Preparation method of cyclododecanone oxime

Abstract

The invention relates to the technical field of cyclododecanone oxime preparation, and discloses a preparation method of cyclododecanone oxime. The invention relates to a cyclododecanone oxime preparation method, which comprises: in the presence of a solid acid catalyst and an ammonium salt auxiliary agent, carrying out an oxime exchange reaction on reaction raw materials such as cyclododecanone and an oxime compound to obtain cyclododecanone oxime, the ratio of pyridine infrared B acid to L acid at 350 DEG C of the solid acid catalyst is (0.5-2.5): 1. According to the method, the conversion rate of the raw materials and the selectivity of the target product can be improved, meanwhile, the solid acid serves as the catalyst, the preparation process is clean, economical efficiency is good, and the method has good industrialization prospects and has huge potential in development of environment-friendly processes and promotion of sustainable development.

Description

Technical Field

[0001] This invention relates to the field of cyclododecanone oxime preparation, and more specifically to a method for preparing cyclododecanone oxime. Background Technology

[0002] Cyclododecone oxime is an important chemical raw material, mainly used in the synthesis of polyamide 12 (PA12, commonly known as nylon 12). Nylon 12 is a special high-performance polymer that combines the properties of nylon 6, nylon 66, and polyolefins (PE, PP) – low water absorption, lowest density, low melting point, impact resistance, abrasion resistance, low temperature resistance, fuel resistance, good dimensional stability, good noise reduction, and excellent dielectric properties. It achieves a combination of lightweight and superior physicochemical properties, resulting in significant performance advantages. Nylon 12 is widely used in plastic alloys, automotive manufacturing, aerospace materials, 3D printing, electronic and electrical products, medical technology, and the oil and gas industry, demonstrating its strong irreplaceable role.

[0003] Currently, most domestic and international companies use the traditional Raschig liquid process to produce cyclododecanone oximes by reacting hydroxylamine salts with ketones. Patents such as US20130023697A, US8163899A, US3462417A, and CN109516941A mention the reaction of cyclododecanone with hydroxylamine, using a one- or two-stage oximation process in isopropylcyclohexane solvent or solvent-free conditions to prepare cyclododecanone oximes. Ammonia is used to neutralize the hydroxylamine salt, and the reaction is carried out step-by-step under these conditions for specific times by adjusting the pH value. This technology, through step-by-step reaction, is beneficial for controlling the ability of iron ions to decompose hydroxylamine and reducing the loss of hydroxylamine raw materials. However, this process generates a large amount of ammonium sulfate as a byproduct, resulting in serious waste generation and environmental pollution. Furthermore, since hydroxylamine salts are solid compounds, industrial production involves dust pollution and a harsh operating environment. On the other hand, the reaction system requires precise temperature and pH control, resulting in limited operational flexibility. Industrial-scale plant interlocking and control are complex and unstable.

[0004] Patents such as CN1860098A, CN1235872C, and CN109746041A employ a reaction process involving the ammonium oximeation of cyclododecanone. While this process can solve the byproduct problem of ammonium sulfate produced by the traditional Raschig liquid process and is environmentally friendly, the hydroxylamine intermediate is easily decomposed, resulting in low utilization efficiency. The high hydrogen peroxide feed ratio leads to low hydrogen peroxide utilization and high process risk. Furthermore, it uses expensive titanium-silicon molecular sieves as catalysts, and the reaction system involves material separation. The cyclododecanone oximeation product has a high boiling point, resulting in high separation energy consumption.

[0005] CN110015974A discloses a method for preparing cyclododecanone oxime, comprising mixing cyclododecanone, a small molecule oxime, an organosilicon ether, a pH buffer, and a solvent, and using a liquid acid catalyst to adjust the pH of the system to 1-3 for oxime exchange reaction. The oxime exchange process does not use sulfur dioxide and nitrogen oxides, which cause air pollution, fundamentally eliminating the emission of such waste gases. Furthermore, the reaction conditions are mild, the investment is low, and there are no byproducts such as ammonium sulfate, improving the operating environment. At the same time, this process is more economical than the Raschig process. However, current oxime exchange reactions all use traditional liquid acid catalysts, which cause severe corrosion to equipment and generate large amounts of wastewater, making them environmentally unfriendly. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of complex preparation processes, wastewater generation, environmental unfriendliness, high cost, low raw material conversion rate, and low target product selectivity in existing oxime exchange reactions. This invention provides a method for preparing cyclododecanone oxime that can improve the conversion rate of raw materials and the selectivity of target products. At the same time, this method uses solid acid as a catalyst, the process is clean, economical, and has good prospects for industrialization. It also has great potential in developing environmentally friendly processes and promoting sustainable development.

[0007] To achieve the above objectives, the present invention provides a method for preparing cyclododecanone oxime, wherein the method includes the following steps:

[0008] In the presence of a solid acid catalyst and an ammonium salt auxiliary, the reactant cyclododecanone and an oxime compound undergo an oxime exchange reaction to yield cyclododecanone oxime;

[0009] The ratio of β-acid to L-acid in the pyridine infrared spectroscopy at 350℃ for solid acid catalysts is 0.5-2.5:1.

[0010] The method provided by this invention uses solid acid as a catalyst. Solid acid catalysts are non-toxic, non-corrosive to equipment, have a high reusability, do not pollute the environment, and have the characteristics of high activity and high selectivity, which meet the requirements of green chemistry. By introducing ammonium salt promoters to cooperate with solid acid catalysts, the oxime exchange reaction rate is improved, while the decomposition of intermediate hydroxylamine during the reaction is reduced, thereby further improving the reaction activity, so as to improve the raw material conversion rate and the selectivity of the target product.

[0011] The method provided by this invention uses a solid acid as a catalyst, and the 350°C pyridine infrared spectroscopy of the solid acid catalyst provides H+. +In the oxime exchange reaction, the Lewis acid provides empty orbitals to adsorb reactants, and the two work synergistically to achieve efficient conversion. The results of the embodiments of this invention show that a ratio of Brønsted acid to Lewis acid within the above-mentioned preferred range results in a high raw material conversion rate and target product selectivity. A ratio that is too high or too low will affect the adsorption / desorption of reactants and the conversion of small molecule oximes, leading to a decrease in conversion rate.

[0012] The method provided by this invention is clean, has low process cost, high safety factor, and produces no ammonium sulfate byproduct, and has good prospects for industrialization. It also has great potential in developing environmentally friendly processes and promoting sustainable development.

[0013] Compared to the traditional method of synthesizing cyclododecanone oxime by reacting cyclododecanone and hydroxylamine in aqueous solution, the method provided by this invention is green, environmentally friendly, and suitable for continuous industrial production, avoiding the generation of large amounts of wastewater and ammonium sulfate byproducts.

[0014] The method provided by this invention uses oxime compounds instead of expensive and easily decomposed hydroxylamine as a reaction raw material, does not use excess hydroxylamine in the reaction process, has a high reaction safety factor, and low production cost.

[0015] In the preferred embodiment of the method provided by this invention, the oxime exchange reaction is carried out under a protective atmosphere, which effectively avoids the oxidation and volatilization of oxime compounds and improves the activity and selectivity of the reaction.

[0016] The method provided by this invention has a short reaction time, high raw material conversion rate, high selectivity for cyclododecanone oxime, easy product separation, reduced separation cost, and is suitable for continuous industrial production. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] This invention provides a method for preparing cyclododecanone oxime, wherein the method includes the following steps:

[0019] In the presence of a solid acid catalyst and an ammonium salt auxiliary, the reactant cyclododecanone and an oxime compound undergo an oxime exchange reaction to yield cyclododecanone oxime;

[0020] The ratio of β-acid to L-acid in the pyridine infrared spectroscopy at 350℃ for solid acid catalysts is 0.5-2.5:1.

[0021] The method provided by this invention uses a solid acid catalyst as the catalyst for preparing dodecaketone oxime. Solid acid catalysts are non-toxic, non-corrosive to equipment, have a high reusability rate, do not pollute the environment, and have the characteristics of high activity and high selectivity, which meet the requirements of green chemistry. By introducing ammonium salt promoters to cooperate with solid acid catalysts, the reaction activity is further improved, thereby improving the raw material conversion rate and the selectivity of the target product.

[0022] The method provided by this invention is clean, has low process cost, high safety factor, and produces no ammonium sulfate byproduct, and has good prospects for industrialization. It also has great potential in developing environmentally friendly processes and promoting sustainable development.

[0023] Compared with liquid acid catalysts, the solid acid catalysts provided by this invention have advantages such as high activity, high stability, tunable structure, easy separation and recovery, less corrosion to equipment, and environmental friendliness.

[0024] In this invention, pyridine infrared spectroscopy is used to determine the content of Brønsted acid (B acid) and Lewis acid (L acid) and to calculate the ratio of B acid to L acid. The specific method is as follows: The self-supporting sheet of the solid acid catalyst is first pretreated under vacuum for 2 hours, then cooled to 423 K to collect background data. Pyridine is then introduced into the in-situ cell for 30 minutes to allow for sufficient adsorption of the sample. Afterward, vacuum degassing is continued for 60 minutes to remove physically adsorbed pyridine, and infrared spectra are collected. Increasing the temperature further removes weakly adsorbed pyridine from the sample surface, ultimately obtaining pyridine infrared data at 350℃. The data is then analyzed at 1540 cm⁻¹. -1 Peak characterization of Brønsted acid, with 1450 cm⁻¹ -1 The peak characterizes L acid, and then the ratio of Brønsted acid to L acid is calculated.

[0025] In this invention, preferably, the ratio of Brønsted acid to Lewis acid in the pyridine infrared spectroscopy at 350°C of the solid acid catalyst is 0.8-1.7:1. The advantages of this preferred embodiment are high catalyst reactivity, easy reproducibility of the preparation method, simple process flow, and low environmental pollution. When the ratio of Brønsted acid to Lewis acid is within the above-mentioned preferred range, it has a high raw material conversion rate and target product selectivity. If the ratio of Brønsted acid to Lewis acid is too high or too low, it will affect the adsorption / desorption of reactants and the conversion of small molecule oximes, resulting in a decrease in conversion rate.

[0026] In this invention, there is no particular limitation on the type of solid acid catalyst; any solid acid catalyst that meets the aforementioned preferred embodiments can be applied to this invention. Preferably, the solid acid catalyst is a molecular sieve and / or a heteropolyacid.

[0027] In this invention, there is no particular limitation on the type of molecular sieve; for example, it can be a hydrogen-type molecular sieve. The specific type of hydrogen-type molecular sieve is not particularly limited. Preferably, the molecular sieve is selected from at least one of HZSM-5 molecular sieve, HZSM-11 molecular sieve, Hβ molecular sieve, and HY molecular sieve, and more preferably from at least one of HZSM-5 molecular sieve, HY molecular sieve, and Hβ molecular sieve.

[0028] In this invention, preferably, the silicon-to-aluminum molar ratio of the molecular sieve is 1.5-100.

[0029] In this invention, there is no particular limitation on the specific type of heteropolyacid. Preferably, the heteropolyacid is selected from at least one of solid heteropolyacids, heteropolyacid salts, and supported heteropolyacids, such as phosphotungstic acid and molybdate heteropolyacid.

[0030] According to a preferred embodiment of the present invention, the solid acid catalyst is selected from at least one of HZSM-5 molecular sieve, HY-type molecular sieve, and Hβ molecular sieve. By selecting the above-mentioned solid acid catalysts, the advantages of moderate acid strength, synergistic effect of Brønsted acid and Lewis acid, and simple preparation and easy synthesis are achieved.

[0031] In this invention, there is no particular limitation on the source of the solid acid catalyst. For example, it can be obtained commercially or prepared by methods conventionally defined in the art.

[0032] In this invention, there is no particular limitation on the amount of solid acid catalyst used. Preferably, the amount of solid acid catalyst is 1-10% of the mass of cyclododecanone, more preferably 2-6%, for example, it can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5% or 6%.

[0033] In this invention, there is no particular limitation on the type of ammonium salt auxiliaries. Preferably, the ammonium salt auxiliaries are selected from at least one of ammonium salts containing halides, sulfates, nitrates, phosphates, and organic carboxylic acids, for example, at least one of ammonium chloride, ammonium sulfate, ammonium nitrate, ammonium phosphate, ammonium oxalate, ammonium acetate, ammonium formate, and ammonium citrate, and more preferably at least one of ammonium acetate and ammonium oxalate.

[0034] In this invention, there is no particular limitation on the amount of ammonium salt auxiliaries used. Preferably, the amount of the ammonium salt auxiliaries is 0.05-8% of the mass of cyclododecanone, more preferably 0.2-3%, and even more preferably 0.5-3%, for example, it can be 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, or 3%.

[0035] In this invention, preferably, the mass ratio of the ammonium salt promoter to the solid acid catalyst is 0.05:1-1.8:1, more preferably 0.05:1-0.8:1, and even more preferably 0.1:1-0.5:1. By controlling the mass ratio of the solid acid catalyst to the ammonium salt promoter, the roles of both the solid acid catalyst and the ammonium salt promoter can be fully utilized, resulting in a synergistic effect that enhances the reaction activity, thereby improving the raw material conversion rate and the selectivity of the target product.

[0036] In this invention, small molecule oximes are selected as oxime compounds to carry out oxime exchange reactions with cyclododecanone, which can improve the conversion rate of raw materials and the selectivity of target products. Preferably, the oxime compound is selected from at least one of acetaldehyde oxime, acetone oxime, butanone oxime, 2-pentanone oxime, 3-pentanone oxime, cyclohexanone oxime, acetophenone oxime, and phenylacetone oxime, and more preferably from at least one of acetaldehyde oxime, acetone oxime, and butanone oxime.

[0037] In this invention, preferably, the mass ratio of the oxime compound to cyclododecanone is 0.3:1-1.7:1, and more preferably 0.4:1-1.2:1.

[0038] In this invention, preferably, the oxime exchange reaction is carried out under a protective atmosphere. By introducing a certain amount of protective atmosphere during the oxime exchange reaction, the oxidation and volatilization of oxime compounds are effectively avoided, thereby improving the reaction activity and the selectivity of the target product.

[0039] In this invention, there is no particular limitation on the type of protective atmosphere; any protective atmosphere conventionally defined in the art can be applied to this invention. Preferably, the protective atmosphere is selected from at least one of nitrogen and / or an inert gas, and more preferably nitrogen.

[0040] In this invention, there is no particular limitation on the type of inert gas. Any inert gas conventionally defined in the art can be used in this invention, such as neon, helium, argon, etc.

[0041] In this invention, preferably, the flow rate of the protective atmosphere is 5-15 mL / min relative to 1 g of cyclododecanone.

[0042] In this invention, preferably, the oxime exchange reaction is carried out in the presence of a solvent.

[0043] In this invention, there is no particular limitation on the type of solvent, as long as it can solvent the reactants. Preferably, the solvent is an organic solvent, and more preferably, the organic solvent is selected from alcohol compounds that are miscible with and / or partially miscible with water.

[0044] In this invention, there is no particular limitation on the specific types of alcohol compounds, and those skilled in the art can adjust them according to actual needs. Preferably, the alcohol compounds are selected from at least one of C1-C6 aliphatic and / or cyclic aliphatic compounds, more preferably from at least one of monohydric alcohols and / or polyhydric alcohols, and even more preferably from at least one of methanol, ethanol, n-propanol, isopropanol, tert-butanol, sec-butanol, ethylene glycol, and glycerol.

[0045] In this invention, there is no particular limitation on the amount of alcohol compound used. Preferably, the mass ratio of the alcohol compound to water is 0.1:1 to 20:1.

[0046] In this invention, preferably, the mass ratio of the solvent to cyclododecanone is 2-10:1. It should be noted that the amount of solvent used here includes the amount of water.

[0047] In this invention, preferably, the conditions for the oxime exchange reaction include: a reaction temperature of 30-120°C, more preferably 30-90°C; and a pressure of 0-1 MPa, more preferably 0.1-0.5 MPa.

[0048] In this invention, the oxime exchange reaction is a continuous reaction and / or a batch reaction.

[0049] The present invention will be described in detail below through embodiments. Unless otherwise specified, all raw materials used in the following embodiments are commercially available products.

[0050] In this invention, the conversion rate of the reactant cyclododecanone and the selectivity of the target product cyclododecanone oxime were determined by quantitative analysis using gas chromatography. The chromatographic model was Agilent GC7890A, the column was an HP-INNOWAX capillary column (30m × 0.25mm × 0.25μm), the detector temperature was 300℃, and the injection port temperature was 260℃. The chromatographic analysis conditions were as follows: the initial temperature was 180℃ and held for 10 min, then increased to 230℃ at a rate of 20℃ / min and held for 20 min. The GC peak data were used to calculate the selectivity and conversion rate of the reaction using the area normalization method.

[0051]

[0052]

[0053] The present invention will be described in detail below through embodiments. Unless otherwise specified, all raw materials used in the following embodiments are commercially available products.

[0054] Example 1

[0055] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of HY molecular sieve catalyst (Si / Al = 3), and 0.4 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.5 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 6 h to obtain the product cyclododecanone oxime.

[0056] Example 2

[0057] 13.67 g (0.075 mol) of cyclododecanone, 7.66 g (0.105 mol) of acetone oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of Hβ molecular sieve catalyst (Si / Al = 15), and 0.2 g of ammonium oxalate promoter were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.3 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 7 h to obtain the product cyclododecanone oxime.

[0058] Example 3

[0059] 13.67 g (0.075 mol) of cyclododecanone, 9.15 g (0.105 mol) of butanone oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of HZSM-5 molecular sieve catalyst (Si / Al = 25), and 0.1 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.1 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 8 h to obtain the product cyclododecanone oxime.

[0060] Example 4

[0061] 13.67 g (0.075 mol) of cyclododecanone, 15.66 g (0.105 mol) of phenylacetone oxime, 100 g of tert-butanol (85% by mass), 0.8 g of phosphotungstic acid (Inokai A40091), and 0.2 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, with a flow rate of 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 10 h to obtain the product cyclododecanone oxime.

[0062] Example 5

[0063] 13.67 g (0.075 mol) of cyclododecanone, 10.59 g (0.105 mol) of 2-pentanone oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of HZSM-11 molecular sieve catalyst (Si / Al = 25), and 0.2 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 10 h to obtain the product cyclododecanone oxime.

[0064] Example 6

[0065] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.25 g of HY molecular sieve catalyst (Si / Al = 3), and 0.4 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 50 °C, and the reaction was carried out for 14 h to obtain the product cyclododecanone oxime.

[0066] Example 7

[0067] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of HY molecular sieve catalyst (Si / Al = 3), and 0.06 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 12 h to obtain the product cyclododecanone oxime.

[0068] Example 8

[0069] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of HY molecular sieve catalyst (Si / Al = 3), and 0.3 g of ammonium sulfate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 11 h to obtain the product cyclododecanone oxime.

[0070] Example 9

[0071] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of HY molecular sieve catalyst (Si / Al = 3), and 0.12 g of ammonium chloride auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, and the flow rate of nitrogen gas was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 12 h to obtain the product cyclododecanone oxime.

[0072] Example 10

[0073] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (tert-butanol mass concentration 85%), 0.8 g of HY molecular sieve catalyst (Si / Al = 3), and 0.2 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was not introduced. The nitrogen flow rate was 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 45 °C, and the reaction was carried out for 9 h to obtain the product cyclododecanone oxime.

[0074] Comparative Example 1

[0075] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (85% by mass), and 0.8 g of HY molecular sieve catalyst (Si / Al = 3) were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, with a flow rate of 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 60 °C, and the reaction was carried out for 16 h to obtain the product cyclododecanone oxime.

[0076] Comparative Example 2

[0077] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (85% by mass), and 0.2 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, with a flow rate of 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 60 °C, and the reaction was carried out for 16 h to obtain the product cyclododecanone oxime.

[0078] Comparative Example 3

[0079] 13.67 g (0.075 mol) of cyclododecanone, 6.2 g (0.105 mol) of acetaldehyde oxime, 100 g of tert-butanol (85% by mass), 0.8 g of acetic acid (0.1 mol / L), and 0.2 g of ammonium acetate auxiliary were added to a 200 mL stainless steel reactor. Nitrogen gas was introduced at 0.2 MPa, with a flow rate of 10 mL / min compared to 1 g of cyclododecanone. The temperature was raised to 80 °C, and the reaction was carried out for 10 h to obtain the product cyclododecanone oxime.

[0080] The property parameters of the solid acid catalysts used in the above embodiments and comparative examples are shown in Table 1.

[0081] The above-described embodiments and comparative examples were subjected to quantitative analysis by gas chromatography, and the results are shown in Table 2.

[0082] Table 1

[0083]

[0084]

[0085] Table 2

[0086] Cyclododecanone conversion rate % Cyclododecanone oxime selectivity % Yield / % Example 1 99.94 99.86 99.80 Example 2 99.86 99.88 99.74 Example 3 99.79 99.92 99.71 Example 4 98.44 99.63 98.08 Example 5 98.52 99.84 98.36 Example 6 99.35 99.74 99.09 Example 7 99.43 99.59 99.02 Example 8 99.17 99.62 98.79 Example 9 99.20 99.51 98.71 Example 10 98.98 99.25 98.24 Comparative Example 1 46.89 43.42 20.36 Comparative Example 2 3.47 37.85 1.31 Comparative Example 3 94.87 92.38 87.64

[0087] As can be seen from the table above, the combination of the solid acid catalyst and ammonium salt promoter in the embodiments provided by the present invention can reduce the reaction temperature, and has the advantages of short reaction time, high selectivity of target product and high yield.

[0088] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing cyclododecanone oxime, characterized in that, The method includes the following steps: In the presence of a solid acid catalyst and an ammonium salt auxiliary, the reactant cyclododecanone and an oxime compound undergo an oxime exchange reaction to yield cyclododecanone oxime; The ratio of β-acid to L-acid in the pyridine infrared spectroscopy at 350℃ for solid acid catalysts is 0.5-2.5:

1.

2. The method according to claim 1, wherein, The ratio of β-acid to L-acid in the pyridine infrared spectroscopy at 350°C of the solid acid catalyst is 0.8-1.7:

1.

3. The method according to claim 1 or 2, wherein, The solid acid catalyst is a molecular sieve and / or a heteropoly acid; Preferably, the molecular sieve is selected from at least one of HZSM-5 molecular sieve, HZSM-11 molecular sieve, Hβ molecular sieve and HY molecular sieve; Preferably, the heteropolyacid is selected from at least one of solid heteropolyacids, heteropolyacid salts, and supported heteropolyacids.

4. The method according to any one of claims 1-3, wherein, The amount of the solid acid catalyst used is 1-10% of the mass of cyclododecanone, preferably 2-6%.

5. The method according to any one of claims 1-4, wherein, The ammonium salt auxiliary is selected from at least one of the ammonium salts containing halides, sulfates, nitrates, phosphates, and organic carboxylic acids; Preferably, the amount of the ammonium salt auxiliary is 0.05-8% of the mass of cyclododecanone, more preferably 0.2-3%, and even more preferably 0.5-3%.

6. The method according to any one of claims 1-5, wherein, The mass ratio of the ammonium salt auxiliary agent to the solid acid catalyst is 0.05:1-1.8:1, preferably 0.05:1-0.8:1, and more preferably 0.1:1-0.5:

1.

7. The method according to any one of claims 1-6, wherein, The oxime compound is selected from at least one of acetaldehyde oxime, acetone oxime, butanone oxime, 2-pentanone oxime, 3-pentanone oxime, cyclohexanone oxime, acetophenone oxime, and phenylacetone oxime, preferably selected from at least one of acetaldehyde oxime, acetone oxime, and butanone oxime; Preferably, the mass ratio of the oxime compound to cyclododecanone is 0.3:1-1.7:1, and more preferably 0.4:1-1.2:

1.

8. The method according to any one of claims 1-7, wherein, The oxime exchange reaction is carried out under a protective atmosphere, preferably selected from at least one of nitrogen and / or an inert gas, more preferably nitrogen; Preferably, the flow rate of the protective atmosphere is 5-15 mL / min relative to 1 g of cyclododecanone.

9. The method according to any one of claims 1-8, wherein, The oxime exchange reaction is carried out in the presence of a solvent; Preferably, the solvent is an organic solvent, and more preferably, the organic solvent is selected from alcohol compounds that are miscible with and / or partially miscible with water; Preferably, the alcohol compound is selected from at least one of C1-C6 aliphatic and / or cyclic aliphatic compounds, more preferably from at least one of monohydric alcohols and / or polyhydric alcohols, and even more preferably from at least one of methanol, ethanol, n-propanol, isopropanol, tert-butanol, sec-butanol, ethylene glycol, and glycerol. Preferably, the mass ratio of the alcohol compound to water is 0.1:1 to 20:1; Preferably, the mass ratio of the solvent to cyclododecanone is 2-10:

1.

10. The method according to any one of claims 1-9, wherein, The conditions for the oxime exchange reaction include: a reaction temperature of 30-120℃, preferably 30-90℃; and a pressure of 0-1MPa, preferably 0.1-0.5MPa.

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