Preparation method of unsaturated ketone and used catalyst

Abstract

The invention relates to a preparation method of unsaturated ketone and a used catalyst. Ketone groups and hydroxyl groups in the buprofezin salt ionic liquid and hydrogen atoms and oxygen atoms in propargyl alcohol such as dehydrolinalool can respectively form dihydrogen bonds, so that the effect of activating a substrate is achieved, in addition, electron delocalization exists in a buprofezin structure part, a conjugation effect is achieved, the hydrogen bonds are stronger, the use amount of a catalyst can be greatly reduced, and the cost is reduced. The conversion rate and selectivity of the reaction are improved, the conversion rate of the reaction can reach 99.0% or above, and the selectivity of the reaction can reach 97.5% or above. The loop reactor is adopted for reaction, reaction heat can be effectively removed, temperature control is more stable, the temperature effect in the reaction process is reduced, selectivity can be improved, and continuous production can be achieved.

Description

Technical Field

[0001] The present invention specifically relates to a method for preparing unsaturated ketones and a catalyst used therefor. Background Art

[0002] Unsaturated ketones are important intermediates for synthesizing fragrances, flavors, vitamins, and pharmaceuticals. For example, pseudoionone, also known as 6,10-dimethyl-3,5,9-tridecatrien-2-one, with the molecular formula C 13 H 20 O and the structural formula is an important raw material for synthesizing ionone, vitamin A, β-carotene, etc., and is widely used in the fragrance and pharmaceutical industries.

[0003] In the prior art, the synthesis methods of pseudoionone mainly include the following several kinds:

[0004] (1) Dehydrolinalool undergoes a rearrangement reaction to form citral, and then citral undergoes aldol condensation with acetone under alkaline conditions to obtain pseudoionone. Although this method has been widely used, due to the active nature of citral, it is prone to self-condensation reaction under the action of a base catalyst. In order to obtain pseudoionone products in a higher yield, a large excess of acetone needs to be added; however, acetone is also prone to self-condensation and other side reactions under the action of a base catalyst, and a large amount of three wastes are generated in the reaction, and the unit consumption of acetone is large.

[0005] (2) Dehydrolinalool and ethyl acetoacetate directly obtain pseudoionone through the Carroll rearrangement reaction. The main disadvantages of this method are that the raw material ethyl acetoacetate is expensive, the reaction temperature is relatively high; and the reaction generates equivalent by-products carbon dioxide and methanol, with poor atom economy.

[0006] (3) Dehydrolinalool and 2-methoxypropene undergo the Saucy-Marbet reaction (abbreviated as the SM reaction) under the action of an acid catalyst to form allenone, and then undergo an isomerization reaction under the action of a base catalyst to synthesize pseudoionone. Because of its simple and easily available raw materials, low price, mild reaction conditions, easy operation and scale-up, this method is the most promising synthesis method. In the prior art, the acidic catalysts used in this method are mainly traditional proton strong acids such as sulfuric acid, methanesulfonic acid, and toluenesulfonic acid, which have problems such as serious corrosion, high requirements for equipment materials, limited solubility in organic substances, large catalytic dosage, difficulty in recovering the acid catalyst and the product being miscible after the reaction is completed, and generating excess three wastes when neutralizing the acid. Moreover, in the prior art, this reaction is mostly carried out in batch operation, and the reaction heat cannot be removed in time, while this reaction process is a strong exothermic process, and the temperature rise caused by the exotherm will reduce the product selectivity. Summary of the Invention

[0007] The object of the present invention is to provide a new catalyst, which has a hydroxyl-functionalized bis-acidic buprofezin salt structure, is an ionic liquid, can be used to catalyze the Saucy-Marbet reaction, has low requirements for equipment, low corrosivity, excellent solubility in organic substances, and is convenient for recycling.

[0008] Another object of the present invention is to provide a preparation process of unsaturated ketones, which includes the Saucy-Marbet reaction process, and the aforementioned catalyst is used in this process, and the reaction has high yield and high selectivity.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A buprofezin salt ionic liquid having the structure shown by the following formula:

[0011]

[0012] Wherein, X - is HSO 4 - or CH 3 SO 3 - ;

[0013] n is 1, 2, 3 or 4;

[0014] R 1 is a C1-6 alkyl group substituted with a single hydroxyl group.

[0015] In some embodiments, n is 1 or 2.

[0016] In some embodiments, R 1 is a C1-3 alkyl group substituted with a single hydroxyl group; preferably, R 1 is a straight-chain C1-3 alkyl group substituted with a single hydroxyl group.

[0017] In some embodiments, R 1 is selected from 2-hydroxyethyl, 3-hydroxypropyl or 2-hydroxypropyl.

[0018] In some embodiments, the buprofezin salt ionic liquid is selected from the following structural formulas:

[0019]

[0020]

[0021] The present invention also provides a preparation method of the aforementioned buprofezin salt ionic liquid, and the preparation method includes the following steps:

[0022] 1) React with CI-R 1The phase transfer catalytic reaction is carried out in the presence of a base and a phase transfer catalyst to generate

[0024] 2) The reacts with in the presence of a catalyst to generate

[0025] 3) The reacts with sulfuric acid or methanesulfonic acid in an organic solvent to generate the buprofezin salt ionic liquid;

[0026] In each formula, n and R 1 are defined as in the aforementioned compounds.

[0027] In some embodiments, in step 1), the base is selected from the group consisting of one or more combinations of sodium hydroxide, potassium hydroxide, calcium hydroxide, and barium hydroxide.

[0028] In some embodiments, in step 1), the phase transfer catalyst is selected from the group consisting of one or more combinations of triethylbenzylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogensulfate, and 18-crown-6.

[0029] In some embodiments, in step 1), the temperature of the phase transfer catalytic reaction is 40-70 °C.

[0030] In some embodiments, in step 1), the time of the phase transfer catalytic reaction is 2-5 h.

[0031] In some embodiments, in step 2), the catalyst is selected from the group consisting of one or more combinations of toluene, phenol, xylene, acetonitrile, chloroform, and pyridine.

[0032] In some embodiments, in step 2), the temperature of the reaction is 90-130 °C;

[0033] In some embodiments, in step 2), the time of the reaction is 8-16 h.

[0034] In some embodiments, in step 3), the organic solvent is selected from the group consisting of one or more combinations of dichloromethane, ethyl acetate, acetone, methanol, ethanol, and n-hexane.

[0035] In some embodiments, after the reaction in step 3), the reaction system is phase-separated, and the organic solvent phase is removed to obtain the buprofezin salt ionic liquid.

[0036] The present invention also provides a method for preparing an unsaturated ketone. The preparation method uses propargyl alcohol and alkoxy olefin as raw materials, and undergoes a Saucy-Marbet reaction in the presence of a catalyst to generate the unsaturated ketone; the catalyst is the aforementioned buprofezin salt ionic liquid.

[0037] In the present invention, the Saucy-Marbet reaction refers to a reaction in which propargyl alcohol and alkoxy olefin are used as raw materials and react under the action of a Bronsted acid catalyst to obtain allenic ketone. This method was first reported by Saucy and Marbet et al. (US3029287, US6184420; R. Marbet, G. Saucy, Helv. Chim. Acta. 1967, 50, 1158-1167.).

[0038] The unsaturated ketone of the present invention, namely allenic ketone, can exist stably. It can further undergo an isomerization reaction to generate α,γ-unsaturated dienone, or it can undergo a hydrogenation reaction, etc., and is used as an intermediate for synthesizing other organic chemicals.

[0039] In the prior art, the acidic catalysts used in this method are mainly traditional proton strong acids such as sulfuric acid, methanesulfonic acid, and toluenesulfonic acid, which have problems such as serious corrosion, high requirements for equipment materials, limited solubility in organic substances, large catalytic dosage, difficulty in recovering the acid catalyst and the product after the reaction is completed due to miscibility, and the generation of excess three wastes when neutralizing the acid. The inventors of the present application have found through a large number of studies that by using the aforementioned buprofezin salt ionic liquid with a specific structure as the acidic catalyst for this reaction, the reaction conditions can be mild, the requirements for equipment are low, the catalyst dosage is small, the reaction selectivity is high, and the catalyst is easy to recycle after the reaction. As an emerging green solvent, ionic liquid has strong solubility, low volatility, and basically no corrosion to equipment. In particular, the designability of its functional groups creates conditions for the design and development of ionic liquids with special functions. In the aforementioned ionic liquid of the present invention, the keto group and hydroxyl group can respectively form double hydrogen bonds with the hydrogen atom and oxygen atom in propargyl alcohol such as dehydro linalool, thereby playing a role in activating the substrate. In addition, there is electron delocalization in the buprofezin structure part, having a conjugation effect and stronger hydrogen bonds, which can greatly reduce the catalyst dosage, and has high conversion rate, yield, and selectivity, with less pollution. In addition, the catalyst still has a high conversion rate and yield after being recycled and reused multiple times.

[0040] In some embodiments, the molar amount of the buprofezin salt ionic liquid accounts for 0.5‰~1‰ of the molar amount of the propargyl alcohol. Herein, ‰ refers to per thousand, for example, 0.5‰ refers to 0.5 per thousand.

[0041] In some embodiments, the molar ratio of the alkoxy olefin to the propargyl alcohol is 2.0~4.0:1; preferably 2.0~3.0:1.

[0042] In some embodiments, the temperature of the Saucy-Marbet reaction is 80 to 120 °C; preferably 100 to 110 °C.

[0043] In some embodiments, the time of the Saucy-Marbet reaction is 10 to 50 min; preferably 20 to 40 min.

[0044] In some embodiments, the pressure of the Saucy-Marbet reaction is 0.5 to 1.2 MPa, preferably 0.7 to 0.9 MPa.

[0045] In some embodiments, the Saucy-Marbet reaction is carried out in a loop reactor, and the loop reactor includes:

[0046] A Venturi mixer;

[0047] An SM reactor;

[0048] A heat exchanger for heat exchange between the reaction system and a cooling medium;

[0049] A circulation pump for circulating the reaction system between the Venturi mixer, the SM reactor and the heat exchanger;

[0050] The preparation method includes the steps of mixing the buprofezin salt ionic liquid and propargyl alcohol in the Venturi mixer to obtain a mixture, and starting the circulation pump to circulate the mixture between the Venturi mixer, the SM reactor and the heat exchanger; and introducing an alkoxy olefin into the SM reactor, and carrying out the Saucy-Marbet reaction in a cycle in the SM reactor, the heat exchanger and the Venturi mixer.

[0051] In the prior art, this reaction is mostly carried out in batch operation, and the reaction heat cannot be removed in time. However, this reaction process is a strong exothermic process, and the temperature rise caused by exotherm will reduce the product selectivity. In the present invention, the Saucy-Marbet reaction is carried out in a loop reactor with a heat exchanger. During the reaction process, heat exchange (cooling) is carried out in time by circulating to the heat exchanger. Therefore, the reaction heat can be removed in time, the temperature control is more stable, the temperature effect during the reaction is reduced, the selectivity is improved, and continuous production can be realized. The above loop reactor is an efficient reactor.

[0052] In some embodiments, the loop reactor further includes:

[0053] A first preheater for preheating the buprofezin salt ionic liquid and propargyl alcohol, and connected to the Venturi mixer;

[0054] A second preheater for preheating the alkoxy olefin and connected to the SM reactor.

[0055] In some embodiments, the loop reactor further comprises:

[0056] A catalyst storage tank for storing the buprofezin salt ionic liquid and connected to the first preheater through a feed pump;

[0057] A propargyl alcohol storage tank for storing the propargyl alcohol and connected to the first preheater through a feed pump;

[0058] An alkoxy olefin storage tank for storing the alkoxy olefin and connected to the second preheater through a feed pump.

[0059] In some embodiments, there is one or more heat exchangers; preferably, there are 2 - 4 heat exchangers, and more preferably, the multiple heat exchangers are arranged in parallel.

[0060] In some embodiments, the cooling medium is water.

[0061] In some embodiments, the catalyst exists in the form of a catalyst solution; the boiling point of the solvent in the catalyst solution is 250 - 270 °C. Using this high - boiling - point solvent to dissolve the catalyst can make the catalyst easy to be separated in the form of a solution (e.g., by distillation, etc.) and reused after the reaction.

[0062] In some embodiments, the solvent is a mixture of biphenyl and diphenyl ether; preferably, the mass ratio of biphenyl to diphenyl ether is 20 - 30:70 - 80.

[0063] More preferably, it is a eutectic azeotropic mixture composed of 26.5% biphenyl and 73.5% diphenyl ether by mass percentage.

[0064] In some embodiments, the loop reactor further comprises a distillation column. The distillation column is connected to the circulation pump through a valve. When the conversion rate of the propargyl alcohol in the preparation method reaches more than 99.0%, the reaction system enters the distillation column through the valve. The unsaturated ketone is taken out from the top of the column, and the catalyst solution is taken out from the bottom of the column and circulated to the first preheater. For example, the ionic liquid catalyst and the high - boiling - point solvent are recycled from the distillation column to the feed pipeline, for example, to the feed pump between the catalyst storage tank and the first preheater, and enter the first preheater for preheating together with the newly introduced catalyst solution in the catalyst storage tank. The valve can be a pressure control valve, for example.

[0065] In some embodiments, the circulation ratio of the Saucy - Marbet reaction in the loop reactor is 1 - 20, preferably 6 - 10. The circulation ratio refers to the mass ratio of the total flow circulating in the SM reactor, heat exchanger and Venturi mixer to the raw material feed. By using this higher circulation ratio, the reaction system can be fully heat - exchanged, reducing the impact of reaction heat release on selectivity and improving reaction selectivity.

[0066] In some embodiments, the propargyl alcohol is selected from one or a combination of more than one of dehydro - linalool, 2 - methyl - 3 - butyn - 2 - ol, 3 - methyl - 1 - pentyn - 3 - ol, dehydro - nerolidol, tetrahydro - dehydro - nerolidol, dehydro - isophytol.

[0067] In some embodiments, the alkoxy - olefin is selected from one or a combination of more than one of 2 - methoxypropene, 2 - ethoxypropene, 2 - propoxypropene, 2 - isopropoxypropene.

[0068] The present invention further provides a method for preparing an α,γ - unsaturated diketone. The preparation method includes the step of isomerizing an allenone to generate the α,γ - unsaturated diketone, and the preparation method further includes the step of preparing the allenone by using the aforementioned method for preparing an unsaturated ketone.

[0069] Further, the α,γ - unsaturated diketone can be pseudoionone.

[0070] The present invention further provides a loop reactor for the Saucy - Marbet reaction of propargyl alcohol and alkoxy - olefin, which includes:

[0071] A Venturi mixer;

[0072] An SM reactor;

[0073] A heat exchanger for heat - exchange between the reaction system and a cooling medium;

[0074] A circulation pump for circulating the reaction system between the Venturi mixer, the SM reactor and the heat exchanger.

[0075] In some embodiments, the loop reactor further includes:

[0076] A first pre - heater for pre - heating the thiazolone salt ionic liquid and propargyl alcohol, and connected to the Venturi mixer;

[0077] A second pre - heater for pre - heating the alkoxy - olefin and connected to the SM reactor.

[0078] In some embodiments, the loop reactor further includes:

[0079] A catalyst storage tank for storing the buprofezin salt ionic liquid and connected to the first preheater through a feed pump;

[0080] An propargyl alcohol storage tank for storing the propargyl alcohol and connected to the first preheater through a feed pump;

[0081] An alkoxy olefin storage tank for storing the alkoxy olefin and connected to the second preheater through a feed pump.

[0082] In some embodiments, there is one or more heat exchangers; preferably, there are 2 - 4 heat exchangers, and more preferably, the multiple heat exchangers are arranged in parallel.

[0083] In some embodiments, the loop reactor further includes a distillation column, which is connected to the circulation pump through a valve, and the distillation column is used to separate the catalyst solution and the unsaturated ketone.

[0084] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0085] By using a buprofezin salt ionic liquid with a specific structure as the acidic catalyst for the Saucy - Marbet reaction, the present invention can achieve mild reaction conditions, low requirements for equipment, small catalyst dosage, high reaction selectivity, and easy recycling of the catalyst after the reaction.

[0086] The keto group and hydroxyl group in the buprofezin salt ionic liquid can respectively form double hydrogen bonds with the hydrogen atom and oxygen atom in propargyl alcohol such as dehydro linalool, thus playing a role in activating the substrate. In addition, there is electron delocalization in the buprofezin structure part, having a conjugation effect and stronger hydrogen bonds, which can greatly reduce the catalyst dosage, improve the conversion rate and selectivity of the reaction. The reaction conversion rate of the present invention can reach more than 99.0%, and the reaction selectivity is as high as more than 97.5%.

[0087] The present invention uses a loop reactor for the reaction, which can effectively remove the reaction heat, make the temperature control more stable, reduce the temperature effect during the reaction, improve the selectivity, and enable continuous production. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 It is a schematic diagram of the preparation device for the preparation method of unsaturated ketone in the embodiment of the present invention;

[0089] Among them, 1 - catalyst storage tank; 4 - Venturi mixer; 5 - SM reactor; 6 - heat exchanger; 7 - circulation pump; 8 - first preheater; 9 - second preheater; 10 - distillation column; 11 - valve; 12 - feed pump; a - ionic liquid + high-boiling solvent; b - dehydro linalool DLL; c - 2-methoxypropene IPM; d - cooling water; e - allenone. Specific embodiments

[0090] During the Saucy-Marbet reaction, traditional protonic strong acid catalysts have serious corrosion problems, high requirements for equipment materials, limited solubility in organic substances, large catalytic dosages, cannot be recycled, the reaction is usually batch operation, and the reaction heat cannot be removed in time, etc. Ionic liquids, as an emerging green solvent, have strong solubility, low volatility, and basically no corrosion to equipment. In particular, the designability of their functional groups creates conditions for the design and development of ionic liquids with special functions. Through the design of the functional groups of ionic liquids, the present invention provides a process for continuously preparing unsaturated ketones catalyzed by hydroxyl-functionalized bis-acidic thiazolone salts ionic liquids. In a loop reactor with a heat exchanger, allenone is prepared from propargyl alcohol such as dehydro linalool and alkoxy olefins such as 2-methoxypropene through the Saucy–Marbet reaction. During the reaction process, the reaction heat can be removed in time and continuous production can be achieved. The ketone group and hydroxyl group in the ionic liquid catalyst can respectively form double hydrogen bonds with the hydrogen atom and oxygen atom in propargyl alcohol such as dehydro linalool, thus playing the role of activating the substrate. In addition, there is electron delocalization in the thiazolone structure part, with a conjugation effect, and the hydrogen bond is stronger and the effect is better. Furthermore, the catalyst dosage can be greatly reduced, and the conversion rate, yield, and selectivity are high, with less pollution. In addition, the catalyst still has a high conversion rate and yield after being recycled and reused multiple times.

[0091] The loop reactor and reaction process of the present invention can be specifically implemented as follows:

[0092] As Figure 1As shown in the figure, the loop reactor includes a catalyst storage tank 1 for storing the aforementioned thiazinone salt ionic liquid, a propargyl alcohol storage tank (not shown) for storing propargyl alcohol, an alkoxyalkene storage tank (not shown) for storing alkoxyalkene, and a feed pump for feeding the three. A first preheater 8 for preheating the thiazinone salt ionic liquid and propargyl alcohol, a second preheater 9 for preheating the alkoxyalkene, a Venturi mixer 4, an SM reactor 5, and a heat exchanger 6 for heat exchange between the reaction system and the cooling medium. A circulation pump 7 for circulating the reaction system between the Venturi mixer 4, the SM reactor 5, and the heat exchanger 6, and a distillation column 10 connected to the circulation pump 7 through a valve 11. The first preheater is connected to the Venturi mixer 4; the second preheater 9 is connected to the SM reactor 5. The Venturi mixer 4, the SM reactor 5, and the heat exchanger 6 form a circulation loop through the circulation pump 7. The Venturi mixer 4 can adopt a Venturi mixer 4 with a conventional structure in the art.

[0093] Furthermore, the feed pump 12 is arranged between the catalyst storage tank 1 and the first preheater 8, and is also arranged between the propargyl alcohol storage tank and the first preheater 8, and is also arranged between the alkoxyalkene storage tank and the second preheater 9.

[0094] Furthermore, the catalyst preferably exists in the form of a catalyst solution; and a high-boiling solvent is used for dissolution to facilitate the recovery and reuse of the catalyst after the reaction. The catalyst ionic liquid and the solvent a are mixed and formulated in the catalyst storage tank 1. Propargyl alcohol, such as dehydro linalool b, is fed from the propargyl alcohol storage tank through the feed pump 12, and the catalyst solution is also fed through the feed pump 12. The two are fed and interlocked and mixed before the first preheater 8, and then enter the first preheater 8 for preheating.

[0095] During the reaction, the preheated thiazinone salt ionic liquid and propargyl alcohol are mixed in the Venturi mixer 4 to obtain a mixture; then the circulation pump 7 is started to circulate the mixture between the Venturi mixer 4, the SM reactor 5, and the heat exchanger 6. Alkoxyalkene, such as 2-methoxypropene c, is fed from the alkoxyalkene storage tank through the feed pump 12 and preheated in the second preheater 9. After preheating, the alkoxyalkene is introduced into the SM reactor 5, and the Saucy-Marbet reaction is carried out in a cycle in the SM reactor 5, the heat exchanger 6, and the Venturi mixer 4. When the catalyst is directly mixed with 2-methoxypropene IPM, a violent reaction will occur, while when it is first mixed with dehydro linalool DLL, DLL plays a diluting role, making the reaction more gentle.

[0096] Furthermore, the heat exchanger 6 is one or more; preferably, the heat exchanger 6 is 2-4, and more preferably, multiple heat exchangers 6 are arranged in parallel. Although Figure 1Two heat exchangers 6 are shown, but the scope of protection of the present invention is not limited thereto. Arranging them in parallel can increase the reaction throughput. Of course, a series arrangement can also be adopted.

[0097] Further, the cooling medium is water ( Figure 1 as shown by component d in ). The inside of the heat exchanger 6 is a reaction system channel, and the periphery is a cooling medium channel. The flow directions of the two are usually opposite to facilitate improving the heat exchange efficiency.

[0098] Further, the temperature of the Saucy-Marbet reaction is 80 - 120 °C, preferably 100 - 110 °C. The pressure of the Saucy-Marbet reaction is 0.5 - 1.2 MPa, preferably 0.7 - 0.9 MPa. The residence time of the Saucy-Marbet reaction is 10 - 50 min, preferably 20 - 40 min. The circulation ratio of the Saucy-Marbet reaction in the loop reactor is 1 - 20, preferably 6 - 10.

[0099] By regularly sampling and analyzing the reaction system in the loop reactor, when the conversion rate of propargyl alcohol reaches more than 99.0%, the reaction system enters the distillation column 10 through the valve 11. Unsaturated ketones such as allenyne ketone e are taken out from the top of the column, and the catalyst solution (ionic liquid + high-boiling solvent a) is taken out from the bottom of the column and applied to the feed pump between the catalyst storage tank 1 and the first preheater 8, and enters the first preheater 8 together with the newly introduced catalyst solution in the catalyst storage tank 1 for preheating to achieve the recycling of the catalyst. The valve 11 can be, for example, a pressure control valve, etc.

[0100] The above solution will be further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited by the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0101] Unless otherwise specified in the following embodiments, all raw materials are obtained through commercial purchase or prepared by conventional methods in the art.

[0102] Catalyst Preparation Example

[0103] The preparation method of the catalyst hydroxy-functionalized bis-acidic buprofezin salt ionic liquid is divided into two steps:

[0104] I. Synthesis of hydroxy-functionalized buprofezin ionic liquid

[0105] Under the action of sodium hydroxide, 2-chloroethanol, 3-chloropropanol, and 2-chloropropanol were respectively subjected to a phase-transfer catalytic reaction with 1,3-thiazinan-2-thione at a molar ratio of 1.05:1. Triethylbenzylammonium chloride was used as the phase-transfer catalyst, and the reaction was carried out at 50 °C for 2 h to obtain the corresponding hydroxyl-functionalized thiazinone compounds. The reaction formula is as follows:

[0106]

[0107] Next, using toluene as the catalyst, the hydroxyl-functionalized thiazinone compounds prepared above were respectively stirred and refluxed with 1,3-propane sultone and 1,4-butane sultone at a molar ratio of 1:1.05 in an oil bath at 110 °C for 12 h. After the reaction was completed, it was cooled to room temperature, and it was observed that white solids were formed in the mixture. The solid obtained after filtering the mixture was washed with acetone and dried under vacuum at 80 °C for 12 h to obtain the hydroxyl-functionalized thiazinone ionic liquids. The reaction formula is as follows:

[0108]

[0109] The structural formulas of the hydroxyl-functionalized thiazinone ionic liquids are as follows:

[0110]

[0111] II. Synthesis of Hydroxyl-Functionalized Double-Acid Thiazinone Salt Ionic Liquids

[0112] Dichloromethane and a hydroxyl-functionalized thiazinone ionic liquid (one of IL1 - IL6) were added to a three-necked flask. Concentrated sulfuric acid or methanesulfonic acid equimolar to the ionic liquid was slowly added dropwise while stirring. After the addition was completed, the reaction was stirred at 30 °C for 6 h. After the reaction was completed, the product was automatically phase-separated. The upper layer of dichloromethane was removed by decantation, and the remaining product was washed 3 times with dichloromethane and dried under vacuum at 80 °C for 12 h to obtain a transparent and viscous hydroxyl-functionalized double-acid ionic liquid. The reaction formula is as follows:

[0113]

[0114] The structural formulas of the hydroxyl-functionalized double-acid ionic liquids are as follows:

[0115]

[0116] The characterization of the hydroxyl-functionalized double-acid ionic liquids is as follows:

[0117] IL1-1: 1 H NMR(400MHz,DMSO-d 6) δ 2.0 (s, 3H), 2.29–3.97 (m, 16H). MS (LTQ Orbitrap XL, m / z): calcd for C 9 H 19 NO 8 S 4 [M - HSO 4 + 300.04.

[0118] IL2 - 1: 1 H NMR (400 MHz, DMSO - d 6 ) δ 1.73–1.85 (m, 4H), 2.0 (s, 3H), 2.40–3.97 (m, 14H). MS (LTQ Orbitrap XL, m / z): calcd for C 10 H 21 NO 8 S 4 [M - HSO 4 + 314.06.

[0119] IL3 - 1: 1 H NMR (400 MHz, DMSO - d 6 ) δ 1.92 (s, 2H), 2.0 (s, 3H), 2.29–3.53 (m, 16H). MS (LTQ Orbitrap XL, m / z): calcd for C 10 H 21 NO 8 S 4 [M - HSO 4 + 314.06.

[0120] IL4 - 1: 1 H NMR (400 MHz, DMSO - d 6 ) δ 1.73 - 1.92 (m, 6H), 2.0 (s, 3H), 2.40–3.53 (m, 14H). MS (LTQ Orbitrap XL, m / z): calcd for C 11 H 23 NO 8 S 4 [M - HSO 4 + 328.07.

[0121] IL5 - 1: 1 H NMR (400 MHz, DMSO - d 6 ​​​​)δ1.21(s,3H),2.0(s,3H),2.29–3.39(m,14H),4.02(s,1H).MS(LTQ Orbitrap XL,m / z):calcd for C 10 H 21 NO 8 S 4 [M-HSO 4 + 314.06.

[0122] IL6-1: 1 H NMR(400MHz,DMSO-d 6 )δ1.21(s,3H),1.73–1.85(m,4H),2.0(s,3H),2.40–3.39(m,12H),4.02(s,1H).MS(LTQ Orbitrap XL,m / z):calcd for C 11 H 23 NO 8 S 4 [M-HSO 4 + 328.07.

[0123] Example 1

[0124] This example provides a method for preparing unsaturated ketones, using the loop reactor shown above, with dehydro linalool (also known as 3,7-dimethyl-6-octen-1-yn-3-ol) and 2-methoxypropene as raw materials. The reaction formula is: Figure 1

[0125]

[0126] The specific steps are as follows:

[0127] Preheated buprofezin salt ionic liquid and propargyl alcohol are mixed in a Venturi mixer 4 to obtain a mixture; then the circulation pump 7 is started to circulate the mixture among the Venturi mixer 4, the SM reactor 5, and the heat exchanger 6. An alkoxy olefin such as 2-methoxypropene c is fed from an alkoxy olefin storage tank through a feed pump 12 and preheated in a second preheater 9. After preheating, the alkoxy olefin is introduced into the SM reactor 5 and undergoes the Saucy-Marbet reaction by circulating in the SM reactor 5, the heat exchanger 6, and the Venturi mixer 4.

[0128] The buprofezin salt ionic liquid exists in the form of a solution, and the solvent is a eutectic azeotropic mixture composed of 26.5% biphenyl and 73.5% diphenyl ether by mass percentage (boiling point: 260 °C). The mass percentage concentration of the catalyst solution is 1%.​​​

[0129] Dehydrolinalool DLL, 2-methoxypropene IPM, and hydroxy-functionalized double acidic ionic liquid IL1-1 were respectively pumped into a loop reactor at a flow rate with a molar ratio of 1:3.0:1.0 %%% (reaction pressure was about 0.6 MPa, residence time was 30 min, and reaction temperature was 110 °C). Samples were taken from the sampling port and confirmed to be allenone through gas chromatography-mass spectrometry analysis. The collected solution was analyzed by gas chromatography, and the conversion rate of dehydrolinalool was 99.5% (its retention time was 6.063 min), and the selectivity of the product allenone was 98.107% (its retention time was 8.442 min). It can be seen that the reaction selectivity of the product allenone 1 is very high.

[0130] Gas chromatography test conditions: Instrument model: Thermo Trace1300; Chromatographic column: SE-30 (30 m × 0.32 mm × 0.25 μm); Column temperature: Initial temperature 45 °C, held for 4 min, then heated to 160 °C at a rate of 50 °C / min and held for 24 min; Injection port temperature: 280 °C; Detector type: FID; Detector temperature: 280 °C; Split injection, split ratio 80:1; Injection volume: 0.26 μL; H 2 Flow rate: 30 mL / min; Air flow rate: 400 mL / min; Carrier gas N 2 Flow velocity: 2 mL / min.

[0131] The obtained allenone 1 can be used for isomerization reaction to synthesize pseudoionone; or it can undergo hydrogenation reaction, etc., for the synthesis of intermediates of other organic chemicals.

[0132] Examples 2 - 9:

[0133] Basically the same as Example 1, the only difference is: changing the reaction conditions (different feed molar ratios, different temperatures, different pressures, and different residence times), specifically as shown in Table 1 below, and the reaction results are shown in Table 1 below.

[0134] Table 1

[0135]

[0136]

[0137] Examples 12 - 20:

[0138] Basically the same as Example 1, the only difference is: changing the type and dosage of the catalyst, specifically as shown in Table 2 below, and the reaction results are shown in Table 2 below.

[0139] Table 2

[0140]

[0141] Example 21:

[0142] A small-scale experiment was conducted to verify the reuse of the ionic liquid catalyst. The IL1-1 catalyst was selected. After the reaction, the reaction solution was dissolved in water, and the product was separated from the ionic liquid using phase separation technology. Then, a recycling experiment was carried out in the same manner as in Example 1. The specific results are shown in Table 3 below. It can be seen that the ionic liquid catalyst has stability and good stability after reuse:

[0143] Table 3

[0144]

[0145]

[0146] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. However, the protection scope of the present invention cannot be limited thereby. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. A thiazinone salt ionic liquid having a structure shown in the following formula: in, X - HSO4 - or CH3SO3 - ; n is 1, 2, 3 or 4; R 1 It is a C1-6 alkyl group substituted with a monohydroxy group.

2. The thiazinone salt ionic liquid according to claim 1, characterized in that: n is 1 or 2; and / or, R 1 is a C1-3 alkyl group substituted with a monohydroxyl group; preferably, R 1 It is a C1-3 straight chain alkyl group substituted with a monohydroxy group.

3. The thiazinone salt ionic liquid according to claim 1, characterized in that: R 1 Selected from 2-hydroxyethyl, 3-hydroxypropyl or 2-hydroxypropyl.

4. The thiazinone salt ionic liquid according to claim 1, characterized in that: The thiazinone salt ionic liquid is selected from the following structural formula:

5. A method for preparing the thiazinone salt ionic liquid according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: 1) With Cl-R 1 In the presence of a base and a phase transfer catalyst, a phase transfer catalytic reaction is carried out to generate 2) and In the presence of a catalyst, the reaction is carried out to produce 3) reacting with sulfuric acid or methanesulfonic acid in an organic solvent to generate the thiazinone salt ionic liquid; In each formula, n and R 1 The definition is the same as that in any one of claims 1 to 4.

6. The method for preparing the thiazinone salt ionic liquid according to claim 5, characterized in that: In step 1), the base is selected from a combination of one or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, and barium hydroxide; and / or, in step 1), the phase transfer catalyst is selected from a combination of one or more of triethylbenzylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, and 18-crown ether-6; and / or, in step 1), the temperature of the phase transfer catalytic reaction is 40 to 70° C.; and / or, in step 1), the time of the phase transfer catalytic reaction is 2 to 5 hours.

7. The method for preparing the thiazinone salt ionic liquid according to claim 5, characterized in that: In step 2), the catalyst is selected from a combination of one or more of toluene, phenol, xylene, acetonitrile, chloroform, and pyridine; and / or, in step 2), the reaction temperature is 90-130° C.; and / or, in step 2), the reaction time is 8-16 h.

8. The method for preparing the thiazinone salt ionic liquid according to claim 5, characterized in that: In step 3), the organic solvent is selected from a combination of one or more of dichloromethane, ethyl acetate, acetone, methanol, ethanol, and n-hexane; and / or, in step 3), after the reaction is completed, the reaction system is phase-separated, and the organic solvent phase is removed to obtain the thiazinone salt ionic liquid.

9. A method for preparing an unsaturated ketone, wherein the method uses propargyl alcohol and alkoxy olefin as raw materials, and undergoes a Saucy-Marbet reaction in the presence of a catalyst to produce the unsaturated ketone, characterized in that: The catalyst is the thiazinone salt ionic liquid according to any one of claims 1 to 4.

10. The method for preparing an unsaturated ketone according to claim 9, characterized in that: The molar amount of the thiazinone salt ionic liquid accounts for 0.5% to 1% of the molar amount of the propargyl alcohol; and / or the molar ratio of the alkoxy olefin to the propargyl alcohol is 2.0 to 4.0:

1.

11. The method for preparing an unsaturated ketone according to claim 9, characterized in that: The temperature of the Saucy-Marbet reaction is 80-120° C.; and / or, the time of the Saucy-Marbet reaction is 10-50 min; and / or, the pressure of the Saucy-Marbet reaction is 0.5-1.2 MPa.

12. The method for preparing an unsaturated ketone according to claim 9, characterized in that: The Saucy-Marbet reaction is carried out in a loop reactor, which comprises: Venturi mixer; SM reactor; A heat exchanger, which is used for heat exchange between the reaction system and the cooling medium; A circulation pump, which is used to circulate the reaction system between the Venturi mixer, the SM reactor and the heat exchanger; The preparation method comprises the steps of mixing the thiazinone salt ionic liquid and propargyl alcohol in the venturi mixer to obtain a mixture, and starting the circulation pump to circulate the mixture between the venturi mixer, the SM reactor and the heat exchanger; and introducing an alkoxy olefin into the SM reactor and performing the Saucy-Marbet reaction in the SM reactor, the heat exchanger and the venturi mixer in a cycle.

13. The method for preparing an unsaturated ketone according to claim 12, characterized in that: The loop reactor further comprises: A first preheater, which is used to preheat the thiazinone salt ionic liquid and propargyl alcohol and is connected to the venturi mixer; A second preheater is used for preheating the alkoxy olefin and is connected to the SM reactor.

14. The method for preparing an unsaturated ketone according to claim 13, characterized in that: The loop reactor further comprises: a catalyst storage tank, which is used to store the thiazinone salt ionic liquid and is connected to the first preheater via a feed pump; a propargyl alcohol storage tank, which is used to store the propargyl alcohol and is connected to the first preheater via a feed pump; An alkoxy olefin storage tank is used to store the alkoxy olefin and is connected to the second preheater via a feed pump.

15. The method for preparing an unsaturated ketone according to claim 12, characterized in that: The number of the heat exchanger is one or more; preferably, the number of the heat exchanger is 2-4, and more preferably, the plurality of heat exchangers are arranged in parallel; and / or the cooling medium is water.

16. The method for preparing an unsaturated ketone according to claim 12, characterized in that: The catalyst exists in the form of a catalyst solution; the boiling point of the solvent in the catalyst solution is 250-270°C.

17. The method for preparing an unsaturated ketone according to claim 16, characterized in that: The solvent is a mixture of biphenyl and biphenyl ether; preferably, the mass ratio of biphenyl to biphenyl ether is 20-30:70-80.

18. The method for preparing an unsaturated ketone according to claim 16, characterized in that: The loop reactor also includes a distillation tower, which is connected to the circulation pump through a valve. When the conversion rate of the propargyl alcohol is controlled to reach above 99.0% by the preparation method, the reaction system enters the distillation tower through the valve, the unsaturated ketone is extracted from the top of the tower, and the catalyst solution is extracted from the bottom of the tower and circulated to the first preheater.

19. The method for preparing an unsaturated ketone according to claim 12, characterized in that: The circulation ratio of the Saucy-Marbet reaction in the loop reactor is 1-20.

20. The method for preparing an unsaturated ketone according to claim 1, characterized in that: The propargyl alcohol is selected from one or more combinations of dehydrolinalool, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, dehydronerolidol, tetrahydrodehydronerolidol, and dehydroisophytol; and / or the alkoxy olefin is selected from one or more combinations of 2-methoxypropylene, 2-ethoxypropylene, 2-propoxypropylene, and 2-isopropoxypropylene.

21. A method for preparing an α,γ-unsaturated diene ketone, the method comprising the step of isomerizing allenone to produce the α,γ-unsaturated diene ketone, characterized in that: The preparation method further comprises the step of preparing the allenone by using the preparation method of the unsaturated ketone according to any one of claims 9 to 19.

22. The loop reactor for Saucy-Marbet reaction of propargyl alcohol and alkoxy olefin according to any one of claims 12 to 15, 18 to 19.

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