A preparation method of cyclopentadecalactone intermediate bicyclic olefin ether

Abstract

The present invention relates to the field of chemical production technology, and specifically to a method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether, comprising the following steps: (1) using cyclododecanone as a starting material, and subjecting it to a free radical addition reaction with a fatty acid allyl ester to obtain a cyclododecanone addition ester; and (2) subjecting the cyclododecanone addition ester to a one-step ring-closure reaction in an alcohol solvent under high-temperature acid catalysis to obtain the bicyclic olefin ether. The present invention shortens the three-step reaction of the existing process to two steps, reduces the labor intensity and energy consumption of production, and simultaneously reduces the production cost of the product while increasing production capacity. The present invention fundamentally eliminates the generation of high-salt wastewater, making the entire process more environmentally friendly. The present invention does not use highly toxic chemicals, making the production site safer and healthier. The crude bicyclic olefin ether obtained by the present invention can be directly used in the synthesis of cyclopentadecalactone without undergoing additional purification operations, without affecting product quality.

Description

Technical Field

[0001] The invention relates to the technical field of chemical production, and in particular to a method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether. Background Art

[0002] Cyclopentadecalactone is a colorless, low-melting-point crystal with a very strong musk aroma. It is slightly soluble in water and easily soluble in organic solvents such as ethanol and oily spices. Molecular formula C 15 H 28 O2, molecular weight 240.39, melting point 36-37°C, boiling point 280°C, 176°C (2.0KPa), 128°C (1.3KPa), flash point 110°C, relative density 0.9549g / cm 3 , refractive index 1.4708.

[0003] Cyclopentadecalactone has an elegant and delicate fragrance. Its pleasant aroma can relieve fatigue and bring a sense of well-being. Furthermore, adding cyclopentadecalactone to food and beverages can improve food preferences, thereby enhancing people's lives. Therefore, it is indispensable in our daily lives. Cyclopentadecalactone has excellent aroma-fixing properties, making it widely used in daily fragrances such as woody, oriental, fantasy, amber, and floral. The usage of cyclopentadecalactone in perfumes is 0.08-1.00%, in essences is 0.1-2.0%, in balsams is 0.003-0.010%, and in soaps is 0.005-0.030%.

[0004] Cyclopentadecalactone was first successfully synthesized chemically by Ruzicka and his collaborators in the middle of the last century. Currently, the synthesis of cyclopentadecalactone has made great progress. Its industrial production requires the key intermediate bicyclic olefin ether. The process route is as follows:

[0005]

[0006] Patent CN1867556A from Symrise of Germany provides a method for preparing pentadecalactone, which uses a bicyclic olefin ether as a key intermediate and uses a propionic acid / trifluoroacetic acid / hydrogen peroxide system to obtain pentadecalactone through oxidation and cracking.

[0007] Patent WO2005 / 113533 of Firmenich Company of Switzerland still chooses bicyclic olefin ether as key intermediate, uses toluene / benzenesulfonic acid / hydrogen peroxide system, and obtains cyclopentadecanolide through oxidation and cracking.

[0008] The synthesis method of the key intermediate bicyclic olefin ether is as follows:

[0009] Method 1:

[0010]

[0011] Patent US3856815 uses cyclododecanone and allyl alcohol as raw materials. A free radical addition reaction occurs in the presence of di-tert-butyl peroxide, followed by ring-closure dehydration under acidic conditions to produce a bicyclic alkenyl ether. The allyl alcohol used in this method is highly toxic and poses a significant risk to the human body. Furthermore, allyl alcohol is unstable and easily polymerizes. Using allyl alcohol as the addition reagent results in a cyclododecanone conversion rate of only 17%.

[0012] Method 2:

[0013]

[0014] Patent US3856815 uses cyclododecanone and allyl acetate as raw materials to synthesize bicyclic alkenyl ether. Although it avoids the highly toxic allyl alcohol, it has an additional step of ester hydrolysis reaction in the middle, which will produce a large amount of high-salt wastewater and has poor environmental protection.

[0015] Method 3:

[0016]

[0017] Patent US4268445 uses cyclododecanone and allyl alcohol butyl ether as raw materials to synthesize bicyclic alkenyl ether. The source of allyl alcohol ether used in this method is limited and the price is high, which significantly increases the production cost and has poor economic efficiency. Summary of the Invention

[0018] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether. The present invention shortens the reaction steps of the existing process, is simpler, and eliminates the generation of high-salt wastewater, which is more environmentally friendly.

[0019] The preparation method provided by the present invention is as follows:

[0020]

[0021] The invention uses cyclododecanone and fatty acid allyl ester as raw materials to synthesize cyclododecanone addition ester. The addition ester is catalyzed by high-temperature acid in an alcohol solvent and directly obtains bicyclic alkenyl ether through one-step ring closure.

[0022] To achieve the above object, the present invention provides the following technical solutions:

[0023] A method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether comprises the following steps:

[0024] (1) Cyclododecanone is used as a starting material to undergo a free radical addition reaction with fatty acid allyl ester to obtain a cyclododecanone addition ester;

[0025] (2) Cyclododecanone addition ester is reacted in an alcohol solvent under high temperature acid catalysis to obtain a bicyclic olefin ether by a one-step ring closure reaction.

[0026] Furthermore, the fatty acid allyl ester is one of allyl acetate, allyl butyrate, and allyl hexanoate, and the molar ratio of the cyclododecanone to the fatty acid allyl ester is 2.0 to 5.0; the catalyst used in the free radical addition reaction is di-tert-butyl peroxide, and the molar ratio of the di-tert-butyl peroxide to the fatty acid allyl ester is 0.05 to 0.30; the temperature of the free radical addition reaction is 100 to 200°C.

[0027] Furthermore, the molar ratio of the cyclododecanone to the fatty acid allyl ester is preferably 2.5 to 4.0.

[0028] Furthermore, the molar ratio of the di-tert-butyl peroxide to the fatty acid allyl ester is preferably 0.10 to 0.20.

[0029] Furthermore, the temperature of the free radical addition reaction is preferably 140-170°C.

[0030] Furthermore, the alcohol solvent used in the ring-closure reaction is one of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, n-pentanol, n-hexanol, and cyclohexanol, and the mass ratio of the alcohol solvent to the cyclododecanone addition ester is 2.0 to 10.0; the catalyst used in the ring-closure reaction is one of trifluoroacetic acid, p-toluenesulfonic acid, hydrochloric acid, sulfuric acid, and phosphoric acid, and the mass ratio of the catalyst to the cyclododecanone addition ester is 0.01 to 1%; the temperature of the ring-closure reaction is 30 to 150°C.

[0031] Furthermore, the mass ratio of the alcohol solvent to the cyclododecanone addition ester is preferably 2.5 to 5.0.

[0032] Furthermore, the mass ratio of the catalyst to the cyclododecanone addition ester is preferably 0.05 to 0.5%.

[0033] Furthermore, the temperature of the ring-closure reaction is preferably 60-110°C.

[0034] A cyclopentadecalactone intermediate bicyclic olefin ether is prepared by adopting the above preparation method.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The present invention shortens the three-step reaction of the existing process to two steps, reduces the labor intensity and energy consumption of production, and reduces the production cost of the product while increasing production capacity.

[0037] 2. The present invention fundamentally eliminates the generation of high-salt wastewater, making the entire process more environmentally friendly.

[0038] 3. The present invention does not use highly toxic chemicals, making the production site safer and healthier.

[0039] 4. The crude bicyclic olefin ether obtained in the present invention can be directly used for the synthesis of cyclopentadecalactone without any additional purification operation, without affecting the product quality. DETAILED DESCRIPTION

[0040] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0041] Example 1:

[0042] A method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether comprises the following steps:

[0043] (1) Add 300 g of cyclododecanone to a 1000 ml three-necked flask, heat to 155 ° C, maintain the temperature, and dropwise add a mixture of 54.6 g of allyl acetate and 13.6 g of di-tert-butyl peroxide. The addition time is controlled to 7 h. After the addition is completed, the reaction is continued for 4 h. After the reaction is completed, the unreacted cyclododecanone is recovered using high vacuum, and the residue in the kettle is 150.11 g of cyclododecanone addition ester;

[0044] (2) To 150.11 g of cyclododecanone addition ester obtained in the above step, 400 g of ethanol and 0.1 g of trifluoroacetic acid were added, the temperature was raised to 85° C., and the reaction was kept warm for 11 h. After the reaction was completed, the solvent ethanol was recovered under normal pressure, and high vacuum flash evaporation was used to obtain 64.80 g of a crude bicyclic olefin ether with a content of 91.23% and a yield of 65.79% (based on cyclododecanone).

[0045] Example 2:

[0046] A method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether comprises the following steps:

[0047] (1) Add 300 g of cyclododecanone to a 1000 ml three-necked flask, heat to 155° C., maintain the temperature, and dropwise add a mixture of 85.69 g of allyl hexanoate and 13.6 g of di-tert-butyl peroxide. The addition time is controlled within 7 h. After the addition is completed, the reaction is continued for 4 h. After the reaction is completed, the unreacted cyclododecanone is recovered using high vacuum, and the residue in the kettle is 150.32 g of cyclododecanone addition ester.

[0048] (2) To 150.32 g of cyclododecanone addition ester obtained in the above step, 400 g of methanol and 0.1 g of p-toluenesulfonic acid were added, the temperature was raised to 85° C., and the reaction was kept warm for 11 h. After the reaction was completed, the solvent methanol was recovered under normal pressure, and high vacuum flash evaporation was used to obtain 67.87 g of crude bicyclic olefin ether with a content of 92.30% and a yield of 68.09% (calculated as cyclododecanone).

[0049] Comparative Example 1:

[0050] A method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether comprises the following steps:

[0051] (1) Add 300 g of cyclododecanone to a 1000 ml three-necked flask, heat to 155 ° C, maintain the temperature, and dropwise add a mixture of 54.6 g of allyl acetate and 13.6 g of di-tert-butyl peroxide. The addition time is controlled to 7 h. After the addition is completed, the reaction is continued for 4 h. After the reaction is completed, the unreacted cyclododecanone is recovered using high vacuum, and the residue in the kettle is 149.38 g of cyclododecanone addition ester;

[0052] (2) Add 200 g of a 10 wt% NaOH solution to 149.38 g of the cyclododecanone addition ester obtained in the above step, raise the temperature to 102° C., and keep the temperature to react for 5 h. After the reaction is completed and the temperature is lowered, 100 g of toluene is added, and the mixture is stirred and extracted for 1 h. After separation, 238.5 g of toluene solution is obtained;

[0053] (3) 2.0 g of p-toluenesulfonic acid was added to 238.5 g of toluene solution obtained in the above step, and a reflux water separation device was set up. The temperature was raised to reflux and separate the water until the toluene produced was clear and anhydrous. At this time, the reaction was completed. After recovering the toluene in the three-necked flask, the vacuum degree was increased and flash distillation was performed to obtain 55.83 g of a crude bicyclic olefin ether with a content of 90.89% and a yield of 56.58% (based on cyclododecanone).

[0054] It can be seen from the above Examples 1-2 and Comparative Example 1 that Example 1-2 only requires two steps to prepare bicyclic alkenyl ether, while Comparative Example 1 requires three steps to prepare bicyclic alkenyl ether, and the crude content and yield of bicyclic alkenyl ether prepared in Example 1-2 are higher than those in Comparative Example 1.

[0055] In summary, the present invention shortens the three-step reaction of the existing process to two steps, reduces the labor intensity and energy consumption of production, and reduces the production cost of the product on the basis of improving production capacity. The present invention fundamentally eliminates the generation of high-salt wastewater, making the entire process more environmentally friendly. In addition, the present invention does not use highly toxic chemicals, and the production site is safer and healthier.

[0056] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether, characterized in that: The following steps are involved: (1) Cyclododecanone is used as the starting material to undergo a free radical addition reaction with fatty acid allyl ester to obtain cyclododecanone addition ester; The fatty acid allyl ester is one of allyl acetate, allyl butyrate, and allyl hexanoate, and the molar ratio of cyclododecanone to the fatty acid allyl ester is 2.0-5.0; the catalyst used in the free radical addition reaction is di-tert-butyl peroxide, and the molar ratio of di-tert-butyl peroxide to the fatty acid allyl ester is 0.05-0.30; the temperature of the free radical addition reaction is 100-200° C.; (2) Cyclododecanone addition ester is reacted in an alcohol solvent under high temperature acid catalysis to obtain a bicyclic olefin ether by a one-step ring closure reaction; The catalyst used in the ring-closure reaction is one of trifluoroacetic acid and p-toluenesulfonic acid, and the temperature of the ring-closure reaction is 30-150°C.

2. The method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether according to claim 1, wherein: The molar ratio of the cyclododecanone to the fatty acid allyl ester is 2.5 to 4.

0.

3. The method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether according to claim 1, wherein: The molar ratio of the di-tert-butyl peroxide to the fatty acid allyl ester is 0.10-0.

20.

4. The method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether according to claim 1, wherein: The temperature of the free radical addition reaction is 140-170°C.

5. The method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether according to claim 1, wherein: The alcohol solvent used in the ring-closure reaction is one of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, n-pentanol, n-hexanol, and cyclohexanol. The mass ratio of the alcohol solvent to the cyclododecanone addition ester is 2.0 to 10.0; the mass ratio of the catalyst to the cyclododecanone addition ester is 0.01 to 1%.

6. The method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether according to claim 5, wherein: The mass ratio of the alcohol solvent to the cyclododecanone addition ester is 2.5 to 5.

0.

7. The method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether according to claim 5, wherein: The mass ratio of the catalyst to the cyclododecanone addition ester is 0.05-0.5%.

8. The method for preparing a cyclopentadecalactone intermediate bicyclic olefin ether according to claim 5, wherein: The temperature of the ring-closure reaction is 60-110°C.

Images