Method for synthesizing piroctone olamine salt

Abstract

The invention discloses a method for synthesizing piroctone olamine salt, and relates to the technical field of organic synthesis.The method for synthesizing piroctone olamine salt comprises the following steps that firstly, synthesis raw materials are selected; 2, carrying out a synthetic reaction; and step 3, preparing a piroctone olamine salt finished product. Through cooperative use of the first feeding pipe, the exhaust pipe and the exhaust pump, the problems that byproducts are generated, the post-treatment difficulty is increased and the process safety is greatly reduced due to the fact that hydroxylamine hydrochloride solid raw materials are prone to deliquescence or oxidation failure due to the fact that the hydroxylamine hydrochloride solid raw materials make contact with air for a too long time are solved, it is guaranteed that experiments are conducted safely, and the experiment efficiency is improved. The first feeding pipe, the discharging hopper, the sealing conical rod and the micro electric push rod are used in cooperation, so that when a hydroxylamine hydrochloride solid raw material is added into the first feeding pipe, internal air is sucked away by the sucking pump, negative pressure is formed, and the hydroxylamine hydrochloride solid raw material is more convenient to input.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, and specifically to a method for synthesizing pyrrolidone ethanolamine salt. Background Technology

[0002] Octopirox (OCT) is a novel anti-dandruff and anti-itch agent with superior efficacy compared to other similar agents. It not only mixes well with other additives in shampoos but is also non-toxic, non-irritating, and highly safe, making it a highly promising anti-dandruff and anti-itch agent for widespread application.

[0003] Currently, the method for synthesizing pyrrolidone ethanolamine salt from 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone as a starting material is a two-step process. The first step involves reacting 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone with hydroxylamine hydrochloride in the presence of a base to obtain pyrrolidone; the second step involves reacting pyrrolidone with ethanolamine to obtain pyrrolidone ethanolamine salt.

[0004] The reaction equation for the first step is as follows: The reaction equation for the second step is as follows:

[0005] The base in the first step described above can be a pyridine compound, a basic inorganic compound, or an organic base. Pyridine compounds include pyridine, aminopyridine, aminopyridine with alkyl substituents, and imidazole; however, pyridine compounds are expensive, resulting in high production costs and causing serious environmental pollution. Basic inorganic compounds include alkali metal carbonates or alkali metal bicarbonates, but the yield of pyrrolidone is low. Organic bases include triethylamine, sodium acetate, and hexamethylenetetramine, but the yield of pyrrolidone is also low; literature indicates that the yield of pyrrolidone is 33% when sodium acetate is used as the organic base, and 53% when triethylamine is used.

[0006] The prior art discloses Chinese Patent Publication No. CN114874137A to solve the aforementioned technical problems. The technical solution disclosed in this patent document is as follows: A method for synthesizing pyroxone ethanolamine salt, the method comprising the following steps: Synthesis step: 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone is dissolved in an alcohol solvent, and hydroxylamine hydrochloride and ethanolamine are added sequentially. Ethanolamine and hydroxylamine hydrochloride undergo a neutralization reaction to generate hydroxylamine and ethanolamine hydrochloride. Subsequently, a transesterification reaction of 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone and hydroxylamine occurs simultaneously to generate pyroxone, and a salt formation reaction of pyroxone and ethanolamine occurs simultaneously to generate pyroxone ethanolamine salt, yielding a reaction solution; Post-processing step: The alcohol solvent in the reaction solution is first removed, and then solvent extraction is used to obtain an aqueous phase and an organic phase; the organic phase is crystallized to obtain pyroxone ethanolamine salt. This application improves the yield of pyroxone ethanolamine salt and simplifies the production process.

[0007] The above technical solution will have the following problems in actual use:

[0008] During the use of this method, if the solid hydroxylamine hydrochloride raw material is exposed to air for too long, it is prone to deliquescence or oxidation and failure, which leads to the generation of by-products, increases the difficulty of post-processing, and greatly reduces the safety of the process. Summary of the Invention

[0009] The purpose of this invention is to provide a method for synthesizing pyrrolidone ethanolamine salt, so as to solve the problems mentioned in the background art.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for synthesizing pyrrolidone ethanolamine salt, the method comprising the following steps:

[0011] Step 1: Selection of raw materials for synthesis;

[0012] Step 2: The synthesis reaction proceeds;

[0013] Step 3: Preparation of pyroxone ethanolamine salt product.

[0014] A further improvement to the technical solution of the present invention is that the selection of synthetic raw materials in step one includes the following steps:

[0015] A1: Select a number of 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone, hydroxylamine hydrochloride and ethanolamine in a molar ratio of 1:1.8:2.5.

[0016] A further improvement to the technical solution of the present invention is that the synthesis reaction in step two includes the following steps:

[0017] B1: A certain amount of alcohol solvent is added to 1 through 13, and then 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone solution is added to the reaction vessel through the inlet pipe, and then the inlet pipe is closed.

[0018] B2: Connect the top of 2 to the container storing hydroxylamine hydrochloride raw material, then turn on the electromagnetic control valve and the air pump. Use the air pump to suck out the air inside the first feed pipe, then start the micro electric actuator to push the sealing cone rod upward and release the seal on the feed hopper.

[0019] B3: At this time, hydroxylamine hydrochloride raw material enters the reaction tank through the first feed pipe under the action of gravity. Then, ethanol is added to the reaction tank through the second feed pipe in the same way.

[0020] B4: Ethanolamine and hydroxylamine hydrochloride undergo a neutralization reaction to produce hydroxylamine and ethanolamine hydrochloride. Simultaneously, 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone and hydroxylamine undergo an ester exchange reaction to produce pyroxenone, and pyroxenone and ethanolamine undergo a salt formation reaction to produce pyroxenone ethanolamine salt, resulting in a reaction solution containing pyroxenone ethanolamine salt and ethanolamine hydrochloride.

[0021] A further improvement to the technical solution of the present invention is that the preparation of the pyrrolidone ethanolamine salt product in step three includes the following steps:

[0022] C1: Remove the alcohol solvent from the reaction solution in B4, and then use solvent extraction to obtain an aqueous phase containing ethanolamine hydrochloride and an organic phase containing pyrrolidone ethanolamine salt;

[0023] C2: The organic phase is crystallized to obtain pyrrolidone ethanolamine salt.

[0024] A further improvement of the technical solution of the present invention is that: a first feed pipe is fixedly connected to the top left side of the reaction vessel, a second feed pipe is fixedly connected to the top right side of the reaction vessel, a discharge hopper is fixedly connected to the inner wall of the first feed pipe, a sealing cone rod is movably connected to the inner wall of the discharge hopper, a miniature electric actuator is fixedly connected to the bottom end of the sealing cone rod, and a positioning ring is fixedly connected to the bottom end of the miniature electric actuator.

[0025] The above technical solution utilizes the combined use of a first feed pipe, a hopper, a sealing cone rod, and a micro electric actuator to create negative pressure by drawing away the internal air in the first feed pipe when adding solid hydroxylamine hydrochloride raw material, making it more convenient to add solid hydroxylamine hydrochloride raw material.

[0026] A further improvement of the technical solution of the present invention is that the outer wall of the positioning ring is fixedly connected to the inner wall of the first feed tube.

[0027] A further improvement of the technical solution of the present invention is that: a mounting cover is fixedly connected to one side of the first feed pipe, a suction pipe is fixedly connected to one end of the mounting cover, a suction pump is fixedly connected to the end of the suction pipe away from the mounting cover, an electromagnetic control valve is fixedly connected to the outer wall of the tail end of the suction pipe, and a bearing ring is fixedly connected to the bottom surface of the suction pump.

[0028] By adopting the above technical solution, the combined use of the first feed pipe, the air extraction pipe, and the air extraction pump avoids the problem that the solid hydroxylamine hydrochloride raw material is in contact with air for too long, which can easily lead to deliquescence or oxidation and failure, resulting in the generation of by-products, increasing the difficulty of post-processing, and greatly reducing the safety of the process, thus ensuring the safe conduct of the experiment.

[0029] A further improvement of the technical solution of the present invention is that: a liquid inlet pipe is fixedly connected to the upper surface of the second feed pipe, and a bearing ring is fixedly connected to the front of the reaction vessel.

[0030] Due to the adoption of the above technical solution, the technical progress achieved by this invention compared to the prior art is as follows:

[0031] 1. This invention provides a method for synthesizing pyrrolidone ethanolamine salt. By using a first feed pipe, an exhaust pipe, and an exhaust pump in combination, the problem of hydroxylamine hydrochloride solid raw material being in contact with air for too long, which is prone to deliquescence or oxidation and failure, thus leading to the generation of by-products, increasing the difficulty of post-processing, and greatly reducing the safety of the process is avoided, thus ensuring the safe conduct of the experiment.

[0032] 2. This invention provides a method for synthesizing pyrrolidone ethanolamine salt. By using a combination of a first feed pipe, a hopper, a sealing cone rod, and a micro electric actuator, the air inside the first feed pipe is sucked away by an air pump when adding solid hydroxylamine hydrochloride raw material, creating a negative pressure, which makes it easier to add solid hydroxylamine hydrochloride raw material.

[0033] 3. This invention provides a method for synthesizing pyroxone ethanolamine salt. By using the combined use of a first feed pipe and a second feed pipe installed on the reaction vessel, it is convenient to add different raw materials, ensuring that the raw materials do not remain mixed in the reaction vessel and preventing premature reaction. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the method flow structure of the present invention;

[0035] Figure 2 This is a schematic diagram of the reaction vessel structure of the present invention;

[0036] Figure 3 This is a rear view structural diagram of the reaction vessel of the present invention;

[0037] Figure 4 This is a schematic diagram showing the structural details of the first feed tube of the present invention.

[0038] In the diagram: 1. Reaction vessel; 2. First feed pipe; 3. Second feed pipe; 4. Bearing ring; 5. Vacuum pipe; 6. Electromagnetic control valve; 7. Vacuum pump; 8. Mounting cover; 9. Discharge hopper; 10. Sealing cone rod; 11. Miniature electric actuator; 12. Positioning ring; 13. Liquid inlet pipe; 14. Liquid outlet pipe. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to embodiments:

[0040] Example 1

[0041] like Figure 1-4 As shown, the present invention provides a method for synthesizing pyrrolidone ethanolamine salt, which includes the following steps:

[0042] Step 1: Selection of raw materials for synthesis;

[0043] Step 2: The synthesis reaction proceeds;

[0044] Step 3: Preparation of pyroxone ethanolamine salt product.

[0045] The selection of synthetic raw materials in step one includes the following steps:

[0046] A1: Select a number of 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone, hydroxylamine hydrochloride and ethanolamine in a molar ratio of 1:1.8:2.5.

[0047] The synthesis reaction in step two includes the following steps:

[0048] B1: A certain amount of alcohol solvent is added to 1 through 13, and then 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone solution is added to reaction vessel 1 through inlet pipe 13, and then inlet pipe 13 is closed.

[0049] B2: Connect the top of 2 to the container storing hydroxylamine hydrochloride raw material, then turn on the electromagnetic control valve 6 and the air pump 7, use the air pump 7 to suck out the air inside the first feed pipe 2, then start the micro electric push rod 11 to push the sealing cone rod 10 upward and release the seal on the feed hopper 9.

[0050] B3: At this time, the hydroxylamine hydrochloride raw material enters the reaction tank 1 through the first feed pipe 2 under the action of gravity. Then, ethanol is added to the reaction tank 1 through the second feed pipe 3 in the same way.

[0051] B4: Ethanolamine and hydroxylamine hydrochloride undergo a neutralization reaction to produce hydroxylamine and ethanolamine hydrochloride. Simultaneously, 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone and hydroxylamine undergo an ester exchange reaction to produce pyroxenone, and pyroxenone and ethanolamine undergo a salt formation reaction to produce pyroxenone ethanolamine salt, resulting in a reaction solution containing pyroxenone ethanolamine salt and ethanolamine hydrochloride.

[0052] The preparation of the pyrrolidone ethanolamine salt product in step three includes the following steps:

[0053] C1: Remove the alcohol solvent from the reaction solution in B4, and then use solvent extraction to obtain an aqueous phase containing ethanolamine hydrochloride and an organic phase containing pyrrolidone ethanolamine salt;

[0054] C2: The organic phase is crystallized to obtain pyrrolidone ethanolamine salt.

[0055] Example 2

[0056] like Figure 1-4 As shown, based on Embodiment 1, the present invention provides a technical solution: Preferably, a first feed pipe 2 is fixedly connected to the left side of the top of the reaction vessel 1, a second feed pipe 3 is fixedly connected to the right side of the top of the reaction vessel 1, a feeding hopper 9 is fixedly connected to the inner wall of the first feed pipe 2, a sealing cone rod 10 is movably connected to the inner wall of the feeding hopper 9, a micro electric push rod 11 is fixedly connected to the bottom end of the sealing cone rod 10, and a positioning ring 12 is fixedly connected to the bottom end of the micro electric push rod 11.

[0057] The outer wall of the positioning ring 12 is fixedly connected to the inner wall of the first feed pipe 2. A mounting cover 8 is fixedly connected to one side of the first feed pipe 2. A suction pipe 5 is fixedly connected to one end of the mounting cover 8. A suction pump 7 is fixedly connected to the end of the suction pipe 5 away from the mounting cover 8. An electromagnetic control valve 6 is fixedly connected to the outer wall of the tail end of the suction pipe 5. A bearing ring 4 is fixedly connected to the bottom surface of the suction pump 7.

[0058] The upper surface of the second feed pipe 3 is fixedly connected to the liquid inlet pipe 13, and the front of the reaction vessel 1 is fixedly connected to the bearing ring 4.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0060] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A method for synthesizing pyrrolidone ethanolamine salt, characterized in that: The method for synthesizing piroctone ethanolamine salt includes the following steps: Step 1: Selection of raw materials for synthesis; Step 2: The synthesis reaction proceeds; Step 3: Preparation of pyroxone ethanolamine salt product.

2. The method for synthesizing pyrrolidone ethanolamine salt according to claim 1, characterized in that: The selection of synthetic raw materials in step one includes the following steps: A1: Select a number of 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone, hydroxylamine hydrochloride and ethanolamine in a molar ratio of 1:1.8:2.

5.

3. The method for synthesizing pyrrolidone ethanolamine salt according to claim 1, characterized in that: The synthesis reaction in step two includes the following steps: B1: A certain amount of alcohol solvent is added to 1 through 13, and then 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone solution is added to the reaction vessel (1) through the inlet pipe (13), and then the inlet pipe (13) is closed. B2: Connect the top of 2 to the container storing hydroxylamine hydrochloride raw material, then turn on the electromagnetic control valve (6) and the air pump (7), use the air pump (7) to suck out the air inside the first feed pipe (2), then start the micro electric push rod (11) to push the sealing cone rod (10) to move upward and release the closure of the feed hopper (9); B3: At this time, the hydroxylamine hydrochloride raw material enters the reaction tank (1) through the first feed pipe (2) under the action of gravity. Then, ethanol is added to the reaction tank (1) through the second feed pipe (3) in the same way. B4: Ethanolamine and hydroxylamine hydrochloride undergo a neutralization reaction to produce hydroxylamine and ethanolamine hydrochloride. Simultaneously, 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyranone and hydroxylamine undergo an ester exchange reaction to produce pyroxenone, and pyroxenone and ethanolamine undergo a salt formation reaction to produce pyroxenone ethanolamine salt, resulting in a reaction solution containing pyroxenone ethanolamine salt and ethanolamine hydrochloride.

4. The method for synthesizing pyrrolidone ethanolamine salt according to claim 1, characterized in that: The preparation of the pyrrolidone ethanolamine salt product in step three includes the following steps: C1: Remove the alcohol solvent from the reaction solution in B4, and then use solvent extraction to obtain an aqueous phase containing ethanolamine hydrochloride and an organic phase containing pyrrolidone ethanolamine salt; C2: The organic phase is crystallized to obtain pyrrolidone ethanolamine salt.

5. The method for synthesizing pyrrolidone ethanolamine salt according to claim 3, characterized in that: The top left side of the reaction vessel (1) is fixedly connected to a first feed pipe (2), and the top right side of the reaction vessel (1) is fixedly connected to a second feed pipe (3). The inner wall of the first feed pipe (2) is fixedly connected to a discharge hopper (9), and the inner wall of the discharge hopper (9) is movably connected to a sealing cone rod (10). The bottom end of the sealing cone rod (10) is fixedly connected to a miniature electric actuator (11), and the bottom end of the miniature electric actuator (11) is fixedly connected to a positioning ring (12).

6. The method for synthesizing pyrrolidone ethanolamine salt according to claim 5, characterized in that: The outer wall of the positioning ring (12) is fixedly connected to the inner wall of the first feed pipe (2).

7. The method for synthesizing pyrrolidone ethanolamine salt according to claim 3, characterized in that: A mounting cover (8) is fixedly connected to one side of the first feed pipe (2). A suction pipe (5) is fixedly connected to one end of the mounting cover (8). A suction pump (7) is fixedly connected to the end of the suction pipe (5) away from the mounting cover (8). An electromagnetic control valve (6) is fixedly connected to the outer wall of the tail end of the suction pipe (5). A bearing ring (4) is fixedly connected to the bottom surface of the suction pump (7).

8. The method for synthesizing pyrrolidone ethanolamine salt according to claim 3, characterized in that: The upper surface of the second feed pipe (3) is fixedly connected to the liquid inlet pipe (13), and the front of the reaction vessel (1) is fixedly connected to the bearing ring (4).

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