Process for hydrosilylating olefinic nitriles

Abstract

A method for preparing cyanoalkyl-functional silanes is disclosed, which involves removing cyanide impurities from an olefinic nitrile followed by hydrosilylation of the olefinic nitrile with a hydridosilane.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application asserts the interests of U.S. Provisional Patent Application No. 63 / 071,388, filed on 28 August 2020 under Section 119(e) of the U.S. Patent Act. U.S. Provisional Patent Application No. 63 / 071,388 is incorporated herein by reference.

[0002] (Field of Invention) The present invention relates to an improved method for hydrosilylation of olefinic nitriles and hydridosilanes. More specifically, the present invention relates to an improved method for preparing 3-cyanobutyl-methyldimethoxysilane by platinum-catalyzed hydrosilylation of 2-methyl-3-butenenitrile and methyldimethoxysilane. [Background technology]

[0003] 3-Cyanobutyl-methyldimethoxysilane is prepared from 2-methyl-3-butenenitrile (a commercially available olefinic nitrile) and methyldimethoxysilane by platinum-catalyzed hydrosilylation. In a typical catalyst packing, sufficient amounts of platinum (based on the total weight of 2-methyl-3-butenenitrile and methyldimethoxysilane) are required to supply the reaction mixture to achieve a sufficient reactant conversion rate. Platinum catalysts are expensive and are becoming increasingly scarce.

[0004] [ka] [Overview of the project]

[0005] The method is, 1) To provide A') an olefin-based nitrile containing cyanide impurities, 2) A') Removing all or part of the cyanide impurities from the olefinic nitrile, thereby producing A) a purified olefinic nitrile. 3) At a temperature of 20°C to 150°C, A) The purified olefin-based nitrile, B) Formula R 1 x HSiX (3-x) (In the formula, the subscript x is 0, 1, or 2, and each R 1 X is a monovalent hydrocarbon group consisting of 1 to 18 independently selected carbon atoms, where each X is independently a halogen atom and the formula OR 1 A hydridosilane having (selected from the group consisting of alkoxy groups), and C) A sufficient amount of platinum hydrosilylation catalyst to provide 5 ppm to <200 ppm of Pt based on the total weight of starting materials A), B), and C). Combining the starting materials, Includes. [Modes for carrying out the invention]

[0006] Olefin nitriles are known and commercially available in the art. Preferred olefin nitriles may be supplied by commercial sources, for example, Sigma-Aldrich (St. Louis, Missouri, USA); INVISTA North America S.ar.l.; TCI America, Inc.; or Tokyo Chemical Industry Co., Ltd. (Tokyo). Olefin nitriles may have the formula RC≡N (wherein R represents an aliphatic unsaturated monovalent hydrocarbon group such as an alkenyl group exemplified by vinyl, allyl, methylpropenyl, butenyl, methylbutenyl, and pentenyl). Olefin nitriles are exemplified by acrylonitrile (CH2=CHC≡N), 2-butenenitrile (CH3-CH=CH-C≡N), 3-butenenitrile (CH2=CH-CH2-C≡N), 2-methyl-3-butenenitrile (CAS number 16529-56-9 shown above), and 2-pentenenitrile (CH3-CH2-CH=CH-C≡N). Alternatively, the olefin nitrile may be selected from the group consisting of 3-butenenitrile and 2-methyl-3-butenenitrile. Alternatively, the olefin nitrile may be 2-methyl-3-butenenitrile.

[0007] Olefin nitriles, as provided above, typically contain cyanide impurities, where the cyanide impurity refers to a compound of the formula X'-C≡N (wherein X' is hydrogen, sodium, or potassium). Alternatively, the cyanide impurity may be hydrogen cyanide of the formula HC≡N. The cyanide impurity may be present in amounts of 25 ppm or more, based on the weight of the provided olefin nitrile. Alternatively, the cyanide impurity may be present in amounts of 30 ppm or more, or 35 ppm or more, or 40 ppm or more, or 45 ppm or more, based on the same standard. At the same time, the cyanide impurity may be present in amounts of up to 200 ppm, or up to 175 ppm, or 150 ppm, or 125 ppm, based on the same standard. Alternatively, cyanide impurities may be present in amounts of >25 ppm to 200 ppm, >25 ppm to 125 ppm, or 45 to 125 ppm, depending on the weight of the olefinic nitrile provided.

[0008] The inventors have surprisingly found that cyanide impurities can inhibit the hydrosilylation reaction of olefinic nitriles with hydridosilanes. While not theoretically bound, it is thought that the HC≡N content may be related to the loss of catalytic activity as the amount of platinum catalyst decreases. While not theoretically bound, it is thought that removing all or part of the cyanide impurities from the olefinic nitrile before hydrosilylation of the olefinic nitrile and hydridosilane may improve yield, reduce the amount of expensive platinum catalyst used, or both. Furthermore, if the hydrosilylation reaction proceeds more predictably, is less affected by reactant retention, and / or minimizes the SiH content of by-products, both process and safety may be improved.

[0009] In step 2) of the above method, the purified olefinic nitrile may be prepared by removing all or part of the cyanide impurities. The method for removing the cyanide impurities includes contacting the olefinic nitrile with an adsorbent such as activated carbon or molecular sieves. The activated carbon may be woody, coconut shell, or lignite-based and can be processed in various ways to provide a suitable surface area for contact. For example, one suitable type of activated carbon for use herein includes acid-washed lignite-based activated carbon with a mesh size of 12 × 40, giving an average particle size of 1 mm. The contact between the olefinic nitrile and the adsorbent in step 2) may be carried out under an inert atmosphere. The pressure for contact may be varied, for example, from 0 to 50 psig. The temperature may be varied, for example, from 20 to 60°C. The contact time may be varied, for example, from 1 to 24 hours or from 1 to 8 hours. The amount of adsorbent may be 1% to 10% by weight or 3% to 5% by weight, based on the total weight of the adsorbent and the olefinic nitrile. The particle size of the adsorbent may be, for example, 1 mm to 2 mm.

[0010] Alternatively, step 2) may include contacting an olefinic nitrile with a metal absorbent containing a metal selected from the group consisting of iron (Fe), copper (Cu), silver (Ag), and nickel (Ni) as a powder, particle, or metal on a substrate. The metal absorbent may be elemental Fe, Cu, Ag, or Ni. Alternatively, the metal absorbent may be selected from the group consisting of elemental Fe, Cu, and Ag. Alternatively, the metal absorbent may be the aforementioned metals bonded to a substrate such as carbon or silica. The metal absorbent may be used under conditions that avoid or minimize metal oxidation, such as inert conditions. Contact may be carried out under a wide range of pressures, such as 0 to 50 psig. Contact may be carried out at various temperatures, for example, 20 to 60°C is preferred. Contact may be carried out under a wide range of pressures, such as 0 to 50 psig. Contact may be carried out at various temperatures, such as 20 to 60°C. Contact may be carried out over a period of time, for example, 1 to 24 hours or 1 to 8 hours. The amount of metal absorbent may be 1% to 10% by weight, or 3% to 5% by weight, based on the total weight of the metal absorbent and the olefinic nitrile. The particle size of the metal absorbent may be, for example, 1 mm to 2 mm. Although not bound by theory, it is thought that metals can form complexes with cyanide impurities, which can then be removed by filtration and / or contact with an adsorbent such as activated carbon, as described above. Although not bound by theory, it is thought that cyanide-metal complexes can be formed by contacting olefinic nitriles with metal absorbents, and then the cyanide-metal complexes can be removed by contact with an adsorbent (for example, if the metal is soluble) and / or by filtration (for example, if the metal is bonded to the substrate, or after contact with an adsorbent), as described above.

[0011] Alternatively, step 2) may include contacting the olefinic nitrile with a metal oxide absorbent selected from the group consisting of oxides of Fe, Cu, Ag, or Ni. The contact may be carried out under a wide range of pressures such as 0 to 50 psig. The contact may be carried out at various temperatures, for example, 20 to 60 °C is preferred. The contact in step 2) may be carried out under an inert atmosphere. The contact may be carried out under a wide range of pressures such as 0 to 50 psig. The contact may be carried out at various temperatures such as 20 to 60 °C. The contact may be carried out over a certain period of time, for example, 1 to 24 hours, or 1 to 8 hours. The amount of the adsorbent may be 1 wt% to 10 wt%, or 3 wt% to 5 wt% based on the total weight of the metal oxide and the olefinic nitrile. The particle size of the metal oxide may be, for example, 1 mm to 2 mm. Without being bound by theory, it is considered that the metal in the metal oxide can form a complex with the cyanide impurity, and then this complex can be removed by filtration.

[0012] Alternatively, the olefinic nitrile may be stripped or distilled and / or sparged with another inert gas such as nitrogen or argon. The cyanide impurity is removed in the first "heads" cut, and the purified olefinic nitrile can be left in the pot. This may be carried out near atmospheric pressure to limit the temperature required to achieve the removal of the heads cut. When sparging with an inert gas, the gas may be nitrogen.

[0013] Alternatively, two or more of the above methods may be used. For example, the olefinic nitrile may be contacted with the metal absorbent and the adsorbent simultaneously or sequentially (e.g., the olefinic nitrile may be contacted with the metal absorbent, filtered, and then contacted with an adsorbent such as activated carbon). In step 2), the amount of cyanide impurities in A) the olefinic nitrile is reduced as compared to the amount of cyanide impurities present in A’) the olefinic nitrile provided in step 1). For example, the purified olefinic nitrile may contain 0 ppm of cyanide impurities. Alternatively, the purified organic nitrile may contain at least 10 ppm less cyanide impurities after step 2) as compared to A’) the olefinic nitrile provided in step 1).

[0014] The starting materials comprising A) the purified olefinic nitrile, B) a hydridosilane, and C) a platinum hydrosilylation reaction catalyst prepared as described above are combined in step 3) of the above method. They may be combined by any convenient means such as mixing, optionally with heating. For example, step 3) may be carried out at a temperature of 20 °C to 150 °C, preferably 60 to 100 °C, under an inert atmosphere. Step 3) may be carried out under an inert atmosphere. The pressure is not critical and may be, for example, 0 to 50 psig, or ambient pressure may be used for convenience. Step 3) may be carried out batchwise, semi-batchwise, or continuously, with heating or cooling to control the progress of the reaction.

[0015] Starting material B), the hydridosilane, has the formula R 1 x HSiX (3-x) (where the subscript x is 0, 1, or 2, each R 1 is an independently selected monovalent hydrocarbon group having 1 to 18 carbon atoms, and each X is independently a halogen atom and the formula OR<It may have a alkoxysilane (selected from the group consisting of alkoxy groups). Alternatively, the hydridosilane may be an alkoxysilane. Examples of alkoxysilanes for starting material B) include methyldimethoxysilane, trimethoxysilane, ethyldimethoxysilane, triethoxysilane, and ethyldiethoxysilane. Suitable hydridosilanes are known in the art and are commercially available, for example, from Dow Silicones Corporation (Midland, MI, USA). Starting materials A) and B) may be used in amounts sufficient to provide 1:1 molar equivalents of A) and B). Alternatively, a molar excess of A) or B) may be used. For example, the molar ratio of starting materials A) to B) (A / B ratio) may be 10 / 1 to 1 / 10, or 2 / 1 to 1 / 2, or 1 / 1.5 to 1.5 / 1, or 1 / 1 to 1.1:1, or 1.1 / 1 to 1 / 1.

[0016] The starting material C) is a platinum hydrosilylation catalyst. Platinum hydrosilylation catalysts are known in the art and are commercially available. The platinum hydrosilylation catalyst may contain platinum metal, which may optionally be deposited on a support such as silica, alumina, or activated carbon. Alternatively, the platinum hydrosilylation catalyst may be a platinum compound, such as chloroplatinic acid (Speier catalyst), chloroplatinic acid hexahydrate, or platinum dichloride. Alternatively, the platinum hydrosilylation catalyst may be a complex of such a compound with, for example, a low molecular weight organopolysiloxane. An example of a complex of platinum and a low molecular weight organopolysiloxane is the platinum complex of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane (Karstedt catalyst). Alternatively, the platinum hydrosilylation catalyst may be the platinum compound or platinum complex described above microencapsulated in a matrix or core-shell structure, for example, the compound or complex may be microencapsulated in a resin matrix. Alternatively, the platinum hydrosilylation catalyst may include chloroplatinic acid, a Karstedt catalyst, or platinum on a support selected from carbon, silica, or alumina. Exemplary platinum hydrosilylation catalysts are described, for example, in U.S. Patent No. 2,823,218 by Speier; U.S. Patent No. 3,159,601 by Ashby; U.S. Patent No. 3,220,972 by Lamoreaux; U.S. Patent No. 3,419,593 by Willing; U.S. Patent No. 3,516,946 by Modic; U.S. Patent No. 3,814,730 by Karstedt; U.S. Patent No. 3,989,668 by Lee et al.; U.S. Patent No. 4,766,176 by Lee et al.; U.S. Patent No. 4,784,879 by Lee et al.; U.S. Patent No. 5,017,654 by Togashi; U.S. Patent No. 5,036,117 by Chung et al.; and U.S. Patent No. 5,175,325 by Brown et al.; and in European Patent Application Publication No. 0347895(A) by Togashi. Platinum hydrosilylation catalysts are commercially available; for example, SYS-OFF® 4000 catalyst and SYL-OFF® 2700 are available from Dow Silicones Corporation (Midland, Michigan, USA).The platinum hydrosilylation catalyst may be used in an amount sufficient to provide 5 ppm to 200 ppm, or 5 ppm to <200 ppm, or 5 ppm to 100 ppm, or 35 ppm to 70 ppm of platinum, based on the total weight of the starting materials A), B), and C).

[0017] The above method may optionally further include adding the starting material D) and / or an accelerator during and / or after step 3). Hydrosilylation accelerators are known in the art and can also be applied to improve the reaction of olefinic nitriles.

[0018] Various carboxylic acids can be used as accelerators in the methods described herein. For example, neodecanoic acid may be used as an accelerator. If present, the carboxylic acid may be added in an amount sufficient to provide a carboxylic acid:(hydridosilane + olefinic nitrile) in a ratio of >0:1 to 1:1, or 0.005:1 to 0.02:1, for the following reasons: a component ratio of less than 0.005:1 may result in insufficient effects on product selectivity and product yield, while a ratio greater than 0.02:1 may still produce the advantageous effects of the present invention, but may result in excessive material loss.

[0019] The above method may optionally further include E) delivering one or more of the above starting materials in a solvent. For example, starting material C) hydrosilylation catalyst may be delivered in the solvent. Suitable solvents include, but are not limited to, organic liquids exemplified by aromatic hydrocarbons, aliphatic hydrocarbons, alkyl halides, and aromatic halides. Examples of hydrocarbons include benzene, toluene, xylene, naphtha, hexane, cyclohexane, methylcyclohexane, heptane, octane, decane, hexadecane, isoparaffins, e.g., Isopar L (C11-C13), Isopar H (C11-C12), and hydrogenated polydecene. Alternatively, the solvent may be selected from polyalkylsiloxanes and aromatic hydrocarbons, e.g., toluene, xylene, or combinations thereof. Polyalkylsiloxanes having a suitable vapor pressure may be used as a solvent, including hexamethyldisiloxane, octamethyltrisiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tris(trimethylsiloxy)methylsilane, tetrakis(trimethylsiloxy)silane, dodecamethylcyclohexasiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, tetradecamethylhexasiloxane, hexadecamethylheptasiloxane, heptamethyl-3-{(trimethylsilyl)oxy)}trisiloxane, hexamethyl-3,3,bis{(trimethylsilyl)oxy}trisiloxanepentamethyl{(trimethylsilyl)oxy}cyclotrisiloxane, and combinations thereof. Low molecular weight polyalkylsiloxanes, such as polydimethylsiloxane with a molecular weight of 0.5 to 1.5 cSt, are known in the art and are commercially available from Dow Silicones Corporation as DOWSIL® 200 Fluids and DOWSIL® OS Fluids.

[0020] The amount of solvent varies depending on various factors, including the type and amount of each of the starting materials A), B), and C), and D) if present, as well as their relative compatibility with each other, and the type of equipment used to combine them. However, the amount of solvent may be between 0% and 95% by weight, based on the weight of starting material C).

[0021] In the above method, equation R 1 x R 2 SiX (3-x) (In the formula, the subscripts x and R 1 As defined above, R 2 The compound comprises a group of the formula N≡CD-, where D is a divalent hydrocarbon group (e.g., N≡C-CH(CH3)-CH2-CH2-)), producing a product. The compound may also be a cyanoalkyl functional alkoxysilane (i.e., X is OR 1 (In this case). Cyanoalkyl functional alkoxysilanes, such as (3-cyanobutyl)methyldimethoxysilane, are useful for processing electrical cables, for example, as described in U.S. Patent No. 8,656,586.

[0022] The product may further contain unreacted starting materials, catalysts, accelerators, and solvents, if used. Therefore, the method may optionally further include recovering the compound from the product. Recovery may be carried out by any convenient means, such as stripping and / or distillation. [Examples]

[0023] These examples are intended to illustrate some embodiments of the present invention and should not be construed as limiting the scope of the invention as described in these claims. The starting materials used in these examples are listed in Table 1.

[0024] [Table 1]

[0025] In this Comparative Example 1, 2M3BN and methyldimethoxysilane were hydrosilylated under the following conditions. Reactions were prepared in glass tube reactors measuring 19.7 cm (7.75 inches) in length and 1.9 cm (3 / 4 inch) in diameter, using 1.17 mL of methyldimethoxysilane, 1.19 mL of 2M3BN (25% molar excess relative to methyldimethoxysilane), and 35 μL of neodecanoic acid. Each tube reactor was cooled on dry ice, and then, as summarized in Table 2 below, the Karrstedt catalyst solution was dissolved in toluene so that the resulting catalyst solution containing 1 wt% platinum was added to target various Pt concentrations in the reaction mixture in the different tube reactors. The cyanide impurity concentration in 2M3BN was measured to be 45 ppm, which corresponds to 10 6 This translates to a molar concentration of 140.4 mol of cyanide impurity per 2 mol of 3BN. The hydrosilylation reaction was completed at 100°C for a reaction time of 1 hour using different amounts of Pt catalyst (a 1 wt% Pt solution was prepared using toluene solvent to dilute the Karstedt catalyst, and then various amounts of 1 wt% Pt solution were added). The eluates were analyzed by GC, and the conversion rates of the limiting reagents are shown in Table 2. This comparative example showed that conversion was significantly inhibited as the Pt concentration decreased.

[0026] In this Example 2, the hydrosilylation procedure of Comparative Example 1 was repeated, except that 2M3BN was purified before hydrosilylation. The same 2M3BN used in Comparative Example 1 was purified by passing it through a Cu bed, followed by lignite-based activated carbon (AC), to reduce the cyanide impurity content. The mass ratio of Cu and AC to the treated 2M3BN was 3%. The cyanide impurity concentration of the treated 2M3BN was measured to be 7.3 ppm, which is 10 6 Converted to a molar concentration of 22.8 mol of cyanide impurities per mol of 2M3BN, this represented an 83.8% reduction. Table 2 shows that a high conversion rate of the limiting reagent was maintained even when the Pt concentration decreased.

[0027] In Example 3, the hydrosilylation process of Example 2 was repeated, except that the Cu and AC beds were reused. The 2M3BN was the same as that used in Comparative Example 1. The purified 2M3BN used in Example 3 was obtained as a fourth aliquot of the material passed through the bed described in Example 2, with each aliquot being 3% Cu / AC in mass ratio to 2M3BN. Table 2 shows that the conversion rate was maintained even when the Pt concentration decreased. This Example 3 demonstrates that the bed can be reused.

[0028] In this Comparative Example 4, the reaction of Comparative Example 1 was repeated except that 0.97 mL of 3BN was used instead of 1.19 mL of 2M3BN. The cyanide impurity concentration in the 3BN was measured to be 25.6 ppm, which translates to a molar concentration of 68 moles of cyanide per 10^6 moles of 3BN.

[0029] In Example 5, the reaction of Comparative Example 4 was repeated, except that the 3BN was purified before use to reduce the cyanide impurity content. The 3BN was purified by passing it through a bed of Cu and AC. The mass ratio of Cu and AC to the treated 3BN was 3%. The cyanide impurity concentration after treatment was measured to be 5.2 ppm, which is 10 6 This was converted to a molar concentration of 13.8 moles of cyanide per mole of 3 moles of BN, representing a 79.6% reduction. This Example 5 demonstrated that the conversion rate was maintained even when the Pt concentration decreased.

[0030] [Table 2]

[0031] In this Reference Example 6, a sample of 2M3BN was obtained and analyzed before and after purification to reduce the cyanide impurity concentration. Metal treatment, if used, was performed simultaneously with or before activated carbon treatment. When metal treatment was performed first, this is indicated as "stepwise" in Table 3 below. Metal treatment was performed by adding Cu powder or Ag powder (amounts shown in Table 3) to fresh, untreated 2M3BN. The sample was shaken vigorously for 1 day and then filtered through a 0.45 μm syringe filter. When activated carbon treatment was performed, ground or unground, acidic, basic, or neutral wood-based activated carbon was added to the filtered 2M3BN sample, and the sample was shaken for 1 day. The sample was then filtered through another 0.45 μm syringe filter. The CN- ion content was measured using an ion-selective electrode before and after treatment to determine the reduction in concentration. The samples are summarized in Table 3 below.

[0032] [Table 3]

[0033] In this Reference Example 7, purified 2M3BN and unpurified 2M3BN for comparison, prepared according to the last row of Table 3 above, were used in the following hydrosilylation reaction. Nitrogen tube headspace was used for these experiments. 2.5 mL of methyldimethoxysilane, 2.5 mL of purified 2M3BN, and 44 μL of neodecanoic acid were added to glass tube reactors measuring 19.7 cm (7.75 inches) in length and 1.9 cm (3 / 4 inch) in diameter. Each tube reactor was cooled with dry ice, and then 20 μL of catalyst solution was added with a target of 50 ppm Pt in the reaction mixture, after which the tubes were placed on a heater block at 80°C. The catalyst solution was Karstedt catalyst diluted with xylene so that the resulting catalyst solution contained 1 wt% Pt. The tubes were left on the heater block for 1 hour, and then the progress of the reaction was measured using GC. The results shown in Table 4 below demonstrate that beneficial results were obtained through stepwise treatment under the tested conditions.

[0034] [Table 4]

[0035] In this Reference Example 8, 2M3BN was purified using various adsorbents before being used in the hydrosilylation reaction. The purification was performed as follows: The adsorbent was added to 5 mL of 2M3BN so that the liquid level was directly above the height of the adsorbent. The resulting mixture was immersed for 5 days with periodic shaking. After that, the liquid was syringe filtered from the adsorbent using a 0.2 μm filter. Table 5 summarizes the prepared 2M3BN samples.

[0036] [Table 5]

[0037] Next, the 2M3BN samples in Table 5 were used in the hydrosilylation reaction as follows: Nitrogen tube headspace was used for these experiments. 1.75 mL of methyldimethoxysilane, 1.35 mL of 2M3BN, and 28 μL of neodecanoic acid were added to glass tubes of the same dimensions as those used in Comparative Example 1. Each tube was cooled with dry ice, and then 75 μL of catalyst solution was added with a target of 250 ppm Pt in the reaction mixture. The tubes were then placed on a heater block at 80°C. The catalyst solution was Karstedt catalyst diluted with xylene so that the solution contained 1% Pt. After 5 hours, GC analysis was performed to measure the progress of the reaction. The results are shown in Table 6 below.

[0038] [Table 6]

[0039] Reference Example 8 showed that purification of 2M3BN with silver improved the yield of the hydrosilylation synthesis. Treatment of 2M3BN with activated carbon and molecular sieves moderately improved the yield of the hydrosilylation. Although not bound by theory, the negative results in 8c are thought to be due to inhibition of the reaction by metal oxides and / or complexes of metal oxides with cyanide impurities. Therefore, when using metal oxides to remove cyanide impurities, it is further thought that any metal oxides and / or their complexes should be removed, for example by filtration, before proceeding to step 3) of the method described herein.

[0040] In this Example 9, cyanide impurities were removed from 2M3BN via batch distillation followed by hydrosilylation. Batch distillation was performed using a 1 L three-necked flask and a 10-stage tray glass column. The material was condensed using a water condenser and collected in a 50 mL receiver. Heat was injected into the flask using a heating mantle and mixed with a stirring bar. 450 grams of 2M3BN were packed into the flask. The flask was heated and 30.1 grams of the material was subjected to overhead distillation at a 1:1 reflux ratio. The purified 2M3BN remaining in the flask was found to have a reduced cyanide impurity from 53 μg / mL to 8 μg / mL.

[0041] Both starting 2M3BN and purified 2M3BN were used in the hydrosilylation reaction for comparison. The hydrosilylation reaction was carried out in a semi-batch manner. 270 g of 2M3BN, 13.6 g of neodecanoic acid, and 0.42 g of Karstedt catalyst (24% Pt) were packed into a three-necked flask. 333.7 g of methyldimethoxysilane was packed into a syringe pump. 30 g of 2M3BN was mixed with 13.6 g of neodecanoic acid and added to a second syringe pump. The contents of the syringe pumps were metered and injected over 6 hours. The liquid temperature of the reactor contents was maintained at 80-85°C. The degree of reaction was measured using GC.

[0042] In comparative sample 9-1, the reaction was carried out using control 2M3BN containing 53 μg / mL of cyanide impurities, resulting in a conversion rate of methyldimethoxysilane of 97.98%. When the reaction was carried out using purified 2M3BN containing 8 μg / mL of cyanide impurities, the conversion rate of methyldimethoxysilane was 99.99%.

[0043] Purification of 2M3BN by distillation was effective in reducing the cyanide impurity concentration. Purified 2M3BN exhibited improved hydrosilylation reaction performance, with a 99.5% reduction in residual SiH compared to the control. While the SiH content in the reaction crude with purified 2M3BN was only 0.4 ppm, the sample using control 2M3BN had 96 ppm of residual SiH in the reaction crude. Achieving low levels of SiH is crucial for the safe disposal of waste.

[0044] In this Example 10, distillation of 2M3BN was performed as follows to reduce the cyanide impurity content and improve the hydrosilylation performance. Batch distillation was used with a 250 mL three-necked flask and a 10-stage tray glass column. The material was condensed using a water condenser and collected in a 50 mL receiver. Heat was injected into the three-necked flask using a heating mantle and mixed with a stirring bar. 148.8 g of TCI 2M3BN was packed into the flask. The flask was heated to 122 °C and the column was left under total reflux for 1 hour. Then, various top fractions were collected.

[0045] Hydrosilylation reactions were carried out using various distillation distillates. A nitrogen tube headspace was used for these experiments. 1.0 mL of methyldimethoxysilane and 0.8 mL of 2M3BN were added to a glass tube of the same dimensions as in Comparative Example 1. The tube was cooled on dry ice, and then the catalyst solution was added, targeting 100 ppm of Pt in the reaction mixture. The tube was placed on a heater block at 100°C for 2 hours, and then the progress of the reaction was measured using GC. The results are shown in Table 7 below.

[0046] [Table 7]

[0047] While not bound by theory, this Example 9 is considered to demonstrate that the hydrosilylation reactivity of 2M3BN can be improved by distillation. The early fractions of distillation, which contained a larger amount of (lower boiling point) cyanide impurities, performed very poorly in the hydrosilylation reaction, even worse than the control. On the other hand, the later 2M3BN fractions of distillation (e.g., fractions 4-8) contained fewer cyanide impurities and performed much better in the hydrosilylation reaction than the control (using undistilled 2M3BN).

[0048] Industrial applicability The inventors have surprisingly discovered that cyanide impurities can act as inhibitors of the hydrosilylation of olefinic nitriles and hydridosilanes. Specifically, it was found that the cyanide impurity content is directly related to the loss of activity of the platinum catalyst. It was found that reducing the amount of cyanide impurities in the olefinic nitrile by just 10 ppm increased the conversion rate of the limiting reagent at the same or a lower platinum metal content.

[0049] Use of terminology The summary and abstract of the invention are incorporated herein by reference. All quantities, ratios, and percentages are by weight unless otherwise indicated in the context of the specification. Unless otherwise specified in the context of the specification, the articles "a," "an," and "the" refer to one or more. Disclosures of ranges include the range itself, anything contained within the range, and endpoints. For example, disclosures of ranges >0.3 to 0.8 include not only the range >0.3 to 0.8, but also 0.4, 0.55, 0.6, 0.7, 0.78, and 0.8 individually, as well as any other numbers contained within that range. Furthermore, for example, a disclosure in the range >0.3 to 0.8 includes, for example, 0.4 to 0.6, 0.35 to 0.78, 0.41 to 0.75, 0.78 to 0.8, 0.32 to 0.41, 0.35 to 0.5, and any other subsets included within that range. Similarly, a disclosure of a Markush group includes the entire group and any individual elements and subgroups contained therein. For example, a disclosure of the Markush group vinyl, allyl, or hexenyl includes vinyl as its individual member; vinyl and hexenyl as its subgroups; and any other individual members and subgroups contained therein.

[0050] The abbreviations used in this specification are defined as shown in Table 8 below.

[0051] [Table 8]

[0052] The samples were analyzed by GC under the following conditions: The gas chromatograph used was an Agilent 7890A running Chemstation OpenLab CDS Revision C.01.07 with an RTX-1 column (30m × 250μm × 1.00μm nominal) in a flame ionization detector (FID). An autosampler was used for sample injection. The parameters of the method were as follows: ·Start: Hold at 50℃ for 1 minute Gradient: 15°C / min • Finish: Hold at 260℃ for 5 minutes • Injection port: 250℃ Detector: 300℃ Helium flow rate: 2.1 mL / min • Split 50:1 • Injection volume: 1.0 μL

[0053] Embodiments of the present invention In the first embodiment, a method for preparing a cyanoalkyl functionalized silane is: 1) To provide A') an olefin-based nitrile containing cyanide impurities in an amount of ≥40 ppm, 2) A') Removing all or part of the cyanide impurity from the olefinic nitrile, thereby producing A) a purified olefinic nitrile. 3) At a temperature of 20°C to 150°C, A) The purified olefin-based nitrile, B) Formula R 1 x HSiX (3-x) (In the formula, the subscript x is 0, 1, or 2, and each R 1 X is a monovalent hydrocarbon group consisting of 1 to 18 independently selected carbon atoms, where each X is independently a halogen atom and the formula OR 1 A hydridosilane having (selected from the group consisting of alkoxy groups), and C) A sufficient amount of platinum hydrosilylation catalyst to provide 5 ppm to <200 ppm of Pt based on the total weight of starting materials A), B), and C). Combining the starting materials, Includes.

[0054] In the second embodiment, A') the olefinic nitrile is selected from the group consisting of 3-butennitrile and 2-methyl-3-butennitrile.

[0055] In the third embodiment, the cyanide impurity includes HC≡N.

[0056] In the fourth embodiment, cyanide impurities are present in a concentration of 40 ppm to 200 ppm based on the weight of A') olefinic nitrile.

[0057] In the fifth embodiment, in hydridosilane, x is 0 or 1, and R 1 X is an alkyl group, and X is an alkoxy group.

[0058] In the sixth embodiment, the hydridosilane described in the fifth embodiment has x=1, and R 1 X is a methyl group, and each X is a methoxy group.

[0059] In the seventh embodiment, the hydridosilane is selected from the group consisting of methyltrimethoxysilane and methyldimethoxysilane.

[0060] In the eighth embodiment, the platinum hydrosilylation catalyst comprises chloroplatinic acid, a Karstedt catalyst, or platinum on a support selected from carbon, silica, or alumina.

[0061] In the ninth embodiment, step 2) includes combining the olefinic nitrile with an elemental metal selected from the group consisting of copper, iron, silver, or nickel.

[0062] In the tenth embodiment, the method according to the ninth embodiment further comprises combining the olefinic nitrile with an elemental metal, and then combining the olefinic nitrile with an adsorbent.

[0063] In the eleventh embodiment, the metal is copper in the method of the ninth or tenth embodiment.

[0064] In the twelfth embodiment, step 2) of the method according to any one of the above embodiments includes contacting an olefin nitrile with an adsorbent selected from the group consisting of activated carbon and molecular sieves.

[0065] In the thirteenth embodiment, the method according to any one of the first to eighth embodiments includes contacting an olefinic nitrile with an oxide of a metal selected from the group consisting of copper, iron, silver, and nickel.

[0066] In the fourteenth embodiment, the method according to any one of the embodiments further comprises filtering in step 2) to prepare a purified olefinic nitrile.

[0067] In the 15th embodiment, step 2) of the method according to any one of the embodiments further includes stripping, distillation, or a combination thereof.

[0068] In the sixteenth embodiment, the purified olefin-based nitrile produced in step 2) contains 0 ppm of cyanide impurities.

[0069] In the 17th embodiment, the purified olefin-based nitrile produced in step 2) contains 5 to 40 ppm of cyanide impurities, provided that the purified olefin-based nitrile contains less cyanide impurities than the olefin-based nitrile provided in step 1).

[0070] In the 18th embodiment, the method according to any one of the embodiments further comprises adding the accelerator D) during and / or after step 3).

[0071] In the 19th embodiment, the method according to any one of the above embodiments further comprises delivering one or more starting materials in a solvent.

[0072] In the 20th embodiment, the method described in any one of the above embodiments is expressed as formula R 1 x R 2 SiX (3-x) (In the formula, the subscripts x and R 1 As defined above, R 2 The product contains a compound of the formula N≡CD- (where D is a divalent hydrocarbon group).

Claims

1. Compound of formula R1xR2SiX(3 - x) (wherein each X is independently selected from the group consisting of alkoxy groups of formula OR1, the subscript x is 0 or 1, R1 is an alkyl group having 1 to 18 carbon atoms, and R2 is a group of formula N≡C - D - where D is a divalent hydrocarbon group). A method for preparing a compound of formula (1), comprising: 1) providing an olefinic nitrile A') containing cyanide impurities of formula X' - C≡N (where X' is hydrogen, sodium, or potassium); 2) removing all or part of the cyanide impurities from the olefinic nitrile A') to thereby produce a purified olefinic nitrile A), wherein step 2) comprises combining the olefinic nitrile A') with a single metal selected from the group consisting of copper, iron, silver, or nickel, or combining the olefinic nitrile A') with an adsorbent selected from the group consisting of activated carbon and molecular sieves, or combining the olefinic nitrile A') with a metal selected from the group consisting of copper, iron, silver, or nickel, or oxides of these metals, and then combining the product with an adsorbent to form the purified olefinic nitrile A) comprising one or more of the above; 3) at a temperature of 20°C to 150°C combining the purified olefinic nitrile A), B) Formula R １ ｘ HSiX （３－ｘ） (wherein the subscript x is 0 or 1, each R １ is an alkyl group having 1 to 18 carbon atoms, and each X is independently selected from alkoxy groups of the formula OR １ ), and hydridosilanes having), and a hydrosilylation reaction catalyst C) which provides 5 ppm to < 200 ppm of Pt based on the total weight of the starting materials including the purified olefinic nitrile A), a hydridosilane B), and the hydrosilylation reaction catalyst C), to form a starting material mixture; A method comprising the above steps.

2. The method according to claim 1, wherein the olefinic nitrile A') is selected from the group consisting of 3 - butenenitrile and 2 - methyl - 3 - butenenitrile.

3. The method according to claim 1, wherein in the olefinic nitrile A'), the cyanide impurities contain 25 ppm to 125 ppm of H - C≡N.

4. x = 1 and R １ is a methyl group and each X is a methoxy group, the method according to claim 3.

5. The method according to claim 1, wherein the hydrosilylation reaction catalyst comprises chloroplatinic acid, a Karstedt catalyst, or platinum on a support selected from carbon, silica, or alumina.

6. Step 2) comprises combining the A') olefinic nitrile with a metal selected from the group consisting of copper, iron, silver, or nickel, or oxides of these metals, and then combining the product with an adsorbent to form the A) purified olefinic nitrile, wherein the adsorbent is sub-bituminous coal or coconut shell-based activated carbon, the method according to claim 1.

7. The method according to claim 1, wherein the A) purified olefinic nitrile produced in Step 2) contains from 0 ppm of the cyanide impurity to at least 10 ppm less of the cyanide impurity than the A') olefinic nitrile provided in Step 1).

8. The method according to claim 1, wherein the A) purified olefinic nitrile contains from 5 ppm to 40 ppm of the cyanide impurity.

9. The method according to any one of claims 1 to 8, further comprising adding D) an accelerator during and / or after Step 3).

10. The method according to claim 1, further comprising delivering one or more starting materials in a solvent.

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