortens the reaction time, the acid hydrolysis is inevitably carried out during the hydrolysis, and the generated waste acid still needs to be treated at the later stage. In addition, the 2, 6-dichlorobenzaldehyde is synthesized by hydrolysis by taking 2, 6-dichlorobenzyl as a reaction raw material and a metal salt or a metal oxide as a catalyst, the dosage of the used catalyst is usually more than 6%, the consumption of the catalyst is large, the catalytic reaction temperature is high, and the catalytic efficiency is low.
In conclusion, the research on the method for synthesizing the 2, 6-dichlorobenzaldehyde by using no acid in the catalytic process, and having low catalyst dosage and low reaction temperature has important significance.
Disclosure of Invention
Aiming at the problems of the prior art that acid needs to be added in the catalytic process, the dosage of the catalyst is large and the reaction temperature is high in the method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis, the invention provides the method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis, 2, 6-dichlorobenzyl is taken as a raw material, the used catalyst is a pi complex formed by metal salt and benzaldehyde, the solubility of the reaction raw material 2, 6-dichlorobenzyl is increased, a homogeneous reaction system is formed, the dosage is small, the hydrolysis reaction can be initiated at a lower temperature, and the reaction is stable.
The invention is realized by the following technical scheme:
a method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis comprises the steps of taking 2, 6-dichlorobenzyl chloride as a raw material, taking a pi complex formed by metal salt and benzaldehyde or benzaldehyde derivatives as a catalyst, and adding water for hydrolysis to synthesize 2, 6-dichlorobenzaldehyde; heating 2, 6-dichlorobenzaldehydes to 120-160 ℃, adding 0.05-6 wt% of catalyst, slowly dropwise adding water with the same molar weight as the 2, 6-dichlorobenzaldehydes, stopping reaction when the content of the 2, 6-dichlorobenzaldehydes is lower than 0.05wt%, obtaining a crude product of the 2, 6-dichlorobenzaldehydes, and refining to obtain the 2, 6-dichlorobenzaldehydes;
the catalyst is a pi complex formed by metal salt and benzaldehyde or benzaldehyde derivative.
Further, the pi complex formed by the catalyst metal salt and benzaldehyde is A or/and B;
the preparation method of the catalyst A comprises the steps of heating o-chlorobenzaldehyde to 120 ℃, adding zinc chloride in batches, stirring for reaction for 3 hours, and cooling to room temperature to obtain a pi complex formed by the zinc chloride and the o-chlorobenzaldehyde;
the preparation method of the catalyst B comprises the steps of heating 2, 6-dichlorobenzaldehyde to 135 ℃, adding zinc chloride for 5 times, stirring for reacting for 3 hours, and cooling to room temperature to obtain a pi complex formed by the zinc chloride and the 2, 6-dichlorobenzaldehyde.
Further, the mass ratio of the o-chlorobenzaldehyde to the zinc chloride is 20: 11; the mass ratio of the 2, 6-dichlorobenzaldehyde to the zinc chloride is 27: 10.
Further, the preparation method of the 2, 6-dichlorobenzyl comprises the following steps: under the conditions of micro negative pressure of 0 to-0.02 MPa, heating 2, 6-dichlorotoluene to 110 ℃ and 180 ℃, adding 0.1 to 0.5 weight percent of catalyst in batches under the irradiation of a high-pressure mercury lamp, introducing chlorine gas, stopping the reaction when the content of 2, 6-dichlorobenzyl is lower than 5 percent and the content of 2, 6-dichlorobenzyl is higher than 95 percent, and distilling and separating to obtain the 2, 6-dichlorobenzyl;
further, the catalyst is more than one of azodiisobutyronitrile, benzoyl peroxide and tert-butyl hydroperoxide.
Further, the reaction temperature during the chlorine gas introduction is 130-140 ℃.
Further, the refining method comprises the following steps: adding toluene and water in a mass ratio of 5-6: 1 into the crude 2, 6-dichlorobenzaldehyde, heating to 90 ℃, keeping the temperature and stirring for 1 hour, standing, removing water, cooling to below 10 ℃, and filtering to obtain 2, 6-dichlorobenzaldehyde.
Further, the mass ratio of the 2, 6-dichlorobenzaldehyde crude product to the mixed solution of toluene and water is 1-2: 1.
Further, the adding mode of the catalyst is intermittent adding or continuous adding.
Further, the reaction pressure is 0 to-0.02 MPa; the hydrolysis reaction temperature is 130 ℃.
Advantageous effects
(1) The method takes 2, 6-dichlorobenzyl as a raw material, uses a catalyst which is a pi complex formed by metal salt and benzaldehyde, increases the solubility of the reaction raw material 2, 6-dichlorobenzyl, forms a homogeneous reaction system, has small usage amount, can initiate hydrolysis reaction at lower temperature, and has stable reaction;
(2) the method has the advantages of mild reaction conditions, high yield, less side reactions and environmental friendliness.
Detailed Description
In order to make the technical solutions of the present invention better understood, the following description is provided clearly and completely, and other similar embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application based on the embodiments in the present application.
Example 1
(1) Adding 100g of o-chlorobenzaldehyde into a 250ml four-neck flask with a stirrer and a condenser, heating to 120 ℃, adding 55g of zinc chloride for 5 times, preserving the heat for 3 hours until the zinc chloride is completely dissolved, forming a stable pi complex (catalyst A) by the zinc chloride and the o-chlorobenzaldehyde, and cooling to room temperature for later use;
(2) adding 200g of 2, 6-dichlorotoluene into a 500ml four-neck flask with a micro negative pressure of 0 to-0.02 MPa, stirring and a condenser, heating to 110 ℃, adding 1g of benzoyl peroxide (added every 1 hour) as a catalyst in batches under the illumination of a high-pressure mercury lamp, introducing chlorine gas for reaction, controlling the reaction temperature to be between 130 and 140 ℃ during the chlorine introduction period, controlling the reaction pressure to be 0 to-0.02 MPa, sampling and analyzing once every 2 hours during the chlorine introduction process, reacting for 10.3 hours, introducing 185g of chlorine gas, controlling the content of 2, 6-dichlorobenzyl to be lower than 5 percent and the content of 2, 6-dichlorobenzyl to be higher than 95 percent, finishing the chlorination reaction, and removing 20g of 2, 6-dichlorobenzyl through simple distillation to obtain 265g of 2, 6-dichlorobenzyl;
(3) heating the 2, 6-dichlorobenzalkonium chloride obtained in the step (2) to 130 ℃, adding the catalyst A5g obtained in the step (1), dropwise adding water at the speed of 2ml/h for 11 hours, wherein the content of the 2, 6-dichlorobenzalkonium chloride is lower than 0.05%, and obtaining 190g of crude 2, 6-dichlorobenzaldehyde after the reaction is finished;
(4) and (3) adding 150g of toluene and 30g of water into the crude 2, 6-dichlorobenzaldehyde product obtained in the step (3), heating to 90 ℃, keeping the temperature and stirring for 1 hour, standing, removing water, cooling to below 10 ℃, and filtering to obtain 187g of finished 2, 6-dichlorobenzaldehyde product with the content of more than 99%, wherein the yield is more than 98% (the yield is the yield of the hydrolysis step).
Example 2
(1) Adding 100g of 2, 6-dichlorobenzaldehyde into a 250ml four-neck flask with a stirrer and a condenser, heating to 135 ℃, adding 50g of zinc chloride for 5 times, keeping the temperature for 3 hours until the zinc chloride is completely dissolved, forming a stable pi complex (catalyst B) by the zinc chloride and o-chlorobenzaldehyde, and cooling to room temperature for later use;
(2) adding 200g of 2, 6-dichlorotoluene into a 500ml four-neck flask with a micro negative pressure of 0 to-0.02 MPa, stirring and a condenser, heating to 110 ℃, adding 1g of azodiisobutyronitrile (added every 1 hour) as a catalyst in batches under the illumination of a high-pressure mercury lamp, introducing chlorine gas for reaction, controlling the reaction temperature to be between 130 and 140 ℃ during the chlorine introduction period, controlling the reaction pressure to be 0 to-0.02 MPa, sampling and analyzing once every 2 hours during the chlorine introduction process, after reacting for 10 hours, introducing 185g of chlorine gas, enabling the content of 2, 6-dichlorobenzyl to be lower than 5 percent and the content of 2, 6-dichlorobenzyl to be higher than 95 percent, finishing the chlorination reaction, and removing 22g of 2, 6-dichlorobenzyl through simple distillation to obtain 264g of 2, 6-dichlorobenzyl;
(3) heating the 2, 6-dichlorobenzalkonium chloride obtained in the step (2) to 130 ℃, adding the catalyst B5g obtained in the step (1), dropwise adding water at the speed of 2ml/h for 10.3 hours, wherein the content of the 2, 6-dichlorobenzalkonium chloride is lower than 0.05 percent, and obtaining 200g of a crude product of the 2, 6-dichlorobenzaldehyde after the reaction is finished;
(4) and (3) adding 155g of toluene and 30g of water into the crude 2, 6-dichlorobenzaldehyde product obtained in the step (3), heating to 90 ℃, keeping the temperature and stirring for 1 hour, standing, removing water, cooling to below 10 ℃, and filtering to obtain 197g of finished 2, 6-dichlorobenzaldehyde product with the content of more than 99%, wherein the yield is more than 98% (the yield is the yield of the hydrolysis step).
Comparative example 1
(1) Adding 200g of 2, 6-dichlorotoluene into a 500ml four-neck flask with a micro negative pressure of 0 to-0.02 MPa, stirring and a condenser, heating to 110 ℃, adding 1g of azodiisobutyronitrile (added every 1 hour) as a catalyst in batches under the illumination of a high-pressure mercury lamp, introducing chlorine gas for reaction, controlling the reaction temperature to be between 130 and 140 ℃ during the chlorine introduction period, controlling the reaction pressure to be 0 to-0.02 MPa, sampling and analyzing once every 2 hours during the chlorine introduction process, finishing the chlorination reaction when the introduction amount of chlorine gas is 185g, and removing 22g2, 6-dichlorobenzyl after 10 hours of reaction, so as to obtain 264g2, 6-dichlorobenzyl when the content of 2, 6-dichlorobenzyl is lower than 5% and the content of 2, 6-dichlorobenzyl is higher than 95%;
(2) heating the 2, 6-dichlorobenzyl obtained in the step (1) to 130 ℃, adding 5g of zinc chloride, dripping water at the speed of 2ml/h, wherein the reaction cannot be initiated, the dripping water does not react, the more the 2, 6-dichlorobenzyl accumulates in the four-neck flask, the reflux is formed, the reaction temperature is reduced due to the increase of the water reflux amount, and the content of the 2, 6-dichlorobenzyl is almost unchanged after sampling and analyzing.
Claims (10)
1. The method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis is characterized in that 2, 6-dichlorobenzyl is used as a raw material, a pi complex formed by metal salt and benzaldehyde or benzaldehyde derivatives is used as a catalyst, and water is added for hydrolysis to synthesize the 2, 6-dichlorobenzaldehyde.
2. The preparation method according to claim 1, wherein the synthesis method comprises heating 2, 6-dichlorobenzaldehydes to 120-160 ℃, adding 0.05-6 wt% of a catalyst, slowly adding dropwise water in an amount equal to the molar amount of the 2, 6-dichlorobenzaldehydes, stopping the reaction when the content of the 2, 6-dichlorobenzaldehydes is less than 0.05wt%, obtaining a crude product of the 2, 6-dichlorobenzaldehydes, and refining to obtain the 2, 6-dichlorobenzaldehydes;
the catalyst is a pi complex formed by metal salt and benzaldehyde or benzaldehyde derivative.
3. The preparation method according to claim 2, wherein the pi complex formed by the catalyst metal salt and benzaldehyde is A or/and B;
the preparation method of the catalyst A comprises the steps of heating o-chlorobenzaldehyde to 120 ℃, adding zinc chloride in batches, stirring for reaction for 3 hours, and cooling to room temperature to obtain a pi complex formed by the zinc chloride and the o-chlorobenzaldehyde;
the preparation method of the catalyst B comprises the steps of heating 2, 6-dichlorobenzaldehyde to 135 ℃, adding zinc chloride for 5 times, stirring for reacting for 3 hours, and cooling to room temperature to obtain a pi complex formed by the zinc chloride and the 2, 6-dichlorobenzaldehyde.
4. The preparation method according to claim 3, wherein the mass ratio of the o-chlorobenzaldehyde to the zinc chloride is 20: 11; the mass ratio of the 2, 6-dichlorobenzaldehyde to the zinc chloride is 27: 10.
5. The method according to claim 1, wherein the 2, 6-dichlorobenzyl is prepared by: under the conditions of micro negative pressure of 0 to-0.02 MPa, heating 2, 6-dichlorotoluene to 110 ℃ and 180 ℃, adding 0.1 to 0.5 weight percent of catalyst in batches under the irradiation of a high-pressure mercury lamp, introducing chlorine gas, stopping the reaction when the content of 2, 6-dichlorobenzyl is lower than 5 percent and the content of 2, 6-dichlorobenzyl is higher than 95 percent, and distilling and separating to obtain the 2, 6-dichlorobenzyl.
6. The preparation method according to claim 4, wherein the catalyst is one or more of azobisisobutyronitrile, benzoyl peroxide and tert-butyl hydroperoxide; the reaction temperature during the chlorine gas introduction is 130-140 ℃.
7. The preparation method according to claim 1, wherein the refining method comprises: adding toluene and water in a mass ratio of 5-6: 1 into the crude 2, 6-dichlorobenzaldehyde, heating to 90 ℃, keeping the temperature and stirring for 1 hour, standing, removing water, cooling to below 10 ℃, and filtering to obtain 2, 6-dichlorobenzaldehyde.
8. The preparation method according to claim 7, wherein the mass ratio of the crude 2, 6-dichlorobenzaldehyde to the mixed solution of toluene and water is 1-2: 1.
9. The preparation method according to claim 1, wherein the catalyst is added in a manner of intermittent addition or continuous addition.
10. The production method according to claim 1, wherein the reaction pressure is 0 to-0.02 MPa; the hydrolysis reaction temperature is 140 ℃.
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| CN202010585034.7A CN111718249A (en) | 2020-06-24 | 2020-06-24 | Method for synthesizing 2, 6-dichlorobenzaldehyde by hydrolysis |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115433069A (en) * | 2022-08-23 | 2022-12-06 | 柳州东风容泰化工股份有限公司 | Preparation method of 2, 4-dichlorobenzaldehyde |
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2020
- 2020-06-24 CN CN202010585034.7A patent/CN111718249A/en active Pending
Non-Patent Citations (1)
| Title |
|---|
| 孙文东: "2,6-二氯苯甲醛合成工艺路线的选择", 《辽宁化工》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115433069A (en) * | 2022-08-23 | 2022-12-06 | 柳州东风容泰化工股份有限公司 | Preparation method of 2, 4-dichlorobenzaldehyde |
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Application publication date: 20200929 |