Metal phthalocyanine polymer catalyst as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of organic synthesis, and particularly discloses a metal phthalocyanine polymer catalyst and a preparation method and application thereof.The preparation method comprises the steps that a proper amount of metal phthalocyanine, a phenyl skeleton and a cross-linking agent are mixed in a solvent and stirred to be uniform, then a Lewis acid catalyst is added, heating and stirring are conducted, the temperature is increased to reflux for a reaction, and the metal phthalocyanine polymer catalyst is obtained; after the reaction is finished, filtering, washing and drying in vacuum to obtain a metal phthalocyanine polymer catalyst marked as POL-MPc; the POL-MPc prepared by the invention is used for catalyzing the hydration of methoxy dihydromyrcene to obtain sandalwood ether, and the reaction has high stereospecificity; and the catalyst is easy to separate and recover, can be recycled for multiple times, has no obvious loss of catalytic activity, and has industrial value.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, and relates to the preparation of catalysts for organic synthesis, specifically to a metal phthalocyanine polymer catalyst, its preparation method, and its application in the preparation of santalyl ether in a highly regioselective hydration reaction. Background Technology

[0002] Santal ether, namely 7-methoxy-3,7-dimethyloctyl-2-ol (CAS 31890-92-0, Chemical C... 11 H 24 Sandalwood ether (O2) is an important synthetic fragrance and organic intermediate. At room temperature, it is colorless to slightly yellow. As a fragrance, it has a pleasant aroma and is a key component in the formulation of high-grade sandalwood fragrances. It can also be used to blend woody and floral fragrances, enhancing the complexity and naturalness of the aroma. Its low toxicity and antibacterial and antioxidant properties make it suitable for various applications, such as perfumes, personal care products like skincare, food additives, and pharmaceutical compounds.

[0003] Patent CN101906024 B discloses a method for synthesizing santalyl ether by using dihydromyrcene as a raw material, and by methoxylating, epoxidizing the terminal double bond of dihydromyrcene, and then hydrogenating it to generate hydroxyl groups.

[0004] Traditional hydration reactions often involve the direct addition of strong acids to water. While this method offers relatively simple reaction conditions, it results in low yields and numerous byproducts. Furthermore, the regioselectivity of double bond hydration reactions is poor, rendering it unsuitable for industrial applications.

[0005]

[0006] To achieve highly regioselectivity in double bond hydration, in 2014, Professor Peili Teo's research group used a self-made Pd(II) / Ru(II) catalyst to hydrate double bonds into highly regioselective alcohols, with a selectivity as high as 99%. Chem. Commun (., 2014, 50, 2608-2611). The catalysts used in the above reactions are expensive and cannot be recycled and reused multiple times; therefore, it is necessary to study new catalysts that can be easily recycled while ensuring high regioselectivity to meet the needs of industrial production. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a metal phthalocyanine polymer catalyst. This invention provides a simple method for preparing the metal phthalocyanine polymer catalyst, which is then used as a catalyst for the preparation of santalin ether. The catalyst exhibits high stereospecificity in the reaction of methoxydihydromyrcene to santalin ether; furthermore, the catalyst is easily separated and recovered, can be recycled multiple times, and shows no significant loss of catalytic activity, thus possessing industrial value.

[0008] This invention is achieved through the following technical solution: A metal phthalocyanine polymer catalyst has the following structure:

[0009] M is selected from Co or Fe.

[0010] A further improvement to the present invention is as follows: A method for preparing a metal phthalocyanine polymer catalyst includes the following steps: mixing an appropriate amount of metal phthalocyanine, phenyl skeleton and crosslinking agent in a solvent, stirring evenly, adding Lewis acid catalyst, heating and stirring, raising the temperature to reflux for reaction, and after the reaction is completed, filtering, washing and vacuum drying to obtain the metal phthalocyanine polymer catalyst, denoted as POL-MPc; .

[0011] Furthermore, the phenyl skeleton is one or a mixture of two or more of benzene, toluene, or biphenyl.

[0012] Furthermore, the Lewis acid catalyst is one or a mixture of two or more of FeCl3, AlCl3, or BF3 / Et2O; Furthermore, the crosslinking agent is dimethyl formaldehyde; Furthermore, the solvent is dichloromethane or 1,2-dichloroethane or a mixture of both.

[0013] Furthermore, the molar ratio of the metal phthalocyanine to the phenyl framework, the Lewis acid catalyst, and the crosslinking agent is 1:(1~10):(5~30):(5~30); Furthermore, the heating and stirring temperature is 40~50℃, and the time is 4~6h; the reflux time is 12~48h.

[0014] A further improvement of the present invention is as follows: The application of the above-mentioned metal phthalocyanine polymer catalyst in the preparation of santalinic ether by highly regioselective hydration reaction includes the following steps: methoxydihydromyrcene, the catalyst POL-MPc, and sodium borohydride are mixed in a solvent in proportion and reacted at an appropriate temperature for a certain time; then an appropriate amount of water is added, and after stirring for a period of time, the catalyst POL-MPc is separated and recovered by filtration. The organic layer obtained by the separation of the filtrate is then distilled under reduced pressure to obtain the product santalinic ether.

[0015]

[0016] Furthermore, the solvent is one or a mixture of two or more of methanol, ethanol, ethyl acetate or dichloromethane.

[0017] Furthermore, the molar ratio of methoxydihydromyrcene to sodium borohydride is 1: (1 ~ 6); the mass ratio of methoxydihydromyrcene to POL-MPc is 1: (0.1 ~ 1).

[0018] Furthermore, the reaction temperature is 0 ~ 50 ℃, and the time is 1 ~ 48 h.

[0019] Preferably, the reaction temperature is 20 ~ 30 ℃ and the time is 24 ~ 48 h.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The reaction raw materials used in the preparation method of the catalyst of the present invention are readily available and the preparation process is simple and easy to operate; (2) The catalyst POL-MPc designed and prepared in this invention has a stable structure, and the active components are not easily lost in the catalytic reaction and can be recycled and reused. (3) The catalyst of the present invention has high regioselectivity for santalyl ether (a:b>99).

[0021] Attached Figure Description

[0022] Figure 1 The infrared spectrum of POL-MPc (M=Co) obtained in Example 1; Figure 2 The infrared spectrum of POL-MPc (M=Fe) obtained in Example 2; Figure 3 Electron micrograph of POL-MPc (M=Co) prepared in Example 1; Figure 4 This is an electron microscope image of POL-MPc (M=Fe) prepared in Example 2. Detailed Implementation

[0023] The present invention will now be described in detail with reference to specific embodiments.

[0024] Example 1 (1) Preparation of POL-MPc (M=Co): 6 g MPc (M=Co), 4.3 g benzene, 9 g methyl acetal, and 50 ml 1,2-dichloroethane were added sequentially to a 150 ml round-bottom flask. After stirring until homogeneous, 15.7 g anhydrous ferric chloride was added. The mixture was stirred at 45 ℃ for 5 h, then refluxed at 80 ℃ for 19 h. After the reaction was complete, the mixture was filtered and washed with methanol until the filtrate was colorless and transparent. The filter cake was then placed in a Soxhlet extractor and washed with methanol for 24 h. Finally, it was vacuum dried to obtain POL-MPc (M=Co), weighing 13.1 g. The structure of the obtained catalyst was analyzed using infrared spectroscopy, and the results are shown in [Figure 1]. Figure 1 ,Depend on Figure 1 It can be seen that 3047 cm -1 The absorption peak of the hydrocarbon vibration of the benzene ring is visible at 1508 cm⁻¹. -1 1608 cm -1 and 1646 cm -1 Characteristic peaks of benzene ring and nitrogen heterocycle in phthalocyanine were observed at the site.

[0025] (2) Preparation of santalyl ether: POL-MPc catalyst (8.5 g, M=Co), sodium borohydride (11.4 g, 0.3 mol), and a magnetic stir bar were added to a 500 mL two-necked flask. 250 mL of anhydrous ethanol was added and the reaction system was stirred until homogeneous. Then, methoxydihydromyrcene (17.1 g, 0.1 mol) was added, and the reaction was carried out at room temperature for 48 h. After the reaction was completed, water was added to quench the reaction. The POL-CoPc catalyst was separated by filtration, and most of the anhydrous ethanol was removed by vacuum distillation. The aqueous phase was extracted three times with ethyl acetate, and the organic phases were combined. After drying and filtration, ethyl acetate was removed by vacuum distillation to obtain 16.7 g of santalyl ether, with a yield of 89%.

[0026] After the reaction is complete, the separated POL-CoPc is washed with ethanol and ethyl acetate, dried under vacuum, and can be used again in the reaction.

[0027] Example 2 (1) Preparation of POL-MPc (M=Fe): 6 g MPc (M=Fe), 4.3 g benzene, 9 g methyl acetal, and 50 ml 1,2-dichloroethane were added sequentially to a 150 ml round-bottom flask. After stirring until homogeneous, 15.7 g anhydrous ferric chloride was added. The mixture was stirred at 45 ℃ for 5 h, then refluxed at 80 ℃ for 19 h. After the reaction was complete, the mixture was filtered and washed with methanol until the filtrate was colorless and transparent. The filter cake was then placed in a Soxhlet extractor and washed with methanol for 24 h. Finally, it was vacuum dried to obtain POL-MPc (M=Fe), weighing 13.7 g. The structure of the obtained catalyst was analyzed using infrared spectroscopy. The results are shown in [Figure 1]. Figure 2 ,Depend on Figure 2 It can be seen that 3050 cm -1 The peak at 1512 cm⁻¹ shows the absorption peak of the hydrocarbon vibration of the benzene ring. -1 1610 cm -1 and 1645 cm -1 Characteristic peaks of benzene ring and nitrogen heterocycle in phthalocyanine were observed at the site.

[0028] (2) Preparation of santalyl ether: POL-MPc catalyst (8.5 g, M=Fe), sodium borohydride (11.4 g, 0.3 mol) and magnetic stir bar were added to a 500 mL two-necked flask. 250 mL of anhydrous ethanol was added and the reaction system was stirred until homogeneous. Then, methoxydihydromyrcene (17.1 g, 0.1 mol) was added, and the reaction was carried out at room temperature for 48 h. After the reaction was completed, water was added to quench the reaction. The POL-FePc catalyst was separated by filtration. Most of the anhydrous ethanol was removed by vacuum distillation. The aqueous phase was extracted three times with ethyl acetate and the organic phases were combined. After drying and filtration, ethyl acetate was removed by vacuum distillation to obtain 16.2 g of santalyl ether, with a yield of 86%.

[0029] After the reaction is complete, the separated POL-FePc is washed with ethanol and ethyl acetate, dried under vacuum, and can be used again in the reaction.

[0030]

[0031] Table 1: Comparison of data on double bond hydration catalyzed by various catalysts

[0032] Example 3: Synthesis of Santal Ether by Recovering Catalyst POL-CoPc (8.5 g), sodium borohydride (11.4 g, 0.3 mol), and a magnetic stir bar were added to a 500 mL two-necked flask. 250 mL of anhydrous ethanol was added, and the reaction mixture was stirred until homogeneous. Then, methoxydihydromyrcene (17.1 g, 0.1 mol) was added, and the reaction was carried out at room temperature for 48 h. After the reaction was complete, water was added to quench the reaction. The POL-CoPc catalyst was separated by filtration, and most of the anhydrous ethanol was removed by vacuum distillation. The aqueous phase was extracted three times with ethyl acetate, and the organic phases were combined. After drying and filtration, ethyl acetate was removed by vacuum distillation to obtain the product santalyl ether. After the reaction was complete, the separated POL-CoPc was washed with ethanol and ethyl acetate, dried under vacuum, and reused in the reaction. The results are shown in the table below: Table 2: Yield of santalyl ether after multiple reuses of POL-CoPc catalyst

[0033] The above description of the embodiments is only for illustrating the technical concept and features of the present invention. Its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. Those skilled in the art can obviously easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the above embodiments should not be used to limit the scope of protection of the present invention. All improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A metal phthalocyanine polymer catalyst, characterized in that, The structure is shown in the following formula: ； M is selected from Co or Fe.

2. The method for preparing a metal phthalocyanine polymer catalyst as described in claim 1, characterized in that, Includes the following steps: An appropriate amount of metal phthalocyanine, phenyl framework and crosslinking agent are mixed in a solvent, stirred evenly, and then Lewis acid catalyst is added. The mixture is heated and stirred, and the temperature is raised to reflux for reaction. After the reaction is completed, the metal phthalocyanine polymer catalyst is obtained by filtration, washing and vacuum drying, and is denoted as POL-MPc. 。 3. The preparation method according to claim 2, characterized in that: The phenyl skeleton is one or a mixture of two or more of benzene, toluene, or biphenyl; And / or, the Lewis acid catalyst is one or a mixture of two or more of FeCl3, AlCl3, or BF3 / Et2O; And / or, the crosslinking agent is dimethylformaldehyde; And / or, the solvent is dichloromethane or 1,2-dichloroethane or a mixture thereof.

4. The preparation method according to claim 2, characterized in that: The molar ratio of the metal phthalocyanine to the phenyl skeleton, the Lewis acid catalyst, and the crosslinking agent is 1:(1~10):(5~30):(5~30).

5. The preparation method according to claim 2, characterized in that: The heating and stirring temperature is 40~50℃, and the time is 4~6h; the reflux time is 12~48h.

6. The application of the metal phthalocyanine polymer catalyst as described in claim 1 in the highly regioselective hydration reaction to prepare santalyl ether, characterized in that, Includes the following steps: Methoxydihydromyrcene, the catalyst POL-MPc, and sodium borohydride were mixed in a solvent in a certain proportion and reacted at an appropriate temperature for a certain time. Then, an appropriate amount of water was added, and after stirring for a period of time, the catalyst POL-MPc was separated and recovered by filtration. The organic layer obtained by the separation of the filtrate was distilled under reduced pressure to obtain the product santalyl ether.

7. The application according to claim 6, characterized in that: The solvent is one or a mixture of two or more of methanol, ethanol, ethyl acetate or dichloromethane.

8. The application according to claim 6, characterized in that: The molar ratio of methoxydihydromyrcene to sodium borohydride is 1: (1 ~ 6); the mass ratio of methoxydihydromyrcene to POL-MPc is 1: (0.1 ~ 1).

9. The application according to claim 6, characterized in that: The reaction temperature is 0 ~ 50 ℃, and the time is 1 ~ 48 h.

10. The application according to claim 9, characterized in that: The reaction temperature is 20 ~ 30 ℃, and the time is 24 ~ 48 h.

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