Method for producing delta cyclen compound

Abstract

The purpose of the present invention is to provide a method for producing a delta cyclen compound that is excellent in mass productivity. A method for producing a delta cyclen compound according to the present invention is a method for producing a delta cyclen compound represented by formula (1). The method is characterized by including a step for reacting norbornadiene with an alkyne represented by formula (2) in the presence of a solvent, a catalyst, a reducing agent, and a co-catalyst, wherein the solvent comprises at least one solvent selected from the group consisting of an ether-based solvent, a ketone-based solvent, an ester-based solvent, an amide-based solvent, a nitrile-based solvent, and a hydrocarbon-based solvent excluding benzene. (In formulae (1) and (2), R1 and R2 each independently represent a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, or an alkylsilyl group.)

Description

Manufacturing method of deltacyclens

[0001] The present invention relates to a method for producing deltacyclenes.

[0002] Hydrogenated cyclic olefin ring-opening polymers obtained by hydrogenating cyclic olefin ring-opening polymers obtained by ring-opening polymerization of cyclic olefin monomers are widely used as molding materials for optical elements such as optical lenses because they have excellent transparency, low moisture absorption, heat resistance, insulating properties, chemical resistance, etc. In recent years, among cyclic olefin ring-opening polymers, development has focused on cyclic olefin ring-opening polymers obtained by ring-opening polymerization of norbornene compounds as cyclic olefin monomers.

[0003] Known examples of such norbornene compounds include 1,2,4-methenopentalene-1,2,3,3a,4,6a-hexahydro-(8CI,9CI,ACI) (common name: deltacyclene) and its derivatives (hereinafter collectively referred to as "deltacyclenes"). These compounds are typically produced by reacting norbornadiene with an alkyne in the presence of a solvent and a catalyst (Patent Document 1, Non-Patent Documents 1 to 3).

[0004] U.S. Pat. No. 4,1104,09

[0005] J. Am. Chem. Soc. 1990, 112, 5627-5628J. Am. Chem. Soc. 1995, 117, 6863-6879J. CHEM. SOC. , CHEM. COMMUN. , 19

[0006] However, in the above-mentioned conventional technology, solvents such as benzene and dichloromethane, which have a high environmental impact and are not very versatile, are used as solvents in the synthesis reaction of deltacyclenes, and are therefore not suitable for mass production of deltacyclenes.

[0007] Therefore, an object of the present invention is to provide a method for producing deltacyclenes that is suitable for mass production.

[0008] The present inventors conducted extensive research to solve the above problems and discovered that deltacyclens can be successfully produced by using a versatile solvent instead of benzene or dichloromethane, and that the use of a versatile solvent enables the mass production of deltacyclens, leading to the completion of the present invention.

[0009] That is, the present invention aims to advantageously solve the above-mentioned problems, and the present invention provides: [1] a method for producing deltacyclenes represented by the following formula (1), which includes a step of reacting norbornadiene with an alkyne represented by the following formula (2) in the presence of a solvent, a catalyst, a reducing agent, and a co-catalyst, wherein the solvent is at least one selected from the group consisting of ether-based solvents, ketone-based solvents, ester-based solvents, amide-based solvents, nitrile-based solvents, and hydrocarbon-based solvents excluding benzene. (In formulas (1) and (2), R １ and R ２ each independently represents a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, or an alkylsilyl group.) In this way, by producing deltacyclens using a specific, highly versatile solvent, the mass productivity of deltacyclens can be improved.

[0010] [2] In the manufacturing method of [1] above, the solvent is preferably at least one selected from the group consisting of toluene, acetone, N,N-dimethylformamide, 1,2-dimethoxyethane, acetonitrile, tetrahydrofuran, methyl ethyl ketone, and ethyl acetate. In this way, the use of the above-mentioned predetermined solvent with higher versatility can further improve the mass productivity of deltacyclenes.

[0011] [3] In the production method of [1] or [2] above, the catalyst preferably contains a cobalt catalyst. This allows for good production of deltacyclenes, further improving mass productivity of deltacyclenes.

[0012] [4] In the production method of the above [3], the cobalt catalyst is CoBr ２ (dppe). Thus, the cobalt catalyst preferably contains CoBr ２ If (dppe) is contained, deltacyclens can be produced satisfactorily, and the mass productivity of deltacyclens can be further improved.

[0013] [5] In any of the production methods [1] to [4] above, the co-catalyst preferably contains zinc or zinc iodide. When the co-catalyst contains zinc or zinc iodide, deltacyclens can be produced satisfactorily, further improving the mass productivity of deltacyclens.

[0014] [6] In any of the production methods [1] to [5] above, the reducing agent preferably contains tetrabutylammonium borohydride. When the reducing agent contains tetrabutylammonium borohydride, deltacyclens can be produced satisfactorily, further improving the mass productivity of deltacyclens.

[0015] According to the present invention, it is possible to provide a method for producing deltacyclenes that is excellent in mass productivity.

[0016] Hereinafter, embodiments of the present invention will be described in detail.

[0017] (Method for Producing Deltacyclenes) The method for producing deltacyclenes of the present invention (hereinafter simply referred to as the "production method") is a method for producing deltacyclenes represented by the following formula (1), and includes a step of reacting norbornadiene with an alkyne represented by the following formula (2) in the presence of a solvent, a catalyst, a reducing agent, and a co-catalyst, and may optionally include other steps. The production method of the present invention is characterized in that the solvent is at least one selected from the group consisting of ether solvents, ketone solvents, ester solvents, amide solvents, nitrile solvents, and hydrocarbon solvents excluding benzene. The production method of the present invention enables mass production of deltacyclenes. (In formulas (1) and (2), R １ and R２ each independently represents a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, or an alkylsilyl group.

[0018] Here, the above R １ and R ２ The "alkyl group" that can constitute the above group is not particularly limited, and examples thereof include alkyl groups having 1 to 10 carbon atoms. The "alkyl group having 1 to 10 carbon atoms" may be either linear or branched, and examples thereof include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a neopentyl group, a hexyl group, an octyl group, a nonyl group, and a decyl group. Of these, a butyl group is preferred.

[0019] The above R １ and R ２ The "aromatic hydrocarbon ring group" that can constitute the above formula (I) is not particularly limited, and examples thereof include aromatic hydrocarbon ring groups having 6 to 30 carbon atoms. Specific examples of aromatic hydrocarbon ring groups having 6 to 30 carbon atoms include a phenyl group, a naphthyl group, and an anthracenyl group. Of these, a phenyl group is preferred.

[0020] The above R １ and R ２ The "alkylsilyl group" that can constitute the above group is not particularly limited and may be any of a monoalkylsilyl group, a dialkylsilyl group, and a trialkylsilyl group. Furthermore, the "alkyl group" that can constitute the alkylsilyl group is not particularly limited and examples thereof include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, and a neopentyl group. Specific examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a tritert-butylsilyl group, a methyldiethylsilyl group, a dimethylsilyl group, a diethylsilyl group, a methylsilyl group, and an ethylsilyl group, with a trimethylsilyl group being preferred.

[0021] <Reaction Step> In the reaction step, norbornadiene and an alkyne represented by the above formula (2) as starting materials are reacted in the presence of a solvent and a catalyst to obtain deltacyclenes represented by the above formula (1). Specifically, deltacyclenes represented by the above formula (1) are synthesized by cycloaddition of the alkyne represented by the above formula (2) to norbornadiene. The reaction temperature is not particularly limited and can be, for example, from 10°C to 100°C, preferably in the range of 20°C to 70°C. The reaction time is also not particularly limited and may be continued until the deltacyclenes represented by the above formula (1) are produced, but is typically from 1 hour to 48 hours. The amounts of norbornadiene and alkyne represented by the above formula (2) used are not particularly limited, but it is preferable to use 1 mole to 2 moles of the alkyne represented by the above formula (2) per mole of norbornadiene.

[0022] Here, the alkyne represented by the above formula (2) may be appropriately selected depending on the type of desired deltacyclene. １ and R ２ Alkynes (acetylenes) where both R and R are hydrogen atoms; １ and R ２ an alkyne (phenylacetylene) in which one of R is a phenyl group and the other is a hydrogen atom; １ and R ２ an alkyne (butylacetylene) in which one of R is a butyl group and the other is a hydrogen atom; １ and R ２ An alkyne in which one of R is a trimethylsilyl group and the other is a hydrogen atom (trimethylsilylacetylene) is preferred, and acetylene is more preferred. １ and R ２ is the R of the alkyne represented by formula (2) which is the raw material. １ and R ２ For example, when acetylene is used as the alkyne represented by the above formula (2), it reacts with norbornadiene to give deltacyclene represented by the following formula (3) (in formula (1), R １ and R ２and a compound in which both are hydrogen atoms are obtained.

[0023] <<Solvent>> In the production method of the present invention, the solvent used may be an ether solvent, a ketone solvent, an ester solvent, an amide solvent, a nitrile solvent, or a hydrocarbon solvent other than benzene. These solvents may be used alone or in combination. The use of these solvents enables the mass production of deltacyclenes.

[0024] [Ether Solvent] The ether solvent is not particularly limited, and examples thereof include tetrahydrofuran, 1,2-dimethoxyethane, diethyl ether, cyclopentyl methyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, etc. Among these, tetrahydrofuran and diethyl ether are preferred.

[0025] [Ketone Solvent] The ketone solvent is not particularly limited, and examples thereof include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. Among these, acetone is preferred.

[0026] [Ester Solvent] The ester solvent is not particularly limited, and examples thereof include methyl acetate, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, etc. Among these, ethyl acetate is preferred.

[0027] [Amide Solvent] The amide solvent is not particularly limited, and examples thereof include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc. Among these, N,N-dimethylformamide is preferred.

[0028] [Nitrile Solvent] The nitrile solvent is not particularly limited, and examples thereof include acetonitrile, propionitrile, etc. Among these, acetonitrile is preferred.

[0029] [Hydrocarbon Solvent] The hydrocarbon solvent is not particularly limited as long as it is other than benzene, and examples thereof include toluene, xylene, naphthalene, etc. Among these, toluene is more preferred.

[0030] From the viewpoint of further improving the mass productivity of deltacyclens, the solvent is preferably at least one selected from the group consisting of toluene, ether-based solvents, ketone-based solvents, ester-based solvents, amide-based solvents, and nitrile-based solvents, and more preferably at least one selected from the group consisting of toluene, acetone, N,N-dimethylformamide, 1,2-dimethoxyethane, acetonitrile, tetrahydrofuran, methyl ethyl ketone, and ethyl acetate.

[0031] The amount of the solvent used is not particularly limited, but is preferably 6 to 7 times by mass relative to norbornadiene.

[0032] <<Catalyst>> The catalyst used in the production method of the present invention is not particularly limited, and examples thereof include metal catalysts such as cobalt catalysts, iron catalysts, and nickel catalysts. These may be used alone or in combination of two or more. Among these, from the viewpoint of further improving the mass productivity of deltacyclenes, the catalyst preferably contains a cobalt catalyst, and more preferably is a cobalt catalyst.

[0033] [Cobalt Catalyst] The cobalt catalyst is not particularly limited, and is preferably a complex in which a ligand is coordinated to a cobalt compound as a main catalyst. The main catalyst is not particularly limited, and is preferably Co(acac) ３ (Cobalt (III) acetylacetonate), CoI ２ (Cobalt(II) iodide), CoBr ２ (Cobalt(II) bromide), CoCl ２ (cobalt (II) chloride). Among them, cobalt bromide is preferred. The ligand is not particularly limited, and P(CH ３ ) ３ (trimethylphosphine), P(C ２ H ５ ) ３ (triethylphosphine), PPh ３ (triphenylphosphine), P(OMe) ３ (trimethoxyphosphine)), P(OEt) ３ (triethoxyphosphine), P(OPh) ３(triphenyl phosphite), and dppe (1,2-bis(diphenylphosphino)ethane). Of these, dppe is preferred.

[0034] In order to further improve the mass productivity of deltacyclenes, the cobalt catalyst is Co(acac) ３ , CoI ２ (PPh ３ ), CoI2(PPh ３ ) ２ , or CoBr ２ (dppe), and CoBr ２ It is more preferable that the group is (dppe).

[0035] [Iron Catalyst] The iron catalyst is not particularly limited, and is preferably a complex in which a ligand is coordinated to an iron compound as a main catalyst. ２ (iron(II) iodide), FeBr ２ (iron(II) bromide), FeCl ２ (iron (II) chloride). Among them, FeBr ２ (iron(II) bromide) is preferred. The ligand is not particularly limited, and examples thereof include those mentioned above in the section on "cobalt catalyst."

[0036] From the viewpoint of further improving the mass productivity of deltacyclenes, the iron catalyst is Fe(acac) ３ , FeI ２ (PPh ３ ), FeI ２ (PPh ３ ) ２ , or FeBr ２ (dppe), and FeBr ２ It is more preferable that the group is (dppe).

[0037] [Nickel Catalyst] The nickel catalyst is not particularly limited, and is preferably a complex in which a ligand is coordinated to a nickel compound as a main catalyst. ２ (nickel(II) iodide), NiBr ２ (nickel(II) bromide), NiCl ２(nickel (II) chloride). Among them, NiBr ２ (nickel(II) bromide) is preferred. The ligand is not particularly limited, and examples thereof include those mentioned above in the section on "cobalt catalyst."

[0038] From the viewpoint of further improving the mass productivity of deltacyclenes, the nickel catalyst is Ni(acac) ３ , NiI ２ (PPh ３ ), NiI ２ (PPh ３ ) ２ , or NiBr ２ (dppe), and NiBr ２ It is more preferable that the group is (dppe).

[0039] The amount of catalyst used in the production method of the present invention is not particularly limited as long as the desired deltacyclenes can be obtained, and can be 1 mol % or more and 3 mol % or less based on norbornadiene.

[0040] <<Promoter>> The promoter used in the production method of the present invention is not particularly limited and includes zinc, zinc iodide, zinc bromide, zinc chloride, etc. These may be used alone or in combination of two or more. Among these, from the viewpoint of further improving the mass productivity of deltacyclenes, the promoter preferably contains zinc or zinc iodide, more preferably zinc or zinc iodide, and even more preferably zinc iodide. The amount of the promoter is not particularly limited and can be 3 mol % or more and 9 mol % or less relative to norbornadiene.

[0041] <<Reducing Agent>> The reducing agent used in the production method of the present invention is not particularly limited, and may be Et ２ AlCl (diethylaluminum chloride), NaBH ４ (sodium borohydride), NaBH ３ CN (sodium cyanoborohydride), NaBH(OAc) ３ (sodium triacetoxyborohydride), LiBH ４ (lithium borohydride), LiAlH ４(lithium aluminum hydride), HCHO (formaldehyde), NaH (sodium hydride), TBABH ４ (tetrabutylammonium borohydride). These may be used alone or in combination of two or more. From the viewpoint of further improving the mass productivity of deltacyclenes, the reducing agent preferably contains tetrabutylammonium borohydride, and the reducing agent is more preferably tetrabutylammonium borohydride. The amount of the reducing agent is not particularly limited, and can be 1 mol % or more and 3 mol or less relative to norbornadiene.

[0042] <Other Steps> Other steps that may be included in the production method of the present invention include, but are not limited to, a purification step. The purification step is not particularly limited to, and examples thereof include a method of purifying the reaction solution obtained in the reaction step using a conventional purification method. For example, purification can be performed by adding an adsorbent such as silica gel to the reaction solution obtained in the reaction step, followed by stirring, and distilling the filtrate under reduced pressure.

[0043] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples. In the following description, "%" and "parts" representing amounts are based on mass unless otherwise specified. Furthermore, in a polymer produced by copolymerizing multiple types of monomers, the proportion of a structural unit formed by polymerizing a certain monomer in the polymer usually coincides with the ratio (feed ratio) of the certain monomer to all monomers used in the polymerization of the polymer, unless otherwise specified.

[0044] <Mass Producibility> The mass producibility of deltacyclens was evaluated according to the following criteria. Good: Can be produced using common solvents such as tetrahydrofuran and acetone. Poor: Carcinogenic substances such as dichloromethane and benzene, specific hazardous substances, and substances with low boiling and flash points are difficult to handle in large-scale production. <Reaction Conversion Rate> The reaction conversion rate was measured using GC (Agilent 6850) for samples prepared by dissolving the deltacyclens obtained in the Examples and Comparative Examples in solvent. Specifically, the solvent was removed from the obtained GC chart, and the area percentage of deltacyclen relative to the total area percentage was determined and used as the reaction conversion rate.

[0045] Example 1 A reactor whose interior had been replaced with nitrogen was charged with 25 ml of toluene as a solvent, 5 g of norbornadiene, and a cobalt catalyst [CoBr ２ 0.37 g of (dppe) and 0.62 g of zinc iodide as a cocatalyst were added, and the entire mixture was stirred at 25°C. Acetylene gas was blown into the resulting solution, and 0.21 g of tetrabutylammonium borohydride as a reducing agent was gradually added while stirring the entire mixture. Stirring was continued for 1 hour while blowing in acetylene gas. Gas chromatography revealed that the reaction conversion was 10.9%.

[0046] Examples 2 to 8, Comparative Examples 1 and 2 Deltacyclen was obtained in the same manner as in Example 1, except that the solvent used in Example 1 was changed as shown in Table 1. In Table 1, DMF represents N,N-dimethylformamide, DME represents 1,2-dimethoxyethane, THF represents tetrahydrofuran, MEK represents methyl ethyl ketone, TBABH ４ represents tetrabutylammonium borohydride.

[0047] As shown in Table 1, it can be seen that deltacyclene can be mass-produced according to the manufacturing methods of Examples 1 to 8 using the specified solvents.

[0048] According to the present invention, it is possible to provide a method for producing deltacyclenes that is excellent in mass productivity.

Claims

1. A method for producing deltacyclenes represented by the following formula (1), comprising a step of reacting norbornadiene with an alkyne represented by the following formula (2) in the presence of a solvent, a catalyst, a reducing agent, and a co-catalyst, wherein the solvent is at least one selected from the group consisting of ether solvents, ketone solvents, ester solvents, amide solvents, nitrile solvents, and hydrocarbon solvents excluding benzene. (In formulas (1) and (2), R １ and R ２ each independently represents a hydrogen atom, an alkyl group, an aromatic hydrocarbon ring group, or an alkylsilyl group.

2. The method of claim 1, wherein the solvent is at least one selected from the group consisting of toluene, acetone, N,N-dimethylformamide, 1,2-dimethoxyethane, acetonitrile, tetrahydrofuran, methyl ethyl ketone, and ethyl acetate.

3. The process of claim 1, wherein the catalyst comprises a cobalt catalyst.

4. The cobalt catalyst is CoBr ２ The method of claim 3, further comprising:

5. The process of claim 1, wherein the promoter comprises zinc or zinc iodide.

6. The method of any one of claims 1 to 5, wherein the reducing agent comprises tetrabutylammonium borohydride.

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