JP2012148986A - Method of producing monosulfide group-containing benzoxazine compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing monosulfide group-containing benzoxazine compound.SOLUTION: A monosulfide group-containing benzoxazine compound represented by general formula [I] (R, Rare specific group) is produced by reacting a benzoxazine compound having disulfide bond represented by general formula [II] (Ris a specific group) and a compound having at least one epoxy group or vinyl group in one molecule in the presence of a reductant compound.

Description

  The present invention relates to a method for producing a monosulfide group-containing benzoxazine compound. More specifically, the present invention relates to a method for producing a monosulfide group-containing benzoxazine compound that is effectively used as a benzoxazine having a functional group.

  Patent Document 1 describes a benzoxazine resin composition containing a compound having a benzoxazine ring, an epoxy resin, an aromatic amine curing agent, and an ester of a protonic acid. It is described that it is used for a prepreg impregnated in a reinforcing fiber base, a fiber reinforced composite material obtained by curing the prepreg, and the like.

  An example of a compound having a benzoxazine ring in this benzoxazine resin composition is bis (3,4-dihydro-3-phenyl-2H-1,3-benzoxazine) monosulfide. The disulfide compound to be used is not conventionally known.

JP 2008-94961 A Japanese Patent Application No. 2010-1000080

Bull. Chem. Soc. JP. 41 2082-6 (1968)

で表わされるビス(4-ヒドロキシルフェニル)ジスルフィドを、ヘキサヒドロ-1,3,5-トリフェニル-1,3,5-トリアジンおよびホルムアルデヒドと反応させることにより、一般式

(R¹：ヘテロ原子を有してもよい、炭素数1〜18のアルキル基、アリール基または炭素数1〜18のアルキル基で置換されたアリール基)で表わされるジスルフィド結合を有するベンゾオキサジン化合物が得られることを提案している(特許文献２)。 The present applicant previously described a general formula as a benzoxazine compound having a disulfide bond that can be cleaved with heat or light to generate a radical.

Is reacted with hexahydro-1,3,5-triphenyl-1,3,5-triazine and formaldehyde to give a bis (4-hydroxylphenyl) disulfide represented by the general formula

A benzoxazine compound having a disulfide bond represented by (R ¹ : an alkyl group having 1 to 18 carbon atoms, an aryl group, or an aryl group substituted with an alkyl group having 1 to 18 carbon atoms, which may have a hetero atom) (Patent Document 2).

  Benzoxazine having a sulfide bond has a high polymerization property and can be cured even at a low temperature. However, such a benzoxazine is difficult to synthesize, and such a compound is synthesized from a benzoxazine having a thiol group. This is generally difficult with side reactions.

  An object of the present invention is to provide a method for producing a monosulfide group-containing benzoxazine compound that is effectively used as a benzoxazine having a polyfunctional group and is easily synthesized.

(ここで、R¹はヘテロ原子を有してもよい、炭素数1〜18のアルキル基、アリール基または炭素数1〜18のアルキル基で置換されたアリール基である)で表わされるジスルフィド結合を有するベンゾオキサジン化合物および一分子中に少なくとも1個のエポキシ基またはビニル基を有する化合物を還元剤化合物の存在下に反応させ、一般式

(ここで、Rはエポキシ基またはビニル基を有する化合物に由来する1価または2価以上の基であり、R¹は前記定義と同じであり、nは1または2以上の整数である)で表わされるモノスルフィド基含有ベンゾオキサジン化合物を製造する方法によって達成される。 The object of the present invention is to provide a general formula

(Wherein R ¹ is an alkyl group having 1 to 18 carbon atoms, an aryl group, or an aryl group substituted with an alkyl group having 1 to 18 carbon atoms, which may have a hetero atom). A benzoxazine compound having at least one compound having at least one epoxy group or vinyl group in one molecule in the presence of a reducing agent compound;

(Where R is a monovalent or divalent group derived from a compound having an epoxy group or a vinyl group, R ¹ is the same as defined above, and n is an integer of 1 or 2). This is achieved by the method for producing the represented monosulfide group-containing benzoxazine compound.

  The monosulfide group-containing benzoxazine compound obtained by the method of the present invention uses a novel compound, a benzoxazine compound [II] having a disulfide bond, as a raw material, and has at least one epoxy group or vinyl group in one molecule. Since the obtained compound is obtained simply by reacting in the presence of the reducing compound, the reaction is easy, and side reactions are rarely observed. The product monosulfide group-containing benzoxazine compound exhibits favorable characteristics such as heat resistance, low dielectric constant, and good dimensional stability, and is therefore preferably used as an aircraft resin material, an electronic material resin material, and the like.

1 is a ¹ H-NMR spectrum of a reaction product obtained in Example 1. It is a ¹³ C-NMR spectrum of the reaction product obtained in Example 1. ¹ is a ¹ H-NMR spectrum of a reaction product obtained in Example 2. It is a ¹³ C-NMR spectrum of the reaction product obtained in Example 2 ¹ is a ¹ H-NMR spectrum of a reaction product obtained in Example 3. It is a ¹³ C-NMR spectrum of the reaction product obtained in Example 3 ¹ is a ¹ H-NMR spectrum of a reaction product obtained in Example 4. It is a ¹³ C-NMR spectrum of the reaction product obtained in Example 4

で表わされるビス(4-ヒドロキシルフェニル)ジスルフィドを、ヘキサヒドロ-1,3,5-トリフェニル-1,3,5-トリアジンおよびホルムアルデヒドと反応させることによって製造される。 The benzoxazine compound [II] having a disulfide bond used as a raw material in the method of the present invention has the general formula

Is reacted with hexahydro-1,3,5-triphenyl-1,3,5-triazine and formaldehyde.

  Bis (4-hydroxylphenyl) disulfide, which is one of the starting materials for this reaction, is a known compound and is described, for example, in Non-Patent Document 1. Another starting material, hexahydro-1,3,5-triphenyl-1,3,5-triazine, is obtained by reacting aniline with paraformaldehyde that forms a methylene group. Formaldehyde is used together with each of these starting materials. As formaldehyde, paraformaldehyde is generally used for forming a methylene group of the oxazine ring.

  Each of these starting materials theoretically has 2 moles of hexahydro-1,3,5-triphenyl-1,3,5-triazine and 3 moles of formaldehyde per 3 moles of bis (4-hydroxylphenyl) disulfide. Is used in the reaction at a ratio of The reaction is carried out using a solvent such as toluene, tetrahydrofuran, 1,4-dioxane and the like and heating to the reflux temperature for about 1 to 6 hours. After completion of the reaction, the solvent used in the reaction is distilled off under reduced pressure, and the residue is washed with an aqueous sodium hydroxide solution and water for purification.

In the general formula [II], R ¹ may be an alkyl group having 1 to 18 carbon atoms or an alkyl-substituted aryl group having 1 to 18 carbon atoms in addition to the aryl group, and R ¹ is an alkyl group. In this case, the corresponding primary amine is used instead of hexahydro-1,3,5-triphenyl-1,3,5-triazine, and when R ¹ is an alkyl-substituted aryl group, alkyl instead of aniline is used. Hexahydro-1,3,5-tris (alkylphenyl) -1,3,5-triazine synthesized with substituted anilines is used as another starting material. These R ¹ groups may have a heteroatom such as O, S, or N. A preferred R ¹ group is a phenyl group.

  The benzoxazine compound having a disulfide bond represented by the general formula [II] is reacted with a compound having at least one epoxy group or vinyl group in one molecule in the presence of a reducing compound.

Specific examples of the compound having at least one epoxy group, preferably a glycidyl ether group in one molecule, as the monofunctional epoxy compound, phenyl glycidyl ether and the like, as the polyfunctional epoxy compound, for example, resorcinol, catechol, hydroquinone, Diglycidyl ether of polyhydric phenol compounds such as bisphenol, bisphenol A, bisphenol AP [1,1-bis (4-hydroxylphenyl) -1-phenylethane], bisphenol F, bisphenol K, bisphenol M, tetramethylbiphenol, fat family glycol or diglycidyl ethers of polyether glycols such as C ₂ -C ₂₄ alkylene glycols, poly (ethylene oxide) glycol or poly (propylene oxide) diglycidyl ether of glycol; phenol - ho Examples include lumaldehyde novolac, alkyl-substituted phenol-formaldehyde (epoxy novalac (novalac)), phenol-hydroxybenzaldehyde, cresol-hydroxybenzaldehyde, dicyclopentadiene-phenol or polyglycidyl ether of dicyclopentadiene-substituted phenol.

  Besides these, glycidylaminoglycidyl ether derived from aminophenol, aminoalkylphenol, etc., glycidylaminoglycidyl ester derived from aminobenzoic acid, aniline, toluidine, tribromoaniline, xylylenediamine, diaminocyclohexane, bisaminomethyl Examples thereof include glycidylamine compounds derived from cyclohexane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, epoxidized polyolefin, glycidylhydantoin, glycidylalkylhydantoin, triglycidylcyanurate, and the like.

  In particular, from the viewpoint of heat resistance of the produced benzoxazine, a glycidyl compound derived from phenol or aniline is preferably used.

  In addition, the compound having a vinyl group is preferably an acrylate ester, a methacrylate ester, or the like, and the ester group has an alkyl group having 1 to 8 carbon atoms or an alkoxyalkyl group having 2 to 8 carbon atoms. Is used.

  Other vinyl compounds include monofunctional acrylates and methacrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and phenoxyethyl (meth) acrylate; polyethylene glycol di (meth) acrylate, trimethylolethane Tri (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, hexane Diol (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) ether, tri (acryloyloxyethyl) isocyanurate Potential of acrylate or methacrylate are exemplified.

  The reaction between a benzoxazine compound having a disulfide bond and a compound having an epoxy group or a vinyl group stoichiometrically involves 0.5 mole of disulfide benzoxazine per mole of the compound having a monofunctional epoxy group or vinyl group. In addition, 1 mol for difunctional and 1.5 mol of disulfide benzoxazine for trifunctional, respectively, are crystals having a melting point of 79-81 ° C., and are performed in the presence of a reducing agent such as triphenylphosphine that is insoluble in water. However, the reaction is carried out in the presence of water as a proton source. A reducing agent such as triphenylphosphine is generally used in a proportion of equimolar amounts with respect to the benzoxazine compound having a disulfide bond. As a result of this reaction, the disulfide bond of the raw material compound [II] is reduced to thiol, and the generated thiol group reacts with the epoxy group or vinyl group to give the desired product [I]. Here, when a monofunctional compound having an epoxy group or a vinyl group is used, a product of n = 1 is given, and when a multifunctional compound is used, a product of n = 2 or more is given. give.

  The reaction is carried out by reacting in an aprotic polar solvent such as dimethylformamide, diethylformamide, dimethylacetamide, diethylacetamide, dimethylsulfoxide, N-methyl-2-pyrrolidone at about 40 to 120 ° C. for about 3 to 12 hours. Is called. After completion of the reaction, the target compound can be obtained by making the reaction mixture into an ethyl acetate solution, washing with a saturated aqueous sodium chloride solution and then recrystallizing or purifying with a column using silica.

  Next, the present invention will be described with reference to examples.

Reference example
(1) To about 10 ml of methanol solution of 20.2 g (160 mmol) of 4-mercaptophenol, 320 ml of water and 20.3 g (80 mmol) of iodine were added and stirred in a water bath for 3 hours. Crystals precipitated after completion of the reaction were collected by filtration. The resulting crude crystals were purified by recrystallization from toluene / hexane (weight ratio 3/4) to obtain 18.8 g (yield 94%) of bis (4-hydroxylphenyl) disulfide. The melting point of the product was 150 to 151 ° C., which substantially coincided with the melting point of 149 to 150 ° C. described in Non-Patent Document 1.

(2) A mixed solution of 1.86 g (20.0 mmol) of aniline, 0.60 g (20.0 mmol) of paraformaldehyde (CH ₂ O) _n and 15 ml of toluene was produced using Dean-Stark while heating at 110 ° C. for 2 hours. Water was distilled off. To the residue, 15 ml of toluene was added and recrystallized to obtain 1.68 g of hexahydro-1,3,5-triphenyl-1,3,5-triazine (yield 80%).

(3) bis (4-hydroxylphenyl) disulfide 0.75 g (3 mmol) obtained in (1) above, hexahydro-1,3,5-triphenyl-1,3,5 obtained in (2) above -Triazine 0.63 g (2 mmol) and paraformaldehyde (CH ₂ O) _n 0.18 g (6 mmol) were added in 6 ml of toluene and reacted at reflux temperature for 6 hours. After completion of the reaction, the mixture was washed with 5% by weight aqueous sodium hydroxide solution and saturated brine, and the residue was purified by recrystallization from ethyl acetate, and bis (3,4-dihydro-3-phenyl- 1.0 g (yield 68%) of 2H-1,3-benzoxazine) disulfide was obtained.

Example 1
0.44 g (1 mmol) of bis (3,4-dihydro-3-phenyl-2H-1,3-benzoxazine) disulfide obtained in Reference Example and 0.30 g (2 mmol) of phenol monoglycidyl ether were used as a reducing agent. In the presence of 0.262 g (1 mmol) of triphenylphosphine as a water and 0.50 g (28 mmol) of water as a proton source in 13 ml of a dimethylformamide solvent for 13 hours. After completion of the reaction, the reaction mixture was made into an ethyl acetate solution, washed with a saturated aqueous sodium chloride solution to separate the reaction product, recrystallized using ethyl acetate-methanol (weight ratio 1: 1), and a melting point of 104 0.34 g (43% yield) of white crystals of ˜105 ° C. was obtained.

_{-SCH 2 CH (OH) CH 2} OC 6 H ethyl which is a reaction product having a ₅ group 3- (3-phenyl-3,4-dihydro-2H-1,3-benzoxazin-6-ylthio) Puropaneto ¹ H-NMR spectrum and ¹³ C-NMR spectrum are shown in FIGS.

Example 2
In Example 1, 0.20 g (2 mmol) of ethyl acrylate was used instead of phenol monoglycidyl ether, and the reaction time was changed to 4 hours to carry out the reduction reaction. After completion of the reaction, the reaction mixture was made into an ethyl acetate solution, washed with a saturated aqueous sodium chloride solution to separate the reaction product, and 0.51 g (yield 75%) of a viscous yellow liquid was obtained.

1-phenoxy-3- (3-phenyl-3,4-dihydro-2H-1,3-benzoxazin-6-ylthio) propane-2, a reaction product having a -SCH ₂ CH ₂ COOC ₂ H ₅ group The ¹ H-NMR spectrum and ¹³ C-NMR spectrum of -ol are shown in FIGS.

Example 3
In Example 1, 0.34 g (1 mmol) of bisphenol A diglycidyl ether was used instead of phenol monoglycidyl ether, and the reaction time was changed to 6 hours to carry out the reduction reaction. After completion of the reaction, the reaction mixture is made into an ethyl acetate solution, washed with a saturated aqueous sodium chloride solution to separate the reaction products, and then separated by a silica gel column using n-hexane-ethyl acetate (weight ratio 1: 1) as an eluent. Isolation gave 0.65 g (80% yield) of a viscous yellowish liquid.

3,3 '-(4,4, which is a reaction product having a -SCH ₂ CH (OH) CH ₂ OC ₆ H ₄ C (CH ₃ ) ₂ C ₆ H ₄ OCH ₂ CH (OH) CH ₂ S- group '-(Propane-2,2-diyl) bis (4,1-phenylene) bis (oxy) bis (1- (3-phenyl-3,4-dihydro-2H-1,3-benzoxazin-6-ylthio) The ¹ H-NMR spectrum and ¹³ C-NMR spectrum of propan-2-ol) are shown in FIGS.

Example 4
In Example 1, 0.30 g (1 mmol) of dimethylol tricyclodecane diacrylate was used in place of phenol monoglycidyl ether, and the reaction time was changed to 4 hours to carry out the reduction reaction. After completion of the reaction, the reaction mixture is made into an ethyl acetate solution, washed with a saturated aqueous sodium chloride solution to separate the reaction product, and then separated by a silica gel column using n-hexane-ethyl acetate (weight ratio 3: 1) as an eluent. Isolation gave 0.47 g (59% yield) of a viscous yellow liquid.

-SCH ₂ CH ₂ COOCH ₂ C ₁₀ H ₁₄ CH ₂ OC (O) CH ₂ CH ₂ S-group-containing reaction product dimethylol tricyclodecandi (3- (3-phenyl3,4-dihydro-2H The ¹ H-NMR spectrum and ¹³ C-NMR spectrum of 1,3-benzoxazin-6-ylthio) propanate) are shown in FIGS.

Claims (6)

General formula

(Wherein R ¹ is an alkyl group having 1 to 18 carbon atoms, an aryl group, or an aryl group substituted with an alkyl group having 1 to 18 carbon atoms, which may have a hetero atom). A benzoxazine compound having a general formula and a compound having at least one epoxy group or vinyl group in one molecule are reacted in the presence of a reducing agent compound.

(Where R is a monovalent or divalent group derived from a compound having an epoxy group or a vinyl group, R ¹ is the same as defined above, and n is an integer of 1 or 2). The manufacturing method of the monosulfide group containing benzoxazine compound represented. The method for producing a monosulfide group-containing benzoxazine compound according to claim 1, wherein a disulfide bond-containing benzoxazine compound in which R ¹ is a phenyl group is used.   The method for producing a monosulfide group-containing benzoxazine compound according to claim 1, wherein the compound having at least one epoxy group in one molecule is a glycidyl ether compound.   The method for producing a monosulfide group-containing benzoxazine compound according to claim 3, wherein the glycidyl ether compound is phenol monoglycidyl ether or bisphenol-based compound diglycidyl ether.   The method for producing a monosulfide group-containing benzoxazine compound according to claim 1, wherein the compound having a vinyl group is an acrylic ester or a methacrylic ester.   The method for producing a monosulfide group-containing benzoxazine compound according to claim 1, wherein the reducing agent compound is triphenylphosphine.

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