JP2012001521A - Method for manufacturing vinyl group-containing compound dimer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially suitable method for manufacturing a vinyl group-containing compound dimer in a high yield with high selectivity without requiring an expensive catalyst or a complicated manufacturing process.SOLUTION: The method for manufacturing the dimer from a vinyl group-containing compound includes a process for dimerizing the vinyl group-containing compound by subjecting it to a reaction in the presence of an aromatic sulfinate. Indispensably, the aromatic sulfinate is an ammonium salt and/or a phosphonium salt of an aromatic sulfinic acid.

Description

The present invention relates to a method for producing a vinyl group-containing compound dimer. More specifically, various organic compounds such as pharmaceuticals and agricultural chemicals, production of polyester resins for coatings, raw materials for the production of urethane resins and other vinyl group-containing compound dimers used as raw materials for polymers Regarding the method.

Dimers of vinyl group-containing compounds (dimers) are useful for various applications such as various organic compounds such as pharmaceuticals and agricultural chemicals, polyester resins for paints, raw materials for the production of urethane resins and other raw materials for polymers. It is. One dimer of such vinyl group-containing compounds is a dicarboxylic acid diester. Dicarboxylic acid diesters are expected to exhibit different characteristics from ordinary carboxylic acid monoesters because of having two carboxyl groups. For example, dicarboxylic acid diesters obtained from dicarboxylic acid diesters as raw materials When an acid polymer is produced, it becomes a polymer having two carboxyl groups in the side chain, and when this is used as a detergent builder, it is considered that the polymer is excellent in chelating ability such as calcium. Dicarboxylic acid diesters are expected to be used not only as raw materials for such dispersants, water treatment agents and detergent builders, but also in various fields. Thus, the vinyl group-containing compound dimer is a useful compound expected to be used in various applications.

As a method for producing a vinyl group-containing compound dimer, production of a dicarboxylic acid diester using an acrylate ester as a substrate and 1,4-diazabicyclo [2.2.2] octane (DABCO) or trialkylphosphine as a catalyst. A method is disclosed (for example, see Non-Patent Document 1). In addition, a dimerization reaction of an acrylic acid compound using a ruthenium complex having a trialkylphosphine as a ligand as a catalyst is disclosed (for example, see Non-Patent Document 2). Furthermore, dimerization reaction of acrylic acid ester using potassium-benzyl potassium as a basic catalyst and dimerization reaction of acrylic acid ester using sodium alkoxide as a catalyst are disclosed (for example, Non-patent Document 3). 4). In addition, a dimerization reaction of acrylonitrile using an aromatic sulfinic acid alkali metal salt or alkaline earth metal salt or an aromatic selenic acid alkali metal salt or alkaline earth metal salt as a catalyst is disclosed (for example, Patent Document 1). reference.).

JP-A-60-132946 (page 353)

Engelbert Ciganek, “Organic Reactions”, 1997, Vol. 51, p. 201-350 One of Chae S. Yi, “Journal of Organometallic Chemistry”, 1998, Vol. 553, p. 157-161 Two people from Joseph Shabatai, “Journal of Organic Chemistry”, 1978, Vol. 43, No. 21, p. 4086-4090 BA Feit, “European Polymer Journal”, 1967, Vol. 3, p. 523-534

As described above, several methods have been disclosed as methods for producing vinyl group-containing compound dimers. However, in the method using a trialkylphosphine as a catalyst, in addition to the expensive trialkylphosphine, the phosphine is easily oxidized in the air. Therefore, the reaction can be performed in a nitrogen or argon atmosphere to prevent the oxidation. It is necessary and the manufacturing process becomes complicated. In addition, in the production using DABCO as a catalyst, the carboxylic acid ester used as a substrate is limited to phenyl esters that are difficult to obtain, and for the production using a complex of ruthenium and trialkylphosphine as a catalyst, The catalyst is expensive. Furthermore, when potassium-benzylpotassium is used as a basic catalyst, the acrylate ester used as a substrate is limited to a specific type, and an acrylate ester having no bulky ester group is used. The proportion of the polymer that does not stop the reaction by dimerization and is polymerized is high, and the selectivity of the dimer is low. Furthermore, when sodium alkoxide is used as a catalyst, the ratio of the compound in which an oxyalkylene group is added to the terminal of the dimer of the carboxylic acid ester is high, and the selectivity of the dimer of the carboxylic acid ester is high. The result is not high enough. In addition, progress of polymerization is also observed.
As described above, in any of the above methods, a vinyl group-containing compound dimer such as an expensive catalyst, a complicated manufacturing process, or a high selectivity of the vinyl group-containing compound dimer cannot be obtained. There were several problems to be solved in order to be able to efficiently carry out the industrial production of. In order to make the production of vinyl group-containing compound dimers industrially suitable, it is necessary to be a production method that suppresses production costs and does not require complicated steps. When the trimer is mixed with the dimer, the polymer is deteriorated when used as a raw material for the polymer. Therefore, it is necessary to be able to produce the dimer with high selectivity. For this reason, the manufacturing method of the vinyl group containing compound dimer which can solve these subjects is calculated | required.

The present invention has been made in view of the above-mentioned present situation, and does not require an expensive catalyst or a complicated production process, and can suppress the production cost of a vinyl group-containing compound dimer with high yield and high selectivity. It is an object of the present invention to provide a method for producing a vinyl group-containing compound dimer suitable for production of an industrial vinyl group-containing compound dimer.

The present inventor has studied a method capable of producing a vinyl group-containing compound dimer with high yield and high selectivity, and variously examined the optimum catalyst for the dimerization reaction of the vinyl group-containing compound. It has been found that when an ammonium salt and / or a phosphonium salt of a group sulfinic acid is used as a catalyst, a dimer of a vinyl group-containing compound can be obtained with high yield and high selectivity.
Ammonium salts and / or phosphonium salts of aromatic sulfinic acid are not expensive compounds among the compounds used as catalysts, and it is not necessary to carry out the dimerization reaction in a nitrogen or argon atmosphere. In addition, the ammonium salt and / or phosphonium salt of aromatic sulfinic acid is a basic catalyst similar to the above-mentioned potassium-benzyl potassium, sodium alkoxide, etc., but even with the same basic catalyst, potassium-benzyl potassium is The reactivity is too high and the production of polymer increases, and when sodium alkoxide is used, there is a problem that many compounds with an oxyalkylene group added to the end of the dimer are produced. When an ammonium salt and / or phosphonium salt of aromatic sulfinic acid is used, a vinyl group-containing compound dimer can be produced with high yield and high selectivity. In addition, when an ammonium salt and / or phosphonium salt of aromatic sulfinic acid is used, a high yield is obtained even when a carboxylic acid ester is used as a substrate and the ester part has a low bulk. Dicarboxylic acid diesters can be produced with high selectivity, and the range of application of the substrate is wider than when potassium-benzylpotassium is used.

In addition, the present inventor, in particular, among the vinyl group-containing compounds as a reaction substrate, when a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group is used, an ammonium salt of aromatic sulfinic acid and / or phosphonium. The reaction is moderately promoted by using a salt as a catalyst. As a result, the rate of progress of multimerization (trimer, tetramer formation, etc.) is lower than that of the dimerization reaction. It has been found that dicarboxylic diesters which are dimers can be obtained with high yield and high selectivity. Furthermore, when the carboxylic acid ester is used as the reaction substrate, the present inventor can perform the reaction in a solvent-free system that does not use a solvent at the time of the reaction, thereby making the dimerization reaction more efficient. It has been found that dicarboxylic acid diesters can be obtained with a significantly higher yield and higher selectivity. When such a solvent-free reaction is carried out, a process for removing the solvent after the dimerization reaction is not required, and since it can be produced using a smaller reaction vessel than when performing a solvent-based reaction, It becomes possible to make the process simpler and reduce the manufacturing cost.
Thus, for the purpose of producing a dimer of a vinyl group-containing compound, an aromatic sulfinic acid that has not been used as a catalyst for the reaction for producing a dimer of such a vinyl group-containing compound has been conventionally used. By using an ammonium salt and / or phosphonium salt as a reaction catalyst, it has been found that a dimer of a vinyl group-containing compound can be produced at a high yield and high selectivity and at a low production cost, and solves the above-mentioned problems brilliantly. The present inventors have arrived at the present invention. In particular, according to the present invention, it has been found that it is preferable to combine a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group with an ammonium salt and / or a phosphonium salt of an aromatic sulfinic acid. Production of a dicarboxylic acid diester is achieved.

That is, the present invention is a method for producing a dimer from a vinyl group-containing compound, and the production method comprises a step of reacting a vinyl group-containing compound in the presence of an aromatic sulfinate to dimerize. A vinyl group-containing compound dimer production method characterized in that the aromatic sulfinate includes an ammonium salt and / or a phosphonium salt of an aromatic sulfinic acid.
The present invention is described in detail below.

The method for producing a vinyl group-containing compound dimer according to the present invention includes a step of reacting a vinyl group-containing compound in the presence of an aromatic sulfinate to dimerize. These steps may be included. That is, even when a vinyl group-containing compound is produced as an intermediate using other raw materials to produce a vinyl group-containing compound dimer, the step of reacting the vinyl group-containing compound to dimerize As long as it is included, this corresponds to the method for producing a vinyl group-containing compound dimer of the present invention.
In addition, in the manufacturing method of this invention, 1 type may be used for an aromatic sulfinate and a vinyl group containing compound, respectively, and 2 or more types may be used for it.

The aromatic sulfinic acid salt essentially contains an ammonium salt and / or a phosphonium salt of aromatic sulfinic acid. By performing the dimerization reaction of the vinyl group-containing compound in the presence of the ammonium salt and / or phosphonium salt of aromatic sulfinic acid, a dimer of the vinyl group-containing compound can be obtained with high yield and high selectivity. . In addition, ammonium salts and / or phosphonium salts of aromatic sulfinic acid have high solubility in various solvents, and therefore, when the dimerization reaction is performed in a solvent, there are a wide range of solvent options. This is one of the advantages of using an ammonium salt and / or phosphonium salt of aromatic sulfinic acid as a catalyst.

The aromatic sulfinate may contain an ammonium salt and a salt other than the phosphonium salt as long as it contains an ammonium salt and / or phosphonium salt of aromatic sulfinic acid. It is preferable to contain 40 to 100% by mass of an ammonium salt and / or phosphonium salt of aromatic sulfinic acid. In such a range, in the dimerization reaction of the vinyl group-containing compound, the effect of the present invention that the vinyl group-containing compound dimer can be obtained with high yield and high selectivity can be obtained more sufficiently. Can do. More preferably, the aromatic sulfinic acid salt contains 100 to 100% by mass of an ammonium salt and / or phosphonium salt of aromatic sulfinic acid, and more preferably 80 to 100% by mass.

The ammonium salt and / or phosphonium salt of the aromatic sulfinic acid is not particularly limited as long as it is an ammonium salt and / or phosphonium salt of a compound having an aromatic ring and a sulfinic acid group. There may be one, two or more, and may have other functional groups. The aromatic ring may have a substituent.

The ammonium salt and / or phosphonium salt of the aromatic sulfinic acid is represented by the following general formula (1);

(In the formula, X represents an aromatic ring substituent. M represents the number of aromatic ring substituents and is an integer of 0 to 5. Y represents a nitrogen atom and / or a phosphorus atom. R Are the same or different and each represents a hydrogen atom or an organic group having 1 to 18 carbon atoms.

X in the general formula (1) represents an aromatic ring substituent. Examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a halogen group, a nitro group, and a cyano group. A hydroxyl group is preferred.
M in the general formula (1) represents the number of substituents on the aromatic ring, and is an integer of 0 to 5, and when the aromatic ring has a substituent, there may be only one substituent or a plurality of substituents. Also good. Examples of such aromatic sulfinic acid include benzenesulfinic acid, p-toluenesulfinic acid, o-toluenesulfinic acid, pt-butylbenzenesulfinic acid, 2,4,6-trimethylbenzenesulfinic acid, p- Examples thereof include methoxybenzenesulfinic acid, p-cyanobenzenesulfinic acid, p-chlorobenzenesulfinic acid, p-bromobenzenesulfinic acid, p-iodobenzenesulfinic acid, p-nitrobenzenesulfinic acid and the like. Among them, benzenesulfinic acid, p-toluenesulfinic acid, p-t-butylbenzenesulfinic acid, and p-methoxybenzenesulfinic acid are preferable, p-toluenesulfinic acid and p-methoxybenzenesulfinic acid are more preferable, and p-methoxybenzene. Sulfinic acid is more preferred.

Y in the general formula (1) represents a nitrogen atom and / or a phosphorus atom, and when Y is a nitrogen atom, the compound represented by the general formula (1) is an ammonium salt of an aromatic sulfinic acid. When Y is a phosphorus atom, the compound represented by the general formula (1) represents a phosphonium salt of aromatic sulfinic acid.

R in the general formula (1) is the same or different and represents a hydrogen atom or an organic group having 1 to 18 carbon atoms, but at least one of the four Rs is an organic group having 1 to 18 carbon atoms. Is preferred. That is, the ammonium salt and phosphonium salt each have a structure in which at least one organic group having 1 to 18 carbon atoms is bonded to a nitrogen atom, and at least one organic group having 1 to 18 carbon atoms is bonded to a phosphorus atom. It is preferable that it is the structure. More preferably, of the four Rs, there are two organic groups having 1 to 18 carbon atoms, more preferably three, and most preferably all four have 1 to 18 carbon atoms. It is an organic group.

Examples of the organic group having 1 to 18 carbon atoms include a chain saturated hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. Is mentioned. These groups may have a substituent, that is, a substituted chain saturated hydrocarbon group in which at least a part of the hydrogen atoms bonded to the carbon atoms constituting these groups are replaced with a substituent, substituted aliphatic It may be a cyclic hydrocarbon group or a substituted aromatic hydrocarbon group. Especially, the C1-C18 chain | strand-shaped saturated hydrocarbon group which may have a substituent is preferable.
As carbon number of the said C1-C18 organic group, it is preferable that it is 12 or less, More preferably, it is 10 or less, More preferably, it is 8 or less.

As R in the general formula (1), among those described above, an alkyl group having 1 to 18 carbon atoms, a phenyl group, and a benzyl group are preferable. When R is such, a dimer of the vinyl group-containing compound can be obtained with higher yield and higher selectivity. More preferably, they are a C1-C12 alkyl group and a benzyl group. Among these, a C1-C8 alkyl group, such as a methyl group, a butyl group, and an octyl group, and a benzyl group are preferable.
And as said ammonium salt, it is especially suitable that it is the form by which all the hydrogen atoms of ammonium salt were substituted by the butyl group among the forms mentioned above.
The phosphonium salt is particularly preferably in a form in which all hydrogen atoms of the phosphonium salt are substituted with butyl groups.

Specific examples of the aromatic sulfinic acid ammonium salt and / or phosphonium salt include those obtained by combining the above-described aromatic sulfinic acid and ammonium salt or phosphonium salt, specifically, p-toluenesulfinic acid. Alkyl groups having 1 to 18 carbon atoms such as tetramethylammonium, tetrapropylammonium p-toluenesulfinate, tetrabutylammonium p-toluenesulfinate, tetraoctylammonium p-toluenesulfinate, benzyltrimethylammonium p-toluenesulfinate, and the like; Tetraalkylammonium p-toluenesulfinate having a benzyl group; tetramethylphosphonium p-toluenesulfinate, tetrapropylphosphonium p-toluenesulfinate, p-toluenesulfur Tetraalkylphosphonium p-toluenesulfinate having an alkyl group having 1 to 18 carbon atoms and a benzyl group, such as tetrabutylphosphonium phosphate, tetraoctylphosphonium p-toluenesulfinate, benzyltrimethylphosphonium p-toluenesulfinate; benzenesulfinic acid Benzenesulfinate tetraalkylammonium having 1 to 18 carbon atoms such as tetrabutylammonium; benzenesulfinate tetraalkylphosphonium having 1 to 18 carbons such as tetrabutylphosphonium benzenesulfinate; p-chlorobenzene P-chlorobenzenetetraalkylammonium sulfinate having a C1-C18 alkyl group such as tetrabutylammonium sulfinate; p-chloroben P-chlorobenzenesulfinic acid tetraalkylphosphonium having an alkyl group of 1 to 18 carbon atoms such as tetrabutylphosphonium sulfinic acid; p-methoxy having an alkyl group of 1 to 18 carbon atoms such as p-methoxybenzenesulfinic acid tetrabutylammonium Examples include tetraalkylammonium benzenesulfinate; tetraalkylphosphonium p-methoxybenzenesulfinate having an alkyl group having 1 to 18 carbon atoms such as tetrabutylphosphonium p-methoxybenzenesulfinate.
Moreover, these may contain crystal water.
These aromatic sulfinates are synthesized, for example, by reacting an aromatic sulfinic acid with the basic compound forming an ammonium salt and / or phosphonium salt, and distilling off the generated water. can do. Examples of basic compounds that form aromatic sulfinic acid and ammonium salts and / or phosphonium salts include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tetraoctylammonium hydroxide, Examples thereof include benzyltrimethylammonium hydroxide, tetramethylphosphonium hydroxide, tetrabutylphosphonium hydroxide, and tetraoctylphosphonium hydroxide.

In the method for producing a vinyl group-containing compound dimer according to the present invention, the aromatic sulfinate may be added to the reaction system, or the aromatic sulfinic acid, the aromatic sulfinic acid and the ammonium salt, and / or phosphonium. A basic compound that forms a salt may be added to the reaction system to produce an aromatic sulfinate in the system and used as a catalyst. However, when an aromatic sulfinate is generated in the system, the basic compound solvent necessary for stably supplying the basic compound reacts with the basic compound when adding the basic compound. As will be described later, when the reaction can be performed in a solvent-free system, the reaction in the solvent-free system is more effective for the yield of the vinyl group-containing compound dimer, as will be described later. It is preferable for increasing the selectivity. Therefore, in the production method of the present invention, it is preferable to add the aromatic sulfinate to the reaction system.
As a catalyst, aromatic sulfinic acid and the aromatic sulfinic acid and a basic compound forming an ammonium salt and / or phosphonium salt are added to the reaction system to produce an aromatic sulfinate in the system. When is used, it is preferable to perform the dimerization step using a solvent described later.

When the aromatic sulfinate is produced in the reaction system, the above-mentioned aromatic sulfinic acid can be used. Examples of the basic compound that forms an aromatic sulfinic acid and an ammonium salt and / or a phosphonium salt include the above-mentioned compounds. Among these, tetramethylammonium hydroxide, tetrabutylammonium hydroxide, tetraoctylammonium hydroxide, Tetrabutylphosphonium hydroxide is preferred. More preferred is tetrabutylammonium hydroxide.

In the production method of the present invention, the vinyl group-containing compound is reacted to dimerize in the presence of the aromatic sulfinate, but the aromatic sulfinate is present in the dimerization step. If so, in the reaction system, a vinyl group-containing compound as a reaction substrate, an aromatic sulfinate, a dimer of a vinyl group-containing compound obtained by reaction of the substrate and a multimer of trimer or more, which will be described later A solvent and other compounds other than the proton donating compound may be present.
It is preferable that the usage-amount of the said aromatic sulfinate is 0.01-50 mol% with respect to 100 mol% of vinyl group containing compounds. If the aromatic sulfinate is less than 0.01 mol%, the yield of the vinyl group-containing compound dimer may not be sufficiently increased. If it exceeds 50 mol%, the cost for the catalyst becomes high, which is not economically preferable. The amount of the aromatic sulfinate used is more preferably 0.1 to 40 mol%, and still more preferably 1 to 30 mol%.

The vinyl group-containing compound is not particularly limited as long as it contains a vinyl group, but preferably has a structure in which a functional group is directly bonded to the vinyl group.
Examples of the functional group include a nitrile group, a carbonyl group, and a carboxyl group. Among these, since the effect of the present invention appears more remarkably, the vinyl group-containing compound includes those having a structure in which a nitrile group is directly bonded to a vinyl group such as acrylonitrile, and vinyl groups such as methyl vinyl ketone and ethyl vinyl ketone. Those having a structure in which a carbonyl group is directly bonded to the vinyl group, and those having a structure in which a carboxyl group is directly bonded to a vinyl group such as a carboxylic acid ester described later are preferable. Particularly preferred is a structure in which a carboxyl group is bonded directly to a vinyl group. If a structure having a carboxyl group directly bonded to a vinyl group is used, a dimer can be obtained with higher yield and selectivity. This is probably because carboxylic acid esters are less reactive than compounds such as acrylonitrile and vinyl ketone, and due to their reactivity, the progress of reactions that increase in quantity over dimerization reactions is suppressed. Is done.
That is, it is one of the preferred embodiments of the present invention that the vinyl group-containing compound is a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group.
In addition, when the dimerization step in the present invention is performed using a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group as a vinyl group-containing compound, a dicarboxylic acid diester is produced as a vinyl group-containing compound dimer. Will be. Here, in the present invention, the dicarboxylic acid diester means a compound obtained from two molecules of carboxylic acid ester, and does not include a compound having a structural portion derived from a compound other than two molecules of carboxylic acid ester.

The carboxylic acid ester is not particularly limited as long as it is a carboxylic acid ester and has a structure in which a carboxyl group is directly bonded to a vinyl group, and the following general formula (2);

^(Wherein, R 1, ^{R 2} are the same or different, .R ³ represents an organic group of a hydrogen atom or 1 to 30 carbon atoms, represents. The organic group having 1 to 30 carbon atoms) represented by Any compound having a structure can be used.
The organic group of R ¹ and R ² may be linear or branched, and may be cyclic.
If R ^{1, R 2} is an organic group having 1 to 30 carbon atoms, examples of the organic group is preferably an organic group having 1 to 18 carbon atoms. More preferably, it is a C1-C12 organic group, More preferably, it is a C1-C8 organic group.
The organic group for R ³ may be linear, branched, or cyclic. The number of carbon atoms is preferably 1 to 18, more preferably 1 to 12, and still more preferably 1 to 8. Most preferably, it is 1-4. As described above, when potassium-benzylpotassium is used as a basic catalyst, the acrylic ester having no bulky ester group has a high ratio of polymerizing without stopping the reaction by dimerization. When an aromatic sulfinate is used as a catalyst, a dimer can be obtained with high yield and high selectivity even if the ester moiety is not bulky. For this reason, it can be said that the form using such a carboxylate ester whose ester moiety is an organic group having a small number of carbon atoms as a substrate is one of the preferred embodiments of the present invention.

The organic group of R ¹ and R ² is preferably a hydrogen atom, a chain saturated hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group. Among these, a hydrogen atom and a chain saturated hydrocarbon group are preferable. A hydrogen atom is most preferred.
The organic group in R ³ is preferably, for example, a chain saturated hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group. These groups may have a substituent, that is, a substituted chain saturated hydrocarbon group in which at least a part of the hydrogen atoms bonded to the carbon atoms constituting these groups are replaced with a substituent, substituted aliphatic It may be a cyclic hydrocarbon group or a substituted aromatic hydrocarbon group. Among these, a chain saturated hydrocarbon group which may have a substituent is preferable.

Examples of the chain saturated hydrocarbon group include methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-amyl, s-amyl, t-amyl, n-hexyl, s-hexyl, n-heptyl, n-octyl, s-octyl, t-octyl, 2-ethylhexyl, capryl, nonyl, decyl, undecyl, lauryl, tridecyl, myristyl, pentadecyl, cetyl, heptadecyl, stearyl, nonadecyl, eicosyl, Groups such as seryl, melyl and the like are preferred.
Further, at least part of the hydrogen atoms bonded to the carbon atoms constituting the chain saturated hydrocarbon group may be substituted with an alkoxy group, a hydroxy group, a halogen atom, etc., for example, an alkoxy group-substituted chain saturated carbonization Preferred examples include a hydrogen group, a hydroxy group-substituted chain saturated hydrocarbon group, and a halogen group-substituted chain saturated hydrocarbon group.
As the alkoxy group-substituted chain saturated hydrocarbon group, for example, a group such as methoxyethyl, methoxyethoxyethyl, methoxyethoxyethoxyethyl, 3-methoxybutyl, ethoxyethyl, ethoxyethoxyethyl, phenoxyethyl, phenoxyethoxyethyl is preferable. It is mentioned as a thing. Suitable examples of the hydroxy group-substituted chain saturated hydrocarbon group include groups such as hydroxyethyl, hydroxypropyl, and hydroxybutyl. As the halogen group-substituted chain saturated hydrocarbon group, a halogen atom is preferably a fluorine atom or a chlorine atom, for example, a group such as fluoroethyl, difluoroethyl, chloroethyl, dichloroethyl, bromoethyl, dibromoethyl is preferable. As mentioned.

Preferred examples of the alicyclic hydrocarbon group include cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-t-butylcyclohexyl, tricyclodecanyl, isobornyl, adamantyl, dicyclopentadienyl and the like. . Also about this, the substituted alicyclic hydrocarbon group which replaced at least one part of the hydrogen atom couple | bonded with the carbon atom which comprises with an alkoxy group, a hydroxyl group, a halogen atom, etc. may be sufficient.

As the aromatic hydrocarbon group, groups such as phenyl, methylphenyl, dimethylphenyl, trimethylphenyl, 4-t-butylphenyl, benzyl, diphenylmethyl, diphenylethyl, triphenylmethyl, cinnamyl, naphthyl, anthranyl and the like are preferable. It is mentioned as a thing. Also about this, the substituted aromatic hydrocarbon group which replaced at least one part of the hydrogen atom couple | bonded with the carbon atom which comprises with an alkoxy group, a hydroxy group, a halogen atom, etc. may be sufficient.
Other examples of the substituent include a carboxyl group, a carbonyl group, a hydroxyl group, an acetoxy group, an amino group, a dialkyl group, a nitro group, a mercapto group, and a sulfone group.

Specific examples of the carboxylic acid ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, hydroxyethyl acrylate, cyclohexyl acrylate, and the like. Acrylic acid ester; methyl crotonic acid, ethyl crotonic acid, methyl 3,3-dimethyl acrylate, dimethyl maleate, diethyl maleate, dimethyl fumarate, dimethyl fumarate and the like. Among these, acrylate esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, and t-butyl acrylate are preferable. More preferred are acrylate esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, and hydroxyethyl acrylate.

The reaction temperature for the reaction of dimerizing the vinyl group-containing compound is preferably 10 to 150 ° C. When the reaction temperature is lower than 10 ° C., the reaction is slow and takes time. On the other hand, when the temperature is higher than 150 ° C., the raw material is likely to be polymerized. More preferably, it is 30-120 degreeC, More preferably, it is 50-100 degreeC.
The reaction time is preferably 0.1 to 240 hours. More preferably, it is 0.5-160 hours, More preferably, it is 1-80 hours.
The reaction is preferably performed under a pressure condition of 0.01 to 1 MPa. More preferably, it is 0.02-0.5 MPa, More preferably, it is 0.03-0.2 MPa.

The dimerization step may be carried out with or without using a solvent. In particular, a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group is used as a vinyl group-containing compound. In some cases, it is preferable to carry out in a solvent-free system without using a solvent. When the reactivity of the vinyl group-containing compound used as the substrate is high, the reaction in a solvent-free system does not stop at the dimerization reaction, and the production of multimers more than trimers increases. However, the carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group has low reactivity, and the reaction is moderately promoted by carrying out the reaction in a solvent-free system. Therefore, the yield and selectivity of the dimer can be increased. Therefore, in the method for producing a vinyl group-containing compound dimer of the present invention, when a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group is used as the vinyl group-containing compound, dimerization is performed in a solvent. Rather than carrying out the step, the dimerization step in a solvent-free system without using a solvent can obtain a dicarboxylic acid diester that is a vinyl group-containing compound dimer with high yield and high selectivity. it can. Furthermore, since no solvent is used, after the production of the vinyl group-containing compound dimer, there is no need to remove the solvent. The production process can be simplified, for example, the reaction vessel can be made smaller and the reaction vessel can be made smaller, and the same amount of the vinyl group-containing compound dimer can be obtained using a smaller apparatus than the conventional method. It can be manufactured. As a result, the manufacturing cost can be reduced.
That is, in the method for producing a vinyl group-containing compound dimer of the present invention, the dimerization step is performed in a solvent-free system, which is one preferred embodiment of the present invention.
Here, in the present invention, the solventless system means that the compound (solvent component) capable of exhibiting the function as a solvent is not present in the reaction system in an amount sufficient to exhibit the function as a solvent. That is, not only in the case where the solvent component is substantially absent, but also a compound capable of exhibiting the function as a solvent, it is involved in reactions other than the function as a solvent, such as a proton-donating compound described later. In the case of exhibiting other functions, the case where such a compound is included in the reaction system is also included. That is, in the present invention, the solventless system means that the reaction system contains substantially no compound having only a function as a solvent.
Specifically, it represents that the content of the compound having only a function as a solvent in the reaction system is 1% by mass or less with respect to 100% by mass of the vinyl group-containing compound. Furthermore, in the present invention, as described later, it is also one of preferred embodiments that the dimerization step is performed by adding a proton donating compound. When a compound is added and the reaction is carried out in a solvent-free system, the content of the solvent component other than the proton donating compound is preferably 1% by mass or less with respect to 100% by mass of the vinyl group-containing compound.

The dimerization step may be performed using a solvent. When a compound having a structure in which a nitrile group is directly bonded to a vinyl group or a compound having a structure in which a carbonyl group is directly bonded to a vinyl group is used as a vinyl group-containing compound, these are structures in which a carboxyl group is directly bonded to a vinyl group. Because it is more reactive than carboxylic acid esters that contain terpolymers, it is easy to produce trimers or higher in the dimerization process, but dimerization in a solvent suppresses the formation of multimers. It becomes possible to produce a dimer. Therefore, when using a compound having a structure in which a nitrile group is directly bonded to a vinyl group or a compound having a structure in which a carbonyl group is directly bonded to a vinyl group is used as the vinyl group-containing compound, the dimerization step is performed. Is preferably carried out using a solvent.

Examples of the solvent include aprotic solvents such as hexane, benzene, toluene, ethyl acetate, dimethyl sulfoxide (DMSO), dimethylformamide, dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, hexamethylphosphoric triamide, acetone, and acetonitrile. Can be mentioned. Among these, it is preferable to carry out using an aprotic polar solvent. As will be described later, the dimerization reaction of the vinyl group-containing compound proceeds by the generation of an anion on the carbon atom of the vinyl group, but when a protic solvent is used, A large amount of proton-donating compound is present around the anion generated in the reaction, and the vinyl group-containing compound is deactivated by proton donation before the dimerization reaction occurs, so that the dimerization reaction is sufficient. There is a risk that it will not happen. When an aprotic solvent is used, since the reaction active species caused by the solvent is not deactivated, the dimerization reaction can be sufficiently advanced. By using an aprotic solvent, the yield and selectivity of the dimer of the vinyl group-containing compound can be increased. The aprotic polar solvent is preferably dimethyl sulfoxide (DMSO), dimethylformamide, or dimethylacetamide, and more preferably dimethyl sulfoxide (DMSO).
1 type (s) or 2 or more types can be used for a solvent.

When using a solvent in the said dimerization process, it is preferable that it is 1-1000 mass% with respect to 100 mass% of vinyl group containing compounds as a usage-amount of a solvent. When the amount of the solvent is such, the dimerization reaction can proceed sufficiently. More preferably, it is 50-750 mass%, More preferably, it is 100-500 mass%.

In the method for producing a vinyl group-containing compound dimer of the present invention, the dimerization step is preferably performed by adding a proton donating compound.
The reaction mechanism of the step of dimerization by reacting a vinyl group-containing compound in the presence of an aromatic sulfinic acid salt essentially containing an ammonium salt and / or a phosphonium salt of aromatic sulfinic acid is considered as follows. An anion is generated in the aromatic sulfinate, and this is combined with the carbon of the vinyl group of the vinyl group-containing compound to generate an anion on the other carbon atom that has formed the vinyl group. This anion combines with the carbon of the vinyl group of another vinyl group-containing compound to form a dimer. At that time, an anion is generated on the other carbon atom that has formed the vinyl group of the other vinyl group-containing compound. However, when an appropriate amount of the proton-donating compound is present, proton transfer within the molecule occurs. , The catalyst is likely to be liberated and stops at dimerization. However, in the absence of a proton-donating compound, an anion may attack another vinyl group-containing compound between molecules, and a trimer or more may be easily generated. Thus, the selectivity of the vinyl group-containing compound dimer can be increased by adding the proton donating compound and performing the dimerization step.
One or more proton donating compounds can be used.
In the following reaction mechanism diagram, a compound having a structure in which a functional group is directly bonded to a vinyl group is described as the vinyl group-containing compound, but the vinyl group-containing compound is not limited to this. .

The proton donating compound is not particularly limited as long as it is a compound capable of donating a proton, but alcohol, amine, thiol and the like can be used. Among these, alcohol is preferable. More preferably, it is a tertiary alcohol. That is, it is one of the preferred embodiments of the present invention that the proton donating compound is a tertiary alcohol. As the tertiary alcohol, t-butanol, t-amyl alcohol, or the like can be used.

The addition amount of the proton donating compound is preferably 0.001 to 2 equivalents relative to the vinyl group-containing compound. If the proton donating compound is less than 0.001 equivalent, the selectivity of the vinyl group-containing compound dimer may not be sufficiently increased. When the amount is more than 2 equivalents, the vinyl group-containing compound may be deactivated before the dimerization reaction, and the yield of the vinyl group-containing compound dimer may be too low, as in the case of using the protic polar solvent. There is. The amount of the proton donating compound used is more preferably 0.002 to 1.5 equivalents, and still more preferably 0.005 to 1 equivalents. Most preferably, it is 0.01-0.5 equivalent.

The method for producing a vinyl group-containing compound dimer according to the present invention includes a polymerization inhibitor and a molecular form in order to suppress polymerization of a vinyl group-containing compound as a reaction raw material and a vinyl group-containing compound dimer as a product. It is preferable to use oxygen.

The polymerization inhibitor is not particularly limited as long as it is used as a polymerization inhibitor for acrylic monomers and vinyl monomers. For example, o-methoxyphenol, m-methoxyphenol or p-methoxyphenol (methoquinone). Or methoxyphenol having one or more substituents such as methyl group, t-butyl group or hydroxyl group; quinone such as hydroquinone, benzoquinone and p-tert-butylcatechol 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, Alkylphenols such as 2,4,6-tri-tert-butylphenol Alkyls diphenylamine, N, N'-diphenyl-p-phenylenediamine, phenothiazine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6- Amines such as tetramethylpiperidine, 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine, 1-hydroxy-4-benzoyloxy-2,2,6,6-tetramethylpiperidine; dimethyldithiocarbamic acid Copper, copper dithiocarbamate such as copper diethyldithiocarbamate, copper dibutyldithiocarbamate; 2,2,6,6-tetramethylpiperidine 1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1- Oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine 1 Oxyl, 4-hydroxy-2,2,6,6-1-oxyl-ethers esters tetramethylpiperidine 1-oxyl, and the like, can be used alone or in combination of two or more thereof.

The amount of the polymerization inhibitor used is 0.01 ppm or more with respect to the total amount of the raw materials and / or intermediates having polymerizability such as vinyl group-containing compounds from the viewpoints of yield, polymerization inhibition, and economy. It is preferably 0.1 ppm or more, more preferably 1 ppm or more, and particularly preferably 10 ppm or more. Moreover, it is preferable to set it as 5000 ppm or less, 3000 ppm or less is more preferable, 2000 ppm or less is still more preferable, 1500 ppm or less is especially preferable.
With respect to the dimerization step, it is more preferable to set the above range for the total amount of the vinyl group-containing compound and the product vinyl group-containing compound dimer.

As the vinyl group-containing compound used in the method for producing a vinyl group-containing compound dimer according to the present invention, an acrylic ester can be suitably used as described above, and in that case, a 2-methylene glutaric acid diester is produced. can do. Thus, it is one of the suitable embodiment of this invention that the manufacturing method of the vinyl group containing compound dimer of this invention is a method of manufacturing 2-methylene glutaric acid diester from acrylic ester. .

The 2-methyleneglutaric acid diester produced by the above production method is further hydrolyzed to give 2-methyleneglutaric acid monoester, 2-methyleneglutarate monoester, 2-methyleneglutarate, 2-methyleneglutarate and the like. It can be a compound. Such a method for producing a methylene glutaric acid compound obtained by hydrolyzing the 2-methylene glutaric acid diester produced from the acrylic ester by the above-mentioned method to obtain a methylene glutaric acid compound is also one aspect of the present invention. . Furthermore, the 2-methyleneglutaric acid-based compound thus obtained can be suitably used as a raw material for the polymer and the like, and such a vinyl group-containing compound dimer of the present invention can be used. A methylene glutaric acid compound obtained by hydrolyzing 2-methylene glutaric acid diester produced by the production method is also one aspect of the present invention.

The method for producing a vinyl group-containing compound dimer according to the present invention has the above-described configuration, and can produce a vinyl group-containing compound dimer from a vinyl group-containing compound with high yield and high selectivity. In addition, since it does not require expensive catalysts and complicated reaction conditions, it is a production method that can be suitably used for industrial production of vinyl group-containing compound dimers expected to be used in various industrial applications. is there.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

[Evaluation methods]
(Reaction yield and substrate conversion)
The yield of the reaction and the substrate conversion rate are determined by gas chromatography (GC-2014 (trade name), manufactured by SHIMADZU, capillary column InertCap Pure-Wax (trade name) length 30 m × inner diameter 0.25 mm, film thickness 0.25 μm). It was determined by using a calibration curve prepared in advance.
(Selection rate)
The selectivity of the dimer was obtained from the following formula.
(Dimer selectivity) = {(Dimer yield) / (Substrate conversion)} × 100

Example 1
A test tube with a 20 mL lid was charged with 0.86 g of methyl acrylate and 199 mg of tetrabutylammonium p-toluenesulfinate as a catalyst and stirred. The reaction mixture was stirred for 6 hours while maintaining at 1 atm (0.1 MPa) and 80 ° C. to complete the reaction. After completion of the reaction, gas chromatographic analysis revealed that the yield of dimethyl 2-methyleneglutarate was 36 mol% and the conversion rate of the raw material methyl acrylate was 59 mol%. And the selectivity of the dimer was 62 mol%.

Example 2
The same operation as in Example 1 was conducted except that the reaction time was 21 hours. The results are shown in Table 1.
Examples 3-20, Reference Examples 1-4
The reaction was carried out in the same manner as in Example 1 except that the type of substrate and catalyst, the amount of catalyst, the presence or absence of addition of a proton donating compound, the presence or absence of addition of a solvent, and the reaction time were as shown in Table 1. Dimer and trimer yields and substrate conversion were measured by gas chromatography to calculate dimer selectivity. In Examples 12 and 13, in place of the aromatic sulfinate, p-toluenesulfinic acid, which is an aromatic sulfinic acid, and tetrabutylammonium hydroxide, which is a basic compound, are added. Aromatic tetrabutylammonium sulfinate was produced and reacted. The results are shown in Table 1.

Example 21
A 100 mL flask was charged with 10.3 g of dimethyl 2-methyleneglutarate obtained by distilling the reaction solution of Example 1, 7.20 g of sodium hydroxide, 30 mL of methanol, and 30 mL of water and stirred. The reaction was completed by stirring for 3 hours while maintaining the inside of the reaction solution at 80 ° C. A 12N aqueous hydrochloric acid solution was added to the reaction solution to make it acidic, and then methanol was distilled off. Subsequently, the reaction solution was extracted with ethyl acetate, and the organic layer was dried over anhydrous magnesium sulfate, and then ethyl acetate was distilled off to obtain 8.3 g of 2-methyleneglutaric acid (yield 96 mol%). It was.

From the results of Examples, by using a vinyl group-containing compound as a substrate and using an ammonium salt and / or phosphonium salt of an aromatic sulfinic acid as a catalyst, the dimerization reaction proceeds, and the yield of the dimer is high. It was confirmed that a high selectivity can be obtained.
From the comparison between Examples 1 and 2 and Reference Examples 1 and 2, when a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group such as methyl acrylate is used as a substrate, an aromatic sulfinic acid is used as a catalyst. Compared to the case of using sodium, the use of aromatic sulfinic acid ammonium salts and / or phosphonium salts confirmed that dimers can be obtained with high yield and high selectivity in a solvent-free reaction. It was also confirmed that the reaction proceeded more in a short reaction time. From the results of Reference Example 3, it was also confirmed that when sodium aromatic sulfinate was used as a catalyst, a dimer could not be produced in a solvent-free system.
In addition, from the comparison between Examples 1 to 18 using methyl acrylate as a substrate and Examples 19 and 20 using acrylonitrile as a substrate, the production method of the present invention is a vinyl such as methyl acrylate as a substrate. When a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a group is used as a substrate, a dimer can be obtained with high selectivity. In particular, a carboxyl group is bonded directly to a vinyl group. It was confirmed that this is a suitable method for producing a dimer from a carboxylic acid ester having a structure.
From the results of Examples 1 to 4 and 14 to 17, it was confirmed that by increasing the reaction time or optimizing the amount of the catalyst for the substrate, the yield of the dimer and the conversion rate of the substrate are increased. From the comparison between Example 1 and Examples 5 and 6, comparison between Example 7 and Example 8, and comparison between Example 14 and Example 16, an appropriate amount of a proton donating compound was added. By performing the reaction, it was confirmed that the selectivity of the dimer was improved without reducing the yield of the dimer.
From the comparison between Example 1 and Examples 9 to 11, 14, and 18, among aromatic sulfinates, tetrabutylammonium p-toluenesulfinate and tetrabutylammonium p-methoxybenzenesulfinate are vinyl group-containing compounds. It was confirmed that it was preferable as a catalyst for producing a dimer, and tetrabutylammonium p-methoxybenzenesulfinate was particularly preferable in terms of dimer selectivity and yield.
From a comparison between Example 12 and Example 13, as a catalyst, aromatic sulfinic acid and the aromatic sulfinic acid and a basic compound that forms an ammonium salt and / or a phosphonium salt were added to the reaction system. In the case of using an aromatic sulfinate salt produced, it was confirmed that a dimer can be produced by performing a dimerization reaction in a solvent.
In addition, for Examples 19 and 20 and Reference Example 4 using acrylonitrile as a substrate, Table 1 shows that the trimer yield is low and the dimer seems to be selectively produced. When acrylonitrile was used as the substrate, the conversion rate of the substrate was high, and many multimers with four or more substrates bound were produced, resulting in low dimer selectivity. In addition, a comparison between Example 19 and Example 20 confirmed that when acrylonitrile was used as a substrate, a dimer could be produced by performing a dimerization reaction in a solvent. .
In the above examples, the reaction was carried out using a specific compound as a substrate, a catalyst, a proton donating compound, and a solvent, but a vinyl group was present in the presence of an aromatic sulfinate. Since the mechanisms for reacting the contained compounds to dimerize are all the same, the results of the above examples show that the present invention can be used throughout the technical scope of the present invention and in the various forms disclosed herein. It can be said that the present invention can be applied and advantageous effects can be exhibited.

Claims (5)

A method for producing a dimer from a vinyl group-containing compound,
The production method includes a step of dimerization by reacting a vinyl group-containing compound in the presence of an aromatic sulfinate, wherein the aromatic sulfinate converts an ammonium salt and / or a phosphonium salt of aromatic sulfinic acid. A method for producing a vinyl group-containing compound dimer, which is essential. The method for producing a vinyl group-containing compound dimer according to claim 1, wherein the vinyl group-containing compound is a carboxylic acid ester having a structure in which a carboxyl group is directly bonded to a vinyl group. The method for producing a vinyl group-containing compound dimer according to claim 1 or 2, wherein the dimerization step is performed in a solvent-free system. The said manufacturing method is a method of manufacturing 2-methylene glutaric acid diester from acrylic ester, The manufacturing method of the vinyl group containing compound dimer in any one of Claims 1-3 characterized by the above-mentioned. A method for producing a methylene glutaric acid compound, comprising hydrolyzing 2-methylene glutaric acid diester produced by the method according to claim 4 to obtain a methylene glutaric acid compound.