A preparation method of gamma-undecalactone

Abstract

The present invention provides a preparation method of γ-undecalactone, the preparation method comprising: mixing 1-decene with a solvent, then adding a primary catalyst, a co-catalyst and an acid binding agent, and then adding CO2, performing carbonylation reaction, and post-processing to obtain the γ-undecalactone. The preparation method of γ-undecalactone provided by the present invention uses 1-decene as a starting material and produces γ-undecalactone by carbonyl synthesis reaction. The method can circumvent the high temperature working conditions in existing production, has the advantages of mild reaction conditions, high production efficiency, high production stability, high selectivity, high yield, etc., and the γ-undecalactone prepared by the method has high purity and pure smell.

Description

Technical Field

[0001] The invention belongs to the technical field of organic synthesis and relates to a method for preparing gamma-undecalactone. Background Art

[0002] γ-undecalactone, also known as peach aldehyde and γ-undecalactone, is a traditional synthetic fragrance that plays an irreplaceable role in flavors, feed, food additives, etc.

[0003] Gamma-undecalactone is one of the γ-alkyl-butyrolactones. The γ-alkyl-butyrolactone fragrances on the market are mainly derived from chemical synthesis. There are many methods for the chemical synthesis of γ-alkyl-butyrolactone. The more traditional methods include the following five: 1. Preparation of γ-alkyl-butyrolactone by thermal dehydration of hydroxy acids and sulfuric acid; 2. Preparation of γ-alkyl-butyrolactone using α-olefins and acetic acid as raw materials, and high-valent acetates such as cerium and vanadium or manganese acetate (+3 valence) as oxidants; 3. Synthesis of γ-alkyl-butyrolactone through acid-catalyzed cyclization reaction using β,γ-enoic acid as raw materials; 4. Synthesis of intermediate α,β-enoic acid using long-chain fatty aldehydes and malonic acid as raw materials, and then synthesis of γ-unsaturated lactones through acid-catalyzed cyclization reaction; 5. Synthesis of γ-alkyl-butyrolactone using long-chain fatty alcohols and acrylic acid or methyl acrylate as raw materials, through high-temperature reaction initiated by peroxide. The main drawbacks of the first four traditional synthesis methods and processes are high cost, low yield, and the generation of waste products. They have now been largely eliminated, with the fifth method now being the mainstream production process. The drawbacks currently present in the synthesis of γ-alkyl-butyrolactone also exist in the synthesis of γ-undecalactone.

[0004] CN108997271A discloses a method for producing γ-undecalactone synthetic fragrances by reactive distillation. The method uses n-octanol and acrylic acid as starting materials and di-tert-butyl peroxide as an initiator. The reactive distillation process involves side-line extraction during operation, which is difficult to operate and not conducive to continuous and stable production. In addition, the preheating temperature of the di-tert-butyl peroxide is 100-180°C, while the decomposition temperature of di-tert-butyl peroxide is greater than 120°C. Below 160°C, there is a problem of varying degrees of residual di-tert-butyl peroxide. The residual di-tert-butyl peroxide poses a safety risk of abnormally increasing the reaction temperature in the subsequent distillation step due to decomposition heat. It also further increases the risk of side reactions in the product distillation step, affecting product quality.

[0005] CN102276560A discloses the use of tert-butyl perbenzoate as an initiator, octanol and methyl acrylate in a free radical addition reaction to produce peach aldehyde. Since the refined steamed product contains some impurities that affect the product quality, it is necessary to further use alkaline washing on the refined steamed product to further remove impurities, improve the product's odor, and enhance the product quality.

[0006] Existing industrial production processes mostly use acrylic acid or acrylic ester as raw materials and adopt high-temperature operation processes. During production operations, there is a safety hazard that the system may be abnormally pressurized due to the polymerization of acrylic acid or acrylic ester in the gas phase to form blockages. In addition, the oligomers formed by acrylic acid or acrylic ester in the liquid phase reaction space lead to a decrease in product selectivity. At the same time, some low-boiling point impurities generated have a boiling point close to that of the product, which increases the difficulty of separation. Under high-temperature operating conditions, trace alcohol substances such as hexanol, decanol, and nonanol introduced into the raw material octanol are easily oxidized by peroxide to form corresponding aldehydes and ketones. The aldehydes and ketones further react with alcohols and acrylic acid derivatives, further increasing the complexity of the reaction solution and increasing the difficulty of separation. As a result, some aldehydes, ketones, alcohols and some trace impurities with relatively low polymerization degrees enter the product, resulting in an impure odor of the product.

[0007] In view of the shortcomings of the above-mentioned process, it is urgent to develop a new production method for γ-undecalactone to overcome the current production problems, so as to achieve green and gentle production, obtain high-quality products, and meet downstream needs. Summary of the Invention

[0008] In response to the shortcomings of the prior art, the present invention aims to provide a method for preparing gamma-undecalactone, specifically a method for producing gamma-undecalactone using 1-decene as a starting material. The preparation method provided by the present invention can effectively improve production efficiency, ensure the stability of perfume production, avoid the high-temperature conditions commonly encountered in existing production processes, reduce the discharge of three wastes, and achieve environmental protection. The method has the advantages of simple operation and high product yield, and is suitable for industrial application.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a method for preparing gamma-undecalactone, the preparation method comprising:

[0011] 1-decene is mixed with a solvent, and then a main catalyst, a co-catalyst and an acid binding agent are added, and then CO2 is added to carry out a carbonylation reaction, and post-processing is performed to obtain the gamma-undecalactone.

[0012] The present invention provides a method for preparing γ-undecalactone, which uses 1-decene as a starting material and produces γ-undecalactone through a carbonyl synthesis reaction. The method can avoid the high-temperature working conditions in existing production and has the advantages of mild reaction conditions, high production efficiency, high production stability, high selectivity, and high yield. In addition, the γ-undecalactone prepared by the method has high purity and a pure odor.

[0013] The preparation method provided by the present invention also avoids the hidden dangers of clogging fillers and tower pressure changes caused by the precipitation of trace salts in organic matter in the distillation tower in the existing process, can reduce the emission of three wastes, is green and environmentally friendly, and the entire process is safe, green, economical, easy to operate, and suitable for industrial application.

[0014] In the preparation method provided by the present invention, an acid binding agent is added, and the acid binding agent itself is sometimes a catalyst. First, it is to accelerate the speed of the acylation reaction and prevent the generation of chlorinated alkyl. Second, the structure of the acid binding agent itself is relatively stable and will not cause adverse effects on the reactant and the reaction solution. According to the equilibrium shift principle, adding an acid binding agent will help the balance to move to the forward direction, so adding a certain amount of acid binding agent will help the carrying out of this reaction, and different acid binding agents have different reaction times.

[0015] Preferably, the solvent comprises an alcohol compound, preferably a C1-C6 (e.g., C1, C2, C3, C4, C5 or C6) alcohol compound, more preferably any one or a combination of at least two of methanol, ethanol, propanol, tert-butanol, pentanol or isoamyl alcohol, further preferably methanol and / or ethanol.

[0016] Preferably, the mass ratio of the 1-decene to the solvent is 1:(2-25), and 2-25 can be, for example, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, etc., preferably 1:(2-20), and more preferably 1:(2-8).

[0017] Preferably, the main catalyst comprises a transition metal complex, preferably any one or a combination of at least two of a Co transition metal complex, an Rh transition metal complex or an Ih transition metal complex, more preferably a Co transition metal complex.

[0018] Preferably, the Co transition metal complex comprises dicobalt octacarbonyl.

[0019] Preferably, the molar ratio of the 1-decene to the main catalyst is 1:(0.05-0.1), for example, 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1, etc., preferably 1:(0.06-0.08).

[0020] Preferably, the co-catalyst comprises an alkali metal hydroxide and / or an alkaline earth metal hydroxide, preferably any one or a combination of at least two of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide, more preferably sodium hydroxide and / or potassium hydroxide.

[0021] Preferably, the molar ratio of the 1-decene to the co-catalyst is 1:(0.01-0.02), for example, 1:0.011, 1:0.012, 1:0.013, 1:0.014, 1:0.015, 1:0.016, 1:0.017, 1:0.018, 1:0.019, 1:0.02, etc., preferably 1:(0.01-0.015).

[0022] Preferably, the acid binding agent comprises ethylene dichloride and / or triethylamine, preferably ethylene dichloride.

[0023] Preferably, the molar ratio of the 1-decene to the acid binding agent is 1:(0.5-1), such as 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, etc., preferably 1:(0.5-0.8).

[0024] Preferably, the molar ratio of the 1-decene to the CO2 is (1-1.1):1, for example, 1:1, 1.01:1, 1.02:1, 1.03:1, 1.04:1, 1.05:1, 1.06:1, 1.07:1, 1.08:1, 1.09:1, 1.1:1, etc., preferably (1.04-1.06):1.

[0025] Preferably, the feeding temperature of the main catalyst and the co-catalyst is independently 0-50°C, such as 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C, etc., preferably 0-15°C.

[0026] Preferably, the acid binding agent is added in a continuous manner, preferably in a dropwise manner.

[0027] Preferably, the addition temperature of the acid binding agent is 0-50°C, for example, 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C or 50°C, and the addition time is 0.5-10h, for example, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h, etc., preferably added dropwise for 0.5-5h.

[0028] Preferably, the CO2 is added in a continuous manner.

[0029] Preferably, the CO2 addition time is 1-5 hours, such as 1 hour, 2 hours, 3 hours, 4 hours or 5 hours.

[0030] Preferably, the temperature of the carbonylation reaction is 40-60°C, such as 40°C, 45°C, 50°C, 55°C or 60°C, etc., preferably 45-55°C.

[0031] Preferably, the carbonylation reaction is continued for 0.1-10 h after the CO2 addition is completed, for example, 0.1 h, 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h, etc., preferably 0.5-5 h.

[0032] Preferably, the post-treatment includes distillation under reduced pressure and washing.

[0033] As a preferred technical solution of the present invention, the preparation method of the gamma-undecalactone comprises:

[0034] 1-decene is mixed with a solvent, and then a main catalyst and a co-catalyst are added at 0-50° C., and then an acid binding agent is added in a continuous feeding manner at 0-50° C., and the feeding time of the acid binding agent is 0.5-10 hours. Then, CO2 is continuously added at 40-60° C. for a carbonylation reaction, and the feeding time of CO2 is 1-5 hours. After the CO2 feeding is completed, the carbonylation reaction is continued at 40-60° C. for 0.1-10 hours, and the mixture is distilled under reduced pressure and washed to obtain the gamma-undecalactone;

[0035] Among them, the mass ratio of 1-decene to solvent is 1:(2-25); the molar ratio of 1-decene to main catalyst is 1:(0.05-0.1); the molar ratio of 1-decene to co-catalyst is 1:(0.01-0.02); the molar ratio of 1-decene to acid binding agent is 1:(0.5-1); and the molar ratio of 1-decene to CO2 is (1.03-1.08):1.

[0036] As a preferred technical solution of the present invention, through the combination of material design and process, the yield of gamma-undecalactone obtained by the preparation method is ≥90.80% and the purity is ≥96.2%.

[0037] Compared with the prior art, the present invention has at least the following beneficial effects:

[0038] (1) The present invention provides a method for preparing γ-undecalactone, which uses 1-decene as a starting material and produces γ-undecalactone through a carbonyl synthesis reaction. This method can avoid the high-temperature working conditions in existing production and has the advantages of mild reaction conditions, high production efficiency, high production stability, high selectivity, and high yield. In addition, the γ-undecalactone prepared by this method has high purity and pure odor.

[0039] (2) The preparation method provided by the present invention also avoids the hidden dangers of clogging the packing and tower pressure changes caused by the precipitation of trace salts in the organic matter in the distillation tower in the existing process, can reduce the emission of three wastes, is green and environmentally friendly, and the entire process is safe, green, economical, easy to operate, and suitable for industrial application. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0041] The gas chromatography analysis conditions of the products in the examples of the present invention are as follows: Agilent gas chromatograph, RTX-WAX column, 50°C for 5 min; 10°C / min to 80°C, hold for 5 min; 10°C / min to 100°C, hold for 5 min; 10°C / min to 160°C, hold for 15 min.

[0042] Compound structure characterization: Bruker NMR 400MHz was used.

[0043] Unless otherwise specified, the raw materials used in the following examples of the present invention were purchased from commercial sources.

[0044] In the preparation method provided by the present invention, 1-decene is in excess. The following examples are based on CO2 to calculate the yield of the gamma-undecalactone product. The calculation formula is as follows:

[0045] The total yield of γ-undecalactone is: the mass of the γ-undecalactone product*purity / (mass of CO2 / molecular weight of CO2*molecular weight of the γ-undecalactone product)*100%.

[0046] Example 1

[0047] In this embodiment, a method for preparing gamma-undecalactone is provided, the preparation method comprising:

[0048] (1) At room temperature, 241.3 g of methanol, 49.1 g of 1-decene, and 8.38 g of dicobalt octacarbonyl were added to a 1 L three-necked jacketed bottle, mixed, and then 0.2 g of sodium hydroxide was added thereto. The mixture was stirred at 15° C. until the sodium hydroxide was completely dissolved. 30 g of ethylene dichloride was added to the bottle at 30° C. (the addition was completed within 3 hours). 14.5 g of CO2 gas was continuously introduced into the bottle at 50° C. for a carbonylation reaction. The CO2 introduction time was 4.5 hours. After the CO2 addition was completed, the carbonylation reaction was continued at 60° C. for 1.5 hours to obtain a reaction solution. The reaction solution was tested by gas chromatography. At this time, the main components of the reaction solution were: 70.25% of methanol, 0.1826% of 1-decene, and 17.36% of gamma-undecalactone. The conversion rate of CO2 was 100%.

[0049] (2) After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75° C. The 132.4 g of the distilled material was washed with 34.5 g of water and allowed to stand to separate 59.96 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 99.45%, and the rest was waste water.

[0050] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 98.19%.

[0051] The H NMR spectrum of gamma-undecalactone is characterized as follows:

[0052] 1 H-NMR(CDCl3)δ: 0.88(3H), 1.25(4H), 1.29(4H), 1.31(2H), 1.53(2H), 1.94(1H), 2.19(1H), 2.25(1H), 2.35(1H), 4.29(1H).

[0053] Example 2

[0054] In this embodiment, a method for preparing gamma-undecalactone is provided, the preparation method comprising:

[0055] (1) At room temperature, 350.83 g of ethanol, 81.55 g of 1-decene, and 10.36 g of dicobalt octacarbonyl were added to a 1 L three-necked bottle and mixed. Then, 0.5 g of potassium hydroxide was added thereto. The mixture was stirred at 7° C. until the potassium hydroxide was completely dissolved. Then, 44 g of ethylene dichloride was added to the bottle at 25° C. (the addition was completed within 2 h). Then, 24.37 g of CO2 gas was continuously introduced into the bottle to carry out carbonylation reaction at 52° C. The CO2 introduction time was 4 h. After the CO2 addition was completed, the carbonylation reaction was continued at 55° C. for 3 h to obtain a reaction solution. The reaction solution was tested by gas chromatography. At this time, the main components of the reaction solution were: 68.57% of ethanol, 0.1826% of 1-decene, and 18.20% of gamma-undecalactone. The conversion rate of CO2 was 100%.

[0056] (2) After the reaction, unreacted 1-decene and ethanol were removed by vacuum distillation at 70 kPa and 75° C. The 183.2 g of the distilled material was washed with 47.74 g of water and allowed to stand to separate 96.45 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 96.53%, and the rest was waste water.

[0057] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 91.22%.

[0058] Example 3

[0059] In this embodiment, a method for preparing gamma-undecalactone is provided, the preparation method comprising:

[0060] (1) At room temperature, 98.2 g of propanol, 49.1 g of 1-decene, and 12 g of dicobalt octacarbonyl were added to a 1 L three-necked jacketed bottle and mixed. 0.28 g of sodium hydroxide was then added thereto. The mixture was stirred at 15° C. until the sodium hydroxide was completely dissolved. 17.3 g of ethylene dichloride was added to the bottle at 30° C. (the addition was completed within 3 hours). 14.5 g of CO2 gas was continuously introduced into the bottle to carry out carbonylation reaction at 40° C. The CO2 introduction time was 5 hours. After the CO2 addition was completed, the carbonylation reaction was continued at 40° C. for 10 hours to obtain a reaction solution. The reaction solution was tested by gas chromatography. At this time, the main components of the reaction solution were: 51.31% of propanol, 0.172% of 1-decene, and 28.87% of gamma-undecalactone. The conversion rate of CO2 was 100%.

[0061] (2) After the reaction, unreacted 1-decene and propanol were removed by vacuum distillation at 70 kPa and 75° C. 95.18 g of the distilled material was washed with 24.80 g of water and allowed to stand to separate 57.41 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 96.24%, and the rest was waste water.

[0062] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 90.99%.

[0063] Example 4

[0064] In this embodiment, a method for preparing gamma-undecalactone is provided, the preparation method comprising:

[0065] (1) At room temperature, 1220 g of methanol, 49.1 g of 1-decene, and 8.38 g of dicobalt octacarbonyl were added to a 1 L three-necked jacketed bottle, mixed, and then 0.14 g of sodium hydroxide was added thereto. The mixture was stirred at 15° C. until the sodium hydroxide was completely dissolved. Then, 34.5 g of dichloroethane was added to the bottle at 30° C. (the addition was completed within 3 hours). Then, 14.5 g of CO2 gas was continuously introduced into the bottle to carry out carbonylation reaction at 60° C. The CO2 introduction time was 1 hour. After the CO2 addition was completed, the carbonylation reaction was continued at 60° C. for 1.5 hours to obtain a reaction solution. The reaction solution was tested by gas chromatography. At this time, the main components of the reaction solution were: 91.96% of methanol, 0.15% of 1-decene, and 4.16% of gamma-undecalactone. The conversion rate of CO2 was 100%.

[0066] (2) After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75° C. The 110.62 g of the distilled material was washed with 28.82 g of water and allowed to stand to separate 56.38 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 97.80%, and the rest was waste water.

[0067] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 90.80%.

[0068] Example 5

[0069] Before obtaining the reaction solution, the only difference between this embodiment and embodiment 1 is that the amount of CO2 used is 15.4 g, that is, the molar ratio of 1-decene to CO2 is 1:1.

[0070] The reaction liquid was tested using gas chromatography analysis. The main components of the reaction liquid at this time were: 70.07% methanol, 0.28% 1-decene, and 18.36% gamma-undecalactone.

[0071] After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75 ° C. 105.08 g of the distilled material was washed with 27.38 g of water and allowed to stand to separate 63.62 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 99.40%, and the rest was waste water.

[0072] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 98.05%.

[0073] Example 6

[0074] Before obtaining the reaction solution, the only difference between this embodiment and embodiment 1 is that the amount of CO2 used is 13.95 g, that is, the molar ratio of 1-decene to CO2 is 1.1:1.

[0075] The reaction liquid was tested using gas chromatography analysis. The main components of the reaction liquid at this time were: 70.36% methanol, 1.6% 1-decene, 16.69% gamma-undecalactone, and the CO2 conversion rate was 100%.

[0076] After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75 ° C. 109.3 g of the distilled material was washed with 28.48 g of water and allowed to stand to separate 57.78 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 99.05%, and the rest was waste water.

[0077] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 97.96%.

[0078] Example 7

[0079] In this embodiment, a method for preparing gamma-undecalactone is provided, the preparation method comprising:

[0080] (1) At room temperature, 241.3 g of methanol, 49.1 g of 1-decene, and 8.38 g of dicobalt octacarbonyl were added to a 1 L three-necked jacketed bottle, mixed, and then 0.2 g of sodium hydroxide was added thereto. The mixture was stirred at 15° C. until the sodium hydroxide was completely dissolved. Then, 30.7 g of triethylamine was added to the bottle at 30° C. (the addition was completed within 3 hours). Then, 14.5 g of CO2 gas was continuously introduced into the bottle to carry out carbonylation reaction at 50° C. The CO2 introduction time was 4.5 hours. After the CO2 addition was completed, the carbonylation reaction was continued at 60° C. for 1.5 hours to obtain a reaction solution. The reaction solution was tested by gas chromatography. At this time, the main components of the reaction solution were: 70.11% of methanol, 1.29% of 1-decene, and 16.11% of gamma-undecalactone. The conversion rate of CO2 was 100%.

[0081] (2) After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75° C. The 122.5 g of the distilled material was washed with 31.92 g of water and allowed to stand to separate 56.15 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 98.75%, and the rest was waste water.

[0082] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 91.30%.

[0083] Example 8

[0084] Before obtaining the reaction solution, the only difference between this embodiment and embodiment 1 is that the amount of CO2 used is 19.2 g, that is, the molar ratio of 1-decene to CO2 is 0.8:1.

[0085] The reaction liquid was tested by gas chromatography analysis. The main components of the reaction liquid at this time were: 69.30% methanol, 0.1% 1-decene, and 16.80% gamma-undecalactone.

[0086] After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75 ° C. The 123.5 g material after distillation was washed with 32.18 g of water and allowed to stand to separate 59.2 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 98.83%, and the rest was waste water.

[0087] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 90.70%.

[0088] Example 9

[0089] Before obtaining the reaction solution, the only difference between this embodiment and embodiment 1 is that the amount of CO2 used is 12.8 g, that is, the molar ratio of 1-decene to CO2 is 1.2:1.

[0090] The reaction liquid was tested using gas chromatography analysis. The main components of the reaction liquid at this time were: 70.60% methanol, 3.305% 1-decene, 13.97% gamma-undecalactone, and the CO2 conversion rate was 100%.

[0091] After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75 ° C. The 113.56 g material after distillation was washed with 29.59 g of water and allowed to stand to separate 48.4 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 98.63%, and the rest was waste water.

[0092] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 89.05%.

[0093] Example 10

[0094] Before obtaining the reaction solution, the only difference between this embodiment and embodiment 1 is that the amount of methanol used is 49.4 g, that is, the mass ratio of 1-decene to the solvent is 1:1.

[0095] The reaction liquid was tested using gas chromatography analysis. The main components of the reaction liquid at this time were: 32.59% methanol, 3.57% 1-decene, 35.92% gamma-undecalactone, and the CO2 conversion rate was 100%.

[0096] After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75 ° C. 106.95 g of the distilled material was washed with 27.87 g of water and allowed to stand to separate 57.32 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 95%, and the rest was waste water.

[0097] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction was 89.67%.

[0098] Comparative Example 1

[0099] Before obtaining the reaction solution, the only difference between this comparative example and Example 1 is that the preparation raw materials do not include an acid binding agent.

[0100] The reaction liquid was tested using gas chromatography analysis. The main components of the reaction liquid at this time were: 76.97% methanol, 0.92% 1-decene, 18.98% gamma-undecalactone, and the CO2 conversion rate was 100%.

[0101] After the reaction, unreacted 1-decene and methanol were removed by vacuum distillation at 70 kPa and 75 ° C. The 75.37 g material after distillation was washed with 19.64 g of water and allowed to stand to separate 54.35 g of gamma-undecalactone, of which the purity of gamma-undecalactone was 98.78%, and the rest was waste water.

[0102] Calculated with CO2 as the initial raw material, the total yield of the product after the reaction is 88.40%.

[0103] In summary, the preparation method provided by the present invention can avoid the high-temperature conditions in existing production, and has the advantages of mild reaction conditions, high production efficiency, high production stability, high selectivity, and high yield. In addition, the γ-undecalactone prepared by this method has high purity.

[0104] The applicant declares that the present invention uses the above-mentioned examples to illustrate the preparation method of gamma-undecalactone, but the present invention is not limited to the above-mentioned examples, that is, it does not mean that the present invention must rely on the above-mentioned examples to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary ingredients, selection of specific methods, etc., all fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for preparing gamma-undecalactone, characterized in that: The preparation method comprises: Mixing 1-decene with a solvent, then adding a main catalyst, a co-catalyst and an acid binding agent, and continuously adding CO2 to carry out a carbonylation reaction at 40-60°C, wherein the CO2 addition time is 1-5 hours, and after the CO2 addition is completed, continuing the carbonylation reaction at 40-60°C for 0.1-10 hours, and post-treating to obtain the gamma-undecalactone; The main catalyst includes a transition metal complex; The molar ratio of the 1-decene to the main catalyst is 1:(0.05-0.1); The co-catalyst includes alkali metal hydroxide and / or alkaline earth metal hydroxide; The molar ratio of the 1-decene to the co-catalyst is 1:(0.01-0.02).

2. The preparation method according to claim 1, characterized in that The solvent includes an alcohol compound.

3. The preparation method according to claim 2, characterized in that The solvent includes a C1-C6 alcohol compound.

4. The preparation method according to claim 3, characterized in that The solvent includes any one of methanol, ethanol, propanol, tert-butanol, amyl alcohol or isoamyl alcohol, or a combination of at least two thereof.

5. The preparation method according to claim 4, characterized in that The solvent includes methanol and / or ethanol.

6. The preparation method according to claim 1, characterized in that The mass ratio of the 1-decene to the solvent is 1:(2-25).

7. The preparation method according to claim 6, characterized in that The mass ratio of the 1-decene to the solvent is 1:(2-20).

8. The preparation method according to claim 7, characterized in that The mass ratio of the 1-decene to the solvent is 1:(2-8).

9. The preparation method according to claim 1, characterized in that The main catalyst includes any one of a Co transition metal complex, a Rh transition metal complex or an Ih transition metal complex, or a combination of at least two thereof.

10. The preparation method according to claim 9, characterized in that The main catalyst is a Co transition metal complex.

11. The preparation method according to claim 1, characterized in that The molar ratio of the 1-decene to the main catalyst is 1:(0.06-0.08).

12. The preparation method according to claim 1, characterized in that The co-catalyst includes any one of lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide or calcium hydroxide, or a combination of at least two thereof.

13. The preparation method according to claim 12, characterized in that The co-catalyst includes sodium hydroxide and / or potassium hydroxide.

14. The preparation method according to claim 1, characterized in that The molar ratio of the 1-decene to the co-catalyst is 1:(0.01-0.015).

15. The preparation method according to claim 1, characterized in that The acid binding agent includes ethylene dichloride and / or triethylamine.

16. The preparation method according to claim 15, characterized in that The acid binding agent is ethylene dichloride.

17. The preparation method according to claim 1, characterized in that The molar ratio of the 1-decene to the acid binding agent is 1:(0.5-1).

18. The preparation method according to claim 17, characterized in that: The molar ratio of the 1-decene to the acid binding agent is 1:(0.5-0.8).

19. The preparation method according to claim 1, characterized in that The molar ratio of the 1-decene to the CO2 is (1-1.1):

1.

20. The preparation method according to claim 19, characterized in that The molar ratio of the 1-decene to the CO2 is (1.04-1.06):

1.

21. The preparation method according to claim 1, characterized in that The feeding temperature of the main catalyst and the co-catalyst is independently 0-50°C.

22. The preparation method according to claim 21, characterized in that The feeding temperatures of the main catalyst and the co-catalyst are independently 0-15°C.

23. The preparation method according to claim 1, characterized in that The acid binding agent is added in a continuous manner.

24. The preparation method according to claim 23, characterized in that The acid binding agent is added dropwise.

25. The preparation method according to claim 1, characterized in that The acid binding agent is added at a temperature of 0-50° C. and for a time of 0.5-10 h.

26. The preparation method according to claim 25, characterized in that The acid binding agent is added dropwise for 0.5-5 hours.

27. The preparation method according to claim 1, characterized in that The temperature of the carbonylation reaction is 45-55°C.

28. The preparation method according to claim 1, characterized in that After the addition of CO2 is completed, the carbonylation reaction is continued for 0.5-5 hours.

29. The preparation method according to claim 1, characterized in that The post-treatment includes reduced pressure distillation and washing.