CN114656348B - Improved preparation method of methylene quinone compound - Google Patents
Improved preparation method of methylene quinone compound Download PDFInfo
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- CN114656348B CN114656348B CN202210461295.7A CN202210461295A CN114656348B CN 114656348 B CN114656348 B CN 114656348B CN 202210461295 A CN202210461295 A CN 202210461295A CN 114656348 B CN114656348 B CN 114656348B
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- C07C45/56—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds from heterocyclic compounds
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- C07D211/06—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
- C07D211/08—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms
- C07D211/10—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with radicals containing only carbon and hydrogen atoms attached to ring carbon atoms
- C07D211/14—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hydrocarbon or substituted hydrocarbon radicals directly attached to ring carbon atoms with radicals containing only carbon and hydrogen atoms attached to ring carbon atoms with hydrocarbon or substituted hydrocarbon radicals attached to the ring nitrogen atom
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- C07D211/04—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D211/06—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members
- C07D211/36—Heterocyclic compounds containing hydrogenated pyridine rings, not condensed with other rings with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having no double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
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- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/34—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
- C07D307/38—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with substituted hydrocarbon radicals attached to ring carbon atoms
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- C07D333/02—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings
- C07D333/04—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom
- C07D333/06—Heterocyclic compounds containing five-membered rings having one sulfur atom as the only ring hetero atom not condensed with other rings not substituted on the ring sulphur atom with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to the ring carbon atoms
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- C07D405/06—Heterocyclic compounds containing both one or more hetero rings having oxygen atoms as the only ring hetero atoms, and one or more rings having nitrogen as the only ring hetero atom containing two hetero rings linked by a carbon chain containing only aliphatic carbon atoms
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- C07D409/02—Heterocyclic compounds containing two or more hetero rings, at least one ring having sulfur atoms as the only ring hetero atoms containing two hetero rings
- C07D409/06—Heterocyclic compounds containing two or more hetero rings, at least one ring having sulfur atoms as the only ring hetero atoms containing two hetero rings linked by a carbon chain containing only aliphatic carbon atoms
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Abstract
The invention relates to an improved preparation method of methylene quinone compounds, which is characterized in that aldehyde group substituted cyclic A compounds and phenol derivatives react in the presence of piperidine derivatives, and the synthetic route is as follows:
ring A is aryl or heteroaryl, R 1 Independently selected from C1-6 alkyl, the structural formula of the piperidine derivative is
Wherein R is 3 Independently selected from at least one of H, C1-C6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C2-C6 ester group, nitro, hydroxyl, halogen atom and C1-4 alkoxy; provided that R3 cannot all be H. According to the invention, the piperidine derivative is adopted, so that the dosage of the secondary amine is reduced to a catalytic amount, the utilization rate of the secondary amine is improved, and the production cost is greatly reduced. The crude product is passed through a compounded solvent containing alcohol, so that the side reaction of aromatization is avoided, and the yield of the methylene quinone compound is improved.
Description
Technical Field
The application relates to the field of organic synthesis, in particular to a preparation method of an improved methylene quinone compound.
Background
The methylene quinone compound is one kind of important fine chemical intermediate. As an electron acceptor, the compound has wide application in both basic research and industrial application. Some representative compounds, such as 4-phenylmethylene-2, 6-di-tert-butyl-2, 5-cyclohexadiene-1-one (CAS registration number: 7078-98-0), have excellent oxidation resistance and polymerization inhibition performance, can be applied to polymerization inhibition of styrene and acrylic compounds, and are main components of a new generation of compound green polymerization inhibitor.
There are four main methods for the synthesis of methylene quinones: mannich method, methyleneoxy oxidation method, phenyllithium method, grignard reagent method, etc., among which the most practical methods are Mannich method. Several documents and patents have been reported about the mannich method, but the mannich method still has great disadvantages: either the yield is not high or the industrialization is limited. On one hand, expensive or toxic piperidine is generally used as a catalyst, so that the synthesis cost is high and the environment is not friendly; on the other hand, the post-treatment and purification of the product are difficult, because the methylene quinone compound has the electron deficiency and easy aromatization, the addition reaction and aromatization are easy to occur in the post-treatment process, so that the yield is reduced, some reported liquid phase yields are high, and the actual yield is greatly reduced. Therefore, it is very critical to solve the problem of purification in actual production.
At present, benzaldehyde, 2, 6-di-tert-butylphenol and secondary amine are taken as raw materials in the prior art, secondary amine plays a role of a catalyst in the reaction, but secondary amine substances are continuously lost under the reaction condition, so that the dosage of the secondary amine is in a chemical equivalent level. The use of piperidine as a catalyst is reported in the literature to reduce the dosage of the secondary amine catalyst by about half, but the dosage of the secondary amine still belongs to the chemical equivalent, which causes high cost and waste of resources. In addition, piperidine is a compound which is easy to be detoxified, is strictly controlled, is expensive, and is not suitable for large-scale industrial production. In addition, when recrystallization of the crude product is obtained, an alcoholic solvent such as methanol is generally selected, resulting in easy aromatization of the product to obtain the by-product p-MP, resulting in a poor yield.
Disclosure of Invention
In order to solve the defects that the secondary amine used as a catalyst is low in utilization efficiency and low in yield of final products, which causes high production cost of the methylene quinone compounds, when the methylene quinone compounds are prepared in the prior art, the invention provides an improved preparation method of the methylene quinone compounds. Recrystallization is completed by the compounded solvent, so that aromatization reaction is avoided, and the yield is obviously improved.
In order to solve the technical problems, the invention provides the following technical scheme:
an improved preparation method of methylene quinone compounds is characterized in that aldehyde substituted cyclic A compounds and phenol derivatives react in the presence of piperidine derivatives, and the synthetic route is as follows:
ring A is aryl or heteroaryl, R 1 Independently selected from C1-6 alkyl, the structural formula of the piperidine derivative is shown in the specification
Wherein R is 3 Independently selected from at least one of H, C1-C6 alkyl, C2-6 alkenyl, C2-6 alkynyl, C2-C6 ester group, nitro, hydroxyl, halogen atom and C1-4 alkoxy; provided that R3 cannot all be H.
The reactants are aldehyde group substituted ring A and phenol derivatives, and secondary amine piperidine derivatives are used as catalysts.
Preferably, R 1 Is tert-butyl or isopropyl. When R is 1 In the case of t-butyl or isopropyl, the resulting methylenequinone compound can remain stable.
Further, the ring A is at least one of phenyl, naphthyl, anthracenyl, benzanthracenyl, phenanthrenyl, pyrenyl, perylenyl, biphenyl, spirobifluorenyl, thienyl, furanyl, benzofuranyl, indolyl, isoindolyl, carbazolyl, pyridyl, quinolyl, isoquinolyl, pyrazolyl, indazolyl, benzopyrimidinyl, quinoxalinyl, pyrazinyl, phenazinyl, phenothiazinyl, 1,2, 3-triazolyl, 1,2, 4-triazolyl, 1,2, 3-oxadiazolyl, 1,2, 4-oxadiazolyl, 1,2, 5-thiadiazolyl, 1,3, 4-thiadiazolyl, 1,3, 5-triazinyl, 1,2, 4-triazinyl, 1,2, 3-triazinyl. Preferably, ring a is phenyl.
Said C1-C6 alkyl is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl; the C2-6 alkenyl is selected from ethenyl, propenyl and butenyl; the C2-6 alkynyl is selected from ethynyl, propynyl and butynyl; the C1-4 alkoxy group is selected from methoxy, ethoxy, propoxy and butoxy.
Preferably, the piperidine derivative is at least one of alkyl-substituted piperidine, alkoxy-substituted piperidine, and ester-substituted piperidine, and examples thereof include at least one of 2-methylpiperidine, 3-methyl-piperidine, 4-methylpiperidine, 2, 3-dimethylpiperidine, 2, 4-dimethylpiperidine, 3, 5-dimethylpiperidine, methyl 3-piperidinecarboxylate, and ethyl 3-piperidinecarboxylate. Preferably an ester-substituted piperidine such as methyl 3-piperidinecarboxylate, ethyl 3-piperidinecarboxylate. The inventors have unexpectedly found that the substitution of an ester group for piperidine as a secondary amine catalyst can achieve satisfactory yield at lower catalyst usage, probably because the introduction of an ester group results in a decrease in the electron cloud density of the piperidine ring and an increase in the catalytic activity of the N atom; it may also be partly attributed to the increased boiling point and is not readily able to escape from the system.
Further, in the preparation method of the methylene quinone compound, the reactant is added into a container, a solvent is added, the piperidine derivative is slowly added, the temperature is raised to 115-130 ℃, the temperature is raised to 140-155 ℃ after the reaction is carried out for 15-20 hours, the reaction is continued for 2-4 hours, the crude product is obtained through reduced pressure distillation, the solvent containing alcohol is added, the mixture is heated, stirred and dissolved, cooled, crystallized, filtered and washed, and the methylene quinone compound is obtained.
Further, in the reactants, the molar ratio of the aldehyde group substituted cyclic A compound to the phenol derivative to the piperidine derivative is 0.9-1.3:1:0.05-0.1. Compared with the conventional method that the chain secondary amine needs to be used in a chemical equivalent ratio, the method uses the piperidine derivative as the catalyst, only needs a catalytic amount of the piperidine derivative to complete the reaction, and has high yield.
Further, the solvent is selected from at least one of benzene, toluene, petroleum ether, n-hexane and chlorobenzene; the alcohol-containing solvent contains 40-60vol% of alcohol, and the alcohol is selected from at least one of methanol, ethanol, and isopropanol, and is preferably ethanol for cost and safety.
Preferably, the alcohol-containing solvent is a C1-3 alcohol, petroleum ether and acetonitrile in a volume ratio of 40-60:20-30:20-30. The C1-3 alcohol is at least one selected from methanol, ethanol and isopropanol.
If an alcohol solvent such as methanol, ethanol is used alone, the following aromatization side reactions are liable to occur:
the inventor unexpectedly finds that the solvent compounded by the C1-3 alcohol, the petroleum ether and the acetonitrile according to a certain proportion is used as the solvent for recrystallizing the crude product, so that the aromatization trend of the product can be obviously reduced, and the yield of the final product is obviously improved. In the preparation process of the methylene quinone compound, irreversible aromatization side reaction occurs when a crude product is recrystallized, which is an important reason causing low yield. Even if the alcohol content is easy to be higher, the side reaction of aromatization can be obviously inhibited, and the yield of the final product is obviously improved.
Compared with the prior art, the invention at least obtains the following beneficial technical effects:
1. by adopting the piperidine derivative, the dosage of secondary amine is reduced to a catalytic amount, the utilization rate of the secondary amine is improved, and the production cost is greatly reduced. Particularly, the use amount of secondary amine can be obviously reduced by adopting the ester-substituted piperidine derivative, and the yield is higher.
2. The crude product is passed through a compounded solvent containing alcohol, so that the side reaction of aromatization is avoided, and the yield of the methylene quinone compound is improved.
3. The method adopts a one-pot method, has simple operation and cheap and easily obtained raw materials, and is a method which is expected to industrially produce the methylene quinone compound on a large scale.
Drawings
FIG. 1 shows the product obtained in example 1 1 H-NMR chart;
FIG. 2 shows the product obtained in example 8 1 H-NMR chart;
FIG. 3 shows the product obtained in example 9 1 H-NMR chart;
FIG. 4 shows the product obtained in example 10 1 H-NMR chart.
Detailed Description
The present application is further illustrated by the following examples.
Example 1
Adding 46.8g (0.44 mol) of benzaldehyde and 100.0g (0.48 mol) of 2, 6-di-tert-butylphenol into a 500mL three-neck flask, adding 100mL of benzene, slowly dropwise adding 2.4g (0.024 mol) of 2-methylpiperidine, after dropwise adding is finished for 2h, heating to 120 ℃, reacting for 18h, and detecting that the raw materials are basically reacted by TLC; and heating the reaction liquid to 150 ℃, continuing to react for 3 hours, distilling under reduced pressure, evaporating to remove the solvent and removing the 2-methylpiperidine to obtain a crude product. Adding 60mL of ethanol, 20mL of petroleum ether and 20mL of acetonitrile into the system, heating, stirring and dissolving, then placing the system into a low-temperature tank, cooling to-5 ℃, separating out solid, carrying out suction filtration, and washing with ethanol to obtain 115.6.1g of a product, wherein the purity is 98.5%, and the yield is 81.4%. Of the resulting product 1 H-NMR(CDCl 3 ) As shown in FIG. 1, the structure of the product was confirmed to be correct.
Example 2
Other conditions were the same as in example 1 except that 2-methylpiperidine was replaced with an equimolar amount of 3-methylpiperidine. The product of example 2 was tested with 98.3% purity and 81.6% yield.
Example 3
Other conditions were the same as in example 1 except that 2-methylpiperidine was replaced with an equimolar amount of 4-methylpiperidine. The purity of the product of example 3 was 98.4% and the yield was 82.1%.
Example 4
Other conditions were the same as in example 1 except that 2-methylpiperidine was replaced with an equimolar amount of 3, 5-dimethylpiperidine. The purity of the product of example 4 was 98.7% and the yield was 83.2%.
Example 5
Other conditions were the same as in example 1 except that 2-methylpiperidine was replaced with an equimolar amount of methyl 3-piperidinecarboxylate. The purity of the product of example 5 is 98.2% and the yield is 85.6%.
Example 6
The other conditions were the same as in example 1 except that after obtaining a crude product, a crystallization operation was carried out by adding a mixed solvent of 60mL of ethanol and 40mL of petroleum ether to the system. The purity of the final product is 95.3%, and the yield is 73.6%.
Example 7
The other conditions were the same as in example 1 except that the crude product was obtained. A mixed solvent of 60mL of ethanol and 40mL of acetonitrile was added to the system to conduct crystallization. The purity of the final product is 93.8%, and the yield is 74.5%.
Example 8
Other conditions were the same as in example 3, and the ratio of the amounts of the cyclic A compound, 2, 6-di-t-butylphenol, and 4-methylpiperidine was the same, except that the cyclic A compound was furfural. Of the resulting product 1 The H-NMR spectrum is shown in FIG. 2. The final product purity was 97.8% and yield was 78.5%.
Example 9
Other conditions were the same as in example 3, and the ratio of the amounts of the ring A compound, 2, 6-di-t-butylphenol, and 4-methylpiperidine was the same, except that the ring A compound was thiophene-2-carbaldehyde. Of the resulting product 1 The H-NMR spectrum is shown in FIG. 3. The purity of the final product is 98.0%, and the yield is 79.2%.
Example 10
Other conditions were the same as in example 3 except that the cyclic A compound was anisaldehyde, and the ratio of the amounts of 2, 6-di-t-butylphenol, and 4-methylpiperidine was the same. Of the resulting product 1 The H-NMR spectrum is shown in FIG. 4. The purity of the final product is 96.3%, and the yield is 78.2%.
Example 11
Otherwise, the same conditions as in example 3 were used, and the quantitative ratios of the ring A compound, 2, 6-di-t-butylphenol, and 4-methylpiperidine were the same, except that the ring A compound was cinnamaldehyde. The purity of the final product was 95.4% and the yield was 77.8%.
Claims (4)
1. An improved preparation method of methylene quinone compounds is characterized in that aldehyde group substituted ring A compounds and phenol derivatives react in the presence of piperidine derivatives, and the synthetic route is as follows:
the ring A is at least one of phenyl, thienyl and furyl; or
Is->
，/>
At least one of (a); r 1 Is tert-butyl, and the piperidine derivative is at least one of 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine and 3-methylpiperidine formate;
the molar ratio of the aldehyde group substituted cyclic A compound to the phenol derivative to the piperidine derivative is 0.9-1.3:1:0.05-0.1;
the preparation method of the improved methylene quinone compound comprises the following steps: adding the reactant into a container, adding a solvent, slowly adding a piperidine derivative, heating to 115-130 ℃, reacting for 15-20h, heating to 140-155 ℃, continuing to react for 2-4h, carrying out reduced pressure distillation to obtain a crude product, adding an alcohol-containing solvent, heating, stirring, dissolving, cooling, crystallizing, carrying out suction filtration, and washing to obtain the product, namely the methylene quinone compound.
2. The production method according to claim 1, wherein the solvent is at least one selected from the group consisting of benzene, toluene, petroleum ether, n-hexane, and chlorobenzene; in the solvent containing alcohol, the content of alcohol is 40-60vol%.
3. The method according to claim 1, wherein the alcohol-containing solvent is a C1-3 alcohol, petroleum ether and acetonitrile in a volume ratio of 40-60:20-30:20-30 parts of mixed solvent.
4. The method according to claim 3, wherein the C1-3 alcohol is at least one selected from the group consisting of methanol, ethanol, and isopropanol.
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