CN118287162A - Catalyst for preparing 1, 3-dicyclopropyl-2-butene-1-one and preparation method of 1, 3-dicyclopropyl-2-butene-1-one - Google Patents

Abstract

The invention discloses a catalyst for preparing 1, 3-dicyclopropyl-2-butene-1-one and a preparation method of the 1, 3-dicyclopropyl-2-butene-1-one, wherein the catalyst comprises a carrier loaded with an active component; the preparation method comprises the steps of carrying out aldol self-condensation reaction on cyclopropanone under the catalysis of a catalyst in the presence of a water absorbent to obtain 1, 3-dicyclopropyl-2-butene-1-one, wherein the catalyst adopts rare earth oxide with moderate alkalinity to be loaded on the Al ₂O₃ carrier, the specific surface area of the carrier is large, the distribution uniformity of the catalyst in a liquid phase reaction system can be enhanced, aldol condensation reaction is promoted to occur more effectively, the water absorbent is added in the reaction process, the reaction equilibrium is pushed to move rightwards, and the purpose of improving the reaction yield is achieved.

Description

Catalyst for preparing 1, 3-dicyclopropyl-2-butene-1-one and preparation method of 1, 3-dicyclopropyl-2-butene-1-one

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a catalyst for preparing 1, 3-cyclopropyl-2-butene-1-one and a preparation method of 1, 3-cyclopropyl-2-butene-1-one.

Background

The aerospace liquid fuel is an energy source of a power system and is also a working medium of an engine. Most of active fuels come from petroleum refining and rectification, and although the sources are rich and cheap, the limitations of low density and mass heat value exist, the molecular structure cannot be changed, and the requirements of a power system on higher performance cannot be met. Therefore, it is particularly important to develop new fuel synthesis technology.

As a method for increasing the molecular weight and the density, the carbon chain growth reaction can effectively improve the fuel quality and heat value, thereby improving the fuel performance. The aldol condensation reaction is a very important means of C-C bond formation and carbon chain growth. The common raw material for synthesizing the medicine, namely the cyclopropane ketone, has a three-membered ring structure and additional tension energy, and one molecule of water is eliminated through aldol self-condensation reaction to obtain the product 1, 3-dicyclopropyl-2-butene-1-one. The product also has a cyclopropane high-energy structure, can be used for preparing liquid hydrocarbon fuel, improves key performances such as heat value, density and the like, and is an important synthetic intermediate.

The cyclopropane ketone has larger steric hindrance, and the commonly used aldol condensation reaction conditions, such as sodium hydroxide, potassium phosphate, cesium carbonate and other inorganic base catalysts, have insufficient activity and can not generate 1, 3-dicyclopropyl-2-butene-1-ketone. While superstrong alkalis such as sodium methoxide, potassium tert-butoxide, lithium diisopropylamide and the like can generate 1, 3-dicyclopropyl-2-butene-1-one, simultaneously promote the continuous Michael addition reaction of the 1, 3-dicyclopropyl-2-butene-1-one and cyclopropane ketone to generate a terpolymer and even a high polymer, and seriously reduce the selectivity of the reaction.

Since the aldol self-condensation reaction equilibrium of the ketone is severely biased to the reactant side, at least one product must be removed during the reaction to promote the forward progress of the reaction. In the prior art, a soviet union researcher uses potassium hydroxide as a catalyst and a water absorbent simultaneously, and the potassium hydroxide is heated and refluxed to prepare 1, 3-dicyclopropyl-2-butene-1-one, but the yield is only 20 percent, the selectivity is less than 40 percent, and raw materials are wasted and waste solid alkali and high polymer which are difficult to process are generated; the reaction is catalyzed by solid water absorbing agents such as aluminum tert-butoxide or calcium hydride, the yield exceeds 50 percent, but the substances absorb water, namely deteriorate, and cannot be recycled. The existing methods have the problems of low yield and selection, easy failure of the catalyst and incapability of recycling, generate a large amount of three wastes and are not beneficial to reducing the production cost.

In view of this, the present invention has been made.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, provides a catalyst for preparing 1, 3-dicyclopropyl-2-butene-1-one and a preparation method of the 1, 3-dicyclopropyl-2-butene-1-one, wherein the catalyst has higher catalytic activity, is more uniformly distributed in a liquid phase reaction system, is matched with a water absorbent added in the reaction system, pushes the reaction balance to move rightwards, improves the yield and selectivity of the reaction, does not lose the catalyst, is easy to separate after the reaction is finished, and has fewer three wastes, thereby providing a feasible scheme for large-scale industrial production.

In order to solve the technical problems, the invention adopts the basic conception of the technical scheme that:

the invention provides a catalyst for preparing 1, 3-dicyclopropyl-2-butene-1-one, which comprises a carrier and an active component supported on the carrier;

The carrier is of a porous structure Al ₂O₃, is prepared by calcining Al (NO ₃)₃·9H₂ O and has a specific surface area of 260-430 m ²/g;

the active component is selected from one or more combinations of Sc, Y, la, ce, pr, nd.

In the invention, the catalyst is a supported catalyst, and the active components exist in the form of oxides when supported on a carrier and have certain acidity and alkalinity, so that the catalyst can respectively play roles of activating ketocarbonyl and deprotonating when used as the catalyst, and effectively promote aldol condensation reaction. Meanwhile, the alkalinity of the rare earth oxide is weaker than that of alkali metal, alkaline earth metal oxide and hydroxide, and under proper reaction conditions, the product and the cyclopropane ketone can not be caused to continuously react to generate a high polymer, so that the generation of side reaction is reduced, and the aim of improving the yield is fulfilled.

The porous structure Al ₂O₃ prepared by calcining Al (NO ₃)₃·9H₂ O) is used as a carrier for loading active components, which is beneficial to increasing the specific surface area of the carrier, on one hand, enhancing the distribution uniformity of the catalyst in a liquid phase reaction system, and on the other hand, increasing the loading capacity of the active components and uniformly dispersing the active components, thereby obviously improving the catalytic performance.

In a further scheme, the carrier is prepared by calcining Al (NO ₃)₃·9H₂ O in a muffle furnace at a temperature of 400-650 ℃;

Preferably, the calcination temperature is 500 ℃.

In the scheme, the specific surface area of the carrier can reach the level of 260-430 m ²/g, the carrier can be uniformly dispersed in a liquid phase reaction system, is not easy to agglomerate and deactivate, and has longer service life. Meanwhile, higher active component loading can be achieved, the active components are easier to uniformly disperse in the carrier, and the catalytic performance is better. And the catalyst has proper acidity and alkalinity to respectively play roles of activating ketocarbonyl and deprotonating, so as to ensure that aldol condensation reaction is effectively promoted.

In a preferred embodiment, the catalyst is a powder catalyst.

As a specific implementation, the preparation method of the powder catalyst is an isovolumetric impregnation method, namely preparing corresponding metal nitrate aqueous solution according to the percentage of active components in the mass of the carrier, adding the Al ₂O₃ carrier of the powder into the metal nitrate aqueous solution at one time under vigorous stirring, returning the mixture to room temperature, drying in vacuum, heating to 400-650 ℃ in an air atmosphere by using a muffle furnace at a heating rate of 5-30 ℃/min, roasting at the temperature for a period of time, and cooling to room temperature to obtain the spherical powder catalyst.

In the scheme, the preparation method of the catalyst is simple, the catalyst can be prepared in batches for industrial amplification, and the catalyst has reasonable acid-base strength, is easy to regenerate by an air calcination method, is not easy to accumulate carbon, and has good cyclic reusability.

In a further embodiment, the active ingredient is selected from one or more combinations of Y, la, ce, pr, nd;

Preferably, the active component is selected from one or a combination of more of La, ce and Pr;

More preferably, the active component is La.

In the scheme, when the active component is Y, la, ce, pr, nd, the yield of the prepared 1, 3-dicyclopropyl-2-butene-1-one is above 85 percent, and the selectivity is above 99 percent. Wherein, when the active components are La, ce and Pr, the reaction yield can be further improved to more than 90 percent. When the active component is La, the catalyst has the strongest alkalinity and highest activity, can give consideration to the reaction yield and selectivity, and has the optimal catalytic effect.

In a further scheme, the active component accounts for 1-12% of the mass of the carrier, preferably 6-12%, and more preferably 12%.

It was found by test that when the loading of the active component (i.e., the percentage of the active component to the mass of the carrier) was limited to the above range, the reaction yield increased with the increase of the loading of the active component, but after the loading reached 12%, the increase of the loading of the active component was continued, and the reaction yield was not increased any more. Therefore, the active component preferably accounts for 12% of the mass of the carrier under the premise of ensuring higher yield and selectivity of the product.

The invention also provides a preparation method of the 1, 3-dicyclopropyl-2-butene-1-one, which comprises the following steps: under the existence of a water absorbent, the cyclopropaneketone generates aldol self-condensation reaction under the catalysis of the catalyst for preparing the 1, 3-dicyclopropyl-2-butene-1-ketone to prepare the 1, 3-dicyclopropyl-2-butene-1-ketone;

the reaction temperature of the aldol self-condensation reaction is 100-160 ℃, preferably 120-160 ℃, and more preferably 120 ℃.

According to the invention, the catalyst is used for catalyzing the cyclopropanone to generate aldol self-condensation reaction, so that 1, 3-dicyclopropyl-2-butene-1-one is prepared, and the yield and selectivity of a reaction product can be effectively improved. The catalyst adopts the coordination of the carrier with the active component with the porous structure, compared with the traditional free inorganic solid base catalyst, the catalyst has increased catalytic sites, is not easy to generate catalyst aggregation and deactivation, is easy to separate after the reaction is finished, has less three wastes and simple process, and lays a foundation for large-scale industrial production.

The reaction process is carried out in the presence of a water absorbent, and water generated by aldol self-condensation reaction of the cyclopropaneketone can react with the water absorbent, so that the water is removed from a reaction system, and the balance of aldol self-condensation reaction can be pushed to move rightwards, thereby achieving the purpose of improving the reaction yield.

In addition, in the above-defined reaction temperature, the cyclopropanone can produce aldol self-condensation reaction under the catalysis of the catalyst, but if the reaction temperature is too high, side reaction can be produced, and the reaction selectivity is reduced; if the reaction temperature is too low, the reaction is too slow, and the production efficiency is reduced.

In a further scheme, the mass of the catalyst is 1-5% of the mass of the cyclopropane ketone;

preferably, the mass of the catalyst is 3% of the mass of the cyclopropaneketone.

In the invention, when the mass of the catalyst and the mass of the cyclopropane ketone are in the above-defined range, the catalyst has good catalytic effect, can effectively reduce the generation of byproducts, and has convenient post-treatment and high production efficiency; if the catalyst is used in a larger amount, the selectivity of the product is reduced; if the catalyst is used in a small amount, the reaction time is prolonged and the production efficiency is lowered.

In a further embodiment, the water absorbing agent is acetonitrile.

Acetonitrile is a green volatile solvent with low boiling point, can be conveniently removed by atmospheric distillation, and can be recycled. In the invention, acetonitrile is selected as the water absorbent, unreacted acetonitrile is easy to remove after the reaction is finished, and the unreacted acetonitrile can be recycled, thereby being beneficial to reducing the cost.

Specifically, in the scheme, water generated by the self-condensation of the cyclopropaneketone aldol can react with acetonitrile on the surface of a catalyst to generate acetamide with high selectivity. The solubility of acetamide in water exceeds 2g/mL, and can be conveniently removed by water washing, so that the acetamide is easy to separate from a water-insoluble product of 1, 3-dicyclopropyl-2-buten-1-one. Acetamide is mainly used as an organic solvent, and can also be used as a plasticizer, a stabilizer of peroxide, a cosmetic antacid, an organofluorine pesticide antidote and the like, and has wide application. The acetamide generated after the reaction is finished is separated and collected and can be used as a byproduct for preparing 1, 3-dicyclopropyl-2-butene-1-one.

Although other nitrile solvents can also react with water, for example, butyronitrile, benzonitrile and the like have high toxicity, or some solvents have high boiling points and are not easy to separate, so acetonitrile is selected as a water absorbent.

In a preferred embodiment, the molar ratio of acetonitrile to cyclopropanone is 1.0-2.0:1, preferably 1.2:1.

In the above scheme, in order to ensure the reaction yield of preparing 1, 3-cyclopropyl-2-butene-1-one, it is necessary to ensure that acetonitrile is in excess of cyclopropanone so as to sufficiently absorb water generated by the reaction. However, too high an amount of acetonitrile dilutes the reaction system and reduces the reaction rate.

In a further embodiment, the reaction time of the aldol self-condensation reaction is 0.5 to 6 hours, preferably 3 to 4 hours, more preferably 4 hours.

In the above scheme, the reaction time is the time for which the reactants are in contact with the catalyst. Under the above-mentioned limited reaction time, the cyclopropane ketone and catalyst can be fully contacted, and the catalytic reaction can be implemented, and can not produce excessive reaction, so that the utilization rate of raw material and yield of product can be ensured, and the selectivity of product can be raised. If the reaction time is too short, the raw materials cannot be converted in time, so that the yield is too low; if the reaction time is too long, byproducts are easy to generate, the selectivity of the products is reduced, the energy consumption is increased, and the cost is increased.

In a further embodiment, the reaction pressure is 0.1MPa to 5MPa, preferably 0.1MPa to 1.2MPa.

As a specific embodiment, the reaction raw materials are filled into a reaction kettle to carry out the reaction. If the reaction pressure is too high, the pressure-bearing requirement on the inner wall material of the reaction kettle needs to be further improved, and if the pressure-bearing capacity is insufficient, potential safety hazards can be brought.

In a further embodiment, the purity of the cyclopropaneketone is not less than 98.5% and the purity of the acetonitrile is not less than 98%.

In the scheme, the raw material cyclopropaneketone has higher purity, which is favorable for smooth reaction. Too low a degree of purity can extend the reaction time and even poison the catalyst. In addition, both cyclopropanone and acetonitrile are industrial materials, and are convenient to purchase.

In a further scheme, the preparation method comprises the following steps:

adding cyclopropane ketone, water absorbent and catalyst into a reaction kettle, adjusting the temperature to the reaction temperature, and carrying out reaction at the constant temperature;

and after the reaction is finished, carrying out post-treatment on the reaction solution from which the catalyst is removed to obtain the product 1, 3-dicyclopropyl-2-butene-1-one.

In one specific embodiment, after the catalyst and the reactant are filled into the reaction kettle, N ₂ is replaced, then the reaction temperature is adjusted according to the temperature value, and after the reaction kettle is kept at a constant temperature, the reaction is kept until the reaction is finished. And then filtering and separating the catalyst, distilling the reaction liquid to remove unreacted cyclopropanone and acetonitrile, and washing to remove acetamide to obtain the 1, 3-dicyclopropyl-2-butene-1-one.

In the scheme, stirring is applied in a reaction kettle, so that the cyclopropaneketone and acetonitrile fully contact the catalyst to generate 1, 3-dicyclopropyl-2-butene-1-one and acetamide. Because the water generated by the self-condensation of the cyclopropane aldol can be removed with high efficiency, the reaction balance is continuously pushed to move rightwards, and the yield of the 1, 3-dicyclopropyl-2-butene-1-one is improved.

In a further aspect, the post-processing includes: distilling the reaction liquid by using a thorn-type rectifying column to distill out the fractions at the normal pressure of 81+/-1 ℃ and 114+/-1 ℃, adding deionized water into the residual liquid, oscillating and separating the residual liquid to discharge the lower aqueous phase liquid, and obtaining the upper organic phase which is the product of 1, 3-cyclopropyl-2-butene-1-one;

Preferably, the fractions distilled off at 81.+ -. 1 ℃ and 114.+ -. 1 ℃ under normal pressure are collected separately.

In the scheme, the distilled fractions at 81+/-1 ℃ and 114+/-1 ℃ under normal pressure in the distillation process are respectively unreacted already-reacted cyclopropane ketone, and can be collected and recycled. Adding deionized water to wash and separate the solution to obtain lower aqueous phase liquid, namely the acetamide aqueous solution.

The preparation method of the invention is used for preparing 1, 3-dicyclopropyl-2-butene-1-ketone, the reaction yield is up to 97%, and the selectivity is up to 99%.

By adopting the technical scheme, compared with the prior art, the invention has the following beneficial effects.

1. In the invention, rare earth metal is adopted to load the Al ₂O₃ with a porous structure as a catalyst for catalyzing the cyclopropanone to generate aldol self-condensation reaction to prepare the 1, 3-dicyclopropyl-2-butene-1-one, the alkaline strength is reasonable, the generation of high polymers can be avoided, and the reaction selectivity is improved.

2. According to the invention, the carrier of the catalyst is prepared by calcining Al (NO ₃)₃·9H₂ O), has a porous structure and a large specific surface area, so that on one hand, the distribution uniformity of the catalyst in a liquid phase reaction system is improved, agglomeration is not easy, the catalyst is beneficial to fully contacting cyclopropane ketone with the catalyst, the catalytic effect is ensured, and on the other hand, the loading capacity of active components can be increased and uniformly dispersed, thereby obviously improving the catalytic performance, ensuring that the catalyst is not easy to deactivate, has long service life and can effectively promote aldol condensation reaction.

3. In the invention, the water absorbent is added in the reaction system, especially acetonitrile is adopted as the water absorbent, and the acetonitrile can react with water generated by aldol self-condensation reaction to push the reaction balance to move rightwards, thereby improving the yield of the product; meanwhile, the acetamide generated by the reaction of acetonitrile and water has wide industrial application and can be conveniently recycled.

4. The process adopted in the invention has the advantages of easy separation of a reaction system, simple process, simple and convenient operation process, contribution to process amplification and low cost on the basis of improving the yield and selectivity of the product, and lays a foundation for subsequent large-scale industrial production of the product.

The following describes the embodiments of the present invention in further detail.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below, and the following examples are provided for illustrating the present invention but are not intended to limit the scope of the present invention.

Example 1

A. Preparation of the catalyst:

(1) And (3) preparing a carrier: weighing 2000g of Al (NO ₃)₃·9H₂ O carrier, loading into a corundum crucible, placing into a muffle furnace, heating to 500 ℃ at 30 ℃/min in a dry air atmosphere, preserving heat for 4 hours, cooling to room temperature to obtain 272g of white powder, namely Al ₂O₃ carrier, and taking out for later use, wherein the specific surface area of the Al ₂O₃ carrier is 282m ²/g;

(2) Dipping: weighing La (NO ₃)₃·6H₂ O102 g, dissolving in 218mL deionized water, immediately adding the solution into a beaker filled with the Al ₂O₃ carrier, carrying out ultrasonic treatment for 20min to uniformly distribute the impregnating solution on the surface of the carrier, and carrying out forced air drying at 120 ℃ for 1h to obtain a catalyst precursor;

(3) Calcining: taking out the dried catalyst precursor, loading into a corundum crucible, placing into a muffle furnace, heating to 600 ℃ at 5 ℃/min in a dry air atmosphere, preserving heat for 4 hours, cooling to room temperature, taking out the sample, weighing 310g total, and obtaining the powder catalyst of 12% La@Al ₂O₃.

B. Preparation of 1, 3-cyclopropyl-2-buten-1-one:

(1) 1.20kg of cyclopropaneketone, 703g of acetonitrile and 36g of 12% La@Al ₂O₃ powder catalyst are filled into a 2.5L reaction kettle, N ₂ is replaced for 3 times, heated to 120 ℃ and kept at the temperature, and stirred vigorously for 4 hours for reaction;

(2) Cooling to room temperature, and filtering to separate the catalyst; transferring the reaction solution into a 2.5L round bottom flask, heating and distilling, using a 300mm thorn type rectifying column, and sequentially collecting fractions at the temperature of 81+/-1 ℃ and the temperature of 114+/-1 ℃ under normal pressure to obtain unreacted acetonitrile and cyclopropanone;

(3) Transferring the residual liquid to a 2.5L separating funnel, adding 750mL of deionized water, oscillating, standing for 1h to separate liquid, discharging lower aqueous phase liquid, namely acetamide aqueous solution, and obtaining the upper organic phase of the product 1, 3-dicyclopropyl-2-butene-1-one.

Comparative example 1

Based on example 1, 12% La@Al ₂O₃ powder catalyst was replaced with granular KOH, and other preparation conditions were unchanged, and 1, 3-cyclopropyl-2-buten-1-one was prepared according to steps (1) to (3) of step B in example 1.

Comparative example 2

Based on the example 1, 12% La@Al ₂O₃ powder catalyst is replaced by powder La ₂O₃, other preparation conditions are unchanged, and 1, 3-dicyclopropyl-2-butene-1-one is prepared according to the steps (1) to (3) of the step B in the example 1.

Comparative example 3

On the basis of example 1, acetonitrile is not added in the step (1) of the step B, and other preparation conditions are unchanged, so that the 1, 3-dicyclopropyl-2-buten-1-one is prepared.

Comparative example 4

Based on example 1, the step (1) in the step A was not performed, and the Al ₂O₃ carrier in the step (2) was replaced with spherical Al ₂O₃ (40 mesh spherical, specific surface area about 180m ²/g, average pore diameter about 50 nm), and other preparation conditions were unchanged, to finally obtain 1, 3-cyclopropyl-2-butene-1-one.

Test example 1

This test example was conducted on the yield and selectivity of 1, 3-cyclopropyl-2-buten-1-one in example 1 and comparative examples 1 to 4, and the test results are shown in table 1 below.

TABLE 1

The yield of the 1, 3-dicyclopropyl-2-butene-1-one of the embodiment adopting the preparation method of the invention is as high as 97 percent, the selectivity is greater than 99 percent, which proves that the scheme of the invention effectively improves the yield and the selectivity.

The catalyst used in comparative example 1 was KOH, which was too basic, and resulted in lower yields and selectivities of 1, 3-cyclopropyl-2-buten-1-one due to the high amount of polymer formed.

In comparative example 2, powder La ₂O₃ was used as a catalyst, but the specific surface area of powder La ₂O₃ was small and easy to agglomerate, the number of catalytic sites was insufficient, and the productivity was low, although it had very high selectivity.

In comparative example 3, acetonitrile was not added, and since the equilibrium of aldol self-condensation reaction was severely deviated to the left, the equilibrium could not be pushed to the right without removing the resultant water, and thus the yield was extremely low.

In comparative example 4, spherical Al ₂O₃ was selected as the carrier in the catalyst, and the specific surface area of the spherical Al ₂O₃ was significantly lower than that of the porous structure Al ₂O₃ carrier of the present application. Because of poor dispersibility of spherical Al ₂O₃, the catalyst is found to be easy to agglomerate in the actual preparation process, so that the catalyst is not fully contacted with the reaction liquid, and the final yield is low. It was demonstrated that the above-mentioned spherical Al ₂O₃ -supported catalyst was not suitable for liquid phase reaction.

Test example 2

The test example is used for examining the influence of the active component of the catalyst on the aldol self-condensation effect of the cyclopropane. Specifically, referring to the preparation process of example 1, only the rare earth element in the nitrate in step (2) of step a was changed to change the catalyst active component, and other preparation steps and processes were the same as in example 1, to obtain examples 2 to 7.

In this test example, the yield and selectivity of the product 1, 3-cyclopropyl-2-buten-1-one were tested and the results are shown in Table 2 below.

TABLE 2

As can be seen from the data in Table 2, when the active component is Sc, Y, la, ce, pr, nd, the aldol self-condensation reaction of cyclopropanone can be catalyzed, the yield of the prepared 1, 3-dicyclopropyl-2-butene-1-one is above 76%, and the selectivity is above 99%. The rare earth oxide has proper alkalinity and acidity, and plays roles of deprotonation and activating ketocarbonyl respectively, so that the yield of the product is high; and the alkalinity is not too strong, the product can not be caused to react with the cyclopropane ketone, and the selectivity is high.

Further, when Y, la, ce, pr, nd is selected as the active ingredient, a yield of not less than 87% can be achieved; when La, ce and Pr are selected as active components, the yield of not less than 91% can be achieved; under the same conditions, when La was selected as the active ingredient, the yield was as high as 97%, with the highest yield.

Test example 3

The experimental example is used for examining the influence of the loading of the active component of the catalyst on the aldol self-condensation effect of the cyclopropane ketone. Specifically, referring to the preparation procedure of example 1, only the amount of La (NO ₃)₃·6H₂ O) in step (2) of step a was changed to change the mass percentage of the active component to the carrier, and other preparation steps and processes were the same as those of example 1, to obtain examples 8 to 13.

In this test example, the yield and selectivity of the product 1, 3-cyclopropyl-2-buten-1-one were tested, and the results are shown in Table 3 below.

TABLE 3 Table 3

As can be seen from the data in Table 3, when the active component accounts for 1 to 12 percent of the carrier by mass, the selectivity of the preparation of the 1, 3-dicyclopropyl-2-butene-1-one is more than 99 percent, and the yield is greatly improved; especially when the active component accounts for 6 to 12 percent of the mass of the carrier, the yield of the prepared 1, 3-dicyclopropyl-2-butene-1-one is higher than 80 percent. When the active component accounts for 12% of the carrier by mass, the yield of the product is up to 97% and the selectivity is up to 99%. While the yield is not further improved when the loading of the active component is continuously increased.

Therefore, on the premise of ensuring higher yield and selectivity of the product and not increasing the cost, the active component is controlled to be 12% by mass of the carrier without using excessive load. If the active component is too small in mass percentage of the carrier, the catalyst activity is insufficient, resulting in a decrease in productivity.

Test example 4

The test example is used for examining the influence of the reaction temperature on the self-condensation effect of the cyclopropanone aldol. Specifically, referring to the preparation procedure of example 1, only the reaction temperature in step B, step (1), was changed, and the other preparation steps and processes were the same as those of example 1, to obtain examples 14 to 16.

In this test example, the yield and selectivity of the product 1, 3-cyclopropyl-2-buten-1-one were tested, and the results are shown in Table 4 below.

TABLE 4 Table 4

As can be seen from the data in Table 4, the yields of 1, 3-bicyclopropyl-2-buten-1-one prepared were all above 60% at a reaction temperature of 100-160 ℃; wherein, when the reaction temperature is 120-160 ℃, the yield can reach 90% or more; especially when the reaction temperature is 120 ℃, the yield is up to 97% and the selectivity is up to 99%.

However, when the reaction temperature is 140℃or 160℃the selectivity is lower than when the reaction temperature is 120 ℃. It can be seen that if the reaction temperature is too high, a polymer is easily formed, and the reaction selectivity is lowered. The too low reaction temperature can lead to too slow reaction and lower production efficiency.

Test example 5

The test example is used for examining the influence of the catalyst dosage on the self-condensation effect of the cyclopropaneketone aldol. Specifically, referring to the preparation procedure of example 1, only the amount of catalyst added in step B, step (1), was changed, and the other preparation steps and processes were the same as in example 1, giving examples 17 to 21.

In this test example, the yield and selectivity of the product 1, 3-cyclopropyl-2-buten-1-one were tested and the results are shown in Table 5 below.

TABLE 5

As can be seen from the data in table 5, when the mass of the catalyst is 0.2% to 5% of the mass of the cyclopropaneketone, the productivity of the product is gradually improved as the mass of the catalyst is improved, but when the mass of the catalyst is more than 3% of the mass of the cyclopropaneketone, the improvement of the mass of the catalyst has no significant improvement effect on the productivity of the product, but rather the selectivity of the product is reduced.

This is because if the mass of the catalyst is too high as a percentage of the mass of cyclopropane ketone, i.e., if the catalyst is used in a large amount, the adsorption amount of the catalyst to the raw materials increases, which causes deep reaction between the raw materials and/or products to occur, generates byproducts, decreases the selectivity of preparing 1, 3-bicyclopropyl-2-buten-1-one, and is also disadvantageous for post-reaction treatment. If the mass of the catalyst is too low as in example 17, the productivity of the product is lowered, the reaction time is prolonged, and the production efficiency is lowered. Therefore, the mass of the catalyst is controlled to be 1-5%, preferably 3% of the mass of the cyclopropane ketone on the premise of ensuring that the target product can be obtained.

Test example 6

The test example was used to examine the effect of reaction time on the aldol self-condensation effect of cyclopropanone. Specifically, referring to the preparation procedure of example 1, only the stirring reaction duration in step B, step (1), was changed, and the other preparation steps and processes were the same as in example 1, resulting in examples 22 to 27.

In this test example, the yield and selectivity of the product 1, 3-cyclopropyl-2-buten-1-one were tested, and the results are shown in Table 6 below.

TABLE 6

As can be seen from the data in table 6, the yield of the product gradually increased with the extension of the reaction time, and when the reaction time reached 4 hours, the yield increased to 97%, and after the extension of the reaction time, the yield was no longer increased. If the reaction time is too short, the raw materials are not sufficiently converted, and the yield is reduced; if the reaction time is too long, the productivity cannot be further improved, but energy waste is caused, and the production efficiency is reduced. Therefore, in the present invention, the reaction time is preferably controlled to be 3 to 4 hours, and the optimal reaction time is 4 hours.

Test example 7

The test example was used to examine the effect of the water-absorbing agent species on the self-condensation effect of cyclopropanone aldol. Specifically, referring to the preparation procedure of example 1, only acetonitrile in step (1) of step B was replaced with other water absorbing agent, and other preparation steps and processes were the same as those of example 1, to obtain examples 28 to 36.

In this test example, the yield and selectivity of the product 1, 3-cyclopropyl-2-buten-1-one were tested, and the results are shown in Table 7 below.

TABLE 7

As can be seen from the data in Table 7, acetonitrile as a water absorbing agent gave higher levels of both yield and selectivity. The yield of other water absorbing agents is not higher than that of acetonitrile, and the benzonitrile and the butyronitrile are high-toxic substances, so that the water absorbing agent is not suitable for batch preparation. The aluminum isopropoxide and the titanium isopropoxide have higher cost and are not suitable for batch preparation.

Test example 8

The test example was used to examine the effect of the amount of water-absorbing agent on the self-condensation effect of cyclopropanone aldol. Specifically, referring to the preparation procedure of example 1, only the addition amount of acetonitrile in step B, step (1), was changed, and other preparation steps and processes were the same as those of example 1, to obtain examples 37 to 42.

In this test example, the yield and selectivity of the product 1, 3-cyclopropyl-2-buten-1-one were tested and the results are shown in Table 8 below.

TABLE 8

As can be seen from the data in Table 8, the yield of 1, 3-cyclopropyl-2-buten-1-one increased with increasing acetonitrile usage, not less than 85% when the molar ratio reached 1.0:1, but not more when the molar ratio of acetonitrile to cyclopropanone exceeded 1.2:1. In order to avoid material waste caused by excessive acetonitrile consumption, the molar ratio of acetonitrile to cyclopropane ketone is controlled to be 1.0-2.0:1, preferably 1.2:1.

The foregoing description is only illustrative of the preferred embodiment of the present invention, and is not to be construed as limiting the invention, but is to be construed as limiting the invention to any and all simple modifications, equivalent variations and adaptations of the embodiments described above, which are within the scope of the invention, may be made by those skilled in the art without departing from the scope of the invention.

Claims (10)

1. A catalyst for preparing 1, 3-cyclopropyl-2-buten-1-one, characterized by comprising a carrier, and an active component supported on the carrier;

The carrier is of a porous structure Al ₂O₃, is prepared by calcining Al (NO ₃)₃·9H₂ O and has a specific surface area of 260-430 m ²/g;

The active component is selected from one element or a combination of elements in Sc, Y, la, ce, pr, nd.

2. The catalyst for the preparation of 1, 3-cyclopropyl-2-buten-1-one according to claim 1, wherein the support is prepared by calcination of Al (NO ₃)₃·9H₂ O in a muffle furnace at a temperature of 400-650 ℃;

Preferably, the calcination temperature is 500 ℃.

3. The catalyst for preparing 1, 3-dicyclopropyl-2-buten-1-one according to claim 1 or 2, wherein the active component is one element or a combination of elements selected from Y, la, ce, pr, nd;

preferably, the active component is selected from one element or a combination of a plurality of elements in La, ce and Pr;

More preferably, the active component is La.

4. A catalyst for the preparation of 1, 3-cyclopropyl-2-buten-1-one according to any one of claims 1-3, characterised in that the active component comprises 1% to 12% by mass of the support, preferably 6% to 12% by mass, more preferably 12% by mass.

5. A process for the preparation of 1, 3-cyclopropyl-2-buten-1-one, comprising: in the presence of a water absorbent, the cyclopropaneketone undergoes aldol self-condensation reaction under the catalysis of the catalyst for preparing the 1, 3-cyclopropyl-2-butene-1-one according to any one of claims 1 to 4 to prepare the 1, 3-cyclopropyl-2-butene-1-one;

the reaction temperature of the aldol self-condensation reaction is 100-160 ℃, preferably 120-160 ℃, and more preferably 120 ℃.

6. The method for producing 1, 3-cyclopropyl-2-buten-1-one according to claim 5, wherein the mass of the catalyst is 1% to 5% of the mass of cyclopropaneketone;

preferably, the mass of the catalyst is 3% of the mass of the cyclopropaneketone.

7. The method for producing 1, 3-cyclopropyl-2-buten-1-one according to claim 5 or 6, wherein the water absorbing agent is acetonitrile;

Preferably, the molar ratio of acetonitrile to cyclopropanone is 1.0-2.0:1, preferably 1.2:1.

8. The process for the preparation of 1, 3-cyclopropyl-2-buten-1-one according to any one of claims 5-7, wherein the aldol self-condensation reaction takes a reaction time of 0.5-6 h, preferably 3-4 h, more preferably 4h.

9. The process for the preparation of 1, 3-cyclopropyl-2-buten-1-one according to any one of claims 5-8, comprising the steps of:

adding cyclopropane ketone, water absorbent and catalyst into a reaction kettle, adjusting the temperature to the reaction temperature, and carrying out reaction at the constant temperature;

and after the reaction is finished, carrying out post-treatment on the reaction solution from which the catalyst is removed to obtain the product 1, 3-dicyclopropyl-2-butene-1-one.

10. The process for the preparation of 1, 3-cyclopropyl-2-buten-1-one according to claim 9, wherein the post-treatment comprises: distilling the reaction liquid by using a thorn-type rectifying column to distill out the fractions at the normal pressure of 81+/-1 ℃ and 114+/-1 ℃, adding deionized water into the residual liquid, oscillating and separating the residual liquid to discharge the lower aqueous phase liquid, and obtaining the upper organic phase which is the product of 1, 3-cyclopropyl-2-butene-1-one;

Preferably, the fractions distilled off at 81.+ -. 1 ℃ and 114.+ -. 1 ℃ under normal pressure are collected separately.