Process for the preparation of high purity norbornene silyl ethers

Abstract

A method for preparing high purity norbornene alkyl silyl ethers is disclosed and claimed. In particular, a method for preparing high purity norbornene methyl silyl ethers on an industrial scale is disclosed and claimed. The high purity monomers prepared according to the method of the present invention can be used in a variety of applications, including but not limited to the preparation of high quality, high purity poly norbornenes that can be used in a variety of electronic applications and other various applications.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 452,364, filed March 15, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present invention relate to an industrial-scale preparation method for various norbornene silyl ethers. More specifically, the present invention relates to a method for preparing high-purity norbornene alkyl silyl ethers, which can be used as monomers in various industrial applications, including as starting materials in the manufacture of electronic / optoelectronic polymer materials. Background Technology

[0004] Functionalized norbornene monomers are widely used in the preparation of polymers with a variety of applications, particularly in the electronics industry. In particular, polynorbornene is used in various electronic materials because its unique film-forming properties help enhance the desired electronic material properties. Other applications include its use as a dielectric, photoresist, and protective layer. However, because these applications require extremely high-purity materials, it is crucial that the various functionalized norbornene monomers are free of any impurities that could hinder the formation of high molecular weight polymers.

[0005] U.S. Patent No. 9,382,271 B2 discloses various methods for preparing norbornene alkyl silane monomers. However, the methods disclosed therein require stoichiometric amounts of alkali, such as potassium tert-butoxide, thus generating significant amounts of waste. Therefore, these methods are not suitable for industrial applications and result in high costs due to waste management.

[0006] In view of the above, there is a need to develop an industrially feasible method for preparing environmentally friendly, high-purity norbornene alkyl silane monomers.

[0007] The following describes in detail other objects and further applications of the present invention. Summary of the Invention

[0008] As further explained below, this invention discloses a method for preparing high-purity norbornene alkyl silane of formula (I). Specifically, this invention discloses an industrial-scale method for preparing high-purity norbornene methyl silane. Surprisingly, as described in this specification, a catalytic amount of tris(pentafluorophenyl)borane promotes the reaction of norbornene alkyl alcohol of formula (II) with silane of formula (III). The high-purity norbornene alkyl silane monomer of formula (I) prepared according to the method of this invention can be used in a variety of applications, including but not limited to the preparation of high-quality, high-purity polynorbornene for various electronic applications and other applications. Detailed Implementation

[0009] Unless otherwise specified, the articles “a / an” and “the” used in this specification include multiple objects.

[0010] Since all figures, values ​​and / or expressions relating to the amount of ingredients, reaction conditions, etc., as used in this specification and the appended claims are subject to various measurement uncertainties encountered in obtaining these values, they should be understood to be modified by the term "about" in all cases unless otherwise specified.

[0011] The numerical ranges disclosed in this specification are continuous, including the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when a range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. And, when multiple ranges are provided to describe a characteristic or feature, these ranges can be combined. In other words, unless otherwise specified, all ranges disclosed in this specification should be understood to encompass all subranges thereof. For example, the specified range "1 to 10" should be considered to include all subranges between the minimum value 1 and the maximum value 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0012] As used in this specification, the term "alkyl" refers to a substituent in a saturated straight-chain or branched hydrocarbon having a specified number of carbon atoms. Specific examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, tert-butyl, etc. Derivative terms such as "alkoxy," "thioalkyl," "alkoxyalkyl," "hydroxyalkyl," "alkylcarbonyl," "alkoxycarbonylalkyl," "alkoxycarbonyl," "diphenylalkyl," "phenylalkyl," "phenylcarboxyalkyl," and "phenoxyalkyl" should be interpreted accordingly.

[0013] The term "cycloalkyl" as used in this specification includes all known cyclic groups. Representative examples of "cycloalkyl" include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. For example, the derived terms "cycloalkoxy," "cycloalkylalkyl," "cycloalkylaryl," and "cycloalkylcarbonyl" should also be interpreted accordingly.

[0014] The term "perhaloalkyl" as used in this specification refers to the aforementioned alkyl groups in which all hydrogen atoms are replaced by halogen atoms selected from fluorine, chlorine, bromine, or iodine. Exemplary examples include trifluoromethyl, trichloromethyl, tribromomethyl, triiodomethyl, pentafluoroethyl, pentachloroethyl, pentabromoethyl, pentaiodoethyl, and straight-chain or branched heptafluoropropyl, heptachloropropyl, heptabromopropyl, nonafluorobutyl, nonachlorobutyl, undecylfluoropentyl, undecylchloropentyl, tridecafluorohexyl, and tridecachlorohexyl. The derived term "perhaloalkoxy" should also be interpreted accordingly. Certain alkyl groups described in this specification, such as "alkyl" that can be partially fluorinated (i.e., only a portion of the hydrogen atoms in the alkyl group are replaced by fluorine atoms), should also be interpreted accordingly.

[0015] The term "acyl" as used in this specification shall have the same meaning as "alkanoyl" and can also be represented structurally as "R-CO-", where R is an "alkyl" having a specified number of carbon atoms. Furthermore, the meaning of "alkylcarbonyl" shall be the same as that of "acyl" as described in this specification. Specifically, "(C1-C4)acyl" shall refer to acyl, acetyl / ethanoyl, propionyl, n-butyryl, etc. For example, the derived terms "acyloxy" and "acyloxyalkyl" shall also be interpreted accordingly.

[0016] As used in this specification, the term "aryl" refers to a substituted or unsubstituted phenyl or naphthyl group. Specific examples of substituted phenyl or naphthyl groups include o-tolyl, p-tolyl, m-tolyl, 1,2-xylyl, 1,3-xylyl, 1,4-xylyl, 1-methylnaphthyl, 2-methylnaphthyl, etc. "Substituted phenyl" or "substituted naphthyl" also includes any possible substituents further described herein or known in the art.

[0017] The term "arylalkyl" as used in this specification refers to an aryl group further linked to an alkyl group. Representative examples include benzyl, phenylethyl, 2-phenylpropyl, 1-naphthylmethyl, 2-naphthylmethyl, etc.

[0018] As used in this specification, the term "alkenyl" refers to a non-cyclic, straight-chain or branched hydrocarbon chain having a specified number of carbon atoms and at least one carbon-carbon double bond, including vinyl and straight-chain or branched propenyl, butenyl, pentenyl, and hexenyl. For example, the derived terms "aryl alkenyl" and 5- or 6-membered "heteroaryl alkenyl" should also be interpreted accordingly. Exemplary examples of such derived terms include furan-2-vinyl, phenyl vinyl, 4-methoxyphenyl vinyl, etc.

[0019] The term "heteroaryl" as used in this specification includes all known aromatic groups containing heteroatoms. Representative 5-membered heteroaryl groups include furanyl, thiophene or phenylthio, pyrrole, isopyrrole, pyrazolyl, imidazolyl, oxazolyl, thiazolyl, isothiazolyl, etc. Representative 6-membered heteroaryl groups include pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, etc. Representative examples of bicyclic heteroaryl groups include benzofuranyl, benzothiophene, indolyl, quinolinyl, isoquinolinyl, cenolinyl, benzimidazolyl, inzolyl, pyridinylfuranyl, pyridinylthiophene, etc.

[0020] The term "heterocyclic" as used in this specification includes all known cyclic groups containing reducing heteroatoms. Representative 5-membered heterocyclic groups include tetrahydrofuranyl, tetrahydrothiophenyl, pyrrolyl, 2-thiazolinyl, tetrahydrothiazolinyl, tetrahydrooxazolyl, etc. Representative 6-membered heterocyclic groups include piperidinyl, piperazineyl, morpholinyl, thiomorpholinyl, etc. Other various heterocyclic groups include, but are not limited to, aziridinyl, azepanyl, diazepanyl, diazabicyclo[2.2.1]hept-2-yl, triazazocanyl, etc.

[0021] "Halogen" or "halogenated" refers to chlorine, fluorine, bromine, and iodine.

[0022] In a broad sense, the term "substituted" includes all permissible substituents in an organic compound. In some specific embodiments disclosed in this specification, the term "substituted" means substituted by more than one substituent, independently selected from the group consisting of (C1-C6)alkyl, (C2-C6)alkenyl, (C1-C6)perfluoroalkyl, phenyl, hydroxyl, -CO2H, ester, amide, (C1-C6)alkoxy, (C1-C6)thioalkyl, and (C1-C6)perfluoroalkoxy. However, any other suitable substituents known to those skilled in the art can also be applied to these embodiments.

[0023] It should be noted that any atom that does not satisfy the valence in the text, schemes, embodiments and tables of this specification is assumed to have an appropriate number of hydrogen atoms to satisfy the valence.

[0024] Therefore, according to an embodiment of the present invention, a method for preparing a compound of formula (I) is provided:

[0025] (I)

[0026] in,

[0027] n is an integer from 1 to 10, where more than one CH2 can be (C1-C 10) alkyl or (C1-C 10 Perfluoroalkyl substitution;

[0028] m is an integer from 0 to 2;

[0029] R1, R2, and R3 may be the same or different, and each is independently chosen from hydrogen, halogen, methyl, ethyl, straight-chain or branched (C3-C4). 12 )alkyl, (C3-C 12 )cycloalkyl, (C6-C 12 Bicycloalkyl, (C7-C 14 Tricycloalkyl, (C6-C 10 )Aryl, (C6-C 10 aryl (C1-C3)alkyl, (C5-C 10 (C5-C) heteroaryl, (C5-C) 10 Heteroaryl (C1-C3)alkyl, (C1-C 12 )alkoxy, (C3-C 12 )cycloalkoxy, (C6-C 12 ) Bicycloalkoxy, (C7-C 14 Tricycloalkoxy, (C6-C 10 ) aryloxy (C1-C3) alkyl, (C5-C 10 ) heteroaryloxy (C1-C3)alkyl, (C6-C 10 ) aryloxy group, (C5-C 10 The group consisting of heteroaryl groups and (C1-C6) acyl groups;

[0030] R4, R5, and R6 may be the same or different, and each is independently selected from methyl, ethyl, straight-chain, or branched (C3-C4) compounds. 12 ) alkyl groups and substituted or unsubstituted (C6-C 14 The group consisting of aryl groups;

[0031] The preparation method includes the following steps:

[0032] Under an inert atmosphere, a tri(pentafluorophenyl)borane solution is placed in a suitable reactor;

[0033] Simultaneously, at a temperature of approximately 40°C to approximately 90°C, for approximately 10 minutes to approximately 120 minutes, the compound of formula (II) and the silane of formula (III) are added to the above solution:

[0034] (II)

[0035] R4R5R6SiH(III);

[0036] Allow the reaction mixture to continue reacting for at least approximately 15 minutes;

[0037] The reaction mixture was cooled to room temperature and treated with an aqueous solution of a base selected from the group consisting of lithium carbonate, lithium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, ammonium hydroxide, tetramethylammonium hydroxide, and pyridine; and

[0038] The reaction mixture was vacuum distilled at a temperature of about 130°C to about 170°C to obtain the compound of formula (I).

[0039] Surprisingly, it has now been found that by metering a mixture containing substantially equimolar amounts of a compound of formula (II) and a compound of formula (III) into a solution containing a catalytic amount of tris(pentafluorophenyl)borane, as shown in Scheme I, a high-purity compound of formula (I) can be obtained in quantitative yield.

[0040] Option I

[0041]

[0042] It should be noted that various other Lewis acid catalysts with properties similar to tris(pentafluorophenyl)borane can also be used as catalysts in the methods of the present invention. As used in this specification, "Lewis acid" refers to any substance that absorbs electron pairs to form covalent bonds; that is, an electron pair acceptor. Examples of such Lewis acids include, but are not limited to, tris(2,4,6-trifluorophenyl)borane, tris(2,6-difluorophenyl)borane, tris(4-fluorophenyl)borane, tris(4-trifluoromethylphenyl)borane, etc.

[0043] Generally, it is preferable to use a Lewis acid that is also soluble in a solvent miscible or compatible with the compounds of formulas (II) and (III) to initiate the reaction intended in scheme I. Therefore, the Lewis acid of formula (IV) is a suitable Lewis acid that can be used in the method of the present invention.

[0044] M(R7) x X y (IV)

[0045] Where M is selected from the group consisting of boron, aluminum, gallium, indium, and thallium; R7 is independently the same or different, and represents the valence of the substituted element (C6-C). 14 ) aryl, wherein it is substituted with at least one electron-withdrawing group selected from the group consisting of -CF3, -NO2, -CN and halogens; X is a halogen; x is an integer from 1 to 3; and y is an integer from 0 to 3, provided that x + y = 3. In some embodiments, R7 is substituted with at least two halogens. In other embodiments, the Lewis acid suitable for the method of the present invention is represented by formula (V):

[0046] B(R8) x X y (V)

[0047] Each R8 is independently identical or different, and independently represents the unit price of the substituted product (C6-C). 14 The aryl group is substituted with at least one electron-withdrawing group selected from the group consisting of -CF3, -NO2, -CN, and halogens; X is a halogen; x is an integer from 1 to 3; and y is an integer from 0 to 3, provided that x + y = 3. In some embodiments, R7 is substituted with at least two halogens.

[0048] Advantageously, it has been found that tris(pentafluorophenyl)borane provides good catalytic activity in the preparation of compounds of formula (I). As mentioned above, the amount of tris(pentafluorophenyl)borane used is a catalytic amount, thus greatly reducing the effort required to purify the final product. The amount of tris(pentafluorophenyl)borane available generally depends on the type of compound of formula (I) to be prepared. Typically, the amount of tris(pentafluorophenyl)borane used is less than 0.1 mol% relative to the amount of compound of formula (II). That is, the molar ratio of compound of formula (II):tris(pentafluorophenyl)borane is typically 2,000:≤2. In other embodiments, the molar ratio of compound of formula (II):tris(pentafluorophenyl)borane is typically 2,000:1. That is, the molar percentage of tris(pentafluorophenyl)borane is about 0.05 mol% relative to the amount of compound of formula (II). Therefore, in some embodiments, less than 0.1 mol% of tris(pentafluorophenyl)borane, such as 0.05 mol%, 0.001 mol%, or even lower mol%, can be used to obtain compounds of formula (I) with higher purity. Similarly, in other embodiments, more than 0.2 mol% of tris(pentafluorophenyl)borane can be used, depending on the type of compound of formula (I) to be prepared. Various catalytic amounts of tris(pentafluorophenyl)borane used are within the scope of the inventive methods of this invention.

[0049] By implementing the inventive method conditions of this invention, compounds of formula (I) with high purity can be prepared. "High purity" as used herein means that the product is independent of other impurities. Therefore, in some embodiments, the purity of the compound of formula (I) prepared according to this invention is at least 99%. In other embodiments, the purity of the compound of formula (I) is at least 99.5%. In still other embodiments, the purity of the compound of formula (I) is at least 99.8%.

[0050] By appropriately using various silanes of formula (III), various norbornene alcohols of formula (II) can be used to form corresponding silanes of formula (I). In some embodiments, in the compounds of formula (II) used, n equals 1, R1, R2 and R3 are hydrogen, R4 is methyl, and R5 and R6 are phenyl.

[0051] Typically, the method of this invention is carried out under an inert atmosphere. Any known inert atmosphere may be used in this specification. In some embodiments, nitrogen is used as the inert atmosphere. Other inert atmospheres that may be used include helium or argon.

[0052] Surprisingly, it has now been discovered that adding an equimolar mixture of compounds of formula (II) and (III) to a solution of tris(pentafluorophenyl)borane at moderately low temperatures forms a compound of formula (I). Tris(pentafluorophenyl)borane is soluble in any inert solvent. Suitable such solvents include hydrocarbon solvents such as hexane, heptane, petroleum ether, benzene, toluene, and xylene; and halogenated hydrocarbon solvents such as dichloromethane, 1,1-dichloroethane, chloroform, and carbon tetrachloride, including mixtures of any combination thereof. In some embodiments, toluene is used as the solvent.

[0053] As mentioned above, the compounds of formula (II) and (III) are typically used in an equimolar ratio. However, as is well known to those skilled in the art, various other molar ratios that can result in higher yields of the compounds of formula (I) can also be used. Therefore, in some embodiments, a slight excess of the compound of formula (III) is used. For example, using more than 5 to 10 mol% of the compound of formula (III) may provide a higher yield of the compound of formula (I).

[0054] As shown in Scheme I, according to the method of the present invention, an equimolar mixture of a compound of approximately formula (II) and a compound of formula (III) is slowly added to a stirred solution of tris(pentafluorophenyl)borane under an inert atmosphere to form the compound of formula (I) while generating hydrogen. The reaction can suitably be carried out at a temperature moderately above room temperature. For example, such a reaction can be carried out in a suitable reactor system at a temperature range of about 40°C to about 90°C. In other embodiments, the reaction can be carried out at a temperature range of about 50°C to about 80°C; in other embodiments, the reaction can be carried out at a temperature range of about 60°C to about 70°C; in still other embodiments, the reaction is carried out at a temperature of about 65°C. In still other embodiments, the reaction can be carried out at a temperature above about 90°C.

[0055] Typically, the reaction of compound (II) with compound (III) in the presence of tris(pentafluorophenyl)borane releases heat; therefore, the order of reactant addition is controlled. The mixture is usually added slowly over a period of more than one hour. In some embodiments, the addition of the mixture takes place over approximately 10 to 120 minutes. In other embodiments, as is well known to those skilled in the art, the addition time can be longer than 120 minutes. Following the addition of the mixture, it is generally advantageous to allow the reaction to proceed for an additional 10 or 20 minutes or longer. Suitable reactor systems include, but are not limited to, ventilated glass reactors, suitable containers and / or reactors made of glass, glass-lined metal, etc.

[0056] After the reaction is complete, it is crucial to remove all residual tris(pentafluorophenyl)borane catalyst from the reaction mixture. Advantageously, it has been found that treating the reaction mixture with a suitable base can essentially remove all residual tris(pentafluorophenyl)borane. Suitable bases include, but are not limited to, alkali metal bases, such as hydroxides, alkoxides, carbonates, and bicarbonates of lithium, sodium, potassium, or cesium; alkaline earth metal bases, such as hydroxides, alkoxides, carbonates, and bicarbonates of calcium or magnesium; and suitable inorganic or organic bases, such as ammonia, trialkylamines, imidazoles, and pyridines. Specific alkali metal bases include, but are not limited to, lithium hydroxide, lithium methoxide, lithium ethoxide, lithium tert-butoxide, lithium carbonate, lithium bicarbonate, sodium hydroxide, sodium methoxide, sodium ethoxide, sodium tert-butoxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, potassium carbonate, potassium bicarbonate, cesium hydroxide, cesium methoxide, cesium ethoxide, cesium tert-butoxide, cesium carbonate, cesium bicarbonate, calcium hydroxide, calcium methoxide, calcium ethoxide, calcium tert-butoxide, calcium carbonate, calcium bicarbonate, magnesium hydroxide, magnesium methoxide, magnesium ethoxide, magnesium tert-butoxide, magnesium carbonate, magnesium bicarbonate, ammonia, trimethylamine, triethylamine, imidazole, and mixtures of any combination thereof. In some embodiments, the base used to remove tris(pentafluorophenyl)borane is sodium carbonate in aqueous solution form.

[0057] Typically, the reaction process can be monitored as follows: aliquots of the sample are taken from the reactor and analyzed by appropriate methods such as thin-layer chromatography (TLC), gas chromatography (GC), liquid chromatography (LC), high-performance liquid chromatography (HPLC), GC / mass spectrometry (MS), LC / MS, and combinations of other known techniques.

[0058] The various norbornene alcohols of formula (II) described in this specification are well known in the art or can be readily prepared by methods known in the art. For example, U.S. Patent No. 9,382,271 B2 discloses a method for preparing high-purity norbornene alcohols, the relevant portions of which are incorporated herein by reference.

[0059] The reaction mixture was treated with an aqueous sodium carbonate solution for separation, followed by distillation. It has been found advantageous to remove volatile organic compounds such as solvents (e.g., toluene) present in the product mixture under relatively low temperatures and vacuum conditions. Therefore, in some embodiments, the product mixture was distilled at about 130°C to 160°C and 100 to 200 Torr. The product was then vacuum distilled at about 160°C to 170°C and 1 to 2 Torr to obtain the compound of formula (I) of extremely high purity as described in this specification.

[0060] Surprisingly, it should be further noted that by implementing the method of the present invention, compounds of formula (I) can be obtained that are substantially free of any boron residue from the catalyst used. Therefore, in some embodiments, the amount of boron present in the compounds of formula (I) is less than 5 ppm, less than 4 ppm, less than 3 ppm, less than 2 ppm, and less than 1 ppm. In other embodiments, the amount of boron present in the compounds of formula (I) is about 1 ppm to 2 ppm. As shown in the specific examples below, when used as monomers for the preparation of high-quality polymers, compounds of formula (I) not only require high purity but also need to be boron-free.

[0061] In another embodiment of the present invention, a method for preparing a compound of formula (I) described in this specification is further provided, the method comprising the following steps:

[0062] Under a nitrogen atmosphere, a solution of tris(pentafluorophenyl)borane in toluene is placed in a suitable reactor;

[0063] At a temperature of about 60°C to about 70°C, for about 120 minutes, stoichiometric amounts of the compound of formula (II) and the silane of formula (III) described in this specification are added to the above solution.

[0064] Continue the reaction mixture for about 15 to about 30 minutes until the reaction is complete;

[0065] The reaction mixture was cooled to room temperature and treated with sodium carbonate.

[0066] Toluene was removed by vacuum distillation at approximately 130°C and 100–200 Torr; and

[0067] Vacuum distillation was performed at a temperature of about 160°C to 170°C and under conditions below 1 Torr to obtain a compound of formula (I) with a purity of at least 99% and boron residue of less than about 5 ppm.

[0068] In another embodiment of the present invention, a method for preparing (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)-diphenylsilane of formula (IB) is also provided:

[0069] (IB)

[0070] The preparation method includes the following steps:

[0071] Under a nitrogen atmosphere, a solution of tris(pentafluorophenyl)borane in toluene is placed in a suitable reactor;

[0072] After approximately 100 to 120 minutes, equimolar amounts of norbornene methanol (IIB) and methyldiphenylsilane (IIIB) are added to the solution:

[0073] (IIB)

[0074] (C6H5)2(CH3)SiH(IIIB);

[0075] Allow the reaction mixture to continue reacting for approximately 20 minutes;

[0076] The reaction mixture was cooled to room temperature and treated with sodium carbonate.

[0077] The toluene was removed by evaporation; and

[0078] Vacuum distillation is performed to obtain (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)-diphenylsilane of formula (IB) with a purity of at least 99% and boron residue of less than about 2 ppm. In another embodiment of the method of the present invention, (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)-diphenylsilane has a purity of at least 99.8% and boron residue of less than about 1 ppm.

[0079] The present invention will be further illustrated by the following embodiments. These embodiments are provided for illustrative purposes only and do not limit the scope of the present invention.

[0080] Implementation Examples (General Rules)

[0081] The following abbreviations used in this specification are used to describe some of the compounds, instruments, and / or methods employed in specific embodiments of the present invention:

[0082] NBMeOH: norbornene methanol; DPMS: diphenylmethylsilane;

[0083] FAB: Tris(pentafluorophenyl)borane; Pd-1206: (acetonitrile)bis(triisopropylphosphine)-(acetic acid)tetra(pentafluorophenyl)borate palladium; DANFABA: Tetra(pentafluorophenyl)borate dimethylaniline; EA: Ethyl acetate; GC-FID: Gas chromatography-flame ionization analyzer; GPC: Gel permeation chromatography; M W: Weight-average molecular weight; PDI: Polydispersity index.

[0084] Example 1

[0085] NBMeOSiPh2Me: (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)diphenylsilane

[0086] FAB (0.98 g) in toluene (2930 mL) was added to a suitably sized stirred reactor. The reactor was then sealed, filled with nitrogen, and pressure tested. The reactor was operated in a high-nitrogen-flow ventilation mode within a venting system. The reactor was heated to 65°C. Once this temperature was reached, a mixture of NBMeOH (584 g) and DPMS (971 g) was metered into the reactor (over 100 min), producing hydrogen and the title compound. At the end of the metering, the reaction mixture was maintained at this temperature for 20 min, then cooled to ambient temperature (approximately 25°C). A sodium carbonate solution (4100 g, 2.5 wt%) was added to the cooled reaction mixture and stirred for 30 min. The layers were allowed to settle for approximately 30–45 min, and the bottom aqueous layer was removed by decanting. The process was repeated twice with deionized water (4100 g). Then, volatile organic compounds (primarily toluene) were removed under vacuum (approximately 100 Torr and 160°C).

[0087] The obtained title compound was then purified by vacuum distillation using a short-path thin-film evaporator. A first distillation pass at 130 °C and approximately 1 Torr removed light impurities (approximately 5% by weight). A second distillation pass at 164 °C and approximately 1 Torr yielded the title compound (approximately 85% recovery). The purity of the title compound, as determined by GC FID and yield analysis, was >99%. Residual boron (derived from FAB) was approximately 1 ppm.

[0088] As shown below, the polymerization of the title compound yielded a high-quality polymer.

[0089] Copolymerization of the title compound in Example 1

[0090] Toluene (15 mL), hexylnorbornene (0.8 g), the title compound of Example 1 (1.5 g), and 1-hexene (0.2 g) were added to a 40 mL vial and heated to 80 °C. Then, 0.1 mL of a catalyst solution of Pd-1206 (0.00044 g) in anhydrous EA and DANFABA (0.00029 g) were added to the reaction mixture to initiate polymerization. After 35 minutes, another 0.2 g of hexylnorbornene was dissolved in 0.4 mL of toluene. After 3.5 hours, the polymer obtained had a conversion of 82%. The molecular weight of the polymer was determined by GPC. WIt is 156,000, and PDI is 3.1.

[0091] Comparative Example 1

[0092] NBMeOSiPh2Me: (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)diphenylsilane

[0093] FAB (0.98 g) in toluene (2900 mL) was placed in a suitably sized stirred reactor. The reactor was then sealed, filled with nitrogen, and pressure tested. The reactor was then operated in a high-nitrogen-flow ventilation mode with a ventilation system. The reactor was then heated to 65 °C. A mixture of NBMeOH (584 g) and DPMS (971 g) was metered into the reactor (over 100 min), producing hydrogen and the title compound. At the end of the metering, the mixture was allowed to react further for 20 min while maintaining the reaction temperature at 65 °C. Then, pyridine (26 g) was added through a closed transferor to deactivate the FAB, and the contents were cooled and removed through a closed transferor. Volatile organic compounds (mainly toluene) were then removed under vacuum stripping (approximately 100 Torr and 160 °C).

[0094] The crude title compound was then purified by vacuum distillation using a short-path thin-film evaporator. A first distillation at 130 °C and approximately 1 Torr further removed remaining light impurities (approximately 5% by weight). A second distillation at 164 °C and approximately 1 Torr yielded the title compound (approximately 85% recovery). The purity of the title compound, as determined by GC FID, was >99%. Residual boron (derived from FAB) was approximately 12 ppm.

[0095] The following examples demonstrate that the title compound produced in Comparative Example 1 yielded a copolymer of poor quality with a low conversion rate.

[0096] Copolymerization of the title compound of Comparative Example 1

[0097] Toluene (15 mL), hexylnorbornene (0.8 g), NBMeOSiPh2Me (1.5 g) from Comparative Example 1, and 1-hexene (0.2 g) were added to a 40 mL vial and heated to 80 °C. Then, 0.1 mL of a catalyst solution of Pd-1206 (0.00044 g) in anhydrous EA and DANFABA (0.00029 g) were added to the reaction mixture to initiate polymerization. After 35 minutes, another 0.2 g of hexylnorbornene was dissolved in 0.4 mL of toluene. After 3.5 hours, the conversion of the obtained polymer was approximately 36%. The molecular weight of the polymer, M, was determined by GPC. W It is 245,000, and PDI is 2.1.

[0098] Comparative Example 2

[0099] NBMeOSiPh2Me: (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)diphenylsilane

[0100] Comparative Example 2 confirmed that adding reactants in any order other than that described in the method of the present invention resulted in low conversion and low purity of the title compound.

[0101] Add 10 g of norbornene methanol (NBMeOH) and 100 mL of toluene to a suitably sized four-necked round-bottom flask equipped with a thermometer inlet, stir bar, N2 needle inlet (with diaphragm), gas outlet, bubbler, and reflux condenser. Then, add a 10 wt% solution of FAB (0.82 g) in 9 mL of toluene under high N2 flow. Slowly add a solution of diphenylmethylsilane (15.9 g) in 80 mL of toluene to the stirred solution to control gas evolution and exothermic reactions (keeping the temperature below 50°C). After the addition is complete (approximately 1 hour), stir the reaction mixture for 18 hours.

[0102] The reaction mixture was then filtered through a silica stopper (10 cm in diameter x 2.5 cm in height). The silica stopper was washed with toluene (100 mL x 2), and the residual washing solvent in the silica filter cake was examined by TLC to ensure that the target product was no longer eluted from the stopper. The resulting solution was concentrated to a small volume without further purification, and 8.9 g (34% yield) of the target material was isolated as a colorless liquid.

[0103] While the invention has been described through some of the above embodiments, it should not be construed as being limited thereto, but rather should be understood that the invention covers the general scope described above. Various modifications can be made without departing from the spirit and scope of the invention.

Claims

1. A method for preparing a compound of formula (I), （I） in, n is an integer from 1 to 10; m is an integer from 0 to 2; R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, halogen, methyl, ethyl, straight-chain or branched (C3-C4) elements. 12 )alkyl; R4, R5, and R6 may be the same or different, and are independently selected from methyl, ethyl, or straight-chain or branched (C3-C4) compounds. 12 )alkyl and unsubstituted (C6-C) 14 aryl; The preparation method includes the following steps: Under an inert atmosphere, a tris(pentafluorophenyl)borane solution is placed in a reactor; at a temperature of 25°C to 80°C, for 10 to 120 minutes, a mixture of compound (II) and silane (III) is added to the above solution: (II) R4R5R6SiH(III); Continue reacting the reaction mixture for 15 to 120 minutes; The reaction mixture was cooled to room temperature and treated with an alkali selected from lithium carbonate, lithium bicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate; and The reaction mixture was vacuum distilled at a temperature of 130°C to 170°C to obtain the compound of formula (I).

2. The method according to claim 1, wherein, The purity of the compound of formula (I) is at least 99%.

3. The method according to claim 1, wherein, The purity of the compound of formula (I) is at least 99.5%.

4. The method according to claim 1, wherein, The purity of the compound of formula (I) is at least 99.8%.

5. The method according to claim 1, wherein, n is 1, R1, R2 and R3 are each hydrogen, R4 is methyl, and R5 and R6 are each phenyl.

6. The method according to claim 1, wherein, Tris(pentafluorophenyl)borane exists in a catalytic amount.

7. The method according to claim 1, wherein, Based on the molar amount of the compound of formula (II), the amount of tris(pentafluorophenyl)borane used is less than 0.2 moles.

8. The method according to claim 1, wherein, Based on the molar amount of the compound of formula (II), the amount of tris(pentafluorophenyl)borane used is 0.1 mol% to 0.2 mol%.

9. The method according to claim 1, wherein, The inert atmosphere is nitrogen.

10. The method according to claim 1, wherein, Tris(pentafluorophenyl)borane dissolves in toluene.

11. A method for preparing a compound of formula (I), （I） in, n is an integer from 1 to 10; m is an integer from 0 to 2; R1, R2, and R3 may be the same or different, and are independently selected from hydrogen, halogen, methyl, ethyl, straight-chain or branched (C3-C4) elements. 12 )alkyl; R4, R5, and R6 may be the same or different, and are independently selected from methyl, ethyl, or straight-chain or branched (C3-C4) compounds. 12 )alkyl and unsubstituted (C6-C) 14 aryl; The preparation method includes the following steps: Under a nitrogen atmosphere, a solution of tri(pentafluorophenyl)borane in toluene was placed into the reactor; At a temperature of 60°C to 70°C, a mixture of compound (II) and silane (III) is added to the solution for 120 minutes: (II) R4R5R6SiH(III); Allow the reaction mixture to continue reacting for 15 to 30 minutes until the reaction is complete; The reaction mixture was cooled to room temperature and treated with sodium carbonate; and Toluene was removed by vacuum distillation at 130°C and 100–200 Torr. and Vacuum distillation was performed at a temperature of 160°C to 170°C and under conditions below 1 Torr to obtain a compound of formula (I) with a purity of at least 99% and boron residue of less than 5 ppm.

12. The method according to claim 11, wherein, The compound of formula (I) has a purity of at least 99.5% and boron residue of less than 2 ppm.

13. The method according to claim 11, wherein, n is 1, R1, R2 and R3 are each hydrogen, R4 is methyl, and R5 and R6 are each phenyl.

14. The method according to claim 11, wherein, Tris(pentafluorophenyl)borane exists in a catalytic amount.

15. The method according to claim 11, wherein, Based on the molar amount of the compound of formula (II), the amount of tris(pentafluorophenyl)borane used is less than 0.2 moles.

16. The method according to claim 11, wherein, Based on the molar amount of the compound of formula (II), the amount of tris(pentafluorophenyl)borane used is 0.1 mol% to 0.2 mol%.

17. The method according to claim 11, used to prepare (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)-(methyl)diphenylsilane with a purity of at least 99.8%.

18. A method for preparing a (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)-diphenylsilane of formula (IB), (ONE) The preparation method includes the following steps: Under a nitrogen atmosphere, a solution of tri(pentafluorophenyl)borane in toluene was placed into the reactor; After 100-120 minutes, add equimolar amounts of norbornene methanol (IIB) and methyldiphenylsilane (IIIB) to the above solution: (IIB) (C6H5)2(CH3)SiH(IIIB); Allow the reaction mixture to continue reacting for 20 minutes; The reaction mixture was cooled to room temperature and treated with sodium carbonate; and The toluene was removed by evaporation; and Vacuum distillation was performed to obtain (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)(methyl)-diphenylsilane of formula (IB) with a purity of at least 99% and boron residue of less than 2 ppm.

19. The method according to claim 18, wherein, The purity of (bicyclo[2.2.1]hept-5-en-2-ylmethoxy)-(methyl)diphenylsilane is at least 99.8% and the boron residue is less than 1 ppm.

Images