Method for preparing cyclopentadecanolide from cyclopentadecanone

Abstract

The invention relates to a preparation method of cyclopentadecanolide, which is characterized in that cyclopentadecanone is subjected to oxidation in the presence of a catalyst in an ozone atmosphere to prepare cyclopentadecanolide. Wherein the used catalyst is a composite photocatalyst formed by combining inorganic titanium dioxide and organic molecules, and the system shows very high activity under the illumination condition. According to the method, peroxyacetic acid, hydrogen peroxide and other highly dangerous peroxides are not involved in the reaction, the process is safer, and the product yield can reach 97%. # imgabs0 #

Description

Technical Field

[0001] The invention relates to the field of organic synthesis, in particular to a method for preparing cyclopentadecalactone. Background Art

[0002] Musk is a rare animal fragrance with a very special and delicate aroma. It is an expensive fragrance that is indispensable for the preparation of high-end perfumes. Due to its rare source and difficulty in obtaining, and in the process of studying the synthesis of effective fragrance ingredients, compounds with musk aroma that do not exist in natural musk were discovered. Therefore, in recent years, synthetic methods have been used to prepare fragrances with musk aroma.

[0003] Macrolide musks have attracted much attention because they are almost non-toxic. They have an elegant and delicate aroma, contain aromatic components that are closer to natural musk, and have quite stable performance. Among them, pentadecalactone has an elegant and delicate aroma. Its suitable aroma can eliminate fatigue and make people feel happy physically and mentally. Moreover, adding pentadecalactone to food and beverages can improve the food's liking, thereby improving people's lives. Therefore, it is indispensable in people's daily lives.

[0004] Cyclopentadecalactone was first successfully synthesized by Ruzicka and his collaborators in the middle of the last century using chemical methods. At present, the synthesis of cyclopentadecalactone has made great progress. Its industrial production mainly uses cyclododecanone as the starting material. The main process route is as follows:

[0005] Using cyclododecanone addition alcohol as raw material

[0006]

[0007] Cyclododecanone addition alcohol can be easily prepared by the free addition reaction of cyclododecanone and allyl alcohol (see, for example, US Pat. No. 3,856,815).

[0008] Patent CN1867556A of Symrise Company of Germany provides a method for preparing cyclopentadecalactone, which uses cyclododecanone and alcohol as raw materials, oxidizes with 50% aqueous hydrogen peroxide in propionic acid and trifluoroacetic acid to obtain a peroxide suspension; the suspension uses polyethylene glycol as solvent, and is cleaved under the catalysis of copper acetate monohydrate to obtain harbanolide; and hydrogenates to obtain cyclopentadecalactone. This method uses a large amount of organic acid and high-concentration hydrogen peroxide, which poses a great risk in terms of process safety and environmental protection.

[0009] In summary, there is still a need to develop a route for synthesizing cyclopentadecalactone with a simple process, mild reaction conditions and good safety. Summary of the invention

[0010] In view of the above-mentioned deficiencies of the synthesis methods of cyclopentadecalactone in the prior art, the present invention provides a method for preparing cyclopentadecalactone.

[0011] To achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0012] A method for synthesizing cyclopentadecalactone comprises taking cyclopentadecalactone as a raw material, oxidizing cyclopentadecalactone with ozone in an ozone atmosphere in the presence of a composite catalyst to obtain cyclopentadecalactone.

[0013] The reaction route is as follows:

[0014]

[0015] In the present invention, ozone is used as an oxidant to replace peroxides such as peracetic acid, thereby greatly improving the safety of the process.

[0016] In the present invention, the pressure after adding ozone into the system is 0.01-0.10 MPa, preferably 0.01-0.05 MPa.

[0017] In the present invention, the composite catalyst comprises titanium dioxide and organic molecules, wherein the organic molecules are at least one of quinoline, phenanthridine, acridine and 7,8-benzoquinoline; wherein the amount of titanium dioxide is 0.001-1wt.% of the amount of cyclopentadecanone, and the amount of organic molecules is 0.9-1.2 times the mass of titanium dioxide.

[0018] In the present invention, the reaction temperature is 20°C-100°C, preferably 65°C-80°C.

[0019] In the present invention, the reaction needs to be carried out under illumination, and the wavelength of light required for the reaction is between 400-480nm, preferably between 420-460nm.

[0020] In the present invention, the synthesized cyclopentadecalactone is used in the fields of flavors and fragrances.

[0021] The beneficial effects of the present invention are:

[0022] The synthesis route of cyclopentadecalactone provided by the present invention uses ozone as a catalyst to replace peroxides such as peracetic acid, greatly improving the safety of the process, reducing the generation of wastewater, being green and environmentally friendly, and also improving the economy of the existing process. The product yield can be as high as 97% or more. DETAILED DESCRIPTION

[0023] In order to further illustrate the present invention in detail, several specific implementation cases are given below, but the present invention is not limited to these embodiments.

[0024] Example 1

[0025] (1) In a glove box, titanium dioxide (0.22 g, 0.1%), quinoline (0.22 g) and cyclopentadecanone (224.38 g, 1.0 mol) were added to a 1L high-pressure transparent glass kettle, heated to 65°C, and the stirring speed was controlled at 400 rpm. Ozone was used for gas replacement twice, and finally ozone was introduced to a pressure of 0.03 MPa, and then 450 nm blue light was used for irradiation, and the reaction was continued for 2 hours of insulation and stirring. The reaction kettle was sampled by inserting a bottom tube, and the reaction liquid was analyzed by GC. The raw material cyclopentadecanone was completely converted to obtain the product cyclopentadecanone, and the selectivity of the reaction was 97.0%. Then, 231.97 g of pure cyclopentadecanone was obtained by rectification and purification, with a yield of 96.5%.

[0026] NMR data of cyclopentadecalactone:

[0027] 1 HNM R (400MHz, CDCl3): δ4.12(2H,t,J=5.6Hz), 2.33(2H,t,J=6.4Hz), 1.62(4H,m), 1.31(22H,m). 13 CNMR (100MHz, CDCl3): δ174.0,64.3,34.7,29.5,28.7,28.2,27.9,27.8,27.7,27.1,27,26.9,26.8,25.6,25.0.

[0028] Example 2

[0029] (1) In a glove box, titanium dioxide (1.12 g, 0.5%), phenanthridine (1.23 g) and cyclopentadecanone (224.38 g, 1.0 mol) were added to a 1L high-pressure transparent glass kettle, heated to 80°C, the stirring speed was turned on and controlled at 400 rpm, and ozone was used for gas replacement twice. Finally, ozone was introduced to a pressure of 0.05 MPa, and then 420 nm blue light was used for irradiation, and the reaction was continued to be stirred and kept warm for 2 hours. The reaction kettle was sampled by inserting a bottom tube, and the reaction liquid was analyzed by GC. The raw material cyclopentadecanone was completely converted to obtain the product cyclopentadecanone, and the selectivity of the reaction was 98.0%. Then, 233.65 g of pure cyclopentadecanone was obtained by rectification and purification, with a yield of 97.2%.

[0030] Example 3

[0031] (1) In a glove box, titanium dioxide (0.44 g, 0.2%), acridine (0.44 g) and cyclopentadecanone (224.38 g, 1.0 mol) were added to a 1L high-pressure transparent glass kettle, heated to 70°C, the stirring speed was turned on and controlled at 400 rpm, and ozone was used for gas replacement twice. Finally, ozone was introduced to a pressure of 0.01 MPa, and then 460 nm blue light was used for irradiation, and the reaction was continued with insulation and stirring for 2 hours. The reaction kettle was sampled by inserting a bottom tube, and the reaction liquid was analyzed by GC. The raw material cyclopentadecanone was completely converted to obtain the product cyclopentadecanone, and the selectivity of the reaction was 96.5%. Then, 229.08 g of pure cyclopentadecanone was obtained by rectification and purification, with a yield of 95.3%.

Claims

1. A method for synthesizing cyclopentadecalactone, characterized in that: Cyclopentadecanone is used as a raw material, and in the presence of a composite catalyst under an ozone atmosphere, ozone is used to oxidize the cyclopentadecanone to obtain cyclopentadecalactone.

2. The synthesis method according to claim 1, characterized in that: The pressure after adding ozone into the system is 0.01-0.10 MPa, preferably 0.01-0.05 MPa.

3. The synthesis method according to claim 1, characterized in that: The composite catalyst comprises titanium dioxide and organic molecules, and the organic molecules are at least one of quinoline, phenanthridine, acridine and 7,8-benzoquinoline.

4. The synthesis method according to claim 3, characterized in that: The amount of titanium dioxide used is 0.001 to 1 wt.% of the amount of cyclopentadecanone used.

5. The synthesis method according to claim 3 or 4, characterized in that: The amount of organic molecules used is 0.9-1.2 times the mass of titanium dioxide.

6. The synthesis method according to any one of claims 1 to 5, characterized in that: The reaction temperature is 20°C-100°C, preferably 65°C-80°C.

7. The synthesis method according to any one of claims 1 to 5, characterized in that: The reaction is carried out under illumination, with the wavelength of light being between 400-480 nm, preferably between 420-460 nm.

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