JP2022069214A - Method for purifying organic ditelluride compound - Google Patents

Abstract

To provide a method for purifying an organic ditelluride compound, capable of obtaining a high-purity organic ditelluride compound.SOLUTION: A method for purifying an organic ditelluride compound includes: a step (A) of obtaining a mixture by mixing a solution (a1) containing an organic ditelluride compound represented by a following formula (1), and a compound represented by a following formula (2), a base, and a reducing agent (r1) with water; and a step (B) of phase-separating the mixture obtained in the step (A) into an organic phase and a water phase followed by removing the water phase. The reducing agent (r1) is at least one of a sulfur-based reducing agent and a phosphorus-based reducing agent. R11-Te-Te-R11 ... formula (1) [in the formula (1), R11 is a 1-8C alkyl group, an aromatic group or an aromatic heterocyclic group.] (R21)n-Y-Y-(R21)n ... formula (2) [in the formula (2), n is 1-3, Y is an (n+1)-valent linking group, and R21 is an aliphatic group or an aromatic group.]SELECTED DRAWING: None

Description

The present invention relates to a method for purifying an organic diterlide compound.

The living radical polymerization method is a polymerization method that enables precise control of the molecular structure and production of a polymer having a uniform composition while maintaining the convenience and versatility of the conventional radical polymerization method, and is used for the production of new polymer materials. Demonstrate great power. Therefore, in recent years, the development of living radical polymerization technology has been remarkable, and living radical polymerization methods using various methods have been reported. Among them, the TERP (organotellurium-mediated living radical polymerization) method, which is a living radical polymerization method using an organic tellurium compound, has versatility applicable to the polymerization of various types of vinyl monomers and is practical as usual radical polymerization. It is a polymerization method that has attracted particular attention because it can highly control the molecular weight and molecular weight distribution of the polymer under the reaction conditions (see Patent Documents 1 to 4).

Generally, the growth end of the polymer obtained by the living radical polymerization method is referred to as a dormant end in which radicals are reversibly protected by an appropriate protecting group, and the growth end of the polymer obtained by the TERP method is Polymer-. It is a form of Te-R. A polymer from which the dormant end is chemically removed is used as a product.

On the other hand, since tellurium is a rare element having a Clarke number of 2 × 10 ^-7 %, it is required to recover the tellurium removed from the polymerization terminal and regenerate it into an organic tellurium compound which is a chain transfer agent. For example, a method of recovering tellurium removed from the polymerization terminal as an organic diterlide compound (see Patent Document 5) and a method of regenerating an organic tellurium compound from an organic diterlide compound (see Patent Document 6) are known.

International Publication No. 2004/014884 International Publication No. 2004/014962 International Publication No. 2004/072126 International Publication No. 2004/096870 Japanese Unexamined Patent Publication No. 2017-200961 JP-A-2019-73503

However, the method using the hydride reducing agent of Patent Document 5 has a problem that the applicable polymer is limited due to its high reducing property and hydrogen gas is generated. The method using a tellurium compound is not suitable for the tellurium recycling method because it is necessary to newly use another tellurium compound in order to recover the tellurium used in the polymerization.

On the other hand, when a reducing agent having a low reducing power is used so as to act only on the growth end of the polymer, it becomes a mixture of the organic diterlide compound and a by-product, and it is difficult to remove the by-product and the organic diterlide compound can be reused. It is not a form.

An object of the present invention is to provide a method for purifying an organic diterlide compound, which makes it possible to obtain a high-purity organic diterlide compound.

The present inventors have completed the present invention as a result of repeated diligent studies to solve the above problems. That is, the gist of the present invention is as follows.

Item 1 A solution (a1) containing an organic diterlide compound represented by the following formula (1) and a compound represented by the following formula (2), a base, a reducing agent (r1), and water are mixed. The reducing agent (A) comprising a step (A) for obtaining a mixture and a step (B) for separating the mixture obtained in the step (A) into an organic phase and an aqueous phase and removing the aqueous phase. A method for purifying an organic diterlide compound, wherein r1) is at least one of a sulfur-based reducing agent and a phosphorus-based reducing agent.

R ¹¹ -Te-Te-R ¹¹ ... Equation (1)
[In the formula (1), R ¹¹ represents an alkyl group having 1 to 8 carbon atoms, an aromatic group or an aromatic heterocyclic group. ]

(R ²¹ ) _n -Y-Y- (R ²¹ ) _n ... Equation (2)
[In the formula (2), n represents 1 to 3. Y represents a (n + 1) -valued linking group. R ²¹ represents an aliphatic group or an aromatic group. ]

Item 2 The method for purifying an organic diterlide compound according to Item 1, wherein the base is an alkali metal hydroxide.

Item 3 The method for purifying an organic diterlide compound according to Item 1 or Item 2, wherein Y is a sulfur atom, a silicon atom or a tin atom.

Item 4 Item 1 to Item 3 characterized in that the solution (a1) is a tellurium recovery solution obtained in a step of recovering tellurium from a polymerization solution obtained by a living radical polymerization method using an organic tellurium compound. The method for purifying an organic diterlide compound according to any one of the above.

Item 5 The step of recovering tellurium is a step of mixing a polymerization solution containing a vinyl polymer (P2) obtained by a living radical polymerization method using an organic tellurium compound with a reducing agent (r2) to obtain a mixture (step). C), the mixture obtained in the step (C) and the solvent (a2) are mixed, a solution phase containing a vinyl polymer (P1), and an organic diterlide compound represented by the formula (1). It is characterized by comprising a step (D) of separating the phase from the solution phase containing the compound represented by the formula (2) and removing the solution phase containing the vinyl polymer (P1). Item 4. The method for purifying an organic diterlide compound according to Item 4.

Item 6 The organic according to Item 5, wherein the reducing agent (r2) is at least one selected from the group consisting of an organosulfur-based reducing agent, an organosilicon-based reducing agent, and an organotin-based reducing agent. A method for purifying a diterlide compound.

Item 7. The method for purifying an organic diterlide compound according to Item 5 or Item 6, wherein the solvent (a2) is an aliphatic hydrocarbon.

Item 8 Item 5 is characterized in that the growth end of the vinyl polymer (P2) is represented by −Te—R ¹¹ (R ¹¹ is the same as R ¹¹ in the above formula (1)). The method for purifying an organic diterlide compound according to any one of Items 7.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for purifying an organic diterlide compound, which makes it possible to obtain a high-purity organic diterlide compound.

Hereinafter, an example of a preferred embodiment of the present invention will be described. However, the following embodiments are merely examples. The present invention is not limited to the following embodiments.

The method for purifying an organic diterlide compound according to the present invention comprises a solution (a1) containing an organic diterlide compound represented by the following formula (1) and a compound represented by the following formula (2), a base, and a reducing agent ( r1) and water are mixed to obtain a mixture (A), and the mixture obtained in step (A) is phase-separated into an organic phase and an aqueous phase to remove the aqueous phase (B). To prepare for. Further, in the present invention, the reducing agent (r1) is at least one of a sulfur-based reducing agent and a phosphorus-based reducing agent.

R ¹¹ -Te-Te-R ¹¹ ... Equation (1)
[In the formula (1), R ¹¹ represents an alkyl group having 1 to 8 carbon atoms, an aromatic group or an aromatic heterocyclic group. ]

(R ²¹ ) _n -Y-Y- (R ²¹ ) _n ... Equation (2)
[In the formula (2), n represents 1 to 3. Y represents a (n + 1) -valued linking group. R ²¹ represents an aliphatic group or an aromatic group. ]

According to the method for purifying an organic diterlide compound of the present invention, a high-purity organic diterlide compound can be obtained. The compound represented by the above formula (2) is, for example, a by-product in the living radical polymerization method using an organic tellurium compound. Therefore, in the present invention, the compound represented by the above formula (2) is efficiently selected from the solution (a1) containing the organic diterlide compound represented by the above formula (1) and the compound represented by the above formula (2). By removing it well, a high-purity organic diterlide compound can be obtained. Specifically, it can be explained as follows.

In the solution (a1) used in the step (A), the organic diterlide compound represented by the above formula (1) and the compound represented by the above formula (2) tend to be in an equilibrium state as shown in the following formula (3). ..

In the present invention, since the solution (a1), the base, the reducing agent (r1), and water are mixed, the compound represented by the above formula (2) is reduced by the reducing agent (r1), and the base is further reduced. By reacting with, a salt can be formed. Since this salt is extracted on the aqueous phase side when the mixture is phase-separated into the organic phase and the aqueous phase, the purity of the organic diterlide compound in the organic phase is enhanced. Therefore, a high-purity organic diterlide compound can be obtained by removing the aqueous phase and finally distilling off the organic solvent in the organic phase.

Specifically, when Y in the above formula (2) is, for example, a sulfur atom (S), the disulfide in the equilibrium mixture is reduced to a thiol by the reducing agent (r1) as shown in the following formula (4). Then, by mixing with an aqueous solution in which a base is dissolved, thiol becomes a thiol salt and is extracted into an aqueous phase. Thereby, the concentration of the organic diterlide compound in the organic phase can be increased, and a high-purity organic diterlide compound can be obtained.

In the above formula (4), M represents an alkali metal or an alkaline earth metal.

Further, in the method for purifying an organic diterlide compound of the present invention, at least one of a sulfur-based reducing agent and a phosphorus-based reducing agent is used as the reducing agent (r1), so that no hydride reducing agent is used. Therefore, for example, in a wide variety of vinyl polymers obtained by the TERP method, tellurium can be recovered as an organic diterlide compound with high yield and high purity without the possibility of generating hydrogen gas. In addition, since no new tellurium compound is required, it is possible to efficiently recycle tellurium, which is a rare element.

In the present invention, the reaction temperature for reacting by mixing the solution (a1), the base, the reducing agent (r1), and water is not particularly limited, and is, for example, 10 ° C. or higher, preferably 30 ° C. or higher. be able to. The reaction temperature can be, for example, 60 ° C. or lower, preferably 40 ° C. or lower. The reaction time can be, for example, 2 hours or more and 30 hours or less.

(Organic diterlide compound represented by the formula (1))
Equation (1) is as follows.

R ¹¹ -Te-Te-R ¹¹ ... Equation (1)

In the above formula (1), the group represented by R ¹¹ is an alkyl group having 1 to 8 carbon atoms, an aromatic group or an aromatic heterocyclic group, and is specifically as follows.

Alkyl groups having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group and heptyl. Examples thereof include a linear or branched alkyl group such as a group and an octyl group, and a cyclic alkyl group such as a cyclohexyl group. The alkyl group having 1 to 8 carbon atoms is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group.

Examples of the aromatic group include a phenyl group and a naphthyl group.

Examples of the aromatic heterocyclic group include a pyridyl group, a frill group, a thienyl group and the like.

Specific examples of the organic diterlide compound represented by the above formula (1) include dimethylditerlide, diethylditerlide, di-n-propylditerlide, diisopropylditerlide, dicyclopropylditerlide, and di. -N-butyl diterlide, di-s-butyl diterlide, di-t-butyl diterlide, dicyclobutyl diterlide, diphenyl diterlide, bis- (p-methoxyphenyl) diterlide, bis- (p-aminophenyl) diterlide, bis Examples thereof include- (p-nitrophenyl) diterlide, bis- (p-cyanophenyl) diterlide, bis- (p-sulfonylphenyl) diterlide, dinaphthylditerlide, dipyridylditerlide and the like.

(Compound represented by the formula (2))
The compound represented by the formula (2) is as follows.

(R ²¹ ) _n -Y-Y- (R ²¹ ) _n ... Equation (2)

In the above formula (2), n represents 1 to 3. Y represents a linking group of (n + 1) valence. R ²¹ represents an aliphatic group or an aromatic group.

In the above formula (2), n is 1 to 3, preferably 1 or 3, and more preferably 1. The group represented by Y is a (n + 1) -valued linking group. Examples of the group represented by Y include a sulfur atom, a silicon atom, a tin atom and the like, and a sulfur atom is preferable.

The group represented by R ²¹ is an aliphatic group or an aromatic group. The group represented by R ²¹ may have a substituent. Specifically, it is as follows.

Examples of the aliphatic group include a linear alkyl group, a branched chain alkyl group, a cyclic alkyl group and the like.

The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms. Examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, an n-decyl group and an n-lauryl group. Can be mentioned.

The branched-chain alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms, and even more preferably 3 to 5 carbon atoms. Examples of the branched alkyl group include an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 2-ethylhexyl group, a neopentane group, an isooctyl group and the like.

The cyclic alkyl group may have a chain moiety. The cyclic alkyl group preferably has 4 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, and even more preferably 6 to 10 carbon atoms. Examples of the cyclic alkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like. Examples of the chain portion of the cyclic alkyl group having a chain portion include an alkylene group having 1 to 12 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. Be done.

When the aliphatic group has a substituent, examples of the substituent having the aliphatic group include a halogen group, an alkoxy group, and a hydroxy group.

The aromatic group may have a chain moiety. The aromatic group preferably has 6 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, and even more preferably 6 to 8 carbon atoms. Examples of the aromatic group include a phenyl group, a tolyl group, a xylyl group, a mesitylene group and the like. Examples of the chain portion of the aromatic group having a chain portion include an alkylene group having 1 to 12 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. Be done. When the aliphatic group has a substituent, examples of the substituent having the aromatic group include a halogen group, an alkoxy group, and a hydroxy group.

Specific examples of the compound represented by the above formula (2) include dimethyl disulfide, diethyl disulfide, di-n-propyl disulfide, diisopropyl disulfide, di-n-butyl disulfide, di-n-pentyl disulfide, and di-. n-hexyl disulfide, cyclohexyl disulfide, diphenyl disulfide, dibenzyl disulfide, di (p-tolyl) disulfide, 4,4'-dichlorodiphenyl sulfide, di (3,4-dichlorophenyl) disulfide, hexamethyldisilane, 1,2- Examples thereof include dimethyl-1,1,2,2-tetraphenyldisilane, hexaphenyldisilane, hexamethyldistannan, hexabutyldistannan and the like.

(base)
The base is preferably a water-soluble base, and examples thereof include alkali metal hydroxides and hydroxides of tetraalkylammonium, and alkali metal hydroxides are preferable. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium and the like. Of these, potassium and sodium are preferable because they are economically advantageous.

Specific examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and the like. Specific examples of the hydroxide of tetraalkylammonium include tetramethylammonium hydroxide and tetraethylammonium hydroxide.

The amount of the base added is not particularly limited, and can be, for example, 0.5 equivalent to 10 equivalents, preferably 1 equivalent to 5 equivalents, and more preferably 1 equivalent with respect to the compound having the group represented by Y. Equivalent to 3 equivalents.

(Reducing agent (r1))
The reducing agent (r1) is at least one of a sulfur-based reducing agent and a phosphorus-based reducing agent, and is preferably a sulfur-based reducing agent. By using the reducing agent (r1), the YY bond can be reduced without reducing the Te—Te bond.

The sulfur-based reducing agent may be any compound having a reducing sulfur atom, and may be an inorganic compound or an organic compound. That is, examples of the sulfur-based reducing agent include an organic sulfur-based reducing agent and an inorganic sulfur-based reducing agent, and an organic sulfur-based reducing agent is preferable from the viewpoint of solubility in an organic solvent. The most stable oxidation number of sulfur atom is +6 valence, but in general, sulfur atom with less than that oxidation number has reducing property. From the viewpoint of reducing property, a compound having a +2 valent sulfur atom is preferable.

Examples of the organic sulfur-based reducing agent include sulphinic acids such as 2-hydroxy-2-sulfinate acetate and formamidine sulphonic acid; sulphinates such as formaldehyde sulfoxylate sodium; alkylthiols (for example, methanethiol and ethanethiol, etc.). Thiolthiol, butanethiol, etc. with 1 to 20 carbon atoms), thioglycol, thioglycerol, thiolic acid (eg, thioglycolic acid, mercaptopropionic acid), thiolate (eg, ammonium thioglycolate), thiolic acid. Aliper thiols such as esters (eg, methoxybutyl-3-mercaptopropionate); alicyclic thiols such as cyclopentathiols and cyclohexanethiols; aromatic thiols such as thiophenols, benzyl mercaptans and thiosalicylic acids; polyvalent thiols. And so on. Among these, at least one selected from the group consisting of sulfinic acid, sulfinates, and aliphatic thiols is preferable.

The inorganic sulfur-based reducing agent may be an acid type, but is preferably a salt type. As the salt, a monovalent or polyvalent metal salt is preferable, and a monovalent metal salt is more preferable. Among these inorganic sulfur-based reducing agents, an oxygen-containing reducing inorganic salt in which a sulfur atom is bonded to an oxygen atom is preferable. Specifically, sulfites such as sodium bisulfite, potassium sulfite, calcium sulfite, zinc sulfite, ammonium sulfite; hydrogen sulfites such as sodium bisulfite, potassium hydrogen sulfite, calcium hydrogen sulfite, ammonium hydrogen sulfite; sodium pyrosulfite, pyro Pyrosulfites such as potassium sulfite and ammonium pyrosulfite; sodium bisulfite, potassium bisulfite, ammonium bisulfite, calcium bisulfite, zinc bisulfite and the like; Trithionates such as potassium thionate and sodium trithionate; tetrathionates such as potassium tetrathionate and sodium bisulfite; thiosulfates such as sodium thiosulfite, potassium thiosulfate and ammonium bisulfite; sodium bisulfite , Potassium bisulfite, calcium bisulfite, zinc bisulfite and other nitrites and the like.

The phosphorus-based reducing agent may be a compound having a reducing phosphorus atom, and may be an inorganic compound or an organic compound. That is, examples of the phosphorus-based reducing agent include an organic phosphorus-based reducing agent and an inorganic phosphorus-based reducing agent, and an organic phosphorus-based reducing agent is preferable from the viewpoint of solubility in an organic solvent. The most stable oxidation number of a phosphorus atom is +5 valence, but in general, a phosphorus atom having an oxidation number less than that has reducibility. From the viewpoint of reducing property, a compound having a +3 valent phosphorus atom is preferable.

Examples of the organophosphorus reducing agent include phosphines such as tributylphosphine and triphenylphosphine; subphosphate esters such as trimethylphosphine; and phosphinates such as tris (2-carboxyethyl) phosphine hydrochloride. Can be done. Of these, phosphines are preferred.

The inorganic phosphorus-based reducing agent may be of the acid type, but is preferably of the salt type. As the salt, a monovalent or polyvalent metal salt is preferable, and a monovalent salt is more preferable. Among these inorganic phosphorus-based reducing agents, an oxygen-containing reducing inorganic salt in which a phosphorus atom is bonded to an oxygen atom is preferable. Specific examples thereof include hypophosphite; phosphite; pyrophosphite; hypophosphite such as sodium hypophosphite.

The amount of the reducing agent (r1) added is not particularly limited, and may be, for example, 0.1 equivalent to 5 equivalents, preferably 0.3 equivalents to 4 equivalents, relative to the compound having a group represented by Y. It is equivalent, more preferably 0.5 equivalent to 3 equivalent.

(water)
The water is not particularly limited, and tap water, well water, ion-exchanged water, distilled water and the like can be used, but it is preferable to use water that does not contain ionic impurities such as ion-exchanged water and distilled water. .. The amount of water added is not particularly limited, and may be, for example, 0.1 part to 50 parts, preferably 0.5 part to 30 parts, with respect to the compound having a group represented by Y. More preferably, it is 1 to 15 parts.

(Amphiphilic solvent)
In step (A), an amphipathic solvent may be further added and mixed. The amphoteric solvent is a solvent that is easily dissolved in both water and organic solvents, such as methanol, ethanol, n-propanol, isopropyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, propylene glycol, and propylene glycol monomethyl ether. Alcohols; Ethers such as 1,2-dimethoxyethane, tetrahydrofuran, 1,4-dioxane; Ketones such as acetone; Nitrigens such as acetonitrile; Amidos such as dimethylformamide; Sulfoxides such as dimethylsulfoxide; N- Pyrrolidones such as methylpyrrolidone can be used, preferably alcohols and ethers. The amphipathic solvent may be used alone or in combination of two or more.

The amount of the amphipathic solvent added is not particularly limited, and may be, for example, 0.1 part to 50 parts, preferably 0.5 part to 30 parts, with respect to the compound having a group represented by Y. It is more preferably 0.5 to 15 parts.

(Organic solvent)
An organic solvent as a phase separation solvent used for the organic phase can also be further added and mixed in the step (A). The organic solvent as the phase separation solvent used for the organic phase is not particularly limited as long as it can dissolve the organic diterlide compound represented by the above formula (1) and can be phase-separable from water. Examples of such organic solvents include ethers such as diethyl ether and diisopropyl ether; esters such as ethyl acetate; halogenated hydrocarbons such as chloroform, dichloromethane and 1,2- dichloromethane; aromatics such as toluene and xylene. Group Hydrocarbons; aliphatic hydrocarbons such as cyclohexane, hexane, and heptane can be used, and aliphatic hydrocarbons are preferable. The organic solvent may be used alone or in combination of two or more.

The amount of the organic solvent added is not particularly limited, and for example, the total amount of the solvent contained in the solution (a1) and the organic solvent is 1 part to 500 parts with respect to the compound having a group represented by Y. It can be, preferably 30 to 200 parts.

[Living radical polymerization]
In the present invention, the solution (a1) containing the organic diterlide compound represented by the above formula (1) and the compound represented by the above formula (2) was obtained by a living radical polymerization method using an organic tellurium compound. It is preferable that the tellurium recovery solution is obtained in the step of recovering tellurium from the polymerization solution.

In particular, the step of recovering tellurium is a step of mixing a polymerization solution containing a vinyl polymer (P2) obtained by a living radical polymerization method using an organic tellurium compound with a reducing agent (r2) to obtain a mixture (C). ), The mixture obtained in the step (C) and the solvent (a2) are mixed, the solution phase containing the vinyl polymer (P1), the organic diterlide compound represented by the above formula (1), and the above formula. It is preferable to include a step (D) of separating the phase from the solution phase containing the compound represented by (2) and removing the solution phase containing the vinyl polymer (P1).

The living radical polymerization method (TERP method) using an organic tellurium compound is a method for polymerizing a radically polymerizable compound (vinyl monomer) by using an organic tellurium compound as a chain transfer agent, for example, International Publication No. 2004/14848. , International Publication No. 2004/14962, International Publication No. 2004/072126, and International Publication No. 2004/096870.

Specific polymerization methods of the TERP method include the following (a) to (d).

(A) A method for polymerizing a vinyl monomer using an organic tellurium compound represented by the following formula (5).

(B) A method for polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by the following formula (5) and an azo-based polymerization initiator.

(C) A method for polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by the following formula (5) and an organic diterlide compound represented by the above formula (1).

(D) A method for polymerizing a vinyl monomer using a mixture of an organic tellurium compound represented by the following formula (5), an azo-based polymerization initiator and an organic diterlide compound represented by the above formula (1).

In the above formula (5), R ¹¹ is the same as R ¹¹ in the above formula (1). R ¹² and R ¹³ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R ¹⁴ contains an alkyl group having 1 to 8 carbon atoms, an aromatic group, a substituted aromatic group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amide group, an oxycarbonyl group, a cyano group, an allyl group or a propargyl group. show.

The group represented by R ¹¹ is an alkyl group having 1 to 8 carbon atoms, an aromatic group or an aromatic heterocyclic group, and specifically, it is as follows.

Alkyl groups having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group and heptyl. Examples thereof include a linear or branched alkyl group such as a group and an octyl group, and a cyclic alkyl group such as a cyclohexyl group. It is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group.

Examples of the aromatic group include a phenyl group and a naphthyl group.

Examples of the aromatic heterocyclic group include a pyridyl group, a frill group, a thienyl group and the like.

The groups represented by R ¹² and R ¹³ are independently hydrogen atoms or alkyl groups having 1 to 8 carbon atoms, and each group is specifically as follows.

Alkyl groups having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group and heptyl. Examples thereof include a linear or branched alkyl group such as a group and an octyl group, and a cyclic alkyl group such as a cyclohexyl group. It is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group.

The group represented by R ¹⁴ is an alkyl group having 1 to 8 carbon atoms, an aromatic group, a substituted aromatic group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amide group, an oxycarbonyl group, a cyano group and an allyl. It is a group or a propargyl group, and specifically, it is as follows.

Alkyl groups having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group and heptyl. Examples thereof include a linear or branched alkyl group such as a group and an octyl group, and a cyclic alkyl group such as a cyclohexyl group. It is preferably a linear or branched alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group.

Examples of the aromatic group include a phenyl group and a naphthyl group. It is preferably a phenyl group.

Examples of the substituted aromatic group include a phenyl group having a substituent, a naphthyl group having a substituent, and the like. Examples of the substituent of the substituted aromatic group include a halogen atom, a hydroxy group, an alkoxy group, an amino group, a nitro group, a cyano group, and a carbonyl-containing group represented by −COR ¹⁵ (R ¹⁵ has 1 to 8 carbon atoms). An alkyl group, an aryl group, an alkoxy group having 1 to 8 carbon atoms or an aryloxy group), a sulfonyl group, a trifluoromethyl group and the like can be mentioned. Further, it is preferable that these substituents are substituted by one or two.

Examples of the aromatic heterocyclic group include a pyridyl group, a frill group, a thienyl group and the like.

As the alkoxy group, a group in which an alkyl group having 1 to 8 carbon atoms is bonded to an oxygen atom is preferable, and for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert- Examples thereof include a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group and the like.

Examples of the acyl group include an acetyl group, a propionyl group, a benzoyl group and the like.

Examples of the amide group include -CONR ¹⁶¹ R ¹⁶² (R ¹⁶¹ and R ¹⁶² are independently hydrogen atoms and alkyl or aryl groups having 1 to 8 carbon atoms, respectively).

As the oxycarbonyl group, a group represented by −COOR ¹⁷ (R ¹⁷ is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aromatic group) is preferable, and for example, a carboxy group, a methoxycarbonyl group, an ethoxycarbonyl group, or a propoxy. Examples thereof include a carbonyl group, an n-butoxycarbonyl group, a sec-butoxycarbonyl group, a tert-butoxycarbonyl group, an n-pentyloxycarbonyl group, a phenoxycarbonyl group and the like. Preferred oxycarbonyl groups include a methoxycarbonyl group and an ethoxycarbonyl group.

As the allyl group, -CR ¹⁷¹ R ¹⁷² -CR ¹⁷³ = CR ¹⁷⁴ R ¹⁷⁵ (R ¹⁷¹ and R ¹⁷² are independent hydrogen atoms or alkyl groups having 1 to 8 carbon atoms, respectively, and R ¹⁷³ , R ¹⁷⁴ and R ¹⁷⁵ are , Each is an independently hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aromatic group, and each substituent may be connected by a cyclic structure) and the like.

As the propargyl group, -CR ¹⁸¹ R ¹⁸² -C≡CR ¹⁸³ (R ¹⁸¹ and R ¹⁸² are alkyl groups having a hydrogen atom or 1 to 8 carbon atoms, and R ¹⁸³ is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. , Aromatic group or Cyril group) and the like.

Specific examples of the organic tellurium compound represented by the above formula (5) are (methylteranylmethyl) benzene, (methylteranylmethyl) naphthalene, ethyl-2-methyl-2-methylteranyl-propionate, and ethyl-2-. Methyl-2-n-butylteranyl-propionate, (2-trimethylsiloxyethyl) -2-methyl-2-methylteranyl-propionate, (2-hydroxyethyl) -2-methyl-2-methylteranyl-propionate or (3-trimethylsilylpropargyl) )-2-Methyl-2-methylteranyl-propionate, etc., Organics described in International Publication No. 2004/14848, International Publication No. 2004/14962, International Publication No. 2004/072126, and International Publication No. 2004/096870. All of the tellurium compounds can be exemplified.

The azo-based polymerization initiator can be used without particular limitation as long as it is an azo-based polymerization initiator used in ordinary radical polymerization. For example, 2,2'-azobis (isobutyronitrile) (AIBN), 2,2'-azobis (2-methylbutyronitrile) (AMBN), 2,2'-azobis (2,4-dimethylvaleronitrile). ) (ADVN), 1,1'-azobis (1-cyclohexanecarbonitrile) (ACHN), dimethyl-2,2'-azobisisobutyrate (MAIB), 4,4'-azobis (4-cyanovalerian acid) ) (ACVA), 1,1'-azobis (1-acetoxy-1-phenylethane), 2,2'-azobis (2-methylbutylamide), 2,2'-azobis (4-methoxy-2,4) -Dimethylvaleronitrile) (V-70), 2,2'-azobis (2-methylamidinopropane) dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane], 2 , 2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2'-azobis (2,4,4-trimethylpentane), 2-cyano-2-propylazoformamide, 2, , 2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis (N-cyclohexyl-2-methylpropionamide) and the like can be exemplified.

The vinyl monomer is not particularly limited as long as it can be radically polymerized, and specific examples thereof include the following vinyl monomers.

Further, the vinyl polymer (P1) obtained in the present invention may be a copolymer composed of a plurality of vinyl monomers including the following vinyl monomers. In addition, in this specification, a "vinyl monomer" means a monomer having a carbon-carbon double bond which is radically polymerizable in a molecule. "(Meta) acrylic" means "at least one of acrylic and methacrylic", "(meth) acrylic acid" means "at least one of acrylic acid and methacrylic acid", and "(meth) acrylate" means "(meth) acrylate". At least one of acrylate and methacrylate. "

Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, (meth) ) A (meth) acrylate having an aliphatic alkyl group such as tert-butyl acrylate and 2-ethylhexyl (meth) acrylate.

A (meth) acrylate having an alicyclic alkyl group such as cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate.

A (meth) acrylate having an aromatic ring group such as benzyl (meth) acrylate, phenyl (meth) acrylate, and phenoxyethyl (meth) acrylate.

A (meth) acrylate having a hydroxy group such as 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate.

Diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, tetraethylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxy A (meth) acrylate having a polyethylene glycol structural unit such as tetraethylene glycol (meth) acrylate and methoxypolyethylene glycol (meth) acrylate.

Aromatic vinyl monomers such as styrene, α-methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 2-hydroxymethylstyrene and 1-vinylnaphthalene.

Maleic anhydride, succinic anhydride, anhydrous in hydroxyalkyl (meth) acrylates such as (meth) acrylic acid, crotonic acid, maleic acid, itaconic acid, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. A vinyl monomer having a carboxyl group such as a monomer reacted with an acid anhydride such as phthalic acid.

A vinyl monomer having a sulfonic acid group such as styrene sulfonic acid, dimethylpropyl sulfonic acid (meth) acrylamide, ethyl sulfonate (meth) acrylate, ethyl sulfonate (meth) acrylamide, and vinyl sulfonic acid.

A vinyl monomer having a phosphoric acid group such as methacryloxyethyl phosphate ester.

(Meta) acrylamide such as (meth) acrylamide, N-methyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide.

N, N-dimethylaminopropyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, 2- (dimethylamino) ethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, etc. 3 Unsaturated monomer containing a secondary amine.

A quaternary ammonium base-containing unsaturated monomer such as N-2-hydroxy-3-acryloyloxypropyl-N, N, N-trimethylammonium chloride, N-methacryloylaminoethyl-N, N, N-dimethylbenzylammonium chloride.

(Meta) Epoxy group-containing unsaturated monomer such as glycidyl acrylate.

Heterocycle-containing unsaturated monomers such as 2-vinylthiophene, N-methyl-2-vinylpyrrole, 1-vinyl-2-pyrrolidone, 2-vinylpyridine, and 4-vinylpyridine.

Vinyl amides such as N-vinylformamide, N-vinylacetamide, and N-vinyl-ε-captolactam.

Vinyl carboxylic acid such as vinyl acetate, vinyl pivalate, vinyl benzoate.

Α-olefins such as 1-hexene, 1-octene and 1-decene.

Dienes such as butadiene, isoprene, 4-methyl-1,4-hexadiene, 7-methyl-1,6-octadien.

Among these, (meth) acrylates having an aliphatic alkyl group, (meth) acrylates having an alicyclic alkyl group, (meth) acrylates having a hydroxy group, aromatic vinyl monomers, (meth) acrylamides and tertiary amines. The unsaturated monomer contained, the unsaturated monomer containing a heterocycle, and the vinylamide monomer are preferable.

The polymerization step is a container substituted with an inert gas, and the vinyl monomer and the organic tellurium compound of the above formula (5) are further combined for the purpose of promoting a reaction depending on the type of the vinyl monomer, controlling the molecular weight and the molecular weight distribution, and the like. The azo-based polymerization initiator and / or the organic diterlide compound of the above formula (1) are mixed. At this time, examples of the inert gas include nitrogen, argon, and helium. Preferred are argon and nitrogen.

The amount of the vinyl monomer used in the above (a), (b), (c) and (d) may be appropriately adjusted according to the physical properties of the target vinyl polymer (P1). It is preferable that the vinyl monomer is 30 mol to 30,000 mol with respect to 1 mol of the organic tellurium compound of the above formula (5).

When the organic tellurium compound of the above formula (5) and the azo-based polymerization initiator in the above-mentioned (b) are used in combination, 0.01 mol to 10 mol of the azo-based polymerization initiator is added to 1 mol of the organic tellurium compound of the above formula (5). Is preferable.

When the organic tellurium compound of the above formula (5) and the organic diterlide compound of the above formula (1) are used in combination in the above (c), the organic of the above formula (1) is obtained with respect to 1 mol of the organic tellurium compound of the above formula (5). The diterlide compound is preferably 0.01 mol to 100 mol.

When the organic telluryl compound of the above formula (5) in the above (d), the organic diterlide compound of the above formula (1) and the azo-based polymerization initiator are used in combination, the above is obtained with respect to 1 mol of the organic tellurium compound of the above formula (5). The organic diterlide compound of the formula (1) is preferably 0.01 mol to 100 mol, and the azo-based polymerization initiator is preferably 0.01 mol to 10 mol with respect to 1 mol of the organic diterlide compound of the above formula (1).

The polymerization reaction can be carried out without a solvent, but the above mixture may be carried out by stirring using an aprotic solvent or a protic solvent generally used in radical polymerization. Aprotic solvents that can be used include, for example, anisole, benzene, toluene, N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), acetone, 2-butanone (methyl ethyl ketone), dioxane, propylene glycol monomethyl ether acetate, chloroform. , Carbon tetrachloride, tetrahydrofuran (THF), ethyl acetate, trifluoromethylbenzene and the like. Examples of the protonic solvent include water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, hexafluoroisopropanol, diacetone alcohol, propylene glycol monomethyl ether and the like. Be done.

The amount of the solvent used may be appropriately adjusted, for example, 0.01 mL or more, more preferably 0.05 mL or more, still more preferably 0.1 mL or more, and 50 mL or less with respect to 1 g of the vinyl monomer. It is preferable, more preferably 10 mL or less, still more preferably 1 mL or less.

The reaction temperature and reaction time may be appropriately adjusted depending on the molecular weight or molecular weight distribution of the obtained vinyl polymer (P1), but usually, the mixture is stirred at 0 ° C to 150 ° C for 1 minute to 100 hours. The TERP method can obtain a high yield and a precise molecular weight distribution even at a low polymerization temperature and a short polymerization time. At this time, the pressure is usually applied at normal pressure, but may be pressurized or depressurized.

The tellurium recovery solution obtained in the step of recovering tellurium from the polymerization solution after the completion of the polymerization reaction can be used as a solution (a1).

The growth end of the vinyl polymer (P2) obtained by the polymerization reaction is in the form of —TeR ¹¹ derived from the tellurium compound (in the formula, R ¹¹ is the same as R ¹¹ in the above formula (1)). By allowing the reducing agent (r2) to act after the completion of the polymerization reaction, the tellurium atom is removed from the vinyl polymer, and the vinyl polymer (P1) and R11-Te-Y- ^{( R21} ) _n can be obtained. can. Since R ¹¹ -Te-Y- (R ²¹ ) _n is an equilibrium mixture of the organic diterlide compound represented by the above formula (1) and the compound represented by the above formula (2), the organic diterlide compound is high. It is not easy to recover by yield.

However, in the present invention, as described above, the step (A) is performed by mixing the equilibrium mixture, the base, the reducing agent (r1), and water, and then the step (B) is performed. The organic diterlide compound can be recovered in high yield.

(Reducing agent (r2))
The reducing agent (r2) can be used without particular limitation as long as it does not have a Te atom and exhibits reducibility to a group derived from the tellurium compound at the growth end of the vinyl polymer (P2).

The reducing agent (r2) is, for example, at least one selected from the group consisting of an organic sulfur-based reducing agent, an organic silicon-based reducing agent, and an organic tin-based reducing agent, and is more preferably represented by the following formula (6). It is a compound. By using the reducing agent (r2), it can act only on the growth end of the polymer.

(R ²¹ ) _n -YH ... Equation (6)
In the above formula (6), n, Y, R ²¹ are the same as n, Y, R ²¹ in the above formula (2).

n is 1 to 3, preferably 1 or 3, and more preferably 1.

The group represented by Y is a (n + 1) -valent linking group, and examples thereof include a sulfur atom, a silicon atom, and a tin atom, and a sulfur atom is preferable.

The group represented by R ²¹ is an aliphatic group or an aromatic group, and the group represented by R ²¹ may have a substituent. Specifically, it is as follows.

Examples of the aliphatic group include a linear alkyl group, a branched chain alkyl group, a cyclic alkyl group and the like.

The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 1 to 5 carbon atoms. Examples of the linear alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-hexyl group, an n-octyl group, an n-nonyl group, an n-decyl group and an n-lauryl group. Can be mentioned.

The branched-chain alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 10 carbon atoms, and even more preferably 3 to 5 carbon atoms. Examples of the branched alkyl group include an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a 2-ethylhexyl group, a neopentane group and an isooctyl group.

The cyclic alkyl group may have a chain moiety. The cyclic alkyl group preferably has 4 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, and even more preferably 6 to 10 carbon atoms. Examples of the cyclic alkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like. Examples of the chain portion of the cyclic alkyl group having a chain portion include an alkylene group having 1 to 12 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. Be done. Examples of the substituent contained in the aliphatic group include a halogen group, an alkoxy group, a hydroxy group and the like.

The aromatic group may have a chain moiety. The aromatic group preferably has 6 to 18 carbon atoms, more preferably 6 to 12 carbon atoms, and even more preferably 6 to 8 carbon atoms. Examples of the aromatic group include a phenyl group, a tolyl group, a xylyl group, a mesitylene group and the like. Examples of the chain portion of the aromatic group having a chain portion include an alkylene group having 1 to 12 carbon atoms, preferably an alkylene group having 1 to 6 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. Be done. Examples of the substituent having the aromatic group include a halogen group, an alkoxy group, a hydroxy group and the like.

Specific examples of the compound represented by the above formula (6) include alkylthiols such as methanethiol, ethanethiol, propanethiol and butanethiol; thioglycol; thioglycerol; aromatics such as thiophenol, benzyl mercaptan and thiosalicylic acid. Examples thereof include thiol; trialkylsilicon such as tris (trimethylsilyl) silane; trialkyltin such as tributyltin, and aromatic thiol is preferable.

When such a reducing agent (r2) is used, since the hydride reducing agent is not used in all the steps, there is no risk of hydrogen gas being generated in a wide variety of vinyl polymers obtained by the TERP method, and the yield is high. Moreover, tellurium can be recovered as an organic diterlide compound with high purity.

In the present invention, the reaction temperature for reacting by mixing the polymerization solution containing the vinyl polymer (P2) with the reducing agent (r2) is not particularly limited, and is, for example, 0 ° C. or higher, preferably 30 ° C. or higher. As mentioned above, the temperature can be 80 ° C. or lower, preferably 70 ° C. or lower. The reaction time can be, for example, 2 hours or more and 30 hours or less.

(Solvent (a2))
The solvent (a2) may be any solvent that can be phase-separable from the solvent in which the vinyl polymer (P1) is dissolved and can dissolve the organic diterlide compound represented by the formula (1), and is preferable. It is a solvent having a higher hydrophobicity than the solvent in which the vinyl polymer (P1) is dissolved. Examples of such a solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, nonane and decane; aromatic hydrocarbons such as benzene and toluene; halogenated hydrocarbons such as chloroform and carbon tetrachloride. Classes, preferably aliphatic hydrocarbons. The solvent (a2) may be used alone or in combination of two or more.

The amount of the solvent (a2) added can be 0.5 to 10 parts, preferably 2 to 5 parts, relative to the vinyl polymer (P1).

In the step (D), since the solution phase containing the vinyl polymer (P1) is made hydrophilic, a lower alcohol such as methanol and ethanol, or a mixed solvent containing acetonitrile and the like can be further mixed. When a lower alcohol, acetonitrile or the like is mixed, the amount may be 0.1 part to 6 parts, preferably 0.3 part to 2 parts with respect to the vinyl polymer (P1).

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these specific examples.

(Example 1)
In a glass tube, 0.5 g (1.35 mmol) of dibutyl diterlide (DBDT), 0.1 g (0.46 mmol) of diphenyl disulfide, 6.2 g of heptane (Hep), 0.109 g (1.01 mmol) of formamidin sulfinic acid. ), 51 mg (0.91 mmol) of potassium hydroxide (KOH), 1.0 g of ion-exchanged water ( _H2O ), and 0.9 g of propylene glycol monomethyl ether (MP) were added, and the mixture was stirred at 35 ° C. for 20 hours. After stirring, the mixture was allowed to stand until the two phases were separated, and then the aqueous phase was removed. When the remaining heptane phase was analyzed by ¹ H-NMR (manufactured by Bruker Japan Co., Ltd., model number "AVANCE500"), it was confirmed that it was DBDT. The purity was 96%.

(Examples 2 to 10)
Dibutylditerlide was purified in the same manner as in Example 1 except that the reducing agent shown in Table 1 below was used instead of formamidine sulfinic acid. Further, the remaining heptane phase was analyzed by ¹ H-NMR (manufactured by Bruker Japan Co., Ltd., model number "AVANCE500") in the same manner as in Example 1, and it was confirmed that it was DBDT, and its purity was determined.

(Comparative Example 1)
In a glass tube, 0.5 g (1.35 mmol) of dibutyl diterlide (DBDT), 0.1 g (0.46 mmol) of diphenyl disulfide, 6.2 g of heptane (Hep), 0.051 g of hydrazine monohydrate (1. 02 mmol), 51 mg (0.91 mmol) of potassium hydroxide (KOH), 1.0 g of ion-exchanged water ( _H2O ), and 0.9 g of propylene glycol monomethyl ether (MP) were added, and the mixture was stirred at 35 ° C. for 23 hours. After stirring, the mixture was allowed to stand until the two phases were separated, and then the aqueous phase was removed. When the remaining heptane phase was analyzed by ¹ H-NMR (manufactured by Bruker Japan Co., Ltd., model number "AVANCE500"), it was confirmed that it was DBDT. The purity was 76%.

(Comparative Example 2)
In a glass tube, 0.5 g (1.35 mmol) of dibutyl diterlide (DBDT), 0.1 g (0.46 mmol) of diphenyl disulfide, 6.2 g of heptane (Hep), and formaldehyde sulfoxylate sodium dihydrate 0. 157 g (1.02 mmol), 2.0 g of ion-exchanged water ( _H2O ) and 1.8 g of propylene glycol monomethyl ether (MP) were added, and the mixture was stirred at 35 ° C. for 26 hours. After stirring, the mixture was allowed to stand until the two phases were separated, and then the aqueous phase was removed. When the remaining heptane phase was analyzed by ¹ H-NMR (manufactured by Bruker Japan Co., Ltd., model number "AVANCE500"), it was confirmed that it was DBDT. The purity was 77%.

The results are shown in Table 1 below.

From Table 1, in Examples 1 to 10 in which both a sulfur-based reducing agent and a phosphorus-based reducing agent, at least one of the reducing agents, and a base were used, the mixture of the organic diterlide compound and the by-product was of high purity. It was confirmed that an organic diterlide compound could be obtained. On the other hand, in Comparative Example 1 using a reducing agent different from the sulfur-based reducing agent and the phosphorus-based reducing agent and Comparative Example 2 using no base, a high-purity organic diterlide compound could not be obtained.

(Example 11)
In a glass tube, 1.20 g (4.0 mmol) of ethyl-2-methyl-2-n-butylteranyl-propionate (BTEE), 0.74 g (2.0 mmol) of dibutylditerlide (DBDT), 2,2'-. Azobis (isobutyronitrile) (AIBN) 0.13 g (0.8 mmol), propylene glycol monomethyl ether acetate (PMA) 19.4 g, 2- (dimethylamino) ethyl methacrylate (DMAEMA) 20.12 g (128.0 mmol) ) Was added. This solution was stirred at 60 ° C. for 14 hours in a nitrogen atmosphere to obtain poly2- (dimethylamino) ethyl methacrylate having an organic tellurium group at the end. The molecular weight of the obtained polymer measured by gel permeation chromatography (GPC, manufactured by Toso Co., Ltd., model number "HLC-8320", polystyrene standard) is number average molecular weight (Mn) = 4700, and the molecular weight distribution thereof is The weight average molecular weight (Mw) / number average molecular weight (Mn) = 1.31.

Next, 0.48 g (4.4 mmol) of thiophenol was added to the obtained polymer, and the mixture was stirred at 60 ° C. for 6 hours.

82.1 g of heptane and 23.8 g of methanol were added to this solution, and the mixture was stirred. After stirring, the mixture was allowed to stand until the two phases were separated, and then the heptane phase was removed. This liquid separation cleaning operation was repeated 6 times.

Next, in the collected heptane phase, 0.30 g (2.8 mmol) of formamidine sulfinic acid, 0.47 g (8.4 mmol) of potassium hydroxide (KOH), 1.1 g of ion-exchanged water, and propylene glycol monomethyl ether (MP). 1.0 g was added, and the mixture was stirred at 35 ° C. for 4 hours. After stirring, the mixture was allowed to stand until the two phases were separated, the aqueous phase was removed, and the heptane phase was concentrated under reduced pressure. The residue was analyzed by ¹ H-NMR (manufactured by Bruker Japan Co., Ltd., model number "AVANCE500") and confirmed to be DBDT. The purity was 97%. The recovery rate of the tellurium compound by weight measurement was 88%.

(Comparative Example 3)
In a glass tube, 1.20 g (4.0 mmol) of ethyl-2-methyl-2-n-butylteranyl-propionate (BTEE), 0.74 g (2.0 mmol) of dibutylditerlide (DBDT), 2,2'-. Azobis (isobutyronitrile) (AIBN) 0.13 g (0.8 mmol), propylene glycol monomethyl ether acetate (PMA) 19.4 g, 2- (dimethylamino) ethyl methacrylate (DMAEMA) 20.12 g (128.0 mmol) ) Was added. This solution was stirred at 60 ° C. for 14 hours in a nitrogen atmosphere to obtain poly2- (dimethylamino) ethyl methacrylate having an organic tellurium group at the end. The molecular weight of the obtained polymer measured by gel permeation chromatography (GPC, manufactured by Tosoh Corporation, model number "HLC-8320", polystyrene standard) is Mn = 5400, and the molecular weight distribution is Mw / Mn (PDI). ) = 1.32.

Next, 0.48 g (4.4 mmol) of thiophenol was added to the obtained polymer, and the mixture was stirred at 60 ° C. for 6 hours.

82.1 g of heptane and 23.8 g of methanol were added to this solution, and the mixture was stirred. After stirring, the mixture was allowed to stand until the two layers were separated, and then the heptane layer was removed. This liquid separation cleaning operation was repeated 6 times.

Next, the collected heptane layer was concentrated under reduced pressure. The residue was analyzed by ¹ H-NMR (manufactured by Bruker Japan Co., Ltd., model number "AVANCE500") and confirmed to be DBDT. The purity was 69%. The recovery rate of the tellurium compound was 61% by weight measurement.

The results are shown in Table 2 below.

From Table 2, even when the tellurium recovery solution obtained in the step of recovering tellurium from the polymerization solution obtained by the living radical polymerization method using an organic tellurium compound is used, the sulfur-based reducing agent and the phosphorus-based reducing agent are used. In Example 11 using both the reducing agent of at least one of the agents and the base, it was confirmed that a high-purity organic diterlide compound can be obtained from the mixture of the organic diterlide compound and the by-product. On the other hand, in Comparative Example 3 which was not purified using the reducing agent and the base, a high-purity organic diterlide compound could not be obtained.

Claims (8)

A solution (a1) containing an organic diterlide compound represented by the following formula (1) and a compound represented by the following formula (2), a base, a reducing agent (r1), and water are mixed to prepare a mixture. Obtaining step (A) and
A step (B) of separating the mixture obtained in the step (A) into an organic phase and an aqueous phase and removing the aqueous phase is provided.
A method for purifying an organic diterlide compound, wherein the reducing agent (r1) is at least one of a sulfur-based reducing agent and a phosphorus-based reducing agent.
R ¹¹ -Te-Te-R ¹¹ ... Equation (1)
[In the formula (1), R ¹¹ represents an alkyl group having 1 to 8 carbon atoms, an aromatic group or an aromatic heterocyclic group. ]
(R ²¹ ) _n -Y-Y- (R ²¹ ) _n ... Equation (2)
[In the formula (2), n represents 1 to 3. Y represents a (n + 1) -valued linking group. R ²¹ represents an aliphatic group or an aromatic group. ] The method for purifying an organic diterlide compound according to claim 1, wherein the base is an alkali metal hydroxide. The method for purifying an organic diterlide compound according to claim 1 or 2, wherein Y is a sulfur atom, a silicon atom or a tin atom. Claims 1 to 3 are characterized in that the solution (a1) is a tellurium recovery solution obtained in a step of recovering tellurium from a polymerization solution obtained by a living radical polymerization method using an organic tellurium compound. The method for purifying an organic diterlide compound according to any one of the above. The step of recovering tellurium is a step (C) of mixing a polymerization solution containing a vinyl polymer (P2) obtained by a living radical polymerization method using an organotellurium compound with a reducing agent (r2) to obtain a mixture. When,
The mixture obtained in the step (C) and the solvent (a2) are mixed, a solution phase containing a vinyl polymer (P1), an organic diterlide compound represented by the formula (1), and the formula. 4. The fourth aspect of the present invention is characterized by comprising a step (D) of separating the phase from the solution phase containing the compound represented by (2) and removing the solution phase containing the vinyl polymer (P1). The method for purifying an organic diterlide compound according to. The organic diterlide according to claim 5, wherein the reducing agent (r2) is at least one selected from the group consisting of an organic sulfur-based reducing agent, an organic silicon-based reducing agent, and an organic tin-based reducing agent. Method for purifying a compound. The method for purifying an organic diterlide compound according to claim 5 or 6, wherein the solvent (a2) is an aliphatic hydrocarbon. 5. The growth end of the vinyl polymer (P2) is represented by -Te-R ¹¹ (R ¹¹ is the same as R ¹¹ in the formula (1)). The method for purifying an organic diterlide compound according to any one of claims 7.