Method for producing benzoxazine compounds

Abstract

The present invention addresses the problem of providing a method for producing a benzoxazine compound having a hydroxy group or a thiol group with high purity and high efficiency. As a solution, a method for producing a benzoxazine compound represented by general formula (3) is provided, the method being characterized by performing a reaction of a bisphenol compound represented by general formula (1), a formaldehyde component, and an amine compound represented by general formula (2) with one another at a temperature falling within a specified temperature range.　(2): H2N-R4-Y

Description

[Technical Field]

[0001] The present invention relates to a method for producing a benzoxazine compound, specifically to a method for producing a benzoxazine compound having benzoxazine rings at both ends of a bonding group and further having a hydroxy group or a thiol group. [Background technology]

[0002] Benzoxazine compounds are compounds synthesized by reacting phenols, amines, and formaldehyde, and are known as thermosetting resin raw materials that cure by ring-opening polymerization of the benzoxazine ring upon heating without producing volatile by-products, and are used as raw materials for molded articles that can be used as materials for insulating substrates, liquid crystal alignment agents, semiconductor encapsulation resin compositions, etc. For such applications, heat resistance with excellent stability and reliability at high temperatures is required. On the other hand, the curing temperature of benzoxazine compounds is usually relatively high, and in order to lower the polymerization temperature, catalysts, polymerization accelerators, and highly reactive benzoxazine compounds have been developed in recent years. Among these highly reactive benzoxazine compounds, a benzoxazine composition containing a hydroxy group or a nitrogen-containing heterocycle has been reported, which can be cured at a relatively low temperature in a short time by an environmentally friendly method (Patent Document 1). Known methods for synthesizing hydroxyl group-containing benzoxazine compounds include, for example, a method in which the raw materials bisphenol A, an alcoholamine monomer, and paraformaldehyde are mixed together with a solvent and reacted together (Patent Document 2), and a method in which a mixed solution of paraformaldehyde and ethanolamine is first prepared, and then a solution of bisphenol A is added and reacted (Non-Patent Document 1). Furthermore, these methods are performed at high temperatures of 90°C or higher, and it has been reported that the product yield is relatively high. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2011-530570 [Patent Document 2] Chinese Patent Application Publication No. 107573496 [Non-patent literature]

[0004] [Non-Patent Document 1] E. Gilbert. et. al. J. Polym. Res. 2018, Vol.25, p.114. Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors attempted to synthesize the benzoxazine compound having a hydroxy group or a thiol group according to the present invention by referring to the above-mentioned conventionally known production methods. However, as shown in the comparative examples described below, problems occurred, such as the reaction solution solidifying during the reaction, making it impossible to complete the reaction, a decrease in reaction selectivity, and solidification of the solution containing the target compound during the operation of removing the target compound, making it impossible to produce such a benzoxazine compound, or to produce it efficiently. An object of the present invention is to provide a method for efficiently producing a target benzoxazine compound having a hydroxy group or a thiol group with high purity. [Means for solving the problem]

[0006] As a result of intensive research to solve the above-mentioned problems, the present inventors have found that, contrary to the description in the above-mentioned prior art documents, the target benzoxazine compound can be synthesized with high selectivity by reacting a bisphenol compound, formaldehydes, and amines in a lower temperature range, and have thus completed the present invention.

[0007] The present invention is as follows. 1. A method for producing a benzoxazine compound represented by general formula (3), which comprises reacting a bisphenol compound represented by general formula (1), a formaldehyde, and an amine compound represented by general formula (2) at a temperature ranging from 10°C to 80°C. [ka] (In the formula, R1 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and X represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a divalent group represented by general formula (1a) or (1b).) [ka] (In general formulas (1a) and (1b), R2 and R3 each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms; R2 and R3 may be bonded to each other to form a cycloalkylidene group having 5 to 20 carbon atoms as a whole; Ar1 ​​and Ar2 each independently represent an aryl group having 6 to 12 carbon atoms; and * indicates the bonding position.) [ka] (In the formula, R4 represents a divalent group having 1 to 10 carbon atoms, and Y represents a hydroxy group or a thiol group.) [ka] (In the formula, R1 and X are defined as in general formula (1), and R4 and Y are defined as in general formula (2).) [Effects of the Invention]

[0008] According to the method for producing a benzoxazine compound of the present invention, a benzoxazine compound having a hydroxy group or a thiol group can be produced with high selectivity. The benzoxazine compound thus obtained contains a large amount of the benzoxazine compound as an active ingredient, and is therefore very useful as a raw material for curable resins. Furthermore, the method for producing a benzoxazine compound of the present invention is very useful because it can suppress an increase in viscosity or solidification of a solution containing the target compound after completion of the reaction, thereby enabling efficient production of a benzoxazine compound. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Method of producing the benzoxazine compound of the present invention> The method for producing a benzoxazine compound of the present invention is characterized by reacting a bisphenol compound represented by general formula (1), a formaldehyde, and an amine compound represented by general formula (2) within a specific temperature range, and is a production method for producing a benzoxazine compound represented by general formula (3) as a target compound. [ka] (In the formula, R1 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and X represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a divalent group represented by general formula (1a) or (1b).) [ka] (In general formulas (1a) and (1b), R2 and R3 each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms; R2 and R3 may be bonded to each other to form a cycloalkylidene group having 5 to 20 carbon atoms as a whole; Ar1 ​​and Ar2 each independently represent an aryl group having 6 to 12 carbon atoms; and * indicates the bonding position.) [ka] (In the formula, R4 represents a divalent group having 1 to 10 carbon atoms, and Y represents a hydroxy group or a thiol group.) [ka] (In the formula, R1 and X are defined as in general formula (1), and R4 and Y are defined as in general formula (2).)

[0010] R1 in general formulas (1) and (3) is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 carbon atom (methyl group), and particularly preferably a hydrogen atom. When R1 is not a hydrogen atom, the bonding position is preferably the ortho position of the hydroxy group in general formula (1) or the ortho position on the benzene ring relative to the oxygen atom of the benzoxazine ring in general formula (3). When X in general formulas (1) and (3) is general formula (1a), more preferred R2 and R3 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a halogenated alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, still more preferred are hydrogen, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or an aryl group having 6 to 8 carbon atoms, and particularly preferred are hydrogen, an alkyl group having 1 to 4 carbon atoms, or a phenyl group. R2 and R3 may be bonded to each other to form a cycloalkylidene group having 5 to 20 carbon atoms as a whole. The cycloalkylidene group having 5 to 20 carbon atoms may contain an alkyl group as a branched chain. The cycloalkylidene group preferably has 5 to 15 carbon atoms, more preferably 6 to 12 carbon atoms, and particularly preferably 6 to 9 carbon atoms. Specific examples of the cycloalkylidene group include a cyclopentylidene group (5 carbon atoms), a cyclohexylidene group (6 carbon atoms), a 3-methylcyclohexylidene group (7 carbon atoms), a 4-methylcyclohexylidene group (7 carbon atoms), a 3,3,5-trimethylcyclohexylidene group (9 carbon atoms), a cycloheptylidene group (7 carbon atoms), a bicyclo[2.2.1]heptane-2,2-diyl group (7 carbon atoms), a 1,7,7-trimethylbicyclo[2.2.1]heptane-2,2-diyl group (10 carbon atoms), a 4,7,7-trimethylbicyclo[2.2.1]heptane-2,2-diyl group (10 carbon atoms), a tricyclo[5.2.1.0 2,6]decane-8,8-diyl group (10 carbon atoms), 2,2-adamantylidene group (10 carbon atoms), cyclododecanylidene group (12 carbon atoms), etc. Preferred are cyclohexylidene group (6 carbon atoms), 3-methylcyclohexylidene group (7 carbon atoms), 4-methylcyclohexylidene group (7 carbon atoms), 3,3,5-trimethylcyclohexylidene group (9 carbon atoms), and cyclododecanylidene group (12 carbon atoms), more preferred are cyclohexylidene group (6 carbon atoms), 3,3,5-trimethylcyclohexylidene group (9 carbon atoms), and cyclododecanylidene group (12 carbon atoms), and particularly preferred are cyclohexylidene group (6 carbon atoms) and 3,3,5-trimethylcyclohexylidene group (9 carbon atoms). When X in general formulas (1) and (3) is general formula (1b), Ar1 and Ar2 are preferably each independently a benzene ring or a naphthalene ring, and more preferably both Ar1 and Ar2 are benzene rings. For example, when both Ar1 and Ar2 are benzene rings, the group represented by general formula (1b) is a fluorenylidene group. The bonding position of X in general formula (3) to the two benzoxazine rings is preferably the ortho or para position on the benzene ring relative to the oxygen atom of the benzoxazine ring, and similarly, the bonding position of X on the benzene ring in general formula (1), which is the raw material, is preferably the ortho or para position relative to the hydroxy group.

[0011] R4 in general formulas (2) and (3) is a divalent group having 1 to 10 carbon atoms. Specific examples include linear or branched alkylene groups or alkylene groups containing a cyclic alkane having 1 to 10 carbon atoms, such as methylene, ethylene, propane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, cyclohexane-1,3-diyl, and cyclohexane-1,4-diyl; alkylidene groups having 1 to 10 carbon atoms, such as ethylidene, propylidene, isopropylidene, butylidene, cyclopentylidene, and cyclohexylidene; phenylene; and divalent groups having 1 to 10 carbon atoms containing a benzene ring, such as groups represented by the following formulas: [ka] (In the formula, * indicates the bonding position.) Among these, R4 is preferably a linear or branched alkylene group having 1 to 10 carbon atoms, an alkylene group containing a cyclic alkane, or an alkylidene group having 1 to 10 carbon atoms, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms or an alkylene group containing a cyclic alkane, still more preferably a linear or branched alkylene group having 1 to 6 carbon atoms or an alkylene group containing a cyclic alkane, and particularly preferably a linear or branched alkylene group having 1 to 4 carbon atoms.

[0012] Specific examples of the benzoxazine compound represented by general formula (3), which is the target compound of the production method of the present invention, include compounds (p-1) to (p-6) having the following chemical structures. [ka] JPEG0007789998000011.jpg23168

[0013] <Starting material: bisphenol compound represented by general formula (1)> Specific examples of the bisphenol compound represented by general formula (1), which is one of the starting materials in the method for producing a benzoxazine compound of the present invention, include bisphenol F (bis(2-hydroxyphenyl)methane, 2-hydroxyphenyl-4-hydroxyphenylmethane, bis(4-hydroxyphenyl)methane), bisphenol E (1,1-bis(4-hydroxyphenyl)ethane), bisphenol A (2,2-bis(4-hydroxyphenyl)propane), bisphenol C (2,2-bis(4-hydroxy-3-methylphenyl)propane), 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxy-3,3'-dimethylbiphenyl, bis(4-hydroxyphenyl)ether, 4,4'-dihydroxybenzophenone, Bisphenols that may be used include bisphenol A (1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene), bisphenol B (1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane), bisphenol TMC (1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane), bisphenol B (1,1-bis(4-hydroxyphenyl)cyclododecane), bisphenol B (1,1-bis(4-hydroxyphenyl)adamantane), and bisphenol B (1,1-bis(4-hydroxyphenyl)cyclododecane).

[0014] <Starting material: formaldehyde> Specific examples of formaldehydes, which are one of the starting materials in the novel method for producing a benzoxazine compound of the present invention, include an aqueous formaldehyde solution, 1,3,5-trioxane, and paraformaldehyde.

[0015] <Starting material: amine compound represented by general formula (2)> Specific examples of the amine compound represented by general formula (2), which is one of the starting materials in the method for producing a benzoxazine compound of the present invention, include the following compounds. Specific examples of compounds in which "Y" in general formula (2) is a hydroxy group include methanolamine, 2-aminoethanol, 1-amino-2-propanol, 2-amino-1-methylethanol, 2-amino-2-methylethanol, 3-amino-1-propanol, 4-amino-1-butanol, 2-amino-1-butanol, 4-amino-2-butanol, 5-amino-1-pentanol, 6-amino-1-hexanol, 7-amino-1-heptanol, valinol, 2-aminophenol, 3-aminophenol, 4-aminophenol, and 4-aminobenzyl alcohol. Among these, 2-aminoethanol, 2-amino-1-methylethanol, 2-amino-2-methylethanol, 3-amino-1-propanol, 2-aminophenol, 3-aminophenol, and 4-aminophenol are preferred, 2-aminoethanol, 2-aminophenol, 3-aminophenol, and 4-aminophenol are more preferred, and 2-aminoethanol is particularly preferred. Specific examples of "Y" in general formula (2) being a thiol group include 2-aminoethanethiol, 3-amino-1-propanethiol, 2-amino-1-methylethanethiol, 2-amino-2-methylethanethiol, 5-amino-1-pentanethiol, 6-amino-1-hexanethiol, 2-aminothiophenol, 3-aminothiophenol, 4-aminothiophenol, 4-aminobenzyl mercaptan, etc. Among these, 2-aminoethanethiol, 3-amino-1-propanethiol, 2-aminothiophenol, 3-aminothiophenol, and 4-aminothiophenol are preferred, 2-aminoethanethiol, 2-aminothiophenol, 3-aminothiophenol, and 4-aminothiophenol are more preferred, and 2-aminoethanethiol is particularly preferred.

[0016] <Amount of starting materials used> In the production method of the present invention, the amount of formaldehyde used is preferably in the range of 4.0 to 20.0 mol, more preferably in the range of 4.0 to 16.0 mol, and even more preferably in the range of 4.0 to 12.0 mol, per mol of the bisphenol compound represented by general formula (1). In the production method of the present invention, the amount of the amine compound represented by general formula (2) used is preferably in the range of 2.0 to 10.0 mol, more preferably in the range of 2.0 to 8.0 mol, and even more preferably in the range of 2.0 to 6.0 mol, per 1 mol of the bisphenol compound represented by general formula (1).

[0017] <Catalyst> In the production method of the present invention, no catalyst is particularly required to promote the reaction, but an acid catalyst or a base catalyst can be used as necessary. In this case, usable acid catalysts include concentrated hydrochloric acid, hydrochloric acid gas, trifluoroacetic acid, methanesulfonic acid, p-toluenesulfonic acid, benzoic acid, and mixtures thereof, and usable base catalysts include, but are not limited to, sodium hydroxide, sodium carbonate, triethylamine, triethanolamine, and mixtures thereof. <Solvent> In the production method of the present invention, the reaction is usually carried out in the presence of a solvent. The solvent is not particularly limited as long as it does not inhibit the reaction, but preferred examples include toluene, xylene, ethyl acetate, butyl acetate, chloroform, dichloromethane, tetrahydrofuran, and dioxane. These solvents can be used alone or in combination. The amount of solvent used is not particularly limited as long as it does not interfere with the reaction, but is usually used in the range of 0.5 to 5 times by weight, preferably 1 to 3 times by weight, relative to the bisphenol compound represented by general formula (1). <Reaction temperature> The production method of the present invention is characterized in that the reaction is carried out at a temperature in the range of 10° C. to 80° C. The reaction temperature is preferably in the range of 20° C. to 75° C., more preferably in the range of 20° C. to 70° C., even more preferably in the range of 20° C. to 60° C., and particularly preferably in the range of 20° C. to 40° C. By carrying out the reaction within this temperature range, it is possible to improve the reaction selectivity of the target benzoxazine compound represented by general formula (3), suppress the production of high-molecular-weight by-products, and suppress an increase in viscosity or solidification of the liquid after the reaction, which is very useful because it allows the target benzoxazine compound to be produced efficiently with high purity. <Reaction pressure> In the production method of the present invention, the reaction may be carried out under normal pressure, or under increased or reduced pressure. In another embodiment, the method may include a step of removing water derived from the raw materials or water generated during the reaction from the reaction system. The step of removing the generated water from the reaction solution is not particularly limited, and the generated water can be removed by azeotropically distilling the generated water with the solvent system in the reaction solution. The generated water can be removed from the reaction system using, for example, a pressure-equalizing dropping funnel equipped with a stopcock, a Dimroth condenser, a Dean-Stark apparatus, or the like.

[0018] In the production method of the present invention, there is no limitation on the method for mixing the raw materials, namely, the bisphenol compound represented by general formula (1), formaldehydes, and the amine compound represented by general formula (2). Examples include (i) a method in which a mixture containing the bisphenol compound represented by general formula (1) and formaldehydes is mixed with the amine compound represented by general formula (2) to carry out a reaction, and (ii) a method in which a mixture containing formaldehydes and the amine compound represented by general formula (2) is mixed with the bisphenol compound represented by general formula (1). These mixtures may contain the above-mentioned solvents and catalysts, and there is no limitation on the method for mixing the catalyst, but it is preferable to mix the catalyst before mixing the amine compound represented by general formula (2). In the production method of the present invention, there is no limitation on the method for mixing the remaining raw materials with the raw material mixture. However, from the viewpoint of reaction selectivity and suppressing the production of high-molecular-weight by-products, it is preferable to mix the raw materials continuously or intermittently rather than mixing them all at once.

[0019] <After reaction is complete> The benzoxazine compound represented by general formula (3) can be isolated from the reaction mixture obtained in the production method of the present invention by known methods. For example, the target product can be obtained as a residual liquid by distilling off the remaining raw materials and solvent from the reaction mixture. Alternatively, the target product can be obtained by precipitating the residual liquid by adding a poor solvent, or by adding a solvent to the reaction mixture to cause crystallization and filtering the crystals to obtain a powder or granular target product. The benzoxazine compound isolated by the above method can be purified to a high purity by conventional purification means, such as washing with a solvent or water or recrystallization. [Example]

[0020] The present invention will be explained in more detail below with reference to examples. <Analysis method> 1. Reaction solution composition and purity analysis (gel permeation chromatography: GPC) The purity of various benzoxazine compounds synthesized by the production method of the present invention was expressed as the area percentage value of the benzoxazine compound obtained by this analysis. Device: HLC-8320 / Tosoh Corporation Detector: Differential refractometer (RI) [Measurement conditions] Flow rate: 1mL / min Eluent: tetrahydrofuran Temperature: 40℃ Wavelength: 254nm Measurement sample: 1 g of a composition containing a benzoxazine compound was diluted 200 times with tetrahydrofuran.

[0021] Example 1 (Synthesis of Compound p-1) A 1 L four-neck flask equipped with a thermometer, stirrer, condenser, and dropping funnel was charged with 97 g (0.48 mol) of bisphenol F (dinuclear content 90.1 wt%, isomer ratio of which is 18.8 wt% bis(2-hydroxyphenyl)methane, 49.3 wt% 2-hydroxyphenyl-4-hydroxyphenylmethane, and 31.9 wt% bis(4-hydroxyphenyl)methane, polynuclear content 9.9 wt%), 62 g of 94% paraformaldehyde, and 121 g of toluene. After purging the reaction vessel with nitrogen, the temperature of the mixed solution was raised to 70 °C. While maintaining the temperature, 60 g of 2-aminoethanol was added dropwise to the four-neck flask using the dropping funnel over 2 hours. After the addition was completed, the mixture was stirred at 70 °C for an additional 3 hours. The composition of the reaction solution was analyzed by GPC using the analytical method described above. As a result, the proportion of the target compound present in the reaction solution was 51 area %. After the reaction was completed, toluene and water were removed by distillation under reduced pressure at 70°C. The pressure during distillation was gradually reduced to a final pressure of 4.8 kPa. The composition containing the target compound was removed, cooled and solidified, pulverized, and dried at 60°C and 1.5 kPa to obtain 173 g of the target compound (purity 53%, 47% by area of ​​compounds with a higher molecular weight than the target compound). 1 The results of H-NMR analysis confirmed that the target benzoxazine compound (p-1) was obtained. 1 H-NMR analysis (400 MHz, solvent: CDCl3, reference material: tetramethylsilane) 2.43-2.72(2H,brm),2.71-3.16(4H,m),3.41-4.09(12H,m),4.69-5.01(4H,m),6.49-7.07(6H,m).

[0022] Example 2 (Synthesis of Compound p-1) A 1 L four-neck flask equipped with a thermometer, stirrer, condenser, and dropping funnel was charged with 221.5 g (1.11 mol) of bisphenol F (the same product as in Example 1), 173.5 g of 94% paraformaldehyde, and 409.8 g of toluene. After replacing the atmosphere in the reaction vessel with nitrogen, the temperature of the mixed solution was brought to 30°C, and while maintaining the temperature, 135.2 g of 2-aminoethanol was added dropwise to the four-neck flask using the dropping funnel over 2 hours. After the dropwise addition was completed, the mixture was stirred for an additional hour at 30°C. The composition of the reaction solution was analyzed by GPC using the above analytical method, and the proportion of the target compound present in the reaction solution was found to be 77 area %.

[0023] Comparative Example 1 (Synthesis of Compound p-1) A 1 L four-neck flask equipped with a thermometer, stirrer, condenser, and dropping funnel was charged with 97 g (0.48 mol) of bisphenol F (the same product as in Example 1), 62 g of 94% paraformaldehyde, and 121 g of toluene. After replacing the atmosphere in the reaction vessel with nitrogen, the temperature of the mixed solution was raised to 90°C, and while maintaining the temperature, 60 g of 2-aminoethanol was added dropwise to the four-neck flask using the dropping funnel over 2 hours. After the dropwise addition was completed, the mixture was stirred for an additional 3 hours at 90°C. The composition of the reaction solution was analyzed by GPC using the above analytical method, and the proportion of the target compound present in the reaction solution was found to be 47 area %. After the reaction was completed, an attempt was made to remove the toluene and water by distillation under reduced pressure at 70°C, but the solution in the reaction vessel solidified, making it impossible to continue stirring, and therefore it became impossible to remove the composition containing the target compound from the reaction vessel.

[0024] Example 3 (Synthesis of Compound p-2) A 1 L four-neck flask equipped with a thermometer, stirrer, condenser, and dropping funnel was charged with 100 g (0.44 mol) of bisphenol A, 56 g of 94% paraformaldehyde, and 184 g of toluene. After replacing the atmosphere in the reaction vessel with nitrogen, the temperature of the mixed solution was raised to 70°C. While maintaining the temperature, 53 g of 2-aminoethanol was added dropwise to the four-neck flask using the dropping funnel over 2 hours. After the dropwise addition was completed, the mixture was stirred at 70°C for an additional 9.5 hours. The composition of the reaction solution was analyzed by GPC using the above analytical method. As a result, the proportion of the target compound present in the reaction solution was 52 area %. After the reaction was completed, toluene and water were removed by distillation under reduced pressure at 70°C. The pressure during distillation was gradually reduced to 20 kPa. A composition containing the target compound was taken out, yielding 187 g of the target compound (purity: 54%, 46% by area of ​​compounds with a higher molecular weight than the target compound). 1 The results of H-NMR analysis confirmed that the target benzoxazine compound (p-2) was obtained. 1 H-NMR analysis (400 MHz, solvent: CDCl3, reference material: tetramethylsilane) 1.14-1.96(6H,m),2.45-2.77(2H,brm),2.78-3.18(4H,m),3.28-4.19(10H,m),4.70-5.14(4H,m),6.56-7.13(6H,m).

[0025] Example 4 (Synthesis of Compound p-3) A 500 mL four-neck flask equipped with a thermometer, stirrer, condenser, and dropping funnel was charged with 31 g (0.15 mol) of bisphenol F (the same product as in Example 1), 20 g of 94% paraformaldehyde, and 57 g of toluene. After replacing the atmosphere in the reaction vessel with nitrogen, the temperature of the mixed solution was increased to 60°C, and while maintaining the temperature, 24 g of 2-aminoethanethiol was added dropwise to the four-neck flask using the dropping funnel over 1 hour. After the dropwise addition was completed, the mixture was stirred for an additional 2 hours at 60°C. The composition of the reaction solution was analyzed by GPC using the above analytical method, and the proportion of the target compound present in the reaction solution was found to be 41 area %. After the reaction was completed, toluene and water were removed by distillation under reduced pressure at 50°C. The pressure during distillation was gradually reduced to a final pressure of 2.4 kPa. A composition containing the target compound was taken out, yielding 59 g of the target compound (purity: 41%, 59 area % of compounds with a higher molecular weight than the target compound). 1 The results of H-NMR analysis confirmed that the target benzoxazine compound (p-3) was obtained. 1 H-NMR (400 MHz, solvent: CDCl3, reference material: tetramethylsilane) 1.32-1.95(2H,brm),2.91-3.05(4H,m),3.07-3.22(4H,m),3.64-4.13(10H,m),6.66-7.12(6H,m).

[0026] Example 5 (Synthesis of Compound p-3) Using a 1 L four-neck flask equipped with a thermometer, a stirrer, and a condenser, 97 g (0.48 mol) of bisphenol F (the same product as in Example 1), 62 g of 94% paraformaldehyde, 75 g of 2-aminoethanethiol, and 180 g of toluene, a reaction was carried out in the same manner as in Example 4, except that the temperature before the addition of the amine was set to 50°C and stirring was continued for an additional 1 hour at 50°C after the completion of the addition of the amine. The composition of the reaction solution was analyzed by GPC using the above analytical method, and the proportion of the target compound present in the reaction solution was found to be 65 area %. After the reaction was completed, toluene and water were removed by distillation under reduced pressure at 50°C. The pressure during distillation was gradually reduced to a final pressure of 1.5 kPa. The composition containing the target compound was removed, cooled and solidified, pulverized, and vacuum dried at 60°C and 1.5 kPa to obtain 208 g of the target compound (purity: 56%, 44% by area of ​​compounds with a higher molecular weight than the target compound).

[0027] Example 6 (Synthesis of compound p-3) Using a 1 L four-neck flask equipped with a thermometer, a stirrer, and a condenser, 97 g (0.48 mol) of bisphenol F (the same product as in Example 1), 74 g of 94% paraformaldehyde, 75 g of 2-aminoethanethiol, and 180 g of toluene, a reaction was carried out in the same manner as in Example 4, except that the temperature before the addition of the amine was set to 30°C and that after the addition of the amine was completed, the mixture was stirred at 30°C for an additional 3 hours. The composition of the reaction solution was analyzed by GPC using the above analytical method, and the proportion of the target compound present in the reaction solution was found to be 88 area %. After the reaction was completed, the reaction solution was washed with alkaline water using a 3% aqueous sodium hydroxide solution, and then washed with water until the pH of the reaction solution reached 7 or less. Then, toluene and water were removed by distillation under reduced pressure at 30°C. The pressure during distillation was gradually reduced to a final pressure of 2.3 kPa. After some of the solvent had been removed, the remaining solvent was further removed under conditions of 90°C and 2.8 kPa. The composition containing the target compound was taken out, cooled to solidify, and then pulverized to obtain 156 g of the target compound (purity: 75%, 25% by area of ​​compounds with a higher molecular weight than the target compound).

[0028] Example 7 (Synthesis of compound p-3) A 500 mL four-neck flask equipped with a thermometer, stirrer, and condenser was charged with 30 g of 94% paraformaldehyde, 36 g of 2-aminoethanethiol, and 88 g of toluene. The atmosphere in the reaction vessel was then replaced with nitrogen, and the mixed solution was heated to 60°C. While maintaining the temperature, 47 g (0.23 mol) of bisphenol F (the same product as in Example 1) was added. After mixing, the mixture was stirred at 60°C for an additional 3 hours. The composition of the reaction solution was analyzed by GPC using the above analytical method, and the proportion of the target compound present in the reaction solution was found to be 69 area %.

[0029] Comparative Example 2 (Synthesis of Compound p-3) Using a 1 L four-neck flask equipped with a thermometer, a stirrer, and a condenser, 97 g (0.48 mol) of bisphenol F (the same product as in Example 1), 62 g of 94% paraformaldehyde, 75 g of 2-aminoethanethiol, and 180 g of toluene, a reaction was carried out in the same manner as in Example 4, except that the temperature before the addition of the amine was set to 90° C. The reaction liquid solidified during the addition of the amine, making it impossible to continue stirring and completing the reaction.

[0030] Example 8 (Synthesis of Compound p-5) A 1 L four-neck flask equipped with a thermometer, stirrer, condenser, and dropping funnel was charged with 124 g (0.4 mol) of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 63 g of 92% paraformaldehyde, and 230 g of toluene. After purging the atmosphere in the reaction vessel with nitrogen, the temperature of the mixed solution was brought to 30°C. While maintaining the temperature, 49 g of 2-aminoethanol was added dropwise to the four-neck flask using the dropping funnel over 2 hours. After the addition was completed, the mixture was stirred for an additional 4 hours at 30°C. The composition of the reaction solution was analyzed by GPC using the analytical method described above. As a result, the proportion of the target compound present in the reaction solution was 79 area %. After the reaction was completed, the reaction mixture was washed with alkaline water using a 3% aqueous sodium hydroxide solution, and then 350 g of toluene was added and washed with water until the pH of the washings reached 7 or less. The toluene and water were then removed by distillation under reduced pressure at 60°C. The pressure during distillation was gradually reduced to a final pressure of 4.8 kPa. After some of the solvent had been removed, the remaining solvent was further removed under conditions of 90°C and 9.8 kPa. 183 g of the target compound (purity: 76%, 24 area % of compounds with a higher molecular weight than the target compound) was obtained. 1 The results of H-NMR analysis confirmed that the target compound (p-5) was obtained. 1 H-NMR analysis (400 MHz, solvent: CDCl3, reference material: tetramethylsilane) 0.30-0.40(3H, m),0.84(1H,m),0.90-1.00(6H,m),1.10(1H,m),1.76-2.02(2H,m),2.32(1H, m),2.58(1H,m),2.81-3.07(4H,m),3.57-4.05(8H,m),4.73-4.90(4H,m),6.50-7.12(6H,m).

[0031] Example 9 (Synthesis of Compound p-6) A reaction was carried out in the same manner as in Example 4 using a 1 L four-neck flask equipped with a thermometer, a stirrer, and a condenser, 97 g (0.31 mol) of 1,1'-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 48 g of 94% paraformaldehyde, 48 g of 2-aminoethanethiol, and 180 g of toluene, except that the temperature before the addition of the amine was set to 30°C, and after the completion of the addition of the amine, stirring was continued for 3 hours at 30°C, 40°C, and 50°C. The composition of the reaction solution was analyzed by GPC using the above analytical method, and the proportion of the target compound present in the reaction solution was found to be 73 area %. After the reaction was completed, the reaction solution was washed with alkaline water using a 3% aqueous sodium hydroxide solution, and then washed with water until the pH of the reaction solution reached 7 or less. Then, toluene and water were removed by distillation under reduced pressure at 30°C. The pressure during distillation was gradually reduced to a final pressure of 4.2 kPa. After removing a certain amount of the solvent, the remaining solvent was further removed under conditions of 90°C and 20 kPa. The composition containing the target compound was taken out, cooled to solidify, and then pulverized to obtain 188 g of the target compound (purity: 71%, 29 area % of compounds with a higher molecular weight than the target compound). 1 The results of H-NMR analysis confirmed that the target compound (p-6) was obtained. 1 H-NMR (400 MHz, solvent: CDCl3, reference material: tetramethylsilane) 0.25-0.44(3H,m),0.76-1.02(7H,m),1.11(1H,dd),1.36(1H,d),1.75-2.05(2H,m),2.33(1H,brm),2.59(1H,brm),2.77-3.22(8H,m),3.54-3.79(4H,m),3.86-4.07(4H,m),6.51-7.04(6H,m),9.07-10.3(2H,brm).

Claims

1. A method for producing a benzoxazine compound represented by general formula (3), comprising reacting a bisphenol compound represented by general formula (1), a formaldehyde, and an amine compound represented by general formula (2) at a temperature in the range of 10°C or higher and 80°C or lower. 【Chemistry 1】 (In the formula, R １ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and X represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a divalent group represented by general formula (1a) or (1b). 【Chemistry 2】 (In general formulas (1a) and (1b), R ２ and R ３ each independently represents hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms; R ２ and R ３ may be bonded to each other to form a cycloalkylidene group having 5 to 20 carbon atoms as a whole, and Ar １ and Ar ２ each independently represents an aryl group having 6 to 12 carbon atoms, and * indicates the bonding position.) 【Transformation 3】 (In the formula, R ４ represents a divalent group having 1 to 10 carbon atoms, and Y represents a thiol group. 【Chemistry 4】 (In the formula, R １ and X is a group represented by general formula (1), and R ４ and Y are defined as in general formula (2).

2. A method for producing a benzoxazine compound represented by general formula (3), comprising reacting a bisphenol compound represented by general formula (1), a formaldehyde, and an amine compound represented by general formula (2) at a temperature in the range of 20°C or higher and 40°C or lower. 【Transformation 5】 (In the formula, R １ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and X represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a divalent group represented by general formula (1a) or (1b). 【Transformation 6】 (In general formulas (1a) and (1b), R ２ and R ３ each independently represents hydrogen, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms; R ２ and R ３ may be bonded to each other to form a cycloalkylidene group having 5 to 20 carbon atoms as a whole, and Ar １ and Ar ２ each independently represents an aryl group having 6 to 12 carbon atoms, and * indicates the bonding position.) 【Transformation 7】 (In the formula, R ４ represents a divalent group having 1 to 10 carbon atoms, and Y represents a hydroxy group. 【Transformation 8】 (In the formula, R １ and X is a group represented by general formula (1), and R ４ and Y are defined as in general formula (2).

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