Preparation method of diisopropyl hydroxylamine and prepared diisopropyl hydroxylamine

Abstract

The invention relates to the technical field of organic synthesis, and discloses a preparation method of diisopropyl hydroxylamine, and the prepared diisopropyl hydroxylamine comprises the following steps: (1) mixing hydroxylamine salt, 1-halogenated-2-propanol and a first organic solvent to obtain a reaction solution; (2) in the presence of protective gas, mixing an organic alkali solution with the reaction solution, and carrying out addition reaction to obtain a mixed product; (3) separating the mixed product to obtain diisopropyl alcohol hydroxylamine; wherein the molar ratio of the 1-halogenated-2-propyl alcohol to the hydroxylamine salt is (0.5 to 25): 1. According to the method, the hydroxylamine salt, the 1-halogenated-2-propanol and the organic base are adopted to prepare the diisopropyl hydroxylamine in the organic solvent, the product yield and purity are high, the product can be obtained through filtration and simple distillation, and complex processes such as extraction are not needed. The process is simplified, and the yield and purity of the product are improved.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to a method for preparing diisopropanol hydroxylamine and the prepared diisopropanol hydroxylamine. Background Technology

[0002] Diisopropanol hydroxylamine (HPHA) is an important fine chemical, widely used in the styrene polymerization inhibition field due to its excellent inhibitory effect on olefins. Furthermore, its strong reducing properties allow it to be used in the production of antioxidants. Moreover, its reaction with oxygen to form ketoximes allows it to undergo further oxidation reactions, making it suitable for use as a boiler descaling agent.

[0003] Currently, there are few reported methods for synthesizing diisopropanol hydroxylamine. CN106957240A discloses a method for preparing diisopropanol hydroxylamine, which first reacts a substituted hydroxylamine with an alkaline solution to generate a free alkyl hydroxylamine, and then adds propylene oxide to the above solution to generate diisopropanol hydroxylamine. Because the free hydroxylamine generated in the first step is unstable, it needs to be carried out in an ice-water bath. The reaction between the hydroxylamine salt and the alkaline solution releases a large amount of heat, which may cause hydroxylamine decomposition and a decrease in yield. Furthermore, the reaction temperature of propylene oxide is approximately 20°C, requiring heating, which may also cause some hydroxylamine loss. US6028225(A) discloses a method for directly synthesizing diisopropanol hydroxylamine from free hydroxylamine and propylene oxide, but the raw materials used in this method are not stable enough, are easily decomposed, and are inconvenient to store. CN112159333A discloses an improved method in which propylene oxide and hydroxylamine salt are pre-mixed in a solvent, and then an alkaline solution is added dropwise. This allows the two-step reaction to be completed in one step, avoiding the generation and decomposition of free hydroxylamine and improving production safety and product yield. However, the subsequent purification process still requires extraction and distillation. From the above method, it is clear that because an inorganic base is used in the preparation of free hydroxylamine, the inorganic salt and water generated from the inorganic base and hydroxylamine salt are soluble in the solution and cannot be directly purified by distillation. Therefore, further processing steps such as extraction are required, resulting in multiple product purification steps, which affects product yield and increases production costs.

[0004] Therefore, how to provide a low-cost, high-yield method that allows for easy product separation has become an urgent problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of complex purification steps, reduced product yield, and high production costs in the preparation of diisopropanol hydroxylamine using existing technologies. This invention provides a method for preparing diisopropanol hydroxylamine and the resulting diisopropanol hydroxylamine. This method uses hydroxylamine salt, 1-halo-2-propanol, and an organic base in an organic solvent to prepare diisopropanol hydroxylamine. The product yield and purity are high, and the product can be obtained through filtration and simple distillation, eliminating the need for complex processes such as extraction. This simplifies the process and improves the product yield and purity.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for preparing diisopropanol hydroxylamine, wherein the method includes the following steps:

[0007] (1) A reaction solution is obtained by mixing hydroxylamine salt, 1-halo-2-propanol and the first organic solvent;

[0008] (2) In the presence of a protective gas, the organic base solution is mixed with the reaction solution to carry out an addition reaction and obtain a mixed product;

[0009] (3) The mixed product was separated to obtain diisopropanol hydroxylamine;

[0010] The molar ratio of 1-halo-2-propanol to hydroxylamine salt is 0.5-25:1.

[0011] Preferably, the 1-halo-2-propanol is selected from at least one of 1-chloro-2-propanol, 1-bromo-2-propanol, and 1-iodo-2-propanol.

[0012] Preferably, the molar ratio of 1-halo-2-propanol to hydroxylamine salt is 1.9-4:1.

[0013] Preferably, the molar ratio of the organic base in the organic base solution to the hydroxylamine salt in the reaction solution is 2-20:1, more preferably 2.9-9.1:1.

[0014] The second aspect of the present invention provides diisopropanol hydroxylamine prepared by the preparation method described in the first aspect.

[0015] The beneficial effects achieved through the above technical solution are as follows:

[0016] The preparation method described in this invention prepares diisopropanol hydroxylamine under alkaline conditions. The reaction yield is high, the product is easy to purify, and the inorganic salt generated in the reaction is insoluble in organic solutions and can be directly precipitated from the reaction solution. It can be removed by a simple filtration method, and the purity of diisopropanol hydroxylamine can reach 96%. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the process for preparing diisopropanol hydroxylamine.

[0018] Explanation of reference numerals in the attached figures

[0019] 1-Reaction vessel 2-Material pump 3-Vacuum distillation tower Detailed Implementation

[0020] 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.

[0021] The first aspect of this invention provides a method for preparing diisopropanol hydroxylamine, wherein the method includes the following steps:

[0022] (1) A reaction solution is obtained by mixing hydroxylamine salt, 1-halo-2-propanol and the first organic solvent;

[0023] (2) In the presence of a protective gas, the organic base solution is mixed with the reaction solution to carry out an addition reaction and obtain a mixed product;

[0024] (3) The mixed product was separated to obtain diisopropanol hydroxylamine;

[0025] The molar ratio of 1-halo-2-propanol to hydroxylamine salt is 0.5-25:1.

[0026] In this invention, the method for preparing diisopropanol hydroxylamine involves mixing a hydroxylamine salt, 1-halo-2-propanol, and a first organic solvent to obtain a reaction solution, which is then subjected to an addition reaction with an organic base solution to obtain diisopropanol hydroxylamine in one step. The reaction yield is high, the product is easy to purify, and the inorganic salt generated in the reaction is insoluble in the organic solution and can be directly precipitated from the reaction solution. This not only improves the yield but also allows for removal using a simple filtration method.

[0027] The method provided by this invention yields diisopropanol-based hydroxylamine with a purity of over 96%, high product yield and purity, and a simplified preparation process. Existing methods use propylene oxide to prepare diisopropanol-based hydroxylamine, which, under alkaline conditions, easily undergoes hydrolysis to generate the byproduct 1,2-dipropanol. This not only affects product purification but also increases propylene oxide consumption and costs.

[0028] According to the present invention, the type and source of the hydroxylamine salt are not particularly limited. Preferably, the hydroxylamine salt is selected from at least one of hydroxylamine sulfate, hydroxylamine phosphate, and hydroxylamine hydrochloride, and more preferably hydroxylamine hydrochloride.

[0029] According to the present invention, preferably, the 1-halo-2-propanol is selected from at least one of 1-chloro-2-propanol, 1-bromo-2-propanol, and 1-iodo-2-propanol. In this invention, diisopropanol-based hydroxylamine can be prepared by mixing 1-halo-2-propanol with a hydroxylamine salt. Using other halopropanols in the reaction will yield other byproducts, making it impossible to obtain the target product diisopropanol-based hydroxylamine, and thus failing to achieve the technical effects of the present invention.

[0030] According to the present invention, preferably, the molar ratio of 1-halo-2-propanol to hydroxylamine salt is 0.5-25:1, for example 0.5:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.5:1, 1.9:1, 2:1, 3:1, 4:1, 5:1, 6:1, 8:1, 10:1, 15:1, 20:1, 25:1, or any range between the two, preferably 1.9-4:1.

[0031] According to the present invention, the first organic solvent is a conventional organic solvent in the art. Preferably, the first organic solvent is selected from at least one of fatty alcohols, ethers, and haloalkanes, more preferably from at least one of fatty alcohols containing 1-6 carbon atoms, ethers containing 2-6 carbon atoms, and haloalkanes containing 1-6 carbon atoms, and more preferably from at least one of ethanol, diethyl ether, and chloroform. Using the above-mentioned organic solvent to dissolve hydroxylamine salt and 1-halo-2-propanol can effectively dissolve 1-halo-2-propanol and hydroxylamine salt, promote the reaction, and thereby improve the product yield.

[0032] In this invention, the mixing method of the hydroxylamine salt, 1-halo-2-propanol, and the first organic solvent is not particularly limited, and those skilled in the art can use conventional methods that can mix the above substances uniformly. Preferably, the hydroxylamine salt, 1-halo-2-propanol, and the first organic solvent are mixed uniformly by stirring to obtain a reaction solution. The stirring rate is not particularly limited, as long as a uniform reaction solution is obtained.

[0033] According to the present invention, preferably, the mass ratio of the first organic solvent to the hydroxylamine salt is 0.5-25:1, for example, 0.5:1, 0.6:1, 0.8:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 4:1, 5:1, 6:1, 8:1, 10:1, 15:1, 20:1, 25:1, or any range between the two, preferably 0.8-10:1.

[0034] According to the present invention, preferably, the organic base solution comprises an organic base and a second organic solvent. The organic base is a sodium fatty alcohol containing 1-6 carbon atoms and / or a sodium cycloalkanol containing 3-6 carbon atoms, preferably selected from at least one of sodium methoxide, sodium ethoxide, sodium propoxide, sodium n-butoxide, sodium isobutoxide, sodium tert-butoxide, sodium tert-amyl alcohol, and sodium cyclohexanoate. In the present invention, the organic base can rapidly react with hydroxylamine salts to generate inorganic salts, thereby precipitating out as solid precipitates from the organic solvent, further promoting the reaction.

[0035] According to the present invention, preferably, the second organic solvent is a fatty alcohol containing 1-6 carbon atoms and / or a cycloalkanol containing 3-6 carbon atoms, preferably selected from at least one of methanol, ethanol, propanol, n-butanol, isobutanol, tert-butanol, tert-amyl alcohol and cyclohexanol.

[0036] In this invention, the first organic solvent and the second organic solvent can be the same or different. Preferably, the first organic solvent and the second organic solvent are the same organic solvent. "First" and "second" do not indicate the order of addition, but are only used to distinguish the organic solvents added in different steps.

[0037] According to a preferred embodiment of the present invention, the second organic solvent is an alcohol corresponding to an organic base, for example, when the organic base is sodium methoxide, the second organic solvent is methanol.

[0038] According to the present invention, preferably, the mass ratio of the second organic solvent to the organic base is 0.4-25:1, for example, 0.4:1, 0.6:1, 0.9:1, 1:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 10:1, 15:1, 20:1, 25:1, or any range between the two, preferably 0.9-5:1. In the present invention, the second organic solvent and the organic base in the above mass ratio are mixed to obtain an organic base solution, which is then mixed with the reaction solution to carry out an addition reaction. The yield of diisopropanol hydroxylamine is higher. The inorganic salt byproduct generated by the reaction is insoluble in the organic solvent and precipitates directly from the mixed reaction solution, making the removal method simple. If the ratio of the second organic solvent to the organic base is too high, it will increase the energy consumption of subsequent solvent separation; if the ratio of the solvent is too low, the organic base will not be completely dissolved. A suitable ratio is preferred, which has the effect of reducing energy consumption while ensuring the complete reaction.

[0039] According to the present invention, preferably, the molar ratio of the organic base in the organic base solution to the hydroxylamine salt in the reaction solution is 2-20:1, for example 2:1, 2.9:1, 4:1, 6:1, 8:1, 9.1:1, 10:1, 12:1, 14:1, 16:1, 18:1, 20:1, or any range between the two, preferably 2.9-9.1:1.

[0040] In this invention, limiting the molar ratio of the organic base in the organic base solution to the hydroxylamine salt in the reaction solution ensures that the reaction proceeds according to the reaction stoichiometry, reduces raw material waste, increases the yield of diisopropanol hydroxylamine, and reduces the difficulty of subsequent separation.

[0041] According to the present invention, preferably, the conditions for the addition reaction in step (2) include: a reaction temperature of -5 to 85°C, preferably -2 to 50°C, more preferably -1 to 35°C; and a reaction time of 0.5 to 36 h, preferably 0.9 to 12 h, more preferably 1.5 to 5 h.

[0042] In this invention, the protective gas is a conventional oxygen-free gas in the art, preferably selected from at least one of nitrogen, helium and argon, and more preferably nitrogen.

[0043] In this invention, the addition reaction product is separated to obtain diisopropanol hydroxylamine. The separation method is not particularly limited; filtration can be used for solid-liquid separation. Preferably, the solid-liquid separation product is subjected to vacuum distillation to remove the solvent and unreacted raw materials, yielding diisopropanol hydroxylamine with higher purity.

[0044] In this invention, the conditions for vacuum distillation are not particularly limited and are conventional vacuum distillation conditions. Preferably, the operating conditions for vacuum distillation include: a pressure of 5-150 kPa, preferably 10-100 kPa; and a temperature of 60-150°C, preferably 30-100°C.

[0045] In this invention, the reaction equipment for the addition reaction is not particularly limited; those skilled in the art can choose conventional equipment for carrying out addition reactions. Preferably, the addition reaction is carried out in a reaction vessel. According to the present invention, preferably, the reaction vessel is an isothermal reactor, more preferably an isothermal reactor equipped with a stirring and liquid-solid separation device. More preferably, the reaction vessel is equipped with a filtration device using a ceramic membrane and / or a hollow carbon fiber membrane as the filter medium.

[0046] According to a preferred embodiment of the present invention, hydroxylamine salt, 1-halo-2-propanol and a first organic solvent are added to a reaction vessel to obtain a reaction solution, and an organic base is mixed with a second organic solvent to obtain an organic base solution. The organic base solution is then slowly added to the reaction vessel to carry out an addition reaction.

[0047] In this invention, the addition rate of the organic base solution is not particularly limited, and those skilled in the art can adjust the addition rate of the organic base solution according to the mass of the organic base solution and the reaction solution.

[0048] According to a preferred embodiment of the present invention, the preparation method is carried out in a diisopropanol hydroxylamine preparation system, the preparation system comprising:

[0049] The reactor, material pump, and vacuum distillation column are connected in sequence.

[0050] In this invention, the reaction materials in the reaction vessel include a reaction solution and an organic base solution.

[0051] According to a preferred embodiment of the present invention, the preparation method is in Figure 1 The process is carried out in the system shown. Diisopropanol hydroxylamine is prepared in reactor 1. The outlet of reactor 1 is connected to vacuum distillation column 3 via material pump 2. The reaction post-flow in the reactor is introduced into vacuum distillation column 3 via material pump 2. The solvent and unreacted raw materials are removed by vacuum distillation to obtain the diisopropanol hydroxylamine product.

[0052] In this invention, the diisopropanol hydroxylamine product is prepared by the above method with high yield, easy purification and high purity, simplified preparation process and improved economic benefits.

[0053] The second aspect of the present invention provides diisopropanol hydroxylamine prepared by the preparation method described in the first aspect.

[0054] In this invention, the diisopropanol hydroxylamine product prepared by the preparation method described in the first aspect is easy to purify and has high purity, reaching 96%.

[0055] According to a particularly preferred embodiment of the present invention, a method for preparing diisopropanol hydroxylamine is provided, the method comprising the following steps: (1) mixing hydroxylamine salt, 1-halo-2-propanol and a first organic solvent to obtain a reaction solution;

[0056] (2) In the presence of a protective gas, the organic base solution is mixed with the reaction solution to carry out an addition reaction and obtain a mixed product;

[0057] (3) The mixed product was separated to obtain diisopropanol hydroxylamine;

[0058] Wherein, the molar ratio of 1-halo-2-propanol to hydroxylamine salt is 1.2-4:1;

[0059] The organic base solution includes an organic base and a second organic solvent;

[0060] The mass ratio of the second organic solvent to the organic base is 0.9-5:1;

[0061] The molar ratio of the organic base in the organic base solution to the hydroxylamine salt in the reaction solution is 2-20:1.

[0062] The present invention will be described in detail below through examples and comparative examples. Unless otherwise specified, all reagents used in the following examples and comparative examples are commercially available.

[0063] The reaction for preparing diisopropanol hydroxylamine in this invention is as follows: Figure 1 The reaction takes place in the system shown. The outlet of the reactor 1 is connected to the vacuum distillation column 3 via the material pump 2. The reaction post-flow from the reactor is introduced into the vacuum distillation column 3 via the material pump 2. The solvent and unreacted raw materials are removed by vacuum distillation to obtain the diisopropanol hydroxylamine product.

[0064] Example 1

[0065] (1) Add 7.02g of hydroxylamine hydrochloride and 40g of diethyl ether to the reaction vessel. After they are fully mixed and dissolved, add 28.55g of 1-chloro-2-propanol. Control the temperature at 0℃ and keep stirring to obtain the reaction solution.

[0066] (2) Prepare a sodium methoxide-methanol solution and add it dropwise to the reaction vessel. The amount added is 54.72g, of which sodium methoxide is 16.42g. The addition time is 0.5h. After the addition is completed, continue to maintain the temperature and stir thoroughly for 2h to obtain a mixed product.

[0067] (3) The generated NaCl was filtered off, and the solvent was removed by vacuum distillation at a pressure of 100 kPa and a temperature of 40 °C to obtain 13.94 g of diisopropanol hydroxylamine.

[0068] Example 2

[0069] (1) Add 6.95g of hydroxylamine hydrochloride and 50g of chloroform to the reaction vessel. After they are fully mixed and dissolved, add 23.64g of 1-chloro-2-propanol. Control the reaction temperature at 20℃ and keep stirring to obtain the reaction solution.

[0070] (2) Prepare a sodium tert-butoxide-tert-butanol solution and add it dropwise into the reaction vessel. The amount of sodium tert-butoxide-tert-butanol solution added is 144.96g, of which sodium tert-butoxide is 28.99g. The addition time is 0.5h. After the addition is completed, continue to maintain the temperature and stir thoroughly for 3h to obtain the mixed product.

[0071] (3) The generated NaCl was filtered off, and the solvent was removed by vacuum distillation at a pressure of 80 kPa and a temperature of 65 °C to obtain 13.90 g of diisopropanol hydroxylamine.

[0072] Example 3

[0073] (1) Add 8.22g of hydroxylamine sulfate and 40g of ethanol to the reaction vessel. After they are fully mixed and dissolved, add 28.46g of 1-bromo-2-propanol. Control the reaction temperature at 25℃ and keep stirring to obtain the reaction solution.

[0074] (2) Prepare a sodium ethoxide-ethanol solution and add it dropwise to the reaction vessel. The amount of sodium ethoxide-ethanol solution added is 137.36 g, of which sodium ethoxide is 20.60 g. The addition time is 0.5 h. After the addition is completed, continue to maintain the temperature and stir thoroughly for 2 h to obtain a mixed product.

[0075] (3) The generated Na2SO4 was filtered off, and the ethanol solvent was removed by vacuum distillation at a pressure of 60 kPa and a temperature of 70 °C to obtain 13.77 g of diisopropanol hydroxylamine.

[0076] Example 4

[0077] (1) Add 8.21g of hydroxylamine sulfate and 50g of ethanol to the reaction vessel. After they are fully mixed and dissolved, add 23.65g of 1-bromo-2-propanol. Control the reaction temperature at 15℃ and keep stirring to obtain the reaction solution.

[0078] (2) Prepare a sodium methoxide-methanol solution and add it dropwise into the reaction vessel at a rate of 82.35 g, of which 16.47 g is sodium methoxide. The dropwise addition time is 0.5 h. After the addition is complete, continue to maintain the temperature and stir thoroughly for 4 h to obtain a mixed product.

[0079] (3) The generated Na2SO4 was filtered off, and the solvent was removed by vacuum distillation at a pressure of 50 kPa and a temperature of 60 °C to obtain 13.81 g of diisopropanol hydroxylamine.

[0080] Example 5

[0081] Following the method of Example 1, except that the amount of 1-chloro-2-propanol added was changed to 14.18 g, and other conditions were the same as in Example 1, 10.11 g of diisopropanol hydroxylamine was obtained.

[0082] Example 6

[0083] Following the method of Example 1, except that the amount added was 54.72g, the amount of sodium methoxide added was changed to 8.10g, and other conditions were the same as in Example 1, resulting in 6.64g of diisopropanol hydroxylamine.

[0084] Comparative Example 1

[0085] 6.95 g of hydroxylamine hydrochloride and 15 g of deionized water were added to a reaction vessel. After thorough mixing and dissolution, 18.59 g of propylene oxide was added. The reaction temperature was maintained at 0 °C, and stirring was continued. A NaOH aqueous solution was prepared and added dropwise to the reaction vessel at a rate of 16.16 g, of which 4.0 g was NaOH. The dropwise addition took 1 hour, and after the addition was complete, the temperature was maintained and stirring was continued for 4 hours. 0.05 wt% of the reaction product, methyltrioctylammonium chloride, was added, followed by two extractions with dichloromethane, 30 mL each time. The extracts were combined, and the dichloromethane solvent was removed by vacuum distillation to obtain 12.40 g of diisopropanol hydroxylamine solid.

[0086] Comparative Example 2

[0087] Following the method of Example 1, except that 1-chloro-2-propanol was replaced with an equimolar amount of isopropanol, and other conditions were the same as in Example 1, 0 g of diisopropanol hydroxylamine was obtained.

[0088] Comparative Example 3

[0089] Following the method of Example 1, except that 1-chloro-2-propanol was replaced with an equimolar amount of 2-chloro-1-propanol, and other conditions were the same as in Example 1, 0 g of diisopropanol hydroxylamine and 13.02 g of di-n-propanol hydroxylamine were obtained.

[0090] Table 1 shows the yield and purity of diisopropanol hydroxylamine. Yield = actual product quality of diisopropanol hydroxylamine / theoretically obtainable product quality.

[0091] The purity of diisopropanol hydroxylamine was determined by gas chromatography.

[0092] Table 1

[0093]

[0094]

[0095] As can be seen from the results in Table 1, the diisopropanol hydroxylamine prepared in Examples 1-4 of this invention has high yield and high purity, and the preparation method provided by this invention has significantly better results in preparing diisopropanol hydroxylamine.

[0096] 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 diisopropanol hydroxylamine, characterized in that, The method includes the following steps: (1) A reaction solution is obtained by mixing hydroxylamine salt, 1-halo-2-propanol and the first organic solvent; (2) In the presence of a protective gas, the organic base solution is mixed with the reaction solution to carry out an addition reaction and obtain a mixed product; (3) The mixed product was separated to obtain diisopropanol hydroxylamine; The molar ratio of 1-halo-2-propanol to hydroxylamine salt is 0.5-25:

1.

2. The preparation method according to claim 1, wherein, The hydroxylamine salt is selected from at least one of hydroxylamine sulfate, hydroxylamine phosphate, and hydroxylamine hydrochloride; Preferably, the 1-halo-2-propanol is selected from at least one of 1-chloro-2-propanol, 1-bromo-2-propanol, and 1-iodo-2-propanol.

3. The preparation method according to claim 1 or 2, wherein, The molar ratio of 1-halo-2-propanol to hydroxylamine salt is 1.9-4:

1.

4. The preparation method according to any one of claims 1-3, wherein, The first organic solvent is selected from at least one of fatty alcohols, ethers and halogenated hydrocarbons, and preferably from at least one of ethanol, diethyl ether and chloroform; Preferably, the mass ratio of the first organic solvent to the hydroxylamine salt is 0.5-25:1, more preferably 0.8-10:

1.

5. The preparation method according to any one of claims 1-4, wherein, The organic base solution includes an organic base and a second organic solvent; Preferably, the mass ratio of the second organic solvent to the organic base is 0.4-25:1, and more preferably 0.9-5:

1.

6. The preparation method according to claim 5, wherein, The organic base is a sodium fatty alcohol containing 1-6 carbon atoms and / or a sodium cycloalkanol containing 3-6 carbon atoms, preferably selected from at least one of sodium methoxide, sodium ethoxide, sodium propoxide, sodium n-butoxide, sodium isobutoxide, sodium tert-butoxide, sodium tert-amyl alcohol, and sodium cyclohexanol. Preferably, the second organic solvent is a fatty alcohol containing 1-6 carbon atoms and / or a cycloalkanol containing 3-6 carbon atoms, preferably selected from at least one of methanol, ethanol, propanol, n-butanol, isobutanol, tert-butanol, tert-amyl alcohol and cyclohexanol.

7. The preparation method according to any one of claims 1-6, wherein, The molar ratio of the organic base in the organic base solution to the hydroxylamine salt in the reaction solution is 2-20:1, preferably 2.9-9.1:

1.

8. The preparation method according to any one of claims 1-7, wherein, The conditions for the addition reaction in step (2) include: a reaction temperature of -5 to 85°C, preferably -2 to 50°C, more preferably -1 to 35°C; and a reaction time of 0.5 to 36 h, preferably 0.9 to 12 h, more preferably 1.5 to 5 h.

9. The preparation method according to any one of claims 1-8, wherein, The preparation method is carried out in a diisopropanol hydroxylamine preparation system, the preparation system comprising: A reaction vessel, a material pump, and a vacuum distillation column connected in sequence; Preferably, the reaction vessel is an isothermal reactor, and more preferably an isothermal reactor equipped with stirring and liquid-solid separation devices.

10. Diisopropanol hydroxylamine prepared by the preparation method according to any one of claims 1-9.

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