Method for synthesizing ambrogyl ether from ambrogyl glycol

Abstract

The invention relates to a method for synthesizing ambrogyl ether from ambrogyl glycol, and belongs to the technical field of perfume production. The method comprises the following steps: injecting a norambrota glycol solution into a packed bed reactor, controlling the retention time, reaction temperature and reaction pressure of the norambrota glycol solution in the packed bed reactor, carrying out cyclization reaction by using a solid acid catalyst in the packed bed reactor, and carrying out post-treatment on a reaction product to obtain norambrota ether. Through the combined action of the packed bed reactor and the solid acid catalyst, the reaction is rapidly and quantitatively carried out, only water is generated as a byproduct in the whole process, and the method has the characteristics of high efficiency, greenness and environmental protection.

Description

Technical field:

[0001] The invention belongs to the technical field of spice production, and particularly relates to a method for preparing ambrox. Background technology:

[0002] Ambrox, its structural formula is:

[0003]

[0004] Ambroxan, its structural formula is:

[0005] Ambrox is one of the most important ingredients of natural ambergris and the most excellent of all synthetic ambergris fragrances. Because it is non-irritating to the human body, it is widely used in the cosmetics and food industries and is a permitted food additive. Due to the lack of natural ambergris and its high price, how to synthesize ambrox efficiently, greenly and safely has become an urgent problem to be solved. Ambrox is the most direct raw material for synthesizing ambrox, which only needs to undergo dehydration and cyclization to generate ambrox. Domestic and foreign routes for preparing ambrox by dehydration and cyclization of ambrox mostly use ferric chloride, sulfonic acid or sulfonyl chloride as catalysts. Even reagents with high risks, high toxicity or unpleasant odors such as n-butyl lithium, sodium hydride, and pyridine are used. This seriously affects the quality of the final product, and the production process is accompanied by the generation of a large amount of waste, with very low atom economy. Summary of the invention:

[0006] In view of the above problems, the present invention provides a method for synthesizing Ambrox from Ambroxan. The method is characterized in that a solid acid catalyst is used as a catalyst and a quantitative, efficient and rapid cyclization reaction is carried out through a packed bed reactor. The whole reaction has a short reaction time, high selectivity, high yield, simple operation and is environmentally friendly.

[0007] The technical solution of the present invention is:

[0008] A method for synthesizing Ambrox from Ambroxan, the process of which is as follows:

[0009] The ambroxan is mixed with a solvent to obtain an ambroxan solution, a packed bed reactor is preheated, the ambroxan solution is injected into the packed bed reactor, and the residence time, reaction temperature and reaction pressure of the ambroxan solution in the packed bed reactor are controlled, a solid acid catalyst in the packed bed reactor is used to carry out a cyclization reaction, and the reaction product is post-treated to obtain ambroxan. The present invention enables the reaction to occur quickly and quantitatively through the combined action of the packed bed reactor and the solid acid catalyst, and only water is generated as a byproduct in the whole process, which has the characteristics of high efficiency, greenness and environmental protection.

[0010] Preferably, the solvent of the ambroxan solution can be one or more of water, methanol, ethanol, isopropanol, tert-butanol, dioxane, toluene, trifluoroethanol, hexafluoroisopropanol, dichloroethane, dichloromethane, chlorobenzene, acetone, and butanone; and the concentration of the ambroxan solution is 0.001 mol / L to 10 mol / L.

[0011] Preferably, the residence time of the ambroxan solution in the packed bed reactor is 10 s to 60 min, the reaction temperature is 0° C. to 200° C., and the reaction pressure is 0.01 MPa to 3 MPa.

[0012] Preferably, the solid acid catalyst is perfluorosulfonic acid resin or a strongly acidic cation exchange resin with a CAS number of 63182-08-1.

[0013] Preferably, the post-treatment refers to concentration under vacuum.

[0014] Beneficial effects:

[0015] The present invention uses a flow synthesis method, adopts a fixed bed reactor and a solid acid catalyst to carry out the cyclization reaction of ambroxil, realizes the efficient, safe and green synthesis of ambroxil, and has broad industrial prospects. Description of the drawings:

[0016] Figure 1 It is the hydrogen nuclear magnetic resonance spectrum of Ambrox synthesized in the present invention.

[0017] Figure 2 The present invention discloses the carbon-nuclear magnetic resonance spectrum of Ambrox synthesized in the present invention. Specific implementation method:

[0018] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0019] Embodiment 1:

[0020] Ambroxan is prepared with methanol to obtain an ambroxan solution with a concentration of 0.1 mol / L. The solid acid catalyst used is a perfluorosulfonic acid resin. The ambroxan solution is pumped into a packed bed reactor using a feed pump and the cyclization reaction temperature is controlled to 120°C and the reaction pressure is 0.1 MPa. The residence time of the ambroxan solution in the packed bed reactor is 25 min. The effluent is tested using HPLC, with a conversion rate of 100% and a yield of 95%. The effluent is concentrated under vacuum to obtain a white solid of ambroxan.

[0021] Embodiment 2:

[0022] The ambroxan solution was prepared with dichloroethane, and the concentration of the ambroxan solution was 0.5 mol / L. The solid acid catalyst used was perfluorosulfonic acid resin. The ambroxan solution was pumped into the packed bed reactor using a feed pump and the cyclization reaction temperature was controlled to 100°C and the reaction pressure was 0.1 MPa. The residence time of the ambroxan solution in the packed bed reactor was 10 min. The effluent was tested by HPLC, and the conversion rate was 96% and the yield was 90%. The effluent was concentrated under vacuum to obtain a white solid of ambroxan.

[0023] Embodiment 3:

[0024] The ambroxan solution is prepared with trifluoroethanol to obtain a ambroxan solution with a concentration of 0.5 mol / L. The solid acid catalyst used is a strongly acidic cation exchange resin (cas number: 63182-08-1). The ambroxan solution is pumped into a packed bed reactor using a feed pump and the cyclization reaction temperature is controlled to 150°C and the reaction pressure is controlled to 0.5 MPa. The residence time of the ambroxan solution in the packed bed reactor is 1 min. The effluent is detected by HPLC, and the conversion rate is 100% and 99%. The effluent is concentrated under vacuum to obtain a white solid of ambroxan.

[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for synthesizing Ambrox from Ambroxan, the process of which is as follows: The ambroxan is mixed with a solvent to obtain an ambroxan solution, a packed bed reactor is preheated, the ambroxan solution is injected into the packed bed reactor, and the residence time, reaction temperature and reaction pressure of the ambroxan solution in the packed bed reactor are controlled. A cyclization reaction is carried out using a solid acid catalyst in the packed bed reactor, and the reaction product is post-treated to obtain ambroxan.

2. The method for synthesizing Ambrox from Ambroxan according to claim 1, characterized in that: The solvent of the ambroxan solution is one or more of water, methanol, ethanol, isopropanol, tert-butanol, dioxane, toluene, trifluoroethanol, hexafluoroisopropanol, dichloroethane, dichloromethane, chlorobenzene, acetone, and butanone; the concentration of the ambroxan solution is 0.001 mol / L to 10 mol / L.

3. The method for synthesizing Ambrox from Ambroxan according to claim 1, characterized in that: The residence time of the ambroxan solution in the packed bed reactor is 10s to 60min, the reaction temperature is 0°C to 200°C, and the reaction pressure is 0.01Mpa to 3Mpa.

4. The method for synthesizing Ambrox from Ambroxan according to claim 1, characterized in that: The solid acid catalyst is perfluorosulfonic acid resin or a strongly acidic cation exchange resin with a CAS number of 63182-08-1.

5. The method for synthesizing Ambrox from Ambroxan according to claim 1, characterized in that: The work-up refers to concentration under vacuum.

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