Process for the preparation of n-vinyl-2-pyrrolidone intermediates and n-vinyl-2-pyrrolidone intermediates prepared thereby

Abstract

The present invention relates to a method of preparing an N-vinyl-2-pyrrolidone intermediate, an N-vinyl-2-pyrrolidone intermediate prepared by the method of preparation, and an N-vinyl-2-pyrrolidone prepared from the N-vinyl-2-pyrrolidone intermediate. The method of preparation includes the steps of: (1) preparing a reactant containing polyhydroxyalkanoate obtained by microbial cultivation; and (2) reacting the reactant containing polyhydroxyalkanoate with an amine compound at a temperature exceeding 200°C to produce an intermediate product containing.

Description

Technical Field

[0001] This disclosure relates to a method for preparing intermediates (precursors) for the preparation of the high-value-added chemical N-vinyl-2-pyrrolidone (NVP) in high yield. Background Technology

[0002] Biorefining is a technology that uses biological or chemical conversion processes to produce biofuels (energy), electricity, heat, and high-value-added chemicals from biomass.

[0003] In recent years, technologies have been developed for the chemical depolymerization of polyhydroxyalkanoates (PHAs), one of the aforementioned biomass materials, to produce high-value-added chemicals or intermediates. For example, PHAs can be used to prepare N-vinyl-2-pyrrolidone (NVP) intermediates or N-vinyl-2-pyrrolidone (NVP).

[0004] The NVP intermediate is a raw material used to prepare NVP, a high-value-added chemical. Increasing the yield of the NVP intermediate can lead to an increase in NVP production.

[0005] Conventionally, NVP intermediates or NVP are prepared via a procedure in which 1,4-butanediol (1,4-BDO) is obtained from petroleum-derived acetylene, converted to γ-butyrolactone (GBL), and then 2-pyrrolidone, N-vinyl-2-pyrrolidone (NVP), etc. However, this preparation method involves long reaction steps and increases the unit cost of NVP due to the use of expensive metal catalysts.

[0006] Meanwhile, the preparation of NVP intermediates or NVP using polyhydroxyalkanoates involves long and complex reaction steps, and the yields of NVP intermediates and NVP have not reached satisfactory levels. Summary of the Invention

[0007] Technical issues

[0008] As mentioned above, there are conventional limitations in producing NVP intermediates or NVP in high yields in an environmentally friendly and economically feasible manner. In particular, the use of polyhydroxyalkanoates (which are biomass) to prepare NVP intermediates can overcome environmental concerns and the limitations of dwindling petroleum resources; however, it suffers from long and complex reaction steps and significantly reduced NVP intermediate yields.

[0009] The inventors have conducted several studies to address the aforementioned problems. The results show that by controlling the composition of the reactants containing polyhydroxyalkanoates and the reaction temperature, N-vinyl-2-pyrrolidone (NVP) intermediates can be prepared in high yields through relatively simple reaction steps.

[0010] Therefore, one object of this disclosure is to provide a method for preparing N-vinyl-2-pyrrolidone (NVP) intermediates, which enables the production of N-vinyl-2-pyrrolidone (NVP) intermediates in high yields through simple reaction steps while using reactants containing polyhydroxyalkanoates.

[0011] Furthermore, another object of this disclosure is to provide an N-vinyl-2-pyrrolidone (NVP) intermediate prepared by the above preparation method and N-vinyl-2-pyrrolidone (NVP) prepared using the same.

[0012] Technical solution

[0013] To achieve the above objectives, this disclosure provides a method for preparing an N-vinyl-2-pyrrolidone intermediate, the method comprising: (1) preparing a reactant containing a polyhydroxyalkanoate obtained by microbial culture; and (2) reacting the reactant containing the polyhydroxyalkanoate with an amine compound at a temperature exceeding 200°C to generate an intermediate-containing product.

[0014] According to an embodiment of the present disclosure, in step (1), the polyhydroxyalkanoate may contain repeating units derived from 4-hydroxybutyrate.

[0015] According to another embodiment of this disclosure, in step (1), the content of polyhydroxyalkanoate contained in the reactants can be from 60% to 90% by weight, based on the total weight of the reactants.

[0016] According to another embodiment of this disclosure, in step (1), the moisture content of the reactants can be from 0% by weight to 80% by weight, based on the total weight of the reactants.

[0017] According to another embodiment of this disclosure, in step (1), the reactants may also include inorganic substances.

[0018] According to another embodiment of this disclosure, the content of inorganic substances can be greater than 0% by weight to 10% by weight, based on the total weight of the reactants.

[0019] According to another embodiment of this disclosure, the inorganic substance may include at least one selected from the group consisting of calcium carbonate (CaCO3), ferric sulfate (Fe2(SO4)3), and sodium bicarbonate (NaHCO3).

[0020] According to another embodiment of this disclosure, in step (2), the initial reaction pressure of the reactants and amine compounds can be from 1 bar to 120 bar.

[0021] According to another embodiment of this disclosure, in step (2), the amine compound may include a compound selected from the group consisting of monoethanolamine, aqueous monoethanolamine, ammonia, ammonia water, urea, and aqueous urea solution.

[0022] According to another embodiment of this disclosure, in step (2), the reactants and the amine compound can react in an equivalent ratio of 1:1.1 to 3.

[0023] According to another embodiment of this disclosure, in step (2), the intermediate may be N-(2-hydroxyethyl)-2-pyrrolidone.

[0024] Meanwhile, this disclosure provides an N-vinyl-2-pyrrolidone intermediate prepared by a method for preparing an N-vinyl-2-pyrrolidone intermediate.

[0025] Furthermore, this disclosure provides N-vinyl-2-pyrrolidone prepared from N-vinyl-2-pyrrolidone intermediates.

[0026] Furthermore, this disclosure provides a method for preparing N-vinyl-2-pyrrolidone, the method comprising: reacting an N-vinyl-2-pyrrolidone intermediate prepared by a method for preparing an N-vinyl-2-pyrrolidone intermediate with acetic anhydride to obtain an acetate intermediate; and deacetylifying the obtained acetate intermediate.

[0027] Furthermore, this disclosure provides a method for preparing N-vinyl-2-pyrrolidone, the method comprising: in the presence of a catalyst, subjecting an N-vinyl-2-pyrrolidone intermediate prepared by a method for preparing an N-vinyl-2-pyrrolidone intermediate to intramolecular dehydration in the gas phase.

[0028] Beneficial effects of the present invention

[0029] This disclosure enables the preparation of N-vinyl-2-pyrrolidone intermediates (N-vinyl-2-pyrrolidone precursors) in high yield and at low cost through relatively simple (shorter) reaction steps compared to existing technologies without the use of metal catalysts.

[0030] Furthermore, due to the high yield of the N-vinyl-2-pyrrolidone intermediate in this disclosure, the production rate of N-vinyl-2-pyrrolidone prepared using the N-vinyl-2-pyrrolidone intermediate can be improved. As a result, it can help to efficiently provide N-vinyl-2-pyrrolidone, a synthetic raw material for polyvinylpyrrolidone (PVP), which is widely used in the manufacture of cosmetics, food, pharmaceuticals, paper, textiles, pigments, paints, electronic devices, etc. Attached Figure Description

[0031] Figure 1 This is a flowchart illustrating a method for preparing an N-vinyl-2-pyrrolidone intermediate according to an embodiment of the present disclosure.

[0032] Figure 2 This is a graph showing the results based on test example 1. Detailed Implementation

[0033] The best embodiment of the present invention

[0034] This disclosure will be described in detail below. This disclosure is not limited to the forms given below, but can be modified in many ways without altering the spirit of this disclosure.

[0035] In this specification, the term "comprising" is intended to specify a particular feature, area, step, process, element, and / or component. It does not exclude the presence or addition of any other feature, area, step, process, element, and / or component unless specifically stated to the contrary.

[0036] All figures and expressions used in this document relating to component quantities, reaction conditions, etc., should be understood as being modified by the term “about” unless otherwise stated.

[0037] This disclosure provides a method for preparing an N-vinyl-2-pyrrolidone intermediate using a polyhydroxyalkanoate (which is a biomass), the N-vinyl-2-pyrrolidone intermediate prepared by said method, N-vinyl-2-pyrrolidone prepared from said N-vinyl-2-pyrrolidone intermediate, and the method for preparing the same. A key feature of this disclosure is that by optimizing the composition of the reactants containing the polyhydroxyalkanoate (e.g., reactant components, moisture content, etc.) and the reaction temperature, the N-vinyl-2-pyrrolidone intermediate can be prepared in high yields through simple reaction steps without the use of expensive metal catalysts, as will be described in detail below.

[0038] Method for preparing N-vinyl-2-pyrrolidone intermediate

[0039] The method for preparing an N-vinyl-2-pyrrolidone intermediate (hereinafter referred to as "NVP intermediate") according to this disclosure comprises: (1) preparing a reactant containing a polyhydroxyalkanoate obtained by microbial culture; and (2) reacting the reactant containing the polyhydroxyalkanoate with an amine compound at a temperature exceeding 200°C to generate a product containing the intermediate, which will be referred to Figure 1 As described below.

[0040] Step (1): Preparation of reactants

[0041] According to this disclosure, step (1) is the step of preparing a reactant containing polyhydroxyalkanoate obtained by microbial culture (S (1)).

[0042] There are no particular restrictions on the reactants, as long as they are substances containing polyhydroxyalkanoates. Specifically, the reactants are substances obtained from cell fermentation broths containing polyhydroxyalkanoates, and they can include polyhydroxyalkanoates, cells, cell-derived substances, and cell debris. Furthermore, the reactants can be polyhydroxyalkanoates themselves, obtained through procedures that separate and purify substances obtained from cell fermentation broths using conventional methods.

[0043] For example, the reactant can be dried cell material obtained by adding a polymeric flocculant and water (e.g., distilled water) to a cell fermentation broth containing polyhydroxyalkanoates to obtain a cell flocculant, and then dehydrating the obtained cell flocculant. Alternatively, the reactant can be cell fermentation broth that has not undergone flocculation and dehydration, or it can be cell flocculant (or cell flocculant) that has undergone flocculation but not dehydration. The cell fermentation broth or cell flocculant (or cell flocculant) has not undergone a purification process (e.g., dehydration). When applied as a reactant, the preparation process of the NVP intermediate can be shortened, while reducing the costs incurred during purification. Therefore, NVP intermediates and / or NVP can be prepared in an economically feasible manner.

[0044] Cell fermentation broth can be obtained by culturing microorganisms that produce biomass containing polyhydroxyalkanoates. The microorganism may include one or more selected from the group consisting of: Bacillus subtilis, Cupriavidus necator, Bacillus cereus, Bacillus brevis, Caulobacter cresentus, Bacillus sphaericus, Bacillus coagulans, Bacillus megaterium, Bacilllus circulands, Bacillus licheniformis, Escherichia coli, Microlanatus phosphovorous, Rhizobium meliloti, Rhizobium viciae, and Bredyrhizobium spp. The species include, but are not limited to, *Burkholderia cepacia*, *Burkholderia sacchari*, *Cupriavidusnecator*, *Neptunamonas Antarctica*, *Azobacter vinelandii*, *Pseudomonas putida*, *Pseudomonas aeruginosa*, *Aeromonas caviae*, *Aeromonas hydrophila*, *Aeromonas punctate*, *Alcaligeneslatus*, *Halomonas boliviensis*, *Lactobacillus rhamnosus*, and *Fermicutes bacterium*.

[0045] There are no particular limitations on polymeric flocculants, as long as they are polymeric materials capable of flocculating cell fermentation broth. Specifically, polymeric flocculants may include cationic polymeric flocculants with a molecular weight of 1,000,000 Da or higher (e.g., 1,000,000 Da to 10,000,000 Da, 1,000,000 Da to 5,000,000 Da, 1,300,000 Da to 4,500,000 Da, 1,500,000 Da to 4,000,000 Da, 2,000,000 Da to 3,500,000 Da, 2,300,000 Da to 3,000,000 Da, or 2,500,000 Da to 3,000,000 Da). For example, a polymeric flocculant can be a polymeric flocculant solution in which a cationic polymeric flocculant is dissolved or dispersed in a solvent (e.g., distilled water). Because polymeric flocculants include cationic polymeric flocculants, the flocculation efficiency of cell fermentation broths containing anionic polyhydroxyalkanoates can be significantly improved.

[0046] For example, a cationic polymeric flocculant can be a flocculant comprising: acrylamide-based polymers, acryloyl-based polymers, amidine-based polymers, polyethyleneamine-based polymers, diallyldimethylammonium chloride-based polymers, polyamine-based polymers, or combinations thereof. Specifically, it can be a polyacrylamide-based polymeric flocculant.

[0047] The dehydration of the cell flocculant can be performed using at least one of a press and an electroosmotic dehydrator, but is not limited thereto. Specifically, the cell flocculant can be initially dehydrated using a press to obtain flocculants, and then further dehydrated using an electroosmotic dehydrator to obtain the reactants (dried cell material). Through such dehydration, this disclosure can minimize the impurity content in the reactants while controlling the moisture content of the reactants as needed.

[0048] There are no particular restrictions on the type of press, as long as it is a known type of press. Specifically, it can be a screw press, a wedge press, a hydraulic press, etc.

[0049] There are no particular limitations on the operating pressure of the press (e.g., the operating pressure of the pressure plates provided in the press), but it can be from 0.01 MPa to 1 MPa. Specifically, the operating pressure of the press can be from 0.03 MPa to 0.9 MPa, 0.05 MPa to 0.7 MPa, 0.1 MPa to 0.6 MPa, 0.2 MPa to 0.5 MPa, or 0.3 MPa to 0.4 MPa, but is not limited thereto. When the operating pressure of the press is within the above range, preliminary dehydration can be effectively carried out while preventing damage to the polyhydroxyalkanoate.

[0050] There are no particular restrictions on electroosmotic dehydrators, as long as they are dehydrators that apply the principle of electrophoresis.

[0051] There are no particular restrictions on the operating conditions of the electroosmotic dehydrator, but the operating speed can range from 0.1 m / min to 4 m / min, and the applied voltage can range from 10 V to 150 V. Specifically, the operating speed of the electroosmotic dehydrator can be 0.5 m / min to 3.5 m / min, 0.7 m / min to 3 m / min, 0.9 m / min to 2.5 m / min, 1 m / min to 2 m / min, or 1.1 m / min to 1.5 m / min, and the applied voltage can be 12 V to 130 V, 13 V to 100 V, 15 V to 50 V, 17 V to 30 V, or 19 V to 25 V, but is not limited to these. When the operating conditions of the electroosmotic dehydrator are within the above ranges, secondary dehydration and impurity removal can be effectively performed.

[0052] Simultaneously, to enhance the fluidity and chemical reactivity of the cell flocculant, inorganic substances can be added to the cell fermentation broth along with the polymeric flocculant. Consequently, the reactants obtained through flocculation and / or dehydration may also contain inorganic substances.

[0053] According to this disclosure, based on the total weight of the reactants (e.g., reactants with a moisture content of 0% by weight), the content of inorganic substances in the reactants can be greater than 0% by weight and up to 10% by weight. Specifically, based on the total weight of the reactants, the content of inorganic substances in the reactants can be 0.1% by weight to 9.8% by weight, 0.3% by weight to 9.5% by weight, 0.5% by weight to 9% by weight, 1% by weight to 8% by weight, 1.5% by weight to 7% by weight, 2% by weight to 6.5% by weight, 2.5% by weight to 6% by weight, 3% by weight to 5.5% by weight, 3.5% by weight to 5% by weight, or 4% by weight to 5% by weight, but is not limited thereto. When the content of inorganic substances in the reactants is within the above range, the flowability and chemical reactivity of the reactants can be optimized.

[0054] When considering the fluidity and chemical reactivity of reactants, inorganic substances may include at least one selected from the group consisting of calcium carbonate (CaCO3), ferric sulfate (Fe2(SO4)3), and sodium bicarbonate (NaHCO3), but are not limited thereto. For example, inorganic substances may include all of calcium carbonate (CaCO3), ferric sulfate (Fe2(SO4)3), and sodium bicarbonate (NaHCO3).

[0055] According to this disclosure, the moisture content of the reactants can be controlled to increase the yield of NVP intermediates. For example, the moisture content of the reactants obtained by flocculation and dehydration can be 0% by weight, and the moisture content of the reactants can be controlled by adding water (e.g., distilled water) to the reactants with a moisture content of 0% by weight. Furthermore, the reactants are cell fermentation broths that have not undergone flocculation and dehydration, and they can have a controlled moisture content by including water derived from the cell fermentation broth. Additionally, the reactants are cell flocculent liquids (or cell flocculants) that have undergone flocculation but not dehydration, and they can have a controlled moisture content by including water derived from the cell fermentation broth and the cell flocculent liquid (or cell flocculants).

[0056] Specifically, based on the total weight of the reactants, the moisture content in the reactants can be from 0 wt% to 80 wt%. More specifically, based on the total weight of the reactants, the moisture content can be 5 wt% to 80 wt%, 10 wt% to 79 wt%, 15 wt% to 78 wt%, 20 wt% to 77 wt%, 25 wt% to 76 wt%, 30 wt% to 75 wt%, 35 wt% to 74 wt%, 40 wt% to 73 wt%, 45 wt% to 72 wt%, 50 wt% to 71 wt%, or 55 wt% to 70 wt%, but is not limited thereto. When the moisture content of the reactants is within the above range, the conversion rate of polyhydroxyalkanoates can be maximized, thereby significantly improving the yield of NVP intermediates.

[0057] Meanwhile, the polyhydroxyalkanoate (PHA) contained in the reactants is a thermoplastic natural polyester polymer that accumulates in microbial cells. It has physical properties similar to those of petroleum-derived synthetic biodegradable polymers (such as polybutylene terephthalate (PBAT), polybutylene succinate (PBS), polybutylene terephthalate (PBST), and polybutylene adipate (PBSA)), and exhibits excellent properties in terms of biodegradability and biocompatibility.

[0058] The weight-average molecular weight (Mw) of polyhydroxyalkanoates can be from 100,000 g / mol to 1,000,000 g / mol, 200,000 g / mol to 900,000 g / mol, 300,000 g / mol to 800,000 g / mol, 400,000 g / mol to 700,000 g / mol, or 500,000 g / mol to 600,000 g / mol, but is not limited thereto.

[0059] Polyhydroxyalkanoates may comprise repeating units derived from (one or more monomers) at least one of the following groups: 3-hydroxybutyrate (3HB), 3-hydroxypropionate (3HP), 3-hydroxyhexanoate (3HH), 3-hydroxyvalerate (3HV), 4-hydroxybutyrate (4HB), 4-hydroxyvalerate (4HV), 5-hydroxyvalerate (5HV), and 6-hydroxyhexanoate (6HH).

[0060] Specifically, the polyhydroxyalkanoate can be a homopolymer comprising repeating units derived from 3-hydroxybutyrate (3HB) or repeating units derived from 4-hydroxybutyrate (4HB). Alternatively, the polyhydroxyalkanoate can be a copolymer comprising repeating units derived from 3-hydroxybutyrate (3HB) and repeating units derived from 4-hydroxybutyrate (4HB).

[0061] Preferably, the polyhydroxyalkanoate can be a homopolymer (e.g., poly-4-hydroxybutyrate (P4HB)) containing repeating units derived from 4-hydroxybutyrate (4HB). When the polyhydroxyalkanoate contains repeating units derived from 4-hydroxybutyrate (4HB), the reaction with the amine compound described below is optimized at high temperature, thereby improving the yield of the NVP intermediate.

[0062] According to this disclosure, the content of polyhydroxyalkanoates in the reactants can be from 60% to 90% by weight, based on the total weight of the reactants (e.g., reactants with a moisture content of 0% by weight). Specifically, based on the total weight of the reactants, the content of polyhydroxyalkanoates in the reactants can be 63% to 90% by weight, 65% to 89% by weight, 68% to 88% by weight, 70% to 86% by weight, 73% to 85% by weight, 75% to 83% by weight, 76% to 82% by weight, or 78% to 80% by weight, but is not limited thereto. When the content of polyhydroxyalkanoates in the reactants is within the above range, the yield of NVP intermediates can be increased.

[0063] Step (2): Production of products containing intermediates

[0064] According to this disclosure, step (2) is a step of reacting a reactant containing a polyhydroxyalkanoate with an amine compound at a temperature exceeding 200°C to generate an intermediate product (S (2)).

[0065] There are no particular restrictions on the reaction temperature between the reactants and the amine compound, as long as it exceeds 200°C. Specifically, the reaction temperature can be 205°C or higher, 210°C or higher, 215°C or higher, 220°C or higher, 225°C or higher, 230°C or higher, 235°C or higher, 240°C or higher, 245°C or higher, or 250°C or higher, and can be 350°C or lower, 340°C or lower, 330°C or lower, 320°C or lower, 310°C or lower, 300°C or lower, 290°C or lower, 280°C or lower, 270°C or lower, 260°C or lower, or 250°C or lower, but is not limited to these. For example, the reaction temperature can be 210°C to 350°C, 220°C to 330°C, 230°C to 310°C, 240°C to 290°C, or 250°C to 270°C.

[0066] According to this disclosure, the initial reaction pressure (the initial set pressure for the reaction to proceed) of the reactants and amine compounds can be from 1 bar to 120 bar. Specifically, the initial reaction pressure can be from 1 bar to 115 bar, 3 bar to 110 bar, 5 bar to 105 bar, 7 bar to 100 bar, 10 bar to 90 bar, 15 bar to 85 bar, 20 bar to 80 bar, 25 bar to 75 bar, 30 bar to 70 bar, 35 bar to 65 bar, 40 bar to 60 bar, or 50 bar to 55 bar, but is not limited thereto.

[0067] When the reaction temperature and initial reaction pressure are within the ranges described above, the conversion rate of the polyhydroxyalkanoate contained in the reactants to the intermediates required in this disclosure (e.g., N-(2-hydroxyethyl)-2-pyrrolidone) can be significantly improved. As a result, the NVP intermediate can be prepared in high yield through a simple reaction procedure.

[0068] Meanwhile, there are no particular restrictions on the pressure during the reaction, which can be measured 30 minutes after the reaction of the reactants and amine compounds has been underway, but it can be 10 bar to 150 bar, 15 bar to 140 bar, 18 bar to 130 bar, 20 bar to 120 bar, 25 bar to 110 bar, 30 bar to 100 bar, 40 bar to 90 bar, or 50 bar to 80 bar.

[0069] Furthermore, there are no particular limitations on the reaction time between the reactants and the amine compound. However, considering the yield of the NVP intermediate, it can be 1 to 10 hours, 1.5 to 8 hours, 2 to 6 hours, 2.5 to 5 hours, or 3 to 4 hours.

[0070] According to this disclosure, the reaction ratio of the reactant to the amine compound can be an equivalence ratio of 1:1.1 to 3. Specifically, considering the yield of the NVP intermediate, the reaction ratio can be an equivalence ratio of 1:1.3 to 3, 1:1.5 to 2.8, 1:1.8 to 2.5, or 1:1.9 to 2.2, but is not limited thereto.

[0071] There are no particular limitations on the amine compound, as long as it is capable of depolymerizing the polyhydroxyalkanoate contained in the reactant. Specifically, the amine compound can include compounds selected from the group consisting of: monoethanolamine, aqueous monoethanolamine, ammonia, ammonia solution, urea, and aqueous urea solution. When the amine compound contains the above-mentioned compounds, the conversion rate of polyhydroxyalkanoate is improved, thereby increasing the yield of NVP intermediates.

[0072] Furthermore, according to this disclosure, there are no particular limitations on the intermediate contained in the intermediate product, but it can be N-(2-hydroxyethyl)-2-pyrrolidone. When the intermediate is N-(2-hydroxyethyl)-2-pyrrolidone (HEP), the reaction steps to obtain the NVP intermediate are minimized, thereby improving the production efficiency of the NVP intermediate. Specifically, N-(2-hydroxyethyl)-2-pyrrolidone can be the NVP intermediate, which is the target product in this disclosure.

[0073] In addition to intermediates, products containing intermediates may include byproducts such as γ-butyrolactone (GBL), 2-pyrrolidone, N-methylpyrrolidone (NMP), N-vinyl-2-pyrrolidone (NVP), 4-hydroxybutyric acid (4HB), and 4-hydroxy-N-(2-hydroxyethyl)butyramide (4HEBA).

[0074] Specifically, the intermediate product may contain N-(2-hydroxyethyl)-2-pyrrolidone in a high amount and 4-hydroxy-N-(2-hydroxyethyl)butyramide in a low amount. For example, based on the total weight of the intermediate product, the content of N-(2-hydroxyethyl)-2-pyrrolidone contained in the intermediate product may be 10% to 99% by weight, 20% to 90% by weight, 30% to 80% by weight, 40% to 70% by weight, or 50% to 60% by weight, but is not limited thereto. Furthermore, based on the total weight of the intermediate product, the content of 4-hydroxy-N-(2-hydroxyethyl)butyramide contained in the intermediate product may be 0% to 15% by weight, 0.2% to 12% by weight, 0.6% to 9% by weight, 1% to 6% by weight, 1.4% to 3% by weight, or 2% to 2.5% by weight, but is not limited thereto.

[0075] According to this disclosure, after producing the intermediate product through steps (1) and (2), the NVP intermediate can be obtained by conventional filtration and extraction procedures.

[0076] As described above, this disclosure prepares N-vinyl-2-pyrrolidone intermediates via simple reaction steps (1) and (2) without the use of expensive metal catalysts; therefore, it can reduce the cost of preparing N-vinyl-2-pyrrolidone intermediates while achieving high yields.

[0077] According to this disclosure, the yield of N-vinyl-2-pyrrolidone intermediate (e.g., N-(2-hydroxyethyl)-2-pyrrolidone) can be 35% or higher, 38% or higher, 40% or higher, 43% or higher, 45% or higher, 50% or higher, 53% or higher, 55% or higher, 60% or higher, 65% or higher, 70% or higher, 75% or higher, 80% or higher, or 85% or higher (e.g., 35% to 95%, 40% to 93%, 50% to 90%, or 60% to 88%), but is not limited thereto.

[0078] N-vinyl-2-pyrrolidone intermediate

[0079] The N-vinyl-2-pyrrolidone intermediate (precursor) according to this disclosure is prepared by the above preparation method. The N-vinyl-2-pyrrolidone intermediate prepared by the above preparation method has high yield and high purity, and it can be advantageously used to prepare the high value-added chemical N-vinyl-2-pyrrolidone.

[0080] N-Vinyl-2-pyrrolidone and its preparation method

[0081] The N-vinyl-2-pyrrolidone according to this disclosure is prepared from the above-described N-vinyl-2-pyrrolidone intermediate. The preparation of N-vinyl-2-pyrrolidone using the N-vinyl-2-pyrrolidone intermediate can be carried out by conventionally known preparation methods.

[0082] For example, a method for preparing N-vinyl-2-pyrrolidone may include: reacting an N-vinyl-2-pyrrolidone intermediate prepared by a method for preparing an N-vinyl-2-pyrrolidone intermediate with acetic anhydride to obtain an acetate intermediate; and deacetylating the resulting acetate intermediate, but is not limited thereto. The reaction conditions with acetic anhydride and the deacetylation reaction conditions may be set according to the yield of N-vinyl-2-pyrrolidone.

[0083] Furthermore, methods for preparing N-vinyl-2-pyrrolidone may include, but are not limited to, intramolecular dehydration of the N-vinyl-2-pyrrolidone intermediate prepared by the above-described preparation method in the gas phase in the presence of a catalyst. The deacetylation reaction conditions can be set according to the yield of N-vinyl-2-pyrrolidone.

[0084] This disclosure enables the high-yield preparation of N-vinyl-2-pyrrolidone intermediates, thereby increasing the yield of N-vinyl-2-pyrrolidone and reducing the unit cost of N-vinyl-2-pyrrolidone.

[0085] N-Vinyl-2-pyrrolidone can be advantageously used as a synthetic raw material (monomer) for polyvinylpyrrolidone (PVP), which is widely used in the manufacture of cosmetics, food, pharmaceuticals, paper, textiles, pigments, paints, electronic devices, etc.

[0086] The method of the present invention

[0087] The present disclosure will be described in detail below with reference to embodiments, but the scope of the present disclosure is not limited to the embodiments.

[0088] [Reagents, testing equipment, and analytical equipment]

[0089] In the examples, comparative examples, and test examples, the following reagents were used: isopropanol (Daejeong Chemical, HPLC grade), monoethanolamine (TCI, >99.0%), acetonitrile (BURDICK & JACKSON, HPLC grade), distilled water (MALLINCKRODTBAKER, HPLC grade), cationic polymer flocculant (FO4800VHM, SNF Korea), calcium carbonate (CaCO3) (Sigma Aldrich, >99%), ferric sulfate (Fe2(SO4)3) (Chemtech International, iron content 10.5% or higher), and sodium bicarbonate (NaHCO3) (Sigma Aldrich, >99%).

[0090] The following testing equipment was used: a sealed tube (CHEMGLASS LIFE SCIENCES, P05-132-128(1880-04)), a high-temperature and high-pressure reactor (Hanwool Engineering, Reactor system), a heated magnetic stirrer (DaehanScience, DH.WMH03021), a press (Hwain, Screw filter press SP-30), and an electroosmotic dewatering machine (Hwain, EOD-500S).

[0091] High-performance liquid chromatography (HPLC) and gas chromatography (GC) were used as analytical instruments. Specifically, an Agilent Technologies 1260 Infinity instrument was used as the HPLC instrument, and an Osaka Soda Capcell Pak C18MG (4.6 mm × 250 mm × 5 μm, P / N 92635) column was used. In this study, the autosampler temperature was set to 15 °C, the column temperature was set to 35 °C, and triple-distilled water containing 0.2% phosphoric acid and acetonitrile (ACN) was used as the mobile phase solvent. Analysis was performed with varying concentrations (gradients) at a mobile phase rate of 1 mL / min. A GC (Agilent Technologies, 8890) equipped with a DB-WAX (60 m × 250 μm × 0.25 μm) column was used as the GC instrument. In this study, the inlet temperature was set to 250 °C, and the flow rate was 1 mL / min. Furthermore, the flame ionization detector (FID) temperature was set to 300 °C for analysis. Meanwhile, when analyzing the products, the GC sample was diluted with isopropanol (IPA) and the HPLC sample was diluted with distilled water before analysis.

[0092] [Example 1]

[0093] Preparation of reactants containing poly-4-hydroxybutyrate (P4HB)

[0094] A cationic polymeric flocculant and distilled water were added to the cell fermentation broth containing P4HB for flocculation. Subsequently, calcium carbonate (CaCO3), ferric sulfate (Fe2(SO4)3), and sodium bicarbonate (NaHCO3), used to promote flow and chemical reactions, were added in a specific ratio to the already flocculated cell flocculant. Next, the cell flocculant was dehydrated using a press and an electroosmotic dehydrator to obtain a reactant containing P4HB. The resulting reactant contained approximately 78.3% by weight of P4HB, approximately 5% by weight of the total added CaCO3, Fe2(SO4)3, and NaHCO3, 0% by weight of water, and the remainder was cell debris.

[0095] Preparation of products containing N-(2-hydroxyethyl)-2-pyrrolidone (HEP)

[0096]

[0097] 10 g of reactant with a P4HB content of 78.3% by weight, 6.1 g of monoethanolamine (MEA), and 10 g of distilled water were charged into the reaction chamber of a batch high-temperature and high-pressure reactor. After purging with N2 gas and performing a leak check, the reaction was carried out for 3 hours at 1 bar and 250°C with stirring at 500 rpm. Approximately 30 minutes after the temperature in the reaction chamber reached 250°C, the pressure (P2) during the reaction was confirmed to be 23 bar. After the reaction was complete, the reaction liquid was recovered when the temperature of the reaction chamber cooled to room temperature. The recovered reaction liquid was then filtered through a syringe filter to remove the cell-derived biochar, thereby obtaining a HEP-containing product.

[0098] [Example 2]

[0099] Distilled water was added to the reactant containing P4HB used in Example 1 to prepare a reactant with a water content of 50% by weight, and the HEP-containing product was obtained by the same procedure as in Example 1.

[0100] [Examples 3 to 10]

[0101] The HEP-containing products were obtained using the same procedure as in Example 1, except that the MEA equivalent was adjusted by adding distilled water as in Example 2 to adjust the moisture content of the reactants, or by injecting N2 gas to adjust the initial reaction pressure (P1), as shown in Table 1 below.

[0102] [Test Example 1]

[0103] The HEP-containing products obtained in Examples 1 to 10 were analyzed by high performance liquid chromatography (HPLC) and gas chromatography (GC), and the results are shown in Table 1 below.

[0104] Meanwhile, the relationships between HEP ​​yield and MEA equivalent, initial reaction pressure and moisture content are summarized in the figure, as follows: Figure 2 As shown.

[0105] [Table 1]

[0106]

[0107] Referring to Table 1 above, when HEP-containing products are prepared at reaction temperatures exceeding 200°C as described in this disclosure, HEP-containing products with high HEP content are obtained, which are the intermediates required in this disclosure.

[0108] In addition, refer to Figure 2As disclosed in this disclosure, the HEP yield is increased by adjusting the initial reaction pressure (P1) and moisture content (water content). That is, it can be understood that adjusting the MEA equivalent has no significant effect on the change in HEP ​​yield, while adjusting the initial reaction pressure (P1) and moisture content has a significant effect on the change in HEP ​​yield. Specifically, when considering the evaluation results of HEP yield changes with the moisture content of reactants containing P4HB, when the initial reaction pressure (P1) is 30 bar, the HEP yield increases significantly from 50% to 75% moisture content compared to when the moisture content is 0% by weight (see Examples 6, 8, and 9). Furthermore, the HEP yield increases significantly with increasing initial reaction pressure (P1) or pressure during the reaction (P2).

[0109] [Comparative Example 1]

[0110] Reactants containing P4HB were prepared using the same procedure as in Example 1.

[0111] Next, 0.2 g of reactant with a P4HB content of 78.3% by weight, 0.122 g of monoethanolamine (MEA), and 0.2 g of distilled water were added to a 48-mL screw-cap tube, and a mixture was prepared by stirring at 300 rpm. The mixture was then reacted at 1 bar and 120°C for 3 hours using a heated stirrer. After the reaction was complete, the reaction liquid was recovered and filtered through a syringe filter to remove the cell-derived biochar, thus obtaining the product.

[0112] [Comparative Examples 2 to 5]

[0113] The products were obtained using the same procedure as in Comparative Example 1, except that the MEA equivalent was adjusted or the moisture content of the reactants was adjusted by adding distilled water as in Example 2, as shown in Table 2 below.

[0114] [Test Example 2]

[0115] The products obtained in Comparative Examples 1 to 5 were analyzed by high performance liquid chromatography (HPLC) and gas chromatography (GC), and the results are shown in Table 2 below.

[0116] [Table 2]

[0117]

[0118] Referring to Table 2 above, when the product is prepared at a reaction temperature of 120°C, the conditions of this disclosure are not met, and almost no conversion to HEP occurs, resulting in a product with a significantly low HEP content. Specifically, when the MEA equivalent is 2 equivalents or more at a reaction temperature of 120°C, most of the P4HB is converted to 4HEBA, rather than to HEP (which is the intermediate required in this disclosure). Therefore, it is understood that a significant amount of heat is required for the conversion to HEP.

[0119] [Comparative Examples 6 to 11]

[0120] Products were obtained using the same procedure as in Comparative Example 1, except that the reaction temperature was set to 200°C while adjusting the MEA equivalent or adjusting the moisture content of the reactants by adding distilled water as in Example 2, as shown in Table 3 below.

[0121] [Test Example 3]

[0122] The products obtained in Comparative Examples 6 to 11 were analyzed by high performance liquid chromatography (HPLC) and gas chromatography (GC), and the results are shown in Table 3 below.

[0123] [Table 3]

[0124]

[0125] Referring to Table 3 above, even when the reaction temperature is increased to 200°C, the heat required to convert P4HB to HEP is insufficient, thus yielding a product with a low HEP content. Furthermore, when the moisture content of the reactants containing P4HB exceeds 50% by weight, the yields of 4HEBA and other non-HEP byproducts tend to increase.

Claims

1. A method for preparing an N-vinyl-2-pyrrolidone intermediate, comprising: (1) Preparation of reactants containing polyhydroxyalkanoates obtained through microbial culture; as well as (2) Reacting the reactant containing the polyhydroxyalkanoate with an amine compound at a temperature exceeding 200°C to generate an intermediate product.

2. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (1), the polyhydroxyalkanoate comprises repeating units derived from 4-hydroxybutyrate.

3. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (1), the content of polyhydroxyalkanoate contained in the reactants is 60% to 90% by weight, based on the total weight of the reactants.

4. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (1), the moisture content of the reactants is 0% by weight to 80% by weight, based on the total weight of the reactants.

5. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (1), the reactants also contain inorganic substances.

6. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 5, wherein the content of the inorganic substance is greater than 0% by weight and up to 10% by weight based on the total weight of the reactants.

7. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 5, wherein the inorganic substance comprises at least one selected from the group consisting of: calcium carbonate (CaCO3), ferric sulfate (Fe2(SO4)3), and sodium bicarbonate (NaHCO3).

8. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (2), the initial reaction pressure of the reactants and the amine compound is between 1 bar and 120 bar.

9. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (2), the amine compound includes compounds selected from the group consisting of monoethanolamine, aqueous monoethanolamine, ammonia, ammonia water, urea, and aqueous urea water.

10. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (2), the reactant and the amine compound react in an equivalent ratio of 1:1.1 to 3.

11. The method for preparing N-vinyl-2-pyrrolidone intermediate according to claim 1, wherein, In step (2), the intermediate is N-(2-hydroxyethyl)-2-pyrrolidone.

12. An N-vinyl-2-pyrrolidone intermediate prepared by the method according to claim 1.

13. N-vinyl-2-pyrrolidone, which is prepared from the N-vinyl-2-pyrrolidone intermediate according to claim 12.

14. A method for preparing N-vinyl-2-pyrrolidone, comprising: The N-vinyl-2-pyrrolidone intermediate prepared by the method according to claim 1 is reacted with acetic anhydride to obtain an acetate intermediate; The resulting acetate intermediate was then deacetylated.

15. A method for preparing N-vinyl-2-pyrrolidone, comprising: In the presence of a catalyst, the N-vinyl-2-pyrrolidone intermediate prepared by the method according to claim 1 is subjected to intramolecular dehydration in the gas phase.

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