CN111393291A - Novel synthesis method of α -carbonyl acid ester - Google Patents
Novel synthesis method of α -carbonyl acid ester Download PDFInfo
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- CN111393291A CN111393291A CN202010365624.9A CN202010365624A CN111393291A CN 111393291 A CN111393291 A CN 111393291A CN 202010365624 A CN202010365624 A CN 202010365624A CN 111393291 A CN111393291 A CN 111393291A
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- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C67/00—Preparation of carboxylic acid esters
- C07C67/18—Preparation of carboxylic acid esters by conversion of a group containing nitrogen into an ester group
- C07C67/22—Preparation of carboxylic acid esters by conversion of a group containing nitrogen into an ester group from nitriles
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- C—CHEMISTRY; METALLURGY
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- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C253/00—Preparation of carboxylic acid nitriles
- C07C253/30—Preparation of carboxylic acid nitriles by reactions not involving the formation of cyano groups
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Abstract
The invention discloses a new synthesis method of α -carbonyl ester, which comprises the steps of carrying out chlorination reaction on nitrile containing α methylene and chlorine to obtain dichloronitrile, reacting the product in sulfuric acid and water systems to obtain formyl cyanide, then obtaining an imino sulfate compound in the same reaction system, and finally carrying out esterification to obtain a target product.
Description
Technical Field
The invention relates to a novel synthesis method of α -carbonyl acid ester, belonging to the technical field of organic synthesis.
Background
The carbonyl acid ester is a bifunctional compound, has a special structure, is an important intermediate for organic synthesis, is widely applied to the fields of pesticides, medicines, photoinitiators and the like, is also a biological metabolism intermediate, and has wide biological activity.
For example, methyl 2-chlorooxyphenyl acetate can be used for synthesizing clopidogrel for preventing and treating heart, brain and other arterial circulatory disorders caused by platelet high aggregation, methyl 2-methyloxyphenyl acetate can be used for synthesizing trifloxystrobin serving as a bactericide, and four α calcium ketoamino acids contained in the compound α ketonic acid tablet are synthesized by α -carbonyl acid.
For example, CN110183327A introduces a method for preparing α -carbonyl acid ester by catalytic oxidation of hydroxy ester, but the method adopts a critical process, involves high temperature and high pressure and is extremely difficult to realize industrialization, and an improved method for preparing 2- (2-bromomethylphenyl) -2-carbonyl methyl acetate is disclosed in CN103450021A, which uses benzoyl chloride as a raw material to react with solid sodium cyanide to generate benzoyl nitrile which reacts with alcohol in sulfuric acid to be a target product.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a novel synthesis method of α -carbonyl acid ester, the reaction raw materials adopted by the method have wide sources and low price, the use of virulent solid sodium cyanide and other expensive raw materials in the prior art can be avoided, and the synthesis operation is simple and easy to industrialize.
The structural formula of the α -carbonyl acid ester synthesized by the invention is shown as the formula (I), wherein R in the formula (I)1Is an aromatic or aliphatic group; r2Is methyl or ethyl or isopropyl or aryl.
In order to achieve the technical purpose, the technical scheme of the invention is as follows:
a new synthesis method of α -carbonyl acid ester comprises the following steps:
(1) adding a nitrile compound containing α methylene with a general formula II into a reaction container A, then gradually introducing chlorine gas to carry out chlorination reaction at 30-80 ℃, and obtaining a dichloronitrile compound after the raw material nitrile compound completely reacts;
(2) adding sulfuric acid and water into a reaction container B, adding a catalyst y, slowly dropwise adding the dichloronitrile obtained in the step (1) under the condition of controlling the temperature to be 25-50 ℃, and reacting for 4-6 hours at constant temperature after dropwise adding, wherein the molar ratio of the nitrile containing α methylene to water to acid is 1 (1-10) to (1-10);
(3) controlling the temperature of 40-50 ℃ in the reaction liquid obtained in the step (2), and dropwise adding a compound with the general formula R2Carrying out esterification reaction on-OH substances, after dropwise adding, heating to 65-70 ℃, and reacting at constant temperature for 2-3 hours, wherein the molar ratio of alcohol to nitrile containing α methylene is (2-10): 1;
(4) cooling to 20-40 ℃, adding water, stirring for 2-3 hours, standing for layering after the reaction is finished, taking an upper organic layer, and rectifying and purifying to obtain the target product α -carbonyl acid ester, wherein the molar ratio of the nitrile containing α methylene to water is 1 (1-10).
The synthesis reaction related by the invention is shown as formulas III, IV and V:
preferably, the novel synthesis method of α -carbonyl acid ester comprises the following steps:
(1) adding a nitrile compound containing α methylene with a general formula II into a reaction container A, adding a catalyst x, gradually introducing chlorine gas, carrying out chlorination reaction at 30-80 ℃, and obtaining a dichloronitrile compound after the raw material nitrile compound reacts completely;
(2) adding sulfuric acid and water into a reaction container B, adding a catalyst y, slowly dropwise adding the dichloronitrile obtained in the step (1) under the condition of controlling the temperature to be 25-50 ℃, and reacting for 4-6 hours at constant temperature after dropwise adding, wherein the molar ratio of the nitrile containing α methylene to water to acid is 1 (1-10) to (1-10);
(3) controlling the temperature of 40-50 ℃ in the reaction liquid obtained in the step (2), and dropwise adding a compound with the general formula R2Carrying out esterification reaction on-OH substances, after dropwise adding, heating to 65-70 ℃, and reacting at constant temperature for 2-3 hours, wherein the molar ratio of alcohol to nitrile containing α methylene is (2-10): 1;
(4) cooling to 20-40 ℃, adding water, stirring for 2-3 hours, standing for layering after the reaction is finished, taking an upper organic layer, and rectifying and purifying to obtain the target product α -carbonyl acid ester, wherein the molar ratio of the nitrile containing α methylene to water is 1 (1-10).
Preferably, R in the α methylene group-containing nitrile of the general formula II1Is an aromatic radical having the general formula VI.
Wherein:
R3is any one of alkyl, chlorine, bromine, fluorine, nitryl, sulfonic group, alkoxy and trifluoromethyl;
R4is any one of alkyl, chlorine, bromine, fluorine, nitro, sulfonic group, alkoxy and trifluoromethyl.
Preferably, R1 in the α methylene group-containing nitrile having the general formula ii is an aliphatic group.
Preferably, in the step (2), the catalyst y is any one of hydrochloric acid, hydrobromic acid, sodium chloride and sodium bromide.
Preferably, in the step (1), the catalyst x is any one of hydrogen chloride, hydrogen bromide, sulfuryl chloride and thionyl chloride.
Preferably, the general formula is R2the-OH substance is an alcohol or a phenol.
More preferably, the alcohol is any one of methanol, ethanol, and isopropanol.
Further preferably, the phenol is phenol.
As can be seen from the above description, the present invention has the following advantageous effects:
1. the reaction raw materials adopted by the invention have wide sources and low price, can avoid using highly toxic solid sodium cyanide in the prior art, and is environment-friendly. And the synthesis operation is simple and easy for industrialization.
2. The raw material α methylene adopted by the method is easy to generate chlorination reaction, so the content of the product is high.
3. When the intermediate dichloronitrile compound is hydrolyzed in the synthetic process, hydrogen chloride gas is generated and is used as an acyl cyanide hydrolysis catalyst on one hand, and on the other hand, the hydrogen chloride gas carries away reaction heat when being discharged, so that the heat balance of a reaction system is maintained, the decomposition of carbonyl acid ester is avoided, and the yield and the content of the product are improved.
Detailed Description
The features of the invention will be further elucidated by the following examples, without limiting the claims of the invention in any way.
Example 1:
synthesis of methyl 2-chlorobenzoyl formate
(1) Adding 454.5g of 2-chlorobenzene acetonitrile into a 1L four-neck flask, starting a tail gas absorption system, slowly introducing 10g of hydrogen chloride gas at room temperature, slowly introducing chlorine gas at the temperature of 50-60 ℃ for chlorination reaction, tracking, sampling and detecting until the content of the 2-chlorobenzene acetonitrile is lower than 0.5%, stopping introducing the chlorine gas, preserving heat for 3 hours, and obtaining 675g of yellow-green oily liquid after the chlorination reaction is finished, wherein the chlorinated liquid is directly used for the next synthesis without treatment;
(2) adding 200g of water into a 2L four-neck flask, dropwise adding 700g of sulfuric acid at the temperature of 70 ℃, adding 20g of catalyst sodium chloride after dropwise adding, starting a tail gas absorption system, controlling the temperature to be 25-50 ℃, slowly dropwise adding the chlorinated solution obtained in the previous step into prepared dilute sulfuric acid, reacting for 3 hours after dropwise adding, and reacting for 5 hours at constant temperature to finish the reaction;
(3) controlling the temperature to be 40-50 ℃, slowly dripping 320g of methanol into the reaction liquid, taking 1 hour, after finishing dripping, heating to 65-70 ℃ and reacting for 3 hours at constant temperature;
(4) cooling to 30 ℃, adding 200g of water, stirring for 2 hours, standing for layering, taking an upper organic layer as a crude product of the 2-chlorobenzoyl methyl formate, and rectifying and purifying to obtain 453g of light yellow-green oily liquid.
Example 2:
synthesis of methyl 2-methylbenzoyl formate
(1) Adding 131g of 2-methyl phenylacetonitrile into a 500ml four-neck flask, starting a tail gas absorption system, slowly introducing chlorine gas at the temperature of 50-60 ℃ for chlorination reaction, tracking, sampling and detecting until the content of the 2-methyl phenylacetonitrile is lower than 1%, stopping introducing the chlorine gas, preserving heat for 3 hours, finishing the chlorination reaction to obtain 203g of yellowish green oily liquid, wherein the chlorinated liquid is directly used for the next synthesis without treatment;
(2) adding 60g of water into a 1L four-neck flask, dropwise adding 250g of sulfuric acid at the temperature of 70 ℃, adding 10g of catalyst hydrochloric acid after dropwise adding, starting a tail gas absorption system, controlling the temperature to be 25-50 ℃, slowly dropwise adding the chlorination liquid obtained in the previous step into prepared dilute sulfuric acid, taking 1 hour, reacting at constant temperature for 5 hours after dropwise adding, and finishing the reaction;
(3) slowly dripping 100g of methanol into the reaction solution at the temperature of 60 ℃, taking 1 hour, heating to 65-70 ℃ after finishing dripping, and reacting for 3 hours at constant temperature;
(4) cooling to 35 ℃, adding 60g of water, stirring for 2 hours, standing for layering, taking an upper organic layer as a crude product of the methyl 2-methylbenzoyl formate, and rectifying and purifying to obtain 128g of light yellow-green oily liquid.
Example 3:
synthesis of methyl pyruvate
(1) Adding 165g of propionitrile into a 500ml four-neck flask, adding 10g of thionyl chloride, starting a tail gas absorption system, heating to 60 ℃, slowly introducing chlorine gas, heating to 70 ℃ after 5 hours, continuously introducing chlorine gas, heating to 80 ℃ after 6 hours, introducing chlorine gas after 20 hours, supplementing 5g of thionyl chloride, continuously introducing chlorine gas, tracking, sampling and detecting, stopping introducing chlorine gas when the content of 2, 2-dichloropropionitrile is higher than 95%, keeping the temperature for 3 hours, completely performing chlorination reaction to obtain 343g of chlorinated solution, wherein the chlorinated solution is not required to be treated and is directly used for next synthesis;
(2) adding 162g of water into a 1L four-neck flask, dropwise adding 1500g of sulfuric acid at the temperature of 70 ℃, adding 15g of catalyst sodium bromide after dropwise adding, starting a tail gas absorption system, controlling the temperature to be 25-50 ℃, slowly dropwise adding the chlorinated solution obtained in the previous step into prepared dilute sulfuric acid, reacting for 1 hour, reacting at constant temperature after dropwise adding until no hydrogen chloride gas is discharged, and reacting for 3-4 hours after finishing reacting;
(3) slowly dripping 300g of methanol into the reaction solution at the temperature of 40-50 ℃, taking 1 hour, heating to 65-70 ℃ after finishing dripping, and reacting for 3 hours at constant temperature;
(4) cooling to 25 ℃, adding 500g of water, stirring for 2 hours, standing for layering, taking an upper organic layer as a methyl pyruvate crude product, and rectifying and purifying to obtain 223g of light yellow oily liquid.
Example 4:
synthesis of methyl 4-methylbenzoyl formate
(1) Adding 13.1g of 4-methyl phenylacetonitrile into a four-neck flask, starting a tail gas absorption system, slowly introducing chlorine gas at the temperature of 50-60 ℃ for chlorination reaction, tracking, sampling and detecting until the content of the 4-methyl phenylacetonitrile is lower than 0.5%, stopping introducing the chlorine gas, preserving heat for 1 hour, and obtaining 20.4g of yellowish green oily liquid after the chlorination reaction is finished, wherein the chlorinated liquid is directly used for the next synthesis without treatment;
(2) adding 6g of water into a four-neck flask, dropwise adding 25g of sulfuric acid at the temperature of 70 ℃, adding 1g of catalyst sodium chloride after dropwise adding, starting a tail gas absorption system, controlling the temperature to be 25-50 ℃, slowly dropwise adding the chlorinated solution obtained in the previous step into prepared dilute sulfuric acid, taking 30min, reacting at constant temperature for 4 hours after dropwise adding, and finishing the reaction;
(3) slowly dripping 10g of methanol into the reaction solution at the temperature of 40-50 ℃, taking 30min, after finishing dripping, heating to 65-70 ℃ and reacting for 2 hours at constant temperature;
(4) cooling to 20 ℃, adding 6g of water, stirring for 2 hours, standing for layering, taking an upper organic layer as a crude product of the methyl 4-methylbenzoyl formate, and rectifying and purifying to obtain 14.5g of light yellow-green oily liquid.
Example 5:
synthesis of methyl 4-methoxybenzoyl formate
(1) Adding 147g of 4-methoxybenzyl acetonitrile into a chlorination kettle, starting a tail gas absorption system, heating to 45-50 ℃, slowly introducing chlorine gas for chlorination reaction, tracking, sampling and detecting, stopping introducing the chlorine gas until the content of the 4-methoxybenzyl acetonitrile is lower than 1%, preserving heat for reaction for 3 hours, and obtaining a yellow-green chlorination solution after the reaction is finished, wherein the chlorination solution is directly used for the next synthesis without treatment;
(2) adding 60g of water into a four-neck flask, dropwise adding 250g of sulfuric acid at the temperature of 70 ℃, adding 8g of catalyst sodium bromide after dropwise adding, starting a tail gas absorption system, controlling the temperature to be 25-50 ℃, slowly dropwise adding the chlorinated solution obtained in the previous step into prepared dilute sulfuric acid, taking 1 hour, keeping the temperature for 5 hours after dropwise adding, and finishing the reaction;
(3) slowly dripping 100g of methanol into the reaction solution at the temperature of 40-50 ℃, taking 1 hour, heating to 65-70 ℃ after finishing dripping, and reacting for 3 hours at constant temperature;
(4) cooling to 30 ℃, adding 60g of water, stirring for 2 hours, standing for layering, taking an upper organic layer as a crude product of the methyl 4-methoxybenzoyl formate, and rectifying and purifying to obtain 165g of light yellow-green oily liquid.
Example 6:
synthesis of methyl 4-chlorobenzoyl formate
(1) Adding 151.5g of 4-chlorobenzonitrile into a four-neck flask, starting a tail gas absorption system, heating to 60-65 ℃, slowly adding 10g of sulfuryl chloride, slowly introducing chlorine gas for chlorination reaction after the addition is finished, tracking, sampling and detecting, stopping introducing the chlorine gas until the content of the 4-chlorobenzonitrile is lower than 0.5%, completing the chlorination reaction, and directly using the reaction solution for the next synthesis without treatment;
(2) adding 60g of water and 250g of sulfuric acid into a four-neck flask, adding 10g of catalyst hydrobromic acid after the addition is finished, starting a tail gas absorption system, controlling the temperature to be 25-50 ℃, slowly dripping the chlorinated solution obtained in the previous step into prepared dilute sulfuric acid for 3 hours, and reacting at constant temperature for 5 hours after the dripping is finished, thus finishing the reaction.
(3) Controlling the temperature to be 40-50 ℃, dropwise adding 120g of methanol into the reaction solution, wherein the time is 2 hours, and reacting for 2 hours at constant temperature after dropwise adding;
(4) cooling to 25 ℃, adding 60g of water, stirring for 2 hours, standing for layering, taking an upper organic layer as a crude product of the 4-chlorobenzoyl methyl formate, and rectifying and purifying to obtain 148g of light yellow-green oily liquid.
It should be understood that the detailed description of the invention is merely illustrative of the invention and is not intended to limit the invention to the specific embodiments described. It will be appreciated by those skilled in the art that the present invention may be modified or substituted equally as well to achieve the same technical result; as long as the use requirements are met, the method is within the protection scope of the invention.
Claims (9)
1. A new synthesis method of α -carbonyl acid ester is characterized by comprising the following steps:
(1) adding a nitrile compound containing α methylene with a general formula II into a reaction container A, then gradually introducing chlorine gas to carry out chlorination reaction at 30-80 ℃, and obtaining a dichloronitrile compound after the raw material nitrile compound completely reacts;
(2) adding sulfuric acid and water into a reaction container B, adding a catalyst y, slowly dropwise adding the dichloronitrile obtained in the step (1) under the condition of controlling the temperature to be 25-50 ℃, and reacting for 4-6 hours at constant temperature after dropwise adding, wherein the molar ratio of the nitrile containing α methylene to water to acid is 1 (1-10) to (1-10);
(3) controlling the temperature of 40-50 ℃ in the reaction liquid obtained in the step (2), and dropwise adding a compound with the general formula R2Carrying out esterification reaction on-OH substances, after dropwise adding, heating to 65-70 ℃, and reacting at constant temperature for 2-3 hours, wherein the molar ratio of alcohol to nitrile containing α methylene is (2-10): 1;
(4) cooling to 20-40 ℃, adding water, stirring for 2-3 hours, standing for layering after the reaction is finished, taking an upper organic layer, and rectifying and purifying to obtain the target product α -carbonyl acid ester, wherein the molar ratio of the nitrile containing α methylene to water is 1 (1-10).
2. The novel synthesis method of α -carbonyl acid ester according to claim 1, characterized in that, the steps are as follows:
(1) adding a nitrile compound containing α methylene with a general formula II into a reaction container A, adding a catalyst x, gradually introducing chlorine gas, carrying out chlorination reaction at 30-80 ℃, and obtaining a dichloronitrile compound after the raw material nitrile compound reacts completely;
(2) adding sulfuric acid and water into a reaction container B, adding a catalyst y, slowly dropwise adding the dichloronitrile obtained in the step (1) under the condition of controlling the temperature to be 25-50 ℃, and reacting for 4-6 hours at constant temperature after dropwise adding, wherein the molar ratio of the nitrile containing α methylene to water to acid is 1 (1-10) to (1-10);
(3) controlling the temperature of 40-50 ℃ in the reaction liquid obtained in the step (2), and dropwise adding a compound with the general formula R2Carrying out esterification reaction on-OH substances, after dropwise adding, heating to 65-70 ℃, and reacting at constant temperature for 2-3 hours, wherein the molar ratio of alcohol to nitrile containing α methylene is (2-10): 1;
(4) cooling to 20-40 ℃, adding water, stirring for 2-3 hours, standing for layering after the reaction is finished, taking an upper organic layer, and rectifying and purifying to obtain the target product α -carbonyl acid ester, wherein the molar ratio of the nitrile containing α methylene to water is 1 (1-10).
3. The novel synthesis method of α -carbonyl acid ester according to claim 1 or 2, wherein R in the α methylene group-containing nitrile compound having the general formula II1Is an aromatic radical having the general formula VI.
Wherein:
R3is alkyl, chlorine, bromine, fluorine, nitro, sulfoAny one of an acid group, an alkoxy group, and a trifluoromethyl group;
R4is any one of alkyl, chlorine, bromine, fluorine, nitro, sulfonic group, alkoxy and trifluoromethyl.
4. The novel synthesis method of α -carbonyl acid ester according to claim 1 or 2, wherein R in the α methylene group-containing nitrile compound having the general formula II1Is an aliphatic radical.
5. The novel synthesis method of α -carbonyl acid ester according to claim 1 or 2, wherein in step (2), catalyst y is any one of hydrochloric acid, hydrobromic acid, sodium chloride and sodium bromide.
6. The novel process for synthesizing α -carbonyl acid ester according to claim 2, wherein in the step (1), the catalyst x is any one of hydrogen chloride, hydrogen bromide, sulfuryl chloride, and thionyl chloride.
7. The novel process for the synthesis of α -carbonyl acid ester according to claim 1 or 2, wherein the general formula is R2the-OH substance is an alcohol or a phenol.
8. The novel synthesis method of α -carbonyl acid ester according to claim 7, wherein the alcohol is any one of methanol, ethanol, and isopropanol.
9. The novel synthesis method of α -carbonyl acid ester according to claim 7, wherein the phenol is phenol.
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