Preparation method of spice 5-methyl-2-heptene-4-ketone

Abstract

The invention belongs to the technical field of synthesis of 5-methyl-2-heptene-4-ketone, and particularly relates to a preparation method of spice 5-methyl-2-heptene-4-ketone, which comprises the following steps: S100: reacting butanone with 2-methylbutyryl chloride under alkaline conditions to obtain an intermediate 3-methyl-2-pentanone; and S200, enabling the intermediate 3-methyl-2-pentanone to react with acetaldehyde under an acidic condition, so as to obtain the spice 5-methyl-2-heptene-4-ketone. The 5-methyl-2-heptene-4-ketone prepared by the method not only has good yield, but also can reduce the production cost and improve the production efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of 5-methyl-2-heptene-4-one synthesis, and specifically relates to a method for preparing the fragrance 5-methyl-2-heptene-4-one. Background Art

[0002] 5-Methyl-2-heptene-4-one, also known as hazelnut ketone, has a thorny hazelnut-like nutty aroma, as well as roasted, ketone and coffee-like aromas. It is usually used in processing nuts, cocoa, coffee and roasted flavors. It can also be used as a flavoring agent for detergents, cosmetics, etc.

[0003] After searching, the invention patent with announcement number CN102030626B discloses a method for preparing 5-methyl-2-heptene-4-one, using acetoacetate as a raw material, reacting with 2-methylbutyryl chloride to obtain an intermediate 2-methylbutyryl acetate, and then condensing with acetaldehyde to obtain the product 5-methyl-2-heptene-4-one. Although the method for preparing 5-methyl-2-heptene-4-one has a high yield, the process is complicated, the cost is high, and the production efficiency is low. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a fragrance 5-methyl-2-heptene-4-one. The method for preparing 5-methyl-2-heptene-4-one not only has a good yield, but also can reduce production costs and improve production efficiency.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing the fragrance 5-methyl-2-heptene-4-one, comprising:

[0006] S100: reacting butanone with 2-methylbutyryl chloride under alkaline conditions to obtain an intermediate 3-methyl-2-pentanone;

[0007] S200: The intermediate 3-methyl-2-pentanone is reacted with acetaldehyde under acidic conditions to obtain the fragrance 5-methyl-2-hepten-4-one.

[0008] Furthermore, S100 specifically includes the following steps:

[0009] S110: dissolving butanone in ethanol, and then adding a basic catalyst and 2-methylbutyryl chloride thereto to obtain a first mixed material;

[0010] S120: The first mixed material is passed through a molecular sieve and then purified to obtain an intermediate 3-methyl-2-pentanone.

[0011] Furthermore, the alkaline catalyst is at least one of sodium ethoxide, sodium hydroxide, potassium hydroxide, and a solid base catalytic resin.

[0012] Furthermore, the solid base-catalyzed resin is in a granular form, and the particle size is between 0.45 mm and 0.55 mm.

[0013] Furthermore, in S110, the molar ratio of butanone, ethanol, alkaline catalyst and 2-methylbutyryl chloride is (1-1.1):(5-15):(0.8-1.5):(1-1.1).

[0014] Furthermore, S110 specifically includes the following steps:

[0015] Dissolve butanone in ethanol, then add an alkaline catalyst and 2-methylbutyryl chloride thereto, react at a temperature of 35° C.-45° C. for 4 h-5 h, adjust the pH to 7-9, and continue to react for 4 h-5 h to obtain a first mixed material.

[0016] Furthermore, the molecular sieve used in S120 is at least one of 5A molecular sieve, ZSM molecular sieve, and Y-type molecular sieve.

[0017] Furthermore, S200 specifically includes the following steps:

[0018] S210: adding an acidic catalyst and acetaldehyde to the intermediate 3-methyl-2-pentanone to obtain a second mixed material after reaction;

[0019] S220: purifying and distilling the second mixed material to obtain the fragrance 5-methyl-2-heptene-4-one.

[0020] Furthermore, the acidic catalyst is at least one of zirconium dioxide, nickel sulfate, zinc sulfate, sodium sulfate, acetic acid, hydrochloric acid, and sulfuric acid.

[0021] Furthermore, in S120, the molar ratio of the intermediate 3-methyl-2-pentanone, the acidic catalyst, and acetaldehyde is (1-1.2):(0.5-1.5):(1-1.5).

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention uses butanone, 2-methylbutyryl chloride and acetaldehyde as raw materials, which are environmentally friendly, low in cost, easy to obtain, and have little pollution to the environment;

[0024] The invention can prepare the fragrance 5-methyl-2-heptene-4-one through two main steps, the steps are simple, the yield is good, and the energy consumption of production is low, which can further effectively reduce the production cost and improve the production efficiency.

[0025] The present invention can effectively promote the reaction in the designed direction by screening the alkaline catalyst and the acidic catalyst, thereby effectively improving the yield. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below.

[0027] The present invention provides a method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0028] S100: reacting butanone with 2-methylbutyryl chloride under alkaline conditions to obtain an intermediate 3-methyl-2-pentanone;

[0029] S200: The intermediate 3-methyl-2-pentanone is reacted with acetaldehyde under acidic conditions to obtain the fragrance 5-methyl-2-hepten-4-one.

[0030] Wherein, S100 specifically includes the following steps:

[0031] S110: dissolving butanone in ethanol, and then adding a basic catalyst and 2-methylbutyryl chloride thereto to obtain a first mixed material;

[0032] S120: The first mixed material is passed through a molecular sieve and then purified to obtain an intermediate 3-methyl-2-pentanone.

[0033] Preferably, the alkaline catalyst is at least one of sodium ethoxide, sodium hydroxide, potassium hydroxide, and a solid base catalytic resin.

[0034] Preferably, the alkaline catalyst is sodium ethoxide. Using sodium ethoxide as an alkaline catalyst can effectively promote the reaction to proceed along the designed route.

[0035] Preferably, the alkaline catalyst is a solid base catalytic resin, and the solid base catalytic resin is in a granular form with a particle size of 0.45 mm to 0.55 mm. The solid base catalytic resin is easily removed from the reaction and has a higher catalytic efficiency, which can effectively reduce production costs.

[0036] In the present invention, the solid base catalytic resin is Tulsimer A-74MP, which is commercially available.

[0037] Wherein, in S110, the molar ratio of butanone, ethanol, alkaline catalyst, and 2-methylbutyryl chloride is (1-1.1): (5-15): (0.8-1.5): (1-1.1). Preferably, the molar ratio of butanone, ethanol, alkaline catalyst, and 2-methylbutyryl chloride is 1:12:1.1:1.02.

[0038] In order to facilitate further operation, the present invention describes the specific steps of S110: dissolving butanone in ethanol, then adding an alkaline catalyst and 2-methylbutyryl chloride thereto, reacting at a temperature of 35° C. to 45° C. for 4 h to 5 h, then adjusting the pH to 7 to 9, and continuing the reaction for 4 h to 5 h to obtain a first mixed material.

[0039] Preferably, the above reaction is carried out at a temperature of 40° C. for 4 hours, the pH is adjusted to 8.5, and the reaction is continued for 5 hours to obtain the first mixed material.

[0040] In the above steps, the reagent used to adjust the pH is preferably sodium hydroxide.

[0041] Among them, the molecular sieve used in S120 is at least one of 5A molecular sieve, ZSM molecular sieve, and Y-type molecular sieve.

[0042] Preferably, the molecular sieve used in S120 is a Y-type molecular sieve. Preferably, the molecular sieve used in S120 is one of NaY molecular sieve, ammonium Y molecular sieve, Y-60 molecular sieve, and Y-100 molecular sieve. Preferably, the molecular sieve used in S120 is a Y-100 molecular sieve. The Y-100 molecular sieve can further catalyze the reaction and simultaneously play a role in separating impurities, facilitating subsequent purification.

[0043] Among them, the purification process in S120 mainly includes steps such as oil-water separation, washing and solvent removal.

[0044] Wherein, S200 specifically includes the following steps:

[0045] S210: adding an acidic catalyst and acetaldehyde to the intermediate 3-methyl-2-pentanone to obtain a second mixed material after reaction;

[0046] S220: purifying and distilling the second mixed material to obtain the fragrance 5-methyl-2-heptene-4-one.

[0047] In the above steps, the acidic catalyst is at least one of zirconium dioxide, nickel sulfate, zinc sulfate, sodium sulfate, acetic acid, hydrochloric acid and sulfuric acid.

[0048] Preferably, the acidic catalyst is zinc sulfate. Preferably, the acidic catalyst is a mixture of zinc sulfate and sulfuric acid in a molar ratio of 1:0.2.

[0049] Wherein, in S120, the molar ratio of the intermediate 3-methyl-2-pentanone, the acidic catalyst, and acetaldehyde is (1-1.2): (0.5-1.5): (1-1.5). Preferably, the molar ratio of the intermediate 3-methyl-2-pentanone, the acidic catalyst, and acetaldehyde is 1:1.02:1.05.

[0050] To facilitate further operation, the present invention describes the specific steps of S210: adding an acidic catalyst and acetaldehyde to the intermediate 3-methyl-2-pentanone, then reacting at a temperature of 40° C. for 1 hour, adjusting the pH to 5.5 with sulfuric acid, and then reacting at a temperature of 35° C. for 3 hours to obtain a second mixture.

[0051] Embodiment 1

[0052] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0053] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0054] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0055] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.7%.

[0056] Embodiment 2

[0057] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0058] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium hydroxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0059] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0060] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 83.6%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.5%.

[0061] Embodiment 3

[0062] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0063] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of potassium hydroxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0064] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0065] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 82.9%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.4%.

[0066] Embodiment 4

[0067] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0068] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of Tulsimer A-74MP and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0069] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0070] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 89.2%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.9%.

[0071] By comparing Examples 1 to 4, it can be seen that the selection of the alkaline catalyst has a great influence on the formation of the intermediate 3-methyl-2-pentanone, wherein sodium ethoxide and Tulsimer A-74MP can effectively promote the formation of the intermediate 3-methyl-2-pentanone when used as alkaline catalysts.

[0072] Embodiment 5

[0073] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0074] S100: 1 mol of butanone was dissolved in 6 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture. The first mixture was then passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0075] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0076] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 78.4%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 97.2%.

[0077] Embodiment 6

[0078] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0079] S100: 1 mol of butanone was dissolved in 11 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0080] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0081] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.2%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.7%.

[0082] Embodiment 7

[0083] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0084] S100: 1 mol of butanone was dissolved in 13 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0085] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0086] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.7%.

[0087] Embodiment 8

[0088] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0089] S100: 1 mol of butanone was dissolved in 15 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture. The first mixture was then passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0090] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0091] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.7%.

[0092] By comparing Example 1 and Example 5 to Example 8, it can be seen that the ethanol content has a certain influence on the formation of the intermediate 3-methyl-2-pentanone, and it can be seen from the experimental results that when 12 mol of ethanol is selected, the purity of the intermediate 3-methyl-2-pentanone and the fragrance 5-methyl-2-heptene-4-one is generally good, and the problem of high energy consumption in the subsequent treatment process caused by excessive ethanol can be avoided.

[0093] Embodiment 9

[0094] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0095] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 0.8 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture. The first mixture was then passed through a Y-100 molecular sieve and then purified to obtain an intermediate 3-methyl-2-pentanone.

[0096] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0097] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 73.6%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 96.4%.

[0098] Embodiment 10

[0099] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0100] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.5 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture. The first mixture was then passed through a Y-100 molecular sieve and then purified to obtain an intermediate 3-methyl-2-pentanone.

[0101] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0102] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 81.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 97.2%.

[0103] By comparing Example 1, Example 9 and Example 10, it can be seen that the amount of the alkaline catalyst sodium ethoxide has a great influence on the formation of the intermediate 3-methyl-2-pentanone and even the formation of the fragrance 5-methyl-2-heptene-4-one. It can be seen from the experimental data that the amount of sodium ethoxide in Example 1 has the best catalytic effect on the reaction.

[0104] Embodiment 11

[0105] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0106] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 0.8 mol of Tulsimer A-74MP and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0107] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0108] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 82.8%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 97.7%.

[0109] Embodiment 12

[0110] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0111] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.5 mol of Tulsimer A-74MP and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0112] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0113] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 83.2%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 97.8%.

[0114] By comparing Example 4, Example 11 and Example 12, it can be seen that the amount of the alkaline catalyst Tulsimer A-74MP has a great influence on the formation of the intermediate 3-methyl-2-pentanone and even the formation of the fragrance 5-methyl-2-heptene-4-one. It can be seen from the experimental data that the amount of Tulsimer A-74MP in Example 4 has the best catalytic effect on the reaction.

[0115] Embodiment 13

[0116] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0117] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0118] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0119] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 84.4%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.5%.

[0120] Embodiment 14

[0121] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0122] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.1 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture. The first mixture was then passed through a Y-100 molecular sieve and then purified to obtain an intermediate 3-methyl-2-pentanone.

[0123] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0124] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 82.1%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 97.4%.

[0125] By comparing Example 1, Example 13, and Example 14, it can be seen that the amount of 2-methylbutyryl chloride used has a greater effect on the formation of the intermediate 3-methyl-2-pentanone. Too much or too little 2-methylbutyryl chloride is likely to promote the formation of other products. It can be seen from the experimental data that the amount of 2-methylbutyryl chloride used in Example 1 has the best effect on the formation of the overall product.

[0126] Embodiment 15

[0127] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0128] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 35°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0129] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0130] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 85.1%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.2%.

[0131] Embodiment 16

[0132] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0133] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 45°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture. The first mixture was then passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0134] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0135] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 84.9%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.1%.

[0136] By comparing Example 1, Example 15 and Example 16, it can be seen that the reaction temperature in step S100 also has a certain influence on the formation of the product. Too high or too low a temperature will reduce the amount of the intermediate 3-methyl-2-pentanone formed.

[0137] Embodiment 17

[0138] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0139] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-60 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0140] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0141] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 85.7%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.6%.

[0142] Embodiment 18

[0143] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0144] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a NaY molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0145] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0146] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 82.9%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 97.8%.

[0147] By comparing Example 1, Example 17, and Example 18, it can be seen that the selection of the molecular sieve in S100 also has a certain influence on the purity of the intermediate 3-methyl-2-pentanone generated. When the Y-100 molecular sieve is used, the purity of the intermediate 3-methyl-2-pentanone prepared is higher.

[0148] Embodiment 19

[0149] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0150] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of Tulsimer A-74MP and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-60 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0151] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0152] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 87.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.8%.

[0153] Embodiment 20

[0154] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0155] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of Tulsimer A-74MP and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a NaY molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0156] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0157] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 84.2%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.1%.

[0158] By comparing Example 4, Example 19 and Example 20, it can be seen that the selection of the molecular sieve in S100 also has a certain influence on the purity of the intermediate 3-methyl-2-pentanone generated. When the Y-100 molecular sieve is used, the purity of the intermediate 3-methyl-2-pentanone prepared is higher.

[0159] Embodiment 21

[0160] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0161] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0162] S200: Add 1.2 mol of zinc sulfate and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0163] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 96.9%.

[0164] Embodiment 22

[0165] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0166] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0167] S200: Add 1.2 mol of sulfuric acid and 1.05 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, then react at 40°C for 1 hour, adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0168] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 97.2%.

[0169] By comparing Example 1, Example 21 and Example 22, it can be seen that the amount of acidic catalyst used has a great influence on the formation of the final product, the fragrance 5-methyl-2-heptene-4-one. The use of a mixture of zinc sulfate and sulfuric acid as an acidic catalyst can produce a larger amount of the fragrance 5-methyl-2-heptene-4-one.

[0170] Embodiment 23

[0171] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0172] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0173] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0174] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 98.5%.

[0175] Embodiment 24

[0176] A method for preparing a fragrance 5-methyl-2-heptene-4-one, comprising:

[0177] S100: 1 mol of butanone was dissolved in 12 mol of ethanol, and then 1.1 mol of sodium ethoxide and 1.02 mol of 2-methylbutyryl chloride were added thereto, and the mixture was reacted at 40°C for 4 hours, and then the pH was adjusted to 8.5, and the reaction was continued for 5 hours to obtain a first mixture, and then the first mixture was passed through a Y-100 molecular sieve and purified to obtain an intermediate 3-methyl-2-pentanone.

[0178] S200: Add 1 mol of zinc sulfate, 0.2 mol of sulfuric acid and 1.5 mol of acetaldehyde to 1 mol of the intermediate 3-methyl-2-pentanone, and then react at 40°C for 1 hour, then adjust the pH to 5.5 with sulfuric acid, and then react at 35°C for 3 hours to obtain a second mixture, which is then purified and distilled to obtain the fragrance 5-methyl-2-heptene-4-one.

[0179] The prepared intermediate 3-methyl-2-pentanone was tested and found to have a purity of 86.3%. The prepared fragrance 5-methyl-2-heptene-4-one was tested and found to have a purity of 94.8%.

[0180] By comparing Example 1, Example 23 and Example 24, it can be seen that the amount of acetaldehyde in S200 has a great influence on the formation of the final product, the fragrance 5-methyl-2-heptene-4-one. Using the acetaldehyde in the proportion of Example 1 can produce a larger amount of the fragrance 5-methyl-2-heptene-4-one.

[0181] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A method for preparing a fragrance 5-methyl-2-heptene-4-one, characterized in that: include: S100: reacting butanone with 2-methylbutyryl chloride under alkaline conditions to obtain an intermediate 3-methyl-2-pentanone; S200: reacting the intermediate 3-methyl-2-pentanone with acetaldehyde under acidic conditions to obtain the fragrance 5-methyl-2-heptene-4-one.

2. The method for preparing the fragrance 5-methyl-2-heptene-4-one according to claim 1, characterized in that: The S100 specifically includes the following steps: S110: dissolving butanone in ethanol, and then adding a basic catalyst and 2-methylbutyryl chloride thereto to obtain a first mixed material; S120: Passing the first mixed material through a molecular sieve and then purifying it to obtain the intermediate 3-methyl-2-pentanone.

3. The method for preparing the fragrance 5-methyl-2-heptene-4-one as claimed in claim 2, characterized in that: The alkaline catalyst is at least one of sodium ethoxide, sodium hydroxide, potassium hydroxide and a solid base catalytic resin.

4. The method for preparing the fragrance 5-methyl-2-heptene-4-one as claimed in claim 3, characterized in that: The solid base catalytic resin is in granular form, and the particle size is between 0.45 mm and 0.55 mm.

5. The method for preparing the fragrance 5-methyl-2-heptene-4-one as claimed in claim 2, characterized in that: In the S110, the molar ratio of butanone, ethanol, alkaline catalyst and 2-methylbutyryl chloride is (1-1.1):(5-15):(0.8-1.5):(1-1.1).

6. The method for preparing the fragrance 5-methyl-2-heptene-4-one according to claim 2, characterized in that: The S110 specifically includes the following steps: Dissolve butanone in ethanol, then add an alkaline catalyst and 2-methylbutyryl chloride thereto, react at a temperature of 35° C.-45° C. for 4 h-5 h, adjust the pH to 7-9, and continue to react for 4 h-5 h to obtain the first mixed material.

7. The method for preparing the fragrance 5-methyl-2-heptene-4-one as claimed in claim 2, characterized in that: The molecular sieve used in the S120 is at least one of 5A molecular sieve, ZSM molecular sieve, and Y-type molecular sieve.

8. The method for preparing the fragrance 5-methyl-2-heptene-4-one according to claim 1, characterized in that: The S200 specifically includes the following steps: S210: adding an acidic catalyst and acetaldehyde to the intermediate 3-methyl-2-pentanone to obtain a second mixed material after reaction; S220: purifying and distilling the second mixed material to obtain the fragrance 5-methyl-2-heptene-4-one.

9. The method for preparing the fragrance 5-methyl-2-heptene-4-one according to claim 8, characterized in that: The acidic catalyst is at least one of zirconium dioxide, nickel sulfate, zinc sulfate, sodium sulfate, acetic acid, hydrochloric acid and sulfuric acid.

10. The method for preparing the fragrance 5-methyl-2-heptene-4-one according to claim 8, characterized in that: In the S120, the molar ratio of the intermediate 3-methyl-2-pentanone, the acidic catalyst and acetaldehyde is (1-1.2): (0.5-1.5): (1-1.5).