Curable phosphorus-containing compounds and preparation method therefor

Abstract

This invention provides a series of novel curable phosphorus-containing compounds having bis(6H-dibenzo[c,e][1,2]-oxaphosphinine-6-oxide) structure and the preparation methods therefor. Through the unique design of dual reactive ends on the curable phosphorus-containing compounds, these compounds are allowed to be cross-linked with other vinyl-containing monomers and thereby can be used as reactive halogen-free flame retardants. The novel phosphorus-containing compounds are represented by the general formula

Description

Technical Field

[0001] The present invention provides a series of novel curable phosphorus-containing compounds having a bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide structure and represented by the general formula (1).

[0002] Prior Art

[0003] 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) has long been widely used in antimicrobial, antioxidant, anti-fading agent, and flame retardant applications. DOPO is a halogen-free, phosphorus-based flame retardant whose unique planar structure enhances its flame retardant performance. Due to growing environmental awareness and increasingly stringent environmental regulations, halogen-free flame retardants have flourished in the past decade and have gradually replaced halogen-containing flame retardants. The benefits of switching to halogen-free flame retardants also include reducing the severe environmental damage previously posed by the generation of highly corrosive gases and toxic compounds during the combustion of halogen-containing flame retardants. In addition to protecting the surface of chemical products and isolating them from external oxygen and heat through a condensed phase flame retardant mechanism, phosphorus-based flame retardants can also capture and stabilize high-energy free radicals generated during combustion through a free radical capture mechanism to achieve a flame retardant effect.

[0004] However, to achieve a certain effect, additive phosphorus-based flame retardants generally need to be added at a dosage of more than 10% w / w. However, at high dosages, additive flame retardants may cause compatibility issues after the finished product is made or during subsequent processing, including relatively minor problems such as the migration of flame retardants to the surface of the product, or even relatively serious problems such as blooming.

[0005] To address these issues, it's necessary to improve the compatibility between additive phosphorus-based flame retardants and the materials used. Since the materials being processed are generally high-molecular-weight compounds, increasing the molecular weight of DOPO derivatives is one approach. Another approach is to derivatize DOPO to create structures with reactive ends, allowing it to function as a reactive flame retardant. By cross-linking the reactive ends of reactive flame retardants with other reactive groups, the flame-retardant units are directly linked to the material, thus addressing the aforementioned issues with additive flame retardants. Summary of the Invention

[0006] To achieve the aforementioned objectives, the present invention provides a novel curable phosphorus-containing compound having a bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide structure. This novel curable phosphorus-containing compound utilizes a dual reactive end design. This design not only increases molecular weight by approximately two times, thereby improving compatibility with other materials, but also enables the reactive end to undergo cross-linking reactions with other cross-linkable monomers or oligomeric resins, further increasing polymer molecular weight. Furthermore, compared to compounds with only a single reactive end, the dual reactive end design offers the advantage of improved adhesion.

[0007] The curable phosphorus-containing compound of the present invention is represented by the general formula (1):

[0008]

[0009] in,

[0010] Each of A1 and A2 is independently selected from the group consisting of a hydrogen atom, a hydroxyl group (-OH), a nitrile group (-CN), a halogen group, an alkoxy group (-OR), an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an arylalkyl group;

[0011] Each of R1 and R2 is independently selected from the group consisting of: a hydrogen atom, an alkyl group having a carbon number between 1 and 8, a cycloalkyl group having a carbon number between 3 and 8, an aryl group, a heteroaryl group, and an arylalkyl group;

[0012] X represents a single bond, (CH2)n, CR3R4, C=O, or SO2, wherein R3 and R4 are independently selected from the group consisting of a hydrogen atom, a fluorine atom, a fluorinated alkyl group, an alkyl group with 1 to 8 carbon atoms, a cycloalkyl group with 3 to 8 carbon atoms, an aryl group, a heteroaryl group, and an arylalkyl group, and n is an integer from 1 to 12;

[0013] Each Y series is represented independently , where * indicates the bond position; and

[0014] Each Z system is represented independently or , where * indicates the bond position.

[0015] In one embodiment, the curable phosphorus-containing compound of the present invention is selected from one of the following:

[0016] .

[0017] In one embodiment, the curable phosphorus-containing compound of the present invention is selected from one of the following:

[0018] .

[0019] The present invention also provides a method for preparing a curable phosphorus-containing compound having a bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide structure, comprising:

[0020] (1) subjecting bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide to a nucleophilic addition reaction with an aldehyde or ketone compound in the presence of a solvent to obtain a diol intermediate; and

[0021] (2) subjecting the diol intermediate to an esterification reaction with an acylation agent, a solvent, and a catalyst or an acid antacid,

[0022] Wherein, the above steps (1) and (2) are represented by the general formula (2):

[0023] General formula (2)

[0024] in,

[0025] Each of A1 and A2 is independently selected from the group consisting of: hydrogen, hydroxy, nitrile, halogen, alkoxy, alkyl, 3-8 carbon atoms, cycloalkyl, aryl, heteroaryl, and aralkyl;

[0026] Each of R1 and R2 is independently selected from the group consisting of: a hydrogen atom, an alkyl group with a carbon number between 1 and 8, a cycloalkyl group with a carbon number between 3 and 8, an aryl group, a heteroaryl group, and an aralkyl group;

[0027] X represents a single bond, (CH2)n, CR3R4, C=O, or SO2, wherein R3 and R4 are independently selected from the group consisting of a hydrogen atom, a fluorine atom, a fluorinated alkyl group, an alkyl group with 1 to 8 carbon atoms, a cycloalkyl group with 3 to 8 carbon atoms, an aryl group, a heteroaryl group, and an aralkyl group, and n is an integer from 1 to 12;

[0028] Each Y series is represented independently , where * indicates the bonding position;

[0029] Each Z system is represented independently or , where * indicates the bonding position;

[0030] R5 represents a hydrogen atom or a methyl group; and

[0031] R6 represents a chlorine atom, an acryloxy group or a methacryloyloxy group.

[0032] In one embodiment, in the nucleophilic addition reaction of step (1), the equivalent ratio of bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide to the aldehyde or ketone compound is 1:2 to 1:10.

[0033] In one embodiment, the nucleophilic addition reaction of step (1) is carried out by heating a mixture comprising the bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide, the aldehyde or ketone compound and the solvent at 20 to 200°C.

[0034] In one embodiment, the solvent in the nucleophilic addition reaction of step (1) is selected from the group consisting of dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloromethane, ethyl acetate, butyl acetate, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and combinations thereof.

[0035] In one embodiment, the weight percentage of the solvent to the bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide is 1:0.1 to 1:20.

[0036] In one specific embodiment, in the esterification reaction of step (2), the equivalent ratio of the diol intermediate to the acylation reagent is 1:2 to 1:10.

[0037] In one embodiment, the esterification reaction in step (2) is carried out at a temperature of -20 to 150° C. on a mixture comprising the alcohol intermediate, an acylation agent, the solvent, and the catalyst or antacid.

[0038] In one embodiment, the catalyst or antacid in the esterification reaction of step (2) is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, lithium carbonate, lithium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonia, dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, triethylamine, tripropylamine, tributylamine, triethylenediamine (1,4-diazabicyclo[2.2.2]octane, DABCO), pyridine, 2-methylpyridine, 4-methylpyridine, 2,6-lutidine, 4-N,N'-lutidine (DMAP), and combinations thereof.

[0039] In one embodiment, the weight ratio of the catalyst or antacid to the diol intermediate is 0:1 to 5:1.

[0040] In one embodiment, the weight percentage of the solvent to the bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide is 1:0.1 to 1:2. Simple diagram description

[0041] FIG1 is an H-NMR spectrum of the curable phosphorus-containing compound of Example 1 of the present invention.

[0042] FIG2 is an H-NMR spectrum of the curable phosphorus-containing compound of Example 2 of the present invention.

[0043] FIG3 is an FT-IR spectrum of the curable phosphorus-containing compound of Example 2 of the present invention. Implementation Method

[0044] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art will readily understand the advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other embodiments, and the details herein may be modified and altered based on different perspectives and applications without departing from the spirit of the present invention.

[0045] The present invention provides a curable phosphorus-containing compound as shown in the general formula (1),

[0046]

[0047] in,

[0048] Each of A1 and A2 is independently selected from the group consisting of a hydrogen atom, a hydroxyl group (-OH), a nitrile group (-CN), a halogen group, an alkoxy group (-OR), an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an arylalkyl group;

[0049] Each of R1 and R2 is independently selected from the group consisting of: a hydrogen atom, an alkyl group having a carbon number between 1 and 8, a cycloalkyl group having a carbon number between 3 and 8, an aryl group, a heteroaryl group, and an arylalkyl group;

[0050] X represents a single bond, (CH2)n, CR3R4, C=O, or SO2, wherein R3 and R4 are independently selected from the group consisting of a hydrogen atom, a fluorine atom, a fluorinated alkyl group, an alkyl group with 1 to 8 carbon atoms, a cycloalkyl group with 3 to 8 carbon atoms, an aryl group, a heteroaryl group, and an arylalkyl group, and n is an integer from 1 to 12;

[0051] Each Y series is represented independently , where * indicates the bond position; and

[0052] Each Z system is represented independently or , where * indicates the bond position.

[0053] In one embodiment, each of A1, A2, R1, and R2 in the general formula (1) is a hydrogen atom, X is CH2, and Y is , Z is For example, the compound represented by the general formula (1) of the present invention has the structure of the following formula (A-1):

[0054]

[0055] In a specific embodiment, each of A1, A2, R1, and R2 in the general formula (1) is a hydrogen atom, X is C(CH3)2, and Y is , Z is For example, the compound represented by the general formula (1) of the present invention has the structure of the following formula (A-2):

[0056]

[0057] In a specific embodiment, each of A1, A2, R1, and R2 in the general formula (1) is a hydrogen atom, X is C(CH2)5, and Y is , Z is For example, the compound represented by the general formula (1) of the present invention has the structure of the following formula (A-3):

[0058]

[0059] In a specific embodiment, each of A1, A2, R1, and R2 in the general formula (1) is a hydrogen atom, X is SO2, and Y is , Z is For example, the compound represented by the general formula (1) of the present invention has the structure of the following formula (A-4):

[0060]

[0061] In a specific embodiment, each of A1, A2, R1, and R2 in the general formula (1) is a hydrogen atom, X is a single bond, and Y is , Z is For example, the compound represented by the general formula (1) of the present invention has the structure of the following formula (A-5):

[0062]

[0063] The present invention further provides a novel method for preparing a curable phosphorus-containing compound having a bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide structure, comprising: (1) subjecting bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide to a first nucleophilic addition reaction with an aldehyde or ketone compound in the presence of a solvent to obtain a diol intermediate; and (2) subjecting the diol intermediate to a second esterification reaction with an acylation agent, a solvent, and a catalyst (or an acid antacid), wherein the specific synthetic reaction formulas of steps (1) and (2) are represented by general formula (2);

[0064]

[0065] in,

[0066] Each of A1 and A2 is independently selected from the group consisting of a hydrogen atom, a hydroxyl group (-OH), a nitrile group (-CN), a halogen group, an alkoxy group (-OR), an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an arylalkyl group;

[0067] Each of R1 and R2 is independently selected from the group consisting of: a hydrogen atom, an alkyl group having a carbon number between 1 and 8, a cycloalkyl group having a carbon number between 3 and 8, an aryl group, a heteroaryl group, and an arylalkyl group;

[0068] X represents a single bond, (CH2)n, CR3R4, C=O, or SO2, wherein R3 and R4 are independently selected from the group consisting of a hydrogen atom, a fluorine atom, a fluorinated alkyl group, an alkyl group with 1 to 8 carbon atoms, a cycloalkyl group with 3 to 8 carbon atoms, an aryl group, a heteroaryl group, and an arylalkyl group;

[0069] Each Y series is represented independently , where * indicates the bonding position;

[0070] Each Z system is represented independently or , where * indicates the bonding position;

[0071] R5 represents a hydrogen atom or a methyl group; and

[0072] R6 represents a chlorine atom, an acryloxy group or a methacryloyloxy group.

[0073] In one embodiment, each of A1 and A2 is a hydrogen atom and each of R1 and R2 is a hydrogen atom.

[0074] In one embodiment, in the nucleophilic addition reaction of step (1), the equivalent ratio of bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide to the aldehyde or ketone compound is 1:2 to 1:10.

[0075] In one embodiment, in the nucleophilic addition reaction of step (1), a mixture comprising bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide and an aldehyde or ketone compound is reacted at a reaction temperature of 20 to 200°C.

[0076] In one embodiment, in the nucleophilic addition reaction of step (1), the weight percentage of the solvent to the bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide is 1:0.1 to 1:20.

[0077] In one embodiment, in the nucleophilic addition reaction of step (1), the solvent is an organic solvent.

[0078] In one embodiment, in the nucleophilic addition reaction of step (1), the solvent is preferably an aprotic solvent.

[0079] In one embodiment, the aprotic solvent in step (1) is selected from dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloromethane, ethyl acetate, butyl acetate, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, tetrahydrofuran, acetonitrile, N,N'-dimethylformamide, N,N'-dimethylacetamide, 1-Methyl-2-pyrrolidone, dimethyl sulfoxide, and combinations thereof.

[0080] In one embodiment, in the esterification reaction of step (2), the equivalent ratio of the diol intermediate to the acylation agent (or alkylation agent) is 1:2 to 1:20.

[0081] In one embodiment, in the esterification reaction of step (2), the mixture comprising the diol intermediate and the acylation agent (or alkylation agent) is reacted at a reaction temperature of -20 to 150°C.

[0082] In one specific embodiment, in the esterification reaction of step (2), the weight percentage of the diol intermediate to the solvent is 1:0.1 to 1:20.

[0083] In one embodiment, in the esterification reaction of step (2), the solvent is an organic solvent.

[0084] In one embodiment, in the esterification reaction of step (2), the solvent is preferably an aprotic solvent.

[0085] In one embodiment, the aprotic solvent in step (2) is selected from dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloromethane, ethyl acetate, butyl acetate, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, tetrahydrofuran, acetonitrile, N,N'-dimethylformamide, N,N'-dimethylacetamide, 1-Methyl-2-pyrrolidone, dimethyl sulfoxide, and combinations thereof.

[0086] In one specific embodiment, in the esterification reaction of step (2), the weight percentage of the catalyst (or antacid) to the diol intermediate is 0:1 to 5:1.

[0087] In one embodiment, in the esterification reaction of step (2), the catalyst (or antacid) is an inorganic base, an organic base, or both.

[0088] In one embodiment, in the esterification reaction of step (2), preferably, the inorganic base compound is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, lithium carbonate, lithium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, and potassium hydrogen carbonate.

[0089] In one embodiment, in the esterification reaction of step (2), preferably, the organic base compound is selected from the group consisting of ammonia, dimethylamine, diethylamine, di-n-propylamine, diiso-propylamine, dibutylamine, diiso-butylamine, triethylamine, tri-n-propylamine, tributylamine, 1,4-diazabicyclo[2.2.2]octane (DABCO), pyridine, 2-methylpyridine, 4-methylpyridine, 2,6-dimethylpyridine, and 4-N,N'-dimethylpyridine (DMAP).

[0090] Example 1

[0091] Synthesis of (methylenebis(6-oxidodibenzo[c,e][1,2]oxaphosphinine-2,6-diyl))bis(methylene)bis(2-methylacrylate), DI-DOPO-ME-MA, A1

[0092]

[0093] Combine 40 g of 2,2'-methylene-bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide, 160 g of DMAC, and 6 g of polyoxymethylene in a reaction flask, then heat to 70-80°C for 20 hours. After the reaction, slowly add 160 g of water dropwise. After cooling to room temperature, filter and collect the solid, wash twice with water, and vacuum dry. This yields 40 g of the crude diol intermediate, DI-DOPO-ME-FA, as an off-white solid. This solid can be directly used for the next esterification reaction without purification.

[0094] 40 g of the crude diol intermediate, 1.0 g of DMAP, 0.08 g of polymerization inhibitor HQ, and 40 g of DMF were mixed in a reaction flask and heated to 80-90°C. 30.6 g of methacrylic anhydride was slowly added dropwise, and the reaction was maintained at this temperature for 8 hours. The mixture was then cooled to room temperature, the DMF was recovered under reduced pressure, and 200 g of ethyl acetate was added for dilution. The organic layer was washed several times with a 5% aqueous sodium bicarbonate solution. After separation of the organic layer, the solvent was removed in vacuo to yield 39.2 g of an off-white solid product. The two-step yield was approximately 68%. The product was separated on a diatomaceous earth column to obtain an analytical-grade sample with a melting point of 103-105°C.

[0095] 1H-NMR(DMSO-d6,600MHz)δ:1.39(6H,s),4.08(2H,s),4.80(2H,dd),4.90(2H,d),5.23(2H,m),5.35(2H,s),7.22 (2H,d,J=8.40Hz),7.40(2H,t),7.65(2H,td),7.86(2H,t),7.98(2H,dd),8.21(2H,d,J=4.38Hz),8.29(2H,t)ppm

[0096] 31P-NMR(DMSO-d6,243MHz)δ:28.70(s)ppm

[0097] Example 2

[0098] Synthesis of (propane-2,2-diylbis(6-oxidodibenzo[c,e][1,2]oxaphosphinine-2,6-diyl))bis(methylene)bis(2-methylacrylate), DI-DOPO-DM-MA, A2

[0099]

[0100] Combine 21.7 g of 2,2'-propane-2,2'-yl-bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide, 80 g of DMAC, and 3 g of polyoxymethylene in a reaction flask, then heat to 70-80°C for 20 hours. After the reaction, slowly add 80 g of water dropwise. After cooling to room temperature, filter and collect the solid, wash twice with water, and vacuum dry. This yields 21 g of the crude diol intermediate, DI-DOPO-DM-FA, as an off-white solid. This solid can be directly used for the next esterification reaction without purification.

[0101] 21 g of the crude diol intermediate, 0.5 g of DMAP, 0.04 g of polymerization inhibitor HQ, and 21 g of DMF were mixed in a reaction flask. The temperature was raised to 80-90°C, and 15.2 g of methacrylic anhydride was slowly added dropwise. After the addition was complete, the reaction was maintained at this temperature for 8 hours. The mixture was then cooled to room temperature, the DMF was recovered under reduced pressure, and 105 g of ethyl acetate was added for dilution. The organic layer was washed several times with a 5% aqueous sodium bicarbonate solution. After separation of the organic layer, the solvent was removed in vacuo to yield 18.9 g of the product as an off-white solid. The two-step yield was approximately 65%. The product was separated on a diatomaceous earth column to obtain an analytical-grade sample with a melting point of 92-95°C.

[0102] 1H-NMR(DMSO-d6,600MHz)δ:1.45(6H,s),1.81(6H,s),4.82(2H,dd),4.92(2H,d),5.36(2H,s),5.39(2H,s),7.20(2H,d,J=8.58Hz),7. 29(2H,m),7.64(2H,td,J=7.62,2.88Hz),7.84(2H,t,J=7.86Hz),7.99(2H,dd),8.06(2H,t,J=2.1Hz),8.29(2H,dd,J=8.34,5.1Hz)ppm

[0103] 31P-NMR(DMSO-d6,243MHz)δ:28.86(s)ppm

[0104] Example 3

[0105] Synthesis of (cyclohexane-1,1-diylbis(6-oxidodibenzo[c,e][1,2]oxaphosphinine-2,6-diyl))bis(methylene)bis(2-methylacrylate), DI-DOPO-CH-MA, A3

[0106]

[0107] Combine 23.1 g of 2,2'-cyclohexane-1,1'-yl-bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide, 80 g of DMAC, and 3 g of polyoxymethylene in a reaction flask, then heat to 70-80°C for 20 hours. After the reaction, slowly add 80 g of water dropwise. After cooling to room temperature, filter and collect the solid, wash twice with water, and then vacuum dry to obtain 22 g of the crude diol intermediate, DI-DOPO-CH-FA, as an off-white solid. This product was then directly processed into the next esterification reaction without purification.

[0108] 22 g of the crude diol intermediate, 0.48 g of DMAP, 0.039 g of polymerization inhibitor HQ, and 22 g of DMF were mixed in a reaction flask and heated to 80-90°C. 14.8 g of methacrylic anhydride was slowly added dropwise, and the reaction was maintained at this temperature for 8 hours. The mixture was then cooled to room temperature, the DMF was recovered under reduced pressure, and 110 g of ethyl acetate was added for dilution. The organic layer was washed several times with 5% aqueous sodium bicarbonate solution. After separation of the organic layer, the solvent was removed in vacuo to yield 19.0 g of an off-white solid product. The two-step yield was approximately 59.5%. The product was separated on a diatomaceous earth column to obtain an analytical-grade sample.

[0109] 1H-NMR(DMSO-d6,600MHz)δ:1.36(3H,s),1.37(3H,s),1.40~1.60(6H,m), 2.40~2.60(4H,m),4.79(2H,dd),4.90(2H,m),5.20(2H,m),5.31(2H,d),7 .19(2H,dd,J=8.58,1.8Hz),7.47(2H,t,J=8.22Hz),7.63(2H,m),7.85(2H ,t,J=7.8Hz),7.97(2H,dd),8.13(2H,dd,J=7.68,2.34Hz),8.36(2H,t)ppm

[0110] 31P-NMR(DMSO-d6,243MHz)δ:28.89(s)ppm

[0111] Example 4

[0112] Synthesis of (sulfonylbis(6-oxidodibenzo[c,e][1,2]oxaphosphinine-2,6-diyl))bis(methylene)bis(2-methylacrylate), DI-DOPO-SF-MA, A4

[0113]

[0114] Combine 22.3 g of 2,2'-sulfonyl-bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide, 80 g of DMAC, and 3 g of polyoxymethylene in a reaction flask, then heat to 70-80°C for 20 hours. After the reaction, slowly add 80 g of water dropwise. After cooling to room temperature, filter and collect the solid, wash twice with water, and vacuum dry. This yields 20.7 g of the crude diol intermediate, DI-DOPO-SF-FA, as an off-white solid. This product is then directly processed into the next esterification reaction without purification.

[0115] 20.7 g of crude diol intermediate, 0.47 g of DMAP, 0.038 g of polymerization inhibitor HQ, and 20.7 g of DMF were mixed in a reaction flask and heated to 80-90°C. 14.4 g of methacrylic anhydride was slowly added dropwise, and the reaction was maintained at this temperature for 8 hours. The mixture was then cooled to room temperature, the DMF was recovered under reduced pressure, and 103.5 g of ethyl acetate was added for dilution. The organic layer was washed several times with 5% aqueous sodium bicarbonate solution. After separation of the organic layer, the solvent was removed in vacuo to yield 17.1 g of an off-white solid product. The two-step yield was approximately 55%. The product was separated on a diatomaceous earth column to obtain an analytical-grade sample.

[0116] 31P-NMR(DMSO-d6,243MHz)δ:28.65(s)ppm

[0117] Example 5

[0118] Synthesis of (6,6'-dioxido-[2,2'-bidibenzo[c,e][1,2]oxaphosphinine]-6,6'-diyl)bis(methylene)bis(2-methylacrylate), DI-DOPO-MA, A5

[0119]

[0120] Combine 19.8 g of 2,2'-bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide, 80 g of DMAC, and 3 g of polyoxymethylene in a reaction flask, then heat to 70-80°C for 20 hours. After the reaction, slowly add 80 g of water dropwise. After cooling to room temperature, filter and collect the solid, wash twice with water, and then vacuum dry to obtain 17.9 g of the crude diol intermediate DI-DOPO-FA as an off-white solid. This product was directly used for the next esterification reaction without purification.

[0121] 17.9 g of crude diol intermediate, 0.46 g of DMAP, 0.037 g of polymerization inhibitor HQ, and 18 g of DMF were mixed in a reaction flask and heated to 80-90°C. 14.1 g of methacrylic anhydride was slowly added dropwise, and the reaction was maintained at this temperature for 8 hours. The mixture was then cooled to room temperature, the DMF was recovered under reduced pressure, and diluted with 105 g of ethyl acetate. The organic layer was washed several times with a 5% aqueous sodium bicarbonate solution. After separation of the organic layer, the solvent was removed in vacuo to yield 14.4 g of an off-white solid product. The two-step yield was approximately 50%. The product was separated on a diatomaceous earth column to obtain an analytical-grade sample.

[0122] 31P-NMR(DMSO-d6,243MHz)δ:28.75(s)ppm

[0123] Example 6

[0124] The conditions were the same as in Example 1, except that DMAC was replaced with an equal amount of chlorobenzene, 1.0 g of DMAP was replaced with 15.7 g of pyridine, the temperature was lowered to 5-10°C, and 20.7 g of methacrylic acid chloride was slowly added dropwise. The resulting product was 43.24 g of an off-white solid, with a yield of 75%.

[0125] Example 7

[0126] The conditions were the same as in Example 2, except that DMAC was replaced with an equal amount of chlorobenzene, 0.5 g of DMAP was replaced with 7.8 g of pyridine, the temperature was lowered to 5-10°C, and 10.3 g of methacrylic acid chloride was slowly added dropwise. Finally, 20.94 g of an off-white solid was obtained, with a yield of 72%.

[0127] Example 8

[0128] The conditions were the same as in Example 3, except that DMAC was replaced with an equal amount of chlorobenzene, 0.48 g of DMAP was replaced with 7.6 g of pyridine, the temperature was lowered to 5-10°C, and 10 g of methacrylic acid chloride was slowly added dropwise. Finally, 20.44 g of an off-white solid was obtained, with a yield of 64%.

[0129] Example 9

[0130] The conditions were the same as in Example 4, except that DMAC was replaced with an equal amount of chlorobenzene, 0.47 g of DMAP was replaced with 7.4 g of pyridine, the temperature was lowered to 5-10°C, and 9.76 g of methacrylic acid chloride was slowly added dropwise. Finally, 20.94 g of an off-white solid was obtained, with a yield of 72%.

[0131] Example 10

[0132] The conditions were the same as in Example 5, except that DMAC was replaced with an equal amount of chlorobenzene, 0.46 g of DMAP was replaced with 7.22 g of pyridine, the temperature was lowered to 5-10°C, and 9.56 g of methacrylic acid chloride was slowly added dropwise. Finally, 15.26 g of an off-white solid was obtained, with a yield of 53%.

[0133] Example 11

[0134] The conditions were the same as in Example 6, except that 17.9 g of acryloyl chloride was slowly added dropwise. Finally, 38.5 g of an off-white solid was obtained, with a yield of 70%.

[0135] Example 12

[0136] The conditions were the same as in Example 7, except that 8.9 g of acryloyl chloride was slowly added dropwise. Finally, 18.8 g of an off-white solid was obtained, with a yield of 68%.

[0137] Example 13

[0138] The conditions were the same as in Example 8, except that 8.7 g of acryloyl chloride was slowly added dropwise. Finally, 18.3 g of an off-white solid was obtained, with a yield of 60%.

[0139] Example 14

[0140] The conditions were the same as in Example 9, except that 8.45 g of acryloyl chloride was slowly added dropwise. Finally, 17.2 g of an off-white solid was obtained, with a yield of 62%.

[0141] Example 15

[0142] The conditions were the same as in Example 10, except that 8.3 g of acryloyl chloride was slowly added dropwise. Finally, 15.1 g of an off-white solid was obtained, with a yield of 55%.

Claims

1. A curable phosphorus-containing compound having a bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide structure, represented by general formula (1), wherein: Each of A1 and A2 is independently selected from the group consisting of a hydrogen atom, a hydroxyl group, a nitrile group, a halide group, an alkoxy group, an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an aralkyl group; each of R1 and R2 is independently selected from the group consisting of a hydrogen atom, an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an aralkyl group; X represents a single bond, (CH2)n, CR3R4, C=O, or SO2, wherein R3 and R4 are each selected from the group consisting of a hydrogen atom, a fluorine atom, a fluorinated alkyl group, an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an aralkyl group, and n is an integer from 1 to 12; each of Y is independently represented, wherein * represents a bonding position; and each of Z is independently represented or, wherein * represents a bonding position.

2. The compound as described in claim 1, which is selected from one of the following:

3. The compound as described in claim 1, which is selected from one of the following:

4. A method for preparing a curable phosphorus-containing compound having a bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide structure, comprising: (1) reacting bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide with an aldehyde or ketone compound in the presence of a solvent to undergo a nucleophilic addition reaction to obtain a diol intermediate; and (2) subjecting the diol intermediate to an esterification reaction with an acylation agent, a solvent, and a catalyst or an antacid, wherein the above steps (1) and (2) are represented by the general formula (2): General formula (2) wherein, each of A1 and A2 is independently selected from the group consisting of: a hydrogen atom, a hydroxyl group, a nitrile group, a halogen group, an alkoxy group, an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an aralkyl group; each of R1 and R2 is independently selected from the group consisting of: a hydrogen atom, an alkyl group with a carbon number of 1 to 8, a cycloalkyl group with a carbon number of 3 to 8, an aryl group, a heteroaryl group, and an aralkyl group; X represents a single bond, (CH2)n, CR3R4, C=O or SO2, wherein R3 and R4 are each selected from the group consisting of a hydrogen atom, a fluorine atom, a fluorinated alkyl group, an alkyl group with a carbon number between 1 and 8, a cycloalkyl group with a carbon number between 3 and 8, an aryl group, a heteroaryl group and an aralkyl group, and n is an integer from 1 to 12; each Y represents independently, wherein * represents a bonding position; each Z represents independently or, wherein * represents a bonding position; R5 represents a hydrogen atom or a methyl group; and R6 represents a chlorine atom, an acryloxy group or a methacryloyloxy group.

5. The preparation method according to claim 4, wherein: In the nucleophilic addition reaction of step (1), the equivalent ratio of bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide to the aldehyde or ketone compound is 1:2 to 1:

10.

6. The preparation method according to claim 4, wherein: The nucleophilic addition reaction of step (1) is carried out by heating a mixture comprising the bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide, the aldehyde or ketone compound and the solvent at 20 to 200°C.

7. The preparation method according to claim 4, wherein: The solvent in the nucleophilic addition reaction of step (1) is selected from the group consisting of: dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloromethane, ethyl acetate, butyl acetate, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide and combinations thereof.

8. The preparation method according to claim 7, wherein: The weight percentage of the solvent to the bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide is 1:0.1 to 1:

20.

9. The preparation method according to claim 4, wherein: In the esterification reaction of step (2), the equivalent ratio of the diol intermediate to the acylation agent is 1:2 to 1:

10.

10. The preparation method according to claim 4, wherein: The esterification reaction in step (2) is carried out at a temperature of -20 to 150° C. on a mixture comprising the alcohol intermediate, an acylation agent, the solvent, and the catalyst or antacid.

11. The preparation method according to claim 4, wherein: The catalyst or antacid in the esterification reaction of step (2) is selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, lithium carbonate, lithium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonia, dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, triethylamine, tripropylamine, tributylamine, triethylenediamine (1,4-diazabicyclo[2.2.2]octane, DABCO), pyridine, 2-methylpyridine, 4-methylpyridine, 2,6-lutidine, 4-N,N'-lutidine (DMAP), and combinations thereof.

12. The preparation method according to claim 11, wherein: The weight ratio of the catalyst or antacid to the diol intermediate is 0:1 to 5:

1.

13. The preparation method according to claim 4, wherein: The solvent in the esterification reaction of step (2) is selected from the group consisting of: dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloromethane, ethyl acetate, butyl acetate, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide and combinations thereof.

14. The preparation method according to claim 13, wherein: The weight percentage of the solvent to the bis-6H-dibenzo[c,e][1,2]oxaphosphorinane-6-oxide is 1:0.1 to 1:2.

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