Method for producing disulfide compound

Abstract

To provide a method by which a disulfide compound can be produced conveniently and in high yield, without the need for a large quantity of reagent.SOLUTION: A method for producing a disulfide compound (I) expressed by General Formula (1): R1-S-S-R1 (1), the method comprising a step of reacting a thiol compound (II) expressed by General Formula (2): R1-(SH)n (2), in the presence of a catalyst (III) and a base (IV), wherein the catalyst (III) comprises at least one selected from the group consisting of an aromatic disulfide compound (IIIa) expressed by General Formula (3a): R2-S-S-R2 (3a) and an aromatic thiol compound (IIIb) expressed by General Formula (3b): R2-SH (3b), the catalyst (III) being different from the disulfide compound (I) and the thiol compound (II), and an amount of the catalyst (III) used being less than 0.30 mol relative to 1 mol of the thiol compound (II).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a disulfide compound. [Background technology]

[0002] In general, organic disulfide compounds containing sulfur atoms have properties such as a high refractive index, the ability to easily bond with sulfur and metals, and the ability to repeatedly form disulfide and thiol structures through oxidation-reduction caused by electrolysis. Therefore, organic disulfide compounds are used in a wide range of applications, such as lenses that require a high refractive index, such as for eyeglasses, secondary batteries with high energy density, and plating solutions used in electrolytic and electroless plating.

[0003] Known methods for producing disulfide compounds include those that involve oxidizing thiol compounds. Examples of such methods include those that use hydrogen peroxide, permanganate, sodium perborate, or the like as an oxidizing agent (Non-Patent Document 1, etc.). However, these methods require a stoichiometric amount or more of the oxidizing agent, and have the problem of generating by-products due to excessive oxidation. Another known method for oxidizing thiol compounds is an air oxidation reaction that uses oxygen as an oxidizing agent, but this method has the problem of requiring a special catalyst and special reaction conditions (Non-Patent Documents 2 and 3, etc.).

[0004] Furthermore, as a method for producing a disulfide compound, in addition to the above-mentioned method of oxidizing a thiol compound, a method of reducing a sulfonium chloride has also been reported (Patent Document 1). However, the production method of Patent Document 1 is industrially disadvantageous because it requires the use of expensive hydroiodic acid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 58-194855 [Non-patent literature]

[0006] [Non-Patent Document 1] Organic Syntheses 1955, Collective Volume 3, 86. [Non-patent document 2] Synlett 2021, 32, 1227-1230. [Non-patent document 3] Chinese Chemical Letters 2020, 31, 1520-1524. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the current state of the prior art as described above, and a main object of the present invention is to provide a method for producing a disulfide compound simply and in high yield without requiring a large amount of reactants. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to achieve the above-mentioned object. As a result, they have found that by using a small amount of at least one catalyst selected from the group consisting of aromatic disulfide compounds and aromatic thiol compounds, disulfide compounds can be produced easily and in high yield without requiring a large amount of a reactant (e.g., catalyst, etc.). Based on this finding, the present inventors have conducted further research and have completed the present invention. That is, the present invention encompasses the following features.

[0009] Section 1. General formula (1): R 1 -SSR 1 (1) [In the formula, R 1 indicates an organic group. 1 may form a ring together with the adjacent disulfide bonds. A method for producing a disulfide compound (I) represented by the following formula: General formula (2): R 1 -(SH) n (2) [In the formula, R 1 is the same as above. n represents 1 or 2.] A thiol compound (II) represented by In the presence of a catalyst (III) and a base (IV), reacting the The catalyst (III) is represented by the general formula (3a): R 2 -SSR 2 (3a) [In the formula, R 2 represents an aromatic group. An aromatic disulfide compound (IIIa) represented by the formula: General formula (3b): R 2 -SH (3b) [In the formula, R 2 is the same as above.] Aromatic thiol compounds (IIIb) represented by the formula: At least one selected from the group consisting of The catalyst (III) is different from the disulfide compound (I) and the thiol compound (II), The method, wherein the amount of the catalyst (III) used is less than 0.30 moles per mole of the thiol compound (II).

[0010] Section 2. Said R 2 Item 3. The method according to Item 1, wherein: is an aromatic group having an electron-donating group.

[0011] Item 3. The method according to Item 1 or 2, wherein the base (IV) is an alkali metal hydroxide or carbonate.

[0012] Item 4. The method according to any one of Items 1 to 3, wherein the amount of the base (IV) used is 0.01 to 0.2 moles per mole of the thiol compound (II).

[0013] Item 5. The method according to any one of Items 1 to 4, wherein the reaction temperature is 0 to 80°C.

[0014] Item 6. The method according to any one of Items 1 to 5, wherein the reaction is carried out in a solution containing a polar solvent.

[0015] Item 7. The method according to any one of Items 1 to 6, wherein the reaction is carried out under air oxidation conditions.

[0016] Item 8. A catalyst for use in the method according to any one of items 1 to 7, General formula (3a): R 2 -SSR 2 (3a) [In the formula, R 2 represents an aromatic group. and an aromatic disulfide compound (IIIa) represented by the general formula (3b): R 2 -SH (3b) [In the formula, R 2 is the same as above.] Aromatic thiol compounds (IIIb) represented by the formula: At least one selected from the group consisting of The aromatic group comprises a polymeric carrier. catalyst. [Effects of the Invention]

[0017] According to the method of the present invention, a disulfide compound can be produced simply and in high yield without requiring a large amount of reactants. DETAILED DESCRIPTION OF THE INVENTION

[0018] In this specification, the expressions "contain" and "comprise" include any of "contain," "comprise," "consist only of," "consist essentially only of," and "consist only of."

[0019] In this specification, the expression "A to B" indicating a range of values ​​means "greater than or equal to A and less than or equal to B."

[0020] In this specification, the term "yield" refers to the ratio of the molar amount of the produced disulfide compound (I) to the theoretical molar amount of the target disulfide compound (I) produced from the molar amount of the raw material thiol compound (II). The molar amount of the produced disulfide compound (I) can be calculated by NMR measurement using dimethyl sulfone as an internal standard.

[0021] In this specification, the term "organic group" refers to a group containing one or more carbon atoms or a group formed by removing one hydrogen atom from an organic compound, and is a concept that encompasses both aliphatic groups and aromatic groups. Here, the organic group (e.g., aliphatic groups, aromatic groups, etc.) may have a heteroatom inserted or added thereto. The heteroatom is not particularly limited, but examples thereof include a boron atom, a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom, a sulfur atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0022] In this specification, the term "aliphatic group" refers to a group that does not contain an aromatic ring, and preferably refers to a group formed by removing one hydrogen atom from an aliphatic compound. Examples of the aliphatic group include an alkyl group, an alkenyl group, and an alkynyl group.

[0023] In the present specification, the term "alkyl group" is not particularly limited, and examples thereof include linear alkyl groups having 1 to 20 carbon atoms (particularly 1 to 10 carbon atoms), such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group, as well as branched alkyl groups having 3 to 20 carbon atoms (particularly 3 to 10 carbon atoms), such as an isopropyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group, and cyclic alkyl groups having 3 to 20 carbon atoms (particularly 5 to 10 carbon atoms), such as a cyclopentyl group and a cyclohexyl group.

[0024] In the present specification, the term "alkenyl group" is not particularly limited, and examples thereof include linear alkenyl groups having 2 to 20 (particularly 2 to 10) carbon atoms, such as ethenyl group (vinyl group), 2-propenyl group (allyl group), and 2-butenyl group, as well as branched alkenyl groups having 3 to 20 (particularly 3 to 10) carbon atoms, such as isopropenyl group, 2-methyl-1-propenyl group, and 2-methylallyl group.

[0025] In the present specification, the term "alkynyl group" is not particularly limited, and examples thereof include linear alkenyl groups having 2 to 20 (particularly 2 to 10) carbon atoms, such as ethynyl, n-propynyl, and n-butynyl, as well as branched alkynyl groups having 3 to 20 (particularly 3 to 10) carbon atoms, such as isobutynyl, s-butynyl, and isopentynyl.

[0026] As used herein, the term "aromatic group" refers to a group containing an aromatic ring, preferably a group formed by removing one hydrogen atom from an aromatic compound. Examples of aromatic groups include aryl groups and heteroaryl groups.

[0027] In the present specification, the term "aryl group" is not particularly limited, and any of a monocyclic aryl group, a fused ring aryl group, and a polycyclic aryl group can be used. Examples thereof include aryl groups having 6 to 20 carbon atoms (particularly 6 to 14 carbon atoms), such as a phenyl group, a hydroxyphenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, an indolyl group, an imidazolyl group, a pyrenyl group, and a triphenylenyl group.

[0028] In the present specification, the term "heteroaryl group" is not particularly limited, and both a monocyclic heteroaryl group and a polycyclic heteroaryl group can be employed. Examples thereof include a pyrrolidyl group, a pyrrolyl group, a tetrahydrothienyl group, a thienyl group, an oxolanyl group, a furanyl group, an imidazolyl group, an N-methylimidazolyl group, a pyrazolyl group, a thiazolyl group, an oxazolyl group, a piperidyl group, a pyridyl group, an N,N-dimethyl-4-aminopyridyl group, a pyrazyl group, an indolyl group, an isoindolyl group, a benzimidazolyl group, a quinolyl group, an isoquinolyl group, and a quinoxalyl group.

[0029] In this specification, the aliphatic groups (e.g., alkyl groups, alkenyl groups, alkynyl groups, etc.) and aromatic groups (e.g., aryl groups, heteroaryl groups, etc.) may have one or more electron-withdrawing groups and / or electron-donating groups.

[0030] In this specification, the term "electron-withdrawing group" is not particularly limited as long as it has the effect of withdrawing electrons, and preferably refers to a group having a positive Hammett's σp. Here, for an explanation of Hammett's σp and the numerical values ​​of each group, reference can be made to Hansch, C. et al., Chem. Rev., 91, 165-195 (1991). Specific examples of electron-withdrawing groups include halogens (fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), perfluoroalkyl groups, aldehyde groups, ester groups (-COO-), carbonyl groups, sulfonyl groups, cyano groups, nitro groups, and quaternary ammonium groups.

[0031] In this specification, the term "electron-donating group" is not particularly limited as long as it has the effect of donating electrons, and preferably means a group having a negative Hammett's σp value. Specific examples of electron-withdrawing groups include alkyl groups, aryl groups, heteroaryl groups, alkoxy groups (e.g., methoxy, ethoxy, and propoxy), hydroxy groups, and amino groups.

[0032] In this specification, the aliphatic groups (e.g., alkyl groups, alkenyl groups, alkynyl groups, etc.), the aromatic groups (e.g., aryl groups, heteroaryl groups, etc.), and the electron-withdrawing groups and electron-donating groups that these groups may have may further have a substituent. In this specification, examples of the "substituent" include a hydroxy group, a halogen atom, an alkyl group, an aryl group, an alkoxy group, a carbonyl group, an aldehyde group, a carboxy group, an ester group (-COO-), an amino group, a sulfonyl group, a cyano group, a nitro group, and a quaternary ammonium group.

[0033] 1.Object The disulfide compound (I) of the present invention is an organic disulfide. The disulfide compound (I) is represented by the general formula (1): R 1 -SSR 1 (1) [In the formula, R 1 indicates an organic group. 1 may form a ring together with the adjacent disulfide bonds. It is expressed as:

[0034] In general formula (1), R 1 The group represented by R is not particularly limited, and a wide range of known organic groups can be used. 1 Examples of the organic group represented by R include an aliphatic group and an aromatic group. Although it is relatively difficult to produce an aliphatic disulfide compound by conventional methods, the method of the present invention can be applied to the production of such an aliphatic disulfide compound. When the target compound is an aliphatic disulfide compound, R 1 From the viewpoint of yield, the alkyl group is preferably a linear alkyl group having 1 to 20 carbon atoms (particularly 1 to 10 carbon atoms), such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or an n-pentyl group.

[0035] In general formula (1), R 1The group represented by may further have a substituent. The substituent is not particularly limited as long as it is not involved in the reaction. When the group has a substituent, the number of the substituent is not particularly limited, and is preferably 1 to 6, and more preferably 1 to 3.

[0036] In general formula (1), two R 1 can be identical to each other. 1 From the viewpoint of yield, R 1 The production method of the present invention allows the disulfidation reaction to proceed under mild conditions, and therefore has little effect on the substituents contained in the raw materials and the target product. In this respect, the production method of the present invention is advantageous over conventional techniques.

[0037] From the above, specific examples of the disulfide compound (I) include, but are not limited to, didodecyl disulfide, 4,4'-dinitrodiphenyl disulfide, 3,3'-dithiobis(sodium 1-propanesulfonate), 3,3'-dithiobis(1,2-propanediol), and the like.

[0038] The disulfide compound (I) may be a cyclic disulfide compound. That is, in the general formula (1), R 1 may form a ring together with the disulfide bond. In this case, R 1can also be regarded as one divalent group, and the divalent group refers to any group formed by removing one more hydrogen atom from the above organic group. In this case, the thiol compound (II) described below is preferably a dithiol compound having two thiol groups. Specific examples of such cyclic disulfide compounds include cyclic disulfide compounds having one disulfide bond, such as 1,2-dithiacyclobutane (1,2-dithietane), 1,2-dithiacyclopentane (1,2-dithiolane), 1,2-dithiacycloheptane (1,2-dithiane), and 1,2-dithiacycloheptane, and cyclic disulfide compounds having two or more disulfide bonds, such as 1,2,4,5-tetrathiane.

[0039] The disulfide compound (I) obtained by the production method of the present invention can be suitably used, for example, in lenses for eyeglasses and the like that require a high refractive index, secondary batteries with high energy density, plating solutions used in electrolytic and electroless plating, etc.

[0040] 2.Raw materials The thiol compound (II) used as a raw material in the present invention is an organic thiol. The thiol compound (II) is represented by the general formula (2): R 1 -(SH) n (2) [In the formula, R 1 is the same as above. n represents 1 or 2.] It is expressed as:

[0041] In general formula (2), R 1 is the R defined in "1. Objective" above. 1 In conventional methods, it is relatively difficult to produce an aliphatic disulfide compound from an aliphatic thiol compound, but according to the method of the present invention, such an aliphatic thiol compound can also be used. When the raw material is an aliphatic thiol compound, R 1From the viewpoint of yield, the alkyl group is preferably a linear alkyl group having 1 to 20 carbon atoms (particularly 1 to 10 carbon atoms), such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or an n-pentyl group.

[0042] In general formula (2), n may be 1 or 2. When n is 1, the thiol compound (2) is a monothiol, and a non-cyclic disulfide is likely to be obtained as the disulfide compound (I). When n is 2, the thiol compound (2) is a dithiol, and a cyclic disulfide is likely to be obtained as the disulfide compound (I).

[0043] From the above, specific examples of the thiol compound (II) include, but are not limited to, 1-dodecylthiol, nitrobenzenethiol, 3-mercapto-1-propanesulfonic acid (3-MPS) sodium, 1-thioglycerol, and the like.

[0044] The thiol compound (II) may be a dithiol compound. That is, in the general formula (2), R 1 may have two thiol groups bonded thereto. In this case, the disulfide compound (I) is preferably a cyclic disulfide compound. Specific examples of such dithiol compounds include methanedithiol, 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, and 1,5-pentanedithiol.

[0045] 3. Catalyst The catalyst (III) used in the present invention is represented by the general formula (3a): R 2 -SSR 2 (3a) [In the formula, R 2 represents an aromatic group. An aromatic disulfide compound (IIIa) represented by the formula: General formula (3b): R 2 -SH (3b) [In the formula, R 2 is the same as above.] Aromatic thiol compounds (IIIb) represented by the formula: The production method of the present invention uses a small amount of such an aromatic compound as a catalyst, thereby making it possible to produce a disulfide compound simply and in high yield without requiring a large amount of a reactant.

[0046] In general formula (3a) and / or (3b), R 2 The aromatic group represented by R is not particularly limited as long as it is a group having an aromatic ring, and a wide variety of known aromatic groups can be used. 2 From the viewpoint of yield, the aromatic group represented by is preferably an aromatic group having an electron-donating group, and more preferably an aromatic group having an alkyl group (e.g., methyl group, t-butyl group, etc.), a hydroxyl group, or an amino group. In this case, it is advantageous in that the catalyst (III) is easily oxidized.

[0047] In general formula (3a) and / or (3b), R 2 The number of electron-donating groups that the aromatic group represented by the formula (R) can have is within the range of 1 to the maximum number that can be substituted (for example, 1, 2, 3, 4, 5, R 2 In the case of a fused ring or polycyclic ring, the number of rings is preferably 6 or more, and more preferably within the range of 1 to 3.

[0048] In general formula (3a) and / or (3b), R 2 The aromatic group represented by may further have a substituent. The substituent is not particularly limited as long as it is not involved in the reaction. When the aromatic group has a substituent, the number of the substituent is not particularly limited, and is preferably 1 to 6, and more preferably 1 to 3.

[0049] In general formula (3a) and / or (3b), R 2The aromatic group represented by may contain a support. That is, catalyst (III) may be a supported catalyst supported on a support via the aromatic group. In this case, the amount of reactant used can be further reduced, and a disulfide compound with higher purity can be produced easily.

[0050] The carrier is not particularly limited, and examples thereof include polymer carriers, silica carriers, and carbon carriers, with polymer carriers being preferred.

[0051] Specific examples of polymers that can be used as a carrier include, but are not limited to, aromatic vinyl polymers such as polystyrene, poly(α-methylstyrene), polyvinyltoluene, polyvinylbenzyl chloride, polyvinylbiphenyl, and polyvinylnaphthalene; polyolefins such as polyethylene and polypropylene; poly(halogenated polyolefins) such as polyvinyl chloride and polytetrafluoroethylene; nitrile polymers such as polyacrylonitrile; and (meth)acrylic polymers such as polymethyl methacrylate, polyglycidyl methacrylate, and polyethyl acrylate. Among these, aromatic vinyl polymers are preferred, and polystyrene is preferred, from the viewpoint of stability.

[0052] There are no particular limitations on the particle size, particle size distribution, pore volume, specific surface area, etc. of the carrier, and any carrier can be used as long as it does not impair the effects of the present invention.

[0053] In general formula (3a), two R 2 may be the same or different from each other.

[0054] In view of the above, specific examples of catalyst (III) include, but are not limited to, 4-toluenethiol, 4-hydroxybenzenethiol, 4-(t-butyl)benzenethiol, 4-aminothiophenol, 4,4'-ditolyl disulfide, 4,4'-dihydroxydiphenyl disulfide, 4,4'-di(t-butyldiphenyl disulfide), 4,4'-diaminodiphenyl disulfide (4,4'-dithiodianiline), and the like.

[0055] The catalyst (III) is different from both the disulfide compound (I) and the thiol compound (II).

[0056] The catalyst (III) can be used alone or in combination of two or more. In the method of the present invention, the aromatic disulfide compound (IIIa) can be converted into the aromatic thiol compound (IIIb), or the aromatic thiol compound (IIIb) can be converted into the aromatic disulfide compound (IIIa). The converted compound can function as a catalyst again.

[0057] The amount of catalyst (III) used is a catalytic amount, specifically, less than 0.30 mol per mol of thiol compound (II). When the amount of catalyst (III) used is 0.30 mol or more (e.g., 0.33 mol) per mol of thiol compound (II), the yield of the desired disulfide compound (I) significantly decreases. In contrast, according to the method of the present invention, even when the amount of catalyst used is small, the disulfide compound is easily obtained in high yield. Furthermore, from the viewpoint of yield, the amount of catalyst (III) used is preferably 0.001 mol to 0.2 mol, more preferably 0.01 mol to 0.1 mol, and even more preferably 0.02 mol to 0.05 mol per mol of thiol compound (II). When multiple catalysts are used as catalyst (III), the amount of catalyst (III) used means the total amount of each component used.

[0058] 4. Bases The base (IV) used in the present invention is not particularly limited, and a wide variety of known compounds exhibiting basicity can be used. Examples of the base (IV) include basic compounds containing at least one selected from the group consisting of alkali metals such as lithium, sodium, potassium, rubidium, and cesium, and alkaline earth metals such as calcium. Among these, from the viewpoint of producing a thiol salt, the base (IV) preferably contains a hydroxide or carbonate of an alkali metal, more preferably potassium hydroxide, sodium hydroxide, potassium carbonate, or sodium carbonate, and even more preferably potassium hydroxide, potassium carbonate, or sodium carbonate.

[0059] The base (IV) can be used alone or in combination of two or more kinds.

[0060] The amount of base (IV) used is not particularly limited, but from the viewpoint of yield, it is preferably 0.01 mol to 0.2 mol, more preferably 0.03 mol to 0.1 mol, and even more preferably 0.05 mol to 0.1 mol per mol of thiol compound (II). When multiple bases are used as base (IV), the amount of base (IV) used refers to the total amount of each component used. According to the method of the present invention, a disulfide compound can be easily obtained in high yield even when the amount of base used is small.

[0061] The ratio of the amount of catalyst (III) used to the amount of base (IV) used (amount of catalyst (III) used / amount of base (IV) used; molar ratio) is not particularly limited, but from the viewpoint of yield, it is preferably 0.1 to 10, more preferably 0.2 to 2, and even more preferably 0.5 to 1.

[0062] 5. Reaction The method for producing the disulfide compound (I) of the present invention comprises a step of reacting the thiol compound (II) in the presence of the catalyst (III) and the base (IV).

[0063] According to the method of the present invention, it is possible to produce a disulfide compound (I) having a structure corresponding to the structure of the thiol compound (II) used as a reaction raw material. Specifically, according to the method of the present invention, the disulfide compound (I) obtained as a result of the above reaction step has a disulfide bond, and the disulfide bond is derived from two thiol groups possessed by one or two thiol compounds (II). In other words, by appropriately selecting the type of thiol compound (II) used as a reaction raw material, it is possible to produce a variety of disulfide compounds.

[0064] According to the method of the present invention, prior to the reaction step, the thiol compound (II), the catalyst (III), and the base (IV) may be contacted with each other in any order, and the order of contact is not particularly limited.

[0065] The reaction step is preferably carried out in a solution, although not particularly limited thereto. The solvent used in the reaction step is not particularly limited as long as the substrate is soluble therein. For example, water or a wide variety of known organic solvents can be used. In particular, the reaction step is preferably carried out in a solution containing a polar solvent from the viewpoint of dissolving the components and facilitating recovery, reuse, and disposal. The reaction step is preferably carried out in a solution containing at least one solvent selected from the group consisting of water, alcohols (e.g., methanol, ethanol, propanol, butanol, etc.), and aprotic polar solvents (e.g., N,N-dimethylformamide (DMF), acetone, 1,3-dimethyl-2-imidazolidinone, tetrahydrofuran (THF), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), acetonitrile (MeCN), hexamethylphosphoric triamide (HMPA), etc.). Furthermore, when the reaction is carried out in a solution containing water or N,N-dimethylformamide (DMF), the desired reaction is likely to be promoted.

[0066] In the method of the present invention, in addition to the above components, additives used in known disulfide synthesis can be used as appropriate, provided that the effects of the present invention are not impaired.

[0067] The reaction step is preferably carried out in the absence of a catalyst other than the catalyst (III), although it is not particularly limited thereto. Specific examples of catalysts other than the catalyst (III) include peroxides such as hydrogen peroxide, metal oxides such as potassium permanganate, metal catalysts containing iron, cobalt, etc., radical polymerization initiators such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), iodine, etc. According to the method of the present invention, even when these compounds are not used, a disulfide compound can be produced simply and in high yield without requiring a large amount of reactants.

[0068] In the reaction step, the reaction concentration is not particularly limited as long as the reaction can proceed. From the viewpoint of yield, the reaction concentration is preferably 0.1% to 50%, more preferably 1% to 20%, and even more preferably 4% to 10%. In this specification, the reaction concentration refers to the ratio of the amount of thiol compound (I) used to the amount of solvent used (amount of thiol compound (I) used / amount of solvent used; mass ratio).

[0069] The reaction step is preferably carried out under air oxidation conditions, although not particularly limited thereto. That is, in the method of the present invention, it is preferable to use oxygen in the air as the oxidizing agent. However, the reaction is not limited to room temperature or atmospheric pressure, and may be carried out at low or high temperatures, or under reduced or increased pressure. In addition, the reaction does not need to proceed in air, and any oxidizing conditions, such as an oxygen atmosphere, can be used without particular limitation.

[0070] The reaction temperature in the reaction step is not particularly limited as long as the reaction can proceed. From the viewpoint of yield, the reaction temperature is preferably 0°C to 80°C, more preferably 10°C to 60°C, and even more preferably 20°C to 50°C.

[0071] The reaction time of the reaction step can be the time during which the reaction proceeds, and is not particularly limited. From the viewpoint of yield, the reaction time is preferably 1 hour to 100 hours, more preferably 2 hours to 24 hours, even more preferably 2 hours to 14 hours, and particularly preferably 2 hours to 6 hours.

[0072] The reaction product obtained after the above reaction step can be separated or purified by known methods such as extraction, distillation, and crystallization.

[0073] When the catalyst (III) is supported on a carrier (particularly a polymer carrier), it is advantageous in that the catalyst (III) can be easily separated and recovered after the reaction step. The recovered catalyst (III) can be reused as is in the present invention. The recovered catalyst (III) is preferably, if necessary, activated by subjecting it to an activation treatment, although this is not particularly limited.

[0074] The yield of the target product obtained after the above reaction can be preferably 90% or more, more preferably 95% or more, even more preferably 98% or more, and particularly preferably 99% or more. [Example]

[0075] EXAMPLES Hereinafter, examples and comparative examples will be shown to further clarify the features of the present invention, but the present invention is not limited to the following examples.

[0076] ( 1 H-NMR measurement) Each compound 1 H-NMR spectra were recorded using a JEOL JNM-ECZ400. Chemical shifts were measured using deuterated water as the solvent, with δ (ppm) relative to the signal of the external standard DSS-d6 (0.00 ppm), and using deuterated chloroform as the solvent, with δ (ppm) relative to the signal of the internal standard TMS (0.00 ppm). 1 H NMR spectra were recorded at 23°C.

[0077] Examples and Comparative Examples [Example 1] 1-Dodecyl mercaptan (202 mg, 1.0 mmol), 4-toluenethiol (3.7 mg, 3 mol%), and potassium carbonate (4.1 mg, 3 mol%) were added to N,N-dimethylformamide (DMF; 5 mL) under air, and the mixture was stirred at 60°C for 6 hours. Water (20 mL) was added to the reaction mixture, and the mixture was extracted with ethyl acetate (25 mL; twice). The organic layer was then washed with water (20 mL; twice) and saturated brine (20 mL). The organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was removed under reduced pressure to obtain a crude product. The crude product was analyzed by 1H-NMR using dimethyl sulfone as an internal standard, and the yield of the desired product was 95%.

[0078] [Example 2] Except for changing 4-toluenethiol to 4-hydroxybenzenethiol (3.8 mg, 3 mol%), the reaction was carried out under the same conditions as in Example 1. As a result, the yield was 94%.

[0079] [Example 3] Except for changing 4-toluenethiol to 4-(t-butyl)benzenethiol (5.0 mg, 3 mol%), the reaction was carried out under the same conditions as in Example 1. As a result, the yield was 97%.

[0080] [Example 4] The reaction was carried out under the same conditions as in Example 3, except that the reaction temperature was changed to 20° C. and the reaction time was changed to 14 hours. As a result, the yield was 99%.

[0081] [Comparative Example 1] Except for not adding 1-dodecyl mercaptan, the reaction was carried out under the same conditions as in Example 1. As a result, the yield was 57%.

[0082] Comparative Example 2 Except for changing the amount of 4-(t-butyl)benzenethiol added to 30 mol % (50 mg), the reaction was carried out under the same conditions as in Example 3. As a result, the yield was 75%.

[0083] Comparative Example 3 Except for changing the amount of 4-(t-butyl)benzenethiol added to 50 mol % (83 mg), the reaction was carried out under the same conditions as in Example 3. As a result, the yield was 64%.

[0084] The results of Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1.

[0085] [Table 1]

[0086] [Example 5] Under air, 3-mercapto-1-propanesulfonic acid (3-MPS) sodium (800 mg, 4.49 mmol), 4-hydroxybenzenethiol (17 mg, 3 mol%), and potassium carbonate (31 mg, 5 mol%) were added to water (8 mL) and reacted for 24 hours with stirring at 50°C. Dimethyl sulfone was added to the reaction solution as an internal standard, and analysis by 1H-NMR showed that the yield was 98%.

[0087] [Example 6] The reaction was carried out under the same conditions as in Example 5, except that potassium hydroxide (12.6 mg, 5 mol%) was used instead of potassium carbonate, and the resulting yield was 97%.

[0088] [Example 7] The reaction was carried out under the same conditions as in Example 6, except that the amount of potassium hydroxide used was changed to 25.2 mg (10 mol%). As a result, the yield was 94%.

[0089] [Example 8] The reaction was carried out under the same conditions as in Example 5, except that the reaction temperature was changed to 80° C. and the reaction time was changed to 14 hours. As a result, the yield was 95%.

[0090] [Example 9] The reaction was carried out under the same conditions as in Example 8, except that potassium carbonate was changed to sodium carbonate (23.7 mg, 5 mol%). As a result, the yield was 96%.

[0091] Comparative Example 4 The reaction was carried out under the same conditions as in Example 5, except that 4-hydroxybenzenethiol was not added, the base was changed to sodium carbonate (14.3 mg, 3 mol%), and the reaction time was changed to 72 hours. As a result, the yield was 27%.

[0092] Comparative Example 5 Except for not adding 4-hydroxybenzenethiol, the reaction was carried out under the same conditions as in Example 7. As a result, the yield was 49%.

[0093] The results of Examples 5 to 9 and Comparative Examples 4 and 5 are shown in Table 2.

[0094] [Table 2]

[0095] [Example 10] The reaction was carried out under the same conditions as in Example 5, except that 4-hydroxybenzenethiol was replaced with 4-aminothiophenol (17 mg, 3 mol%), the amount of potassium carbonate was changed to 18.6 mg (3 mol%), the reaction temperature was changed to 20°C, and the reaction time was changed to 72 hours. As a result, the yield was 98%.

[0096] [Example 11] The reaction was carried out under the same conditions as in Example 10, except that 4-aminothiophenol was changed to 4,4'-dithiodianiline (17 mg, 1.5 mol%), and the resulting yield was 99%.

[0097] [Example 12] The reaction was carried out under the same conditions as in Example 5, except that the amount of 3-MPS-soda was changed to 5 g (28 mmol), 4-hydroxybenzenethiol was changed to 4,4'-dithiodianiline (348 mg, 5 mol%), and the solvent was changed to a mixed solvent of water (10 mL) and methanol (16 mL). As a result, the yield was 99%.

[0098] [Example 13] The reaction was carried out under the same conditions as in Example 12, except that 4,4'-dithiodianiline was replaced with 4-aminothiophenol (140 mg, 5 mol%), the solvent was changed to a mixed solvent of water (10 mL) and tetrahydrofuran (THF; 18 mL), and the reaction time was changed to 72 hours. As a result, the yield was 94%.

[0099] [Example 14] The reaction was carried out under the same conditions as in Example 13, except that the amounts of 3-MPS-soda and 4-aminothiophenol used were doubled, potassium carbonate was changed to sodium hydroxide (112 mg, 5 mol%), the solvent was changed to N,N-dimethylformamide (19 mL), and the reaction time was changed to 22 hours. As a result, the yield was 99%.

[0100] The results of Examples 10 to 14 are shown in Table 3.

[0101] [Table 3]

[0102] [Example 15] 4-Nitrobenzenethiol (155 mg, 1.0 mmol), 4-aminothiophenol (3.7 mg, 3 mol%), and potassium carbonate (4.1 mg, 3 mol%) were added to DMF (5 ml) under air, and the mixture was allowed to react for 2 hours with stirring at 20°C. The reaction mixture was treated in the usual way, and the resulting crude product was added with dimethyl sulfone as an internal standard. Analysis by 1H-NMR showed that the yield was 91%.

[0103] Comparative Example 6 Except for not adding 4-aminothiophenol, the reaction was carried out under the same conditions as in Example 15. As a result, the yield was 68%.

[0104] The results of Example 15 and Comparative Example 6 are shown in Table 3.

[0105] [Table 4]

[0106] [Example 16] [ka]

[0107] 4-Mercaptophenol (1.26 g, 10 mmol), pyridine (0.81 ml), and triphenylmethyl chloride (trityl chloride TrCl) (2.8 g, 10 mmol) were added to dichloromethane (20 ml), and the mixture was allowed to react at room temperature for 18 hours with stirring. The reaction mixture was treated in the usual way, and the resulting crude product was purified by silica gel column chromatography to give 3.1 g of 4-(tritylthio)phenol (yield 85%).

[0108] Chloromethyl polystyrene (3.46 g: 0.8 mmol / g in terms of chlorine atoms), 4-(tritylthio)phenol (3 molar equivalents), and sodium hydride (3 molar equivalents) were added to DMF (30 ml) and reacted at 60°C for 24 hours. The reaction mixture was filtered and dried under reduced pressure to obtain a crude product. The crude product was suspended in dichloromethane (50 ml), and then trifluoroacetic acid (1 ml) and triethylsilane (2.8 ml) were added and reacted at room temperature for 2 hours. The suspension was filtered and washed to obtain 3.71 g of polystyrene-supported 4-oxybenzenethiol. Elemental analysis revealed that the sulfur atom content was 0.69 mmol / g.

[0109] 1-Dodecyl mercaptan (202 mg, 1.0 mmol), polystyrene-supported aromatic thiol (290 mg), and potassium carbonate (4.1 mg, 3 mol%) were added to DMF (5 mL) under air and reacted for 6 hours with stirring at 60 °C. After removing the catalyst, water (20 mL) was added to the reaction solution, and the reaction solution was extracted with ethyl acetate (25 mL, twice). The organic layer was then washed with water (20 mL, twice) and saturated brine (20 mL). The organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure to obtain a crude product. The reaction concentration was approximately 4% by mass (0.2 M). The polystyrene-supported aromatic thiol was used in an amount such that the amount of thiol groups contained in the catalyst was 0.20 moles per mole of 1-dodecyl mercaptan. Because the amount of thiol groups supported per mole of polystyrene is significantly greater than 1 mole, it will be clear to those skilled in the art that in Example 16, the amount of catalyst used was significantly less than 0.30 moles per mole of 1-dodecyl mercaptan. Dimethyl sulfone was added to the obtained crude product as an internal standard, and analysis by 1H-NMR revealed that the yield of the target product was 89%. The polystyrene-supported aromatic thiol can be recovered by a simple procedure of filtering the suspension after the reaction, washing with methanol, and then drying under reduced pressure. Almost the same amount of catalyst as used can be recovered, and the recovered catalyst can be reused.

[0110] [Example 17] Under air, 3-mercapto-1-propanesulfonic acid (3-MPS) sodium (800 mg, 4.49 mmol), the polystyrene-supported aromatic thiol (1.3 g) prepared in Example 16, and potassium carbonate (31 mg, 5 mol%) were added to water (8 mL) and reacted for 24 hours with stirring at 50°C. The reaction concentration was approximately 10% by mass (0.56 M). The polystyrene-supported aromatic thiol was used in an amount such that the amount of thiol groups contained in the catalyst was 0.20 moles per mole of 3-mercapto-1-propanesulfonic acid (3-MPS) sodium. Since the amount of thiol groups supported per mole of polystyrene was significantly greater than 1 mole, it will be clear to those skilled in the art that the amount of catalyst used in Example 17 was significantly less than 0.30 moles per mole of 3-mercapto-1-propanesulfonic acid (3-MPS) sodium. Dimethyl sulfone was added to the reaction mixture as an internal standard, and analysis by 1H-NMR revealed that the yield was 62%.

[0111] The results of Examples 16 and 17 are shown in Table 5.

[0112] [Table 5]

Claims

1. General formula (1): R １ -S-S-R １ (1) [In the formula, R １ represents an organic group. １ may form a ring together with the adjacent disulfide bond.] A method for producing a disulfide compound (I) represented by the following formula: General formula (2): R １ -(H) ｎ (2) [In the formula, R １ is the same as above. n represents 1 or 2. A thiol compound (II) represented by the following formula: In the presence of a catalyst (III) and a base (IV), reacting the The catalyst (III) is represented by the general formula (3a): R ２ -S-S-R ２ (3a) [In the formula, R ２ represents an aromatic group. and an aromatic disulfide compound (IIIa) represented by the general formula (3b): R ２ -SH (3b) [In the formula, R ２ is the same as above.] Aromatic thiol compound (IIIb) represented by the formula: At least one selected from the group consisting of The catalyst (III) is different from the disulfide compound (I) and the thiol compound (II), The method, wherein the amount of the catalyst (III) used is less than 0.30 moles per mole of the thiol compound (II).

2. The R ２ The method of claim 1 , wherein is an aromatic group having an electron donating group.

3. 3. The method of claim 1 or 2, wherein the base (IV) comprises an alkali metal hydroxide or carbonate.

4. The method according to claim 1 or 2, wherein the amount of the base (IV) used is 0.01 to 0.2 moles per mole of the thiol compound (II).

5. The method according to claim 1 or 2, wherein the reaction temperature is 0 to 80°C.

6. The method of claim 1 or 2, wherein the reaction is carried out in a solution comprising a polar solvent.

7. 3. The method of claim 1, wherein the reaction is carried out under air oxidation conditions.

8. 3. A catalyst for use in the method of claim 1 or 2, comprising: General formula (3a): R ２ -S-S-R ２ (3a) [In the formula, R ２ represents an aromatic group. and an aromatic disulfide compound (IIIa) represented by the general formula (3b): R ２ -SH (3b) [In the formula, R ２ is the same as above.] Aromatic thiol compound (IIIb) represented by the formula: At least one selected from the group consisting of The aromatic group comprises a polymeric carrier. catalyst.

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