CN114478408A

CN114478408A - Method for continuously synthesizing homopiperazine

Info

Publication number: CN114478408A
Application number: CN202210078261.XA
Authority: CN
Inventors: 牟新东; 王喜成; 许宏金
Original assignee: Shanghai Suntian Technology Co ltd
Current assignee: Shandong Sunda New Materials Technology Co ltd
Priority date: 2022-01-24
Filing date: 2022-01-24
Publication date: 2022-05-13
Anticipated expiration: 2042-01-24
Also published as: CN114478408B

Abstract

The invention discloses a method for synthesizing homopiperazine in one step through catalysis, which comprises the following steps: mixing the N- (beta-hydroxy) -1, 3-propane diamine solution with hydrogen or the mixture of hydrogen and ammonia gas, introducing the mixture into a continuous reactor filled with a catalyst for reaction, collecting reaction products, and separating to obtain a high piperazine product. Compared with the prior art, the method uses N- (beta-hydroxyl) -1, 3-propane diamine as a raw material, adopts a heterogeneous noble catalyst, has simple process, safety and reliability, long service life of the catalyst and stable process, and is suitable for industrial continuous production; compared with the existing reported Cu-based catalyst, the catalyst has the advantages of obvious effect and service life. The catalyst used in the invention has the advantages of easily available raw materials, simple preparation, stable activity, long service life and good catalytic effect.

Description

Method for continuously synthesizing homopiperazine

Technical Field

The invention belongs to the technical field of organic synthesis, and particularly relates to a method for continuously synthesizing homopiperazine.

Background

Homopiperazine (Homopiperazine), also known as 1, 4-diazepane or 1, 4-diaminocyclooctane, is an aza-heptacyclic compound. Homopiperazine is an important organic synthesis intermediate, the double nitrogen atom contained in it can react with many organic compounds, and it has very wide application in structural modification of chemical drugs, and is an important product starting from chemical and medical fields. The homopiperazine and the derivative thereof are not only widely applied to the fine chemical fields of antioxidants, foaming agents, emulsifiers, surfactants and the like, but also play an indispensable important role in the fields of medicines and pesticides. The homopiperazine can be used for synthesizing fasudil hydrochloride, homopiperazine hydrochloride, cyclizine, carbamazepine, quinolone, clorazine and other medicaments. Drugs such as quinoline and isoquinoline derivatives, quinolone derivatives, thiazolidine carboxylic acid amide derivatives and the like which are obtained by modifying homopiperazine as a raw material, and drugs for synthesizing pyridazine amine, nitroxyl-containing benzylamine derivatives, water-soluble azoles and the like have good effects on treating cardiovascular diseases, inflammations, allergies and central nervous system disorders. The research on the correlation between the activity and the structure of the medicine shows that the existence of the high piperazine group can obviously improve the activity of the related medicine, so the research on the high piperazine series compounds is more and more emphasized. The market demand of the homopiperazine is increased day by day, and the homopiperazine has considerable application prospect.

Homopiperazine can be synthesized by amine compounds such as ethylenediamine, N- (2-cyanoethyl) ethylenediamine, propylenediamine, N- (2-aminoethyl) -1, 3-propylenediamine, N- (beta-hydroxy) -1, 3-propylenediamine, and the like, and the synthetic routes and methods mainly include the following:

the method comprises the following steps of (I) taking ethylene diamine as a raw material: in 1954, S.M. Mcel et al used ethylenediamine as the starting material, protected the amino group with benzenesulfonyl chloride, then cyclized with 1, 3-dibromopropane, then deprotected with concentrated sulfuric acid or hydrobromic acid, and finally basified to give homopiperazine (J.Am.chem.Soc.,1954,76, 1126-1137).

The method is the most mainstream production method of the high piperazine at home at present, but has the following obvious defects: firstly, the used protecting reagent benzenesulfonyl chloride cannot be recycled, and at least two tons of solid wastes are generated when one ton of high piperazine product is produced; secondly, concentrated sulfuric acid or hydrofluoric acid with high corrosivity and high pollution is required to be used during deprotection, so that the equipment corrosivity is high, and the physical health of operators is greatly damaged. The process has the advantages of more three wastes and high production risk coefficient, and is not suitable for the requirements of modern industrial production. In 2006, Wangdalin et al improved the above method, and used p-toluenesulfonyl chloride with lower toxicity as an amino protection reagent to synthesize homopiperazine through 3 steps of sulfonylation, cyclization and desulfonation, and the total yield reached 78% (chemical reagent, 2006,28 (5): 311-. The synthetic route is as follows:

however, the method still has the same defects as the former method, and not only the three wastes are more, but also the reaction temperature is higher during the deprotection, and the danger is larger. Chinese patent CN10669974A discloses a method, in which ethyl trifluoroacetate is used as an amino group protecting reagent, and under the action of an organic solvent, the ethyl trifluoroacetate is firstly reacted with ethylenediamine to generate acetyl ethylenediamine ditrifluoroacetate; then reacting with a 1, 3-disubstituted propane compound to obtain bistrifluoroacetyl homopiperazine under the action of a solvent and a catalyst; then reacting with a saturated solution of hydrogen chloride and ethanol to obtain homopiperazine dihydrochloride, and recovering ethyl trifluoroacetate; finally, under the action of a solvent and a catalyst, the piperazine is prepared through an alkalization reaction, and the yield can reach 83.05%. The synthetic route is as follows:

the method solves the problem that the protective reagent cannot be recycled and regenerated, avoids high-corrosivity concentrated sulfuric acid and hydrofluoric acid, improves environmental protection and safety, but has the disadvantages of complex operation, long reaction time, high recycling requirement, only small batch intermittent production and incapability of completely meeting the industrial production requirement.

Secondly, N- (2-cyanoethyl) ethylenediamine is used as a raw material: in 1961, Poppludoef et al hydrogenated and cyclized N- (2-cyanoethyl) ethylenediamine as the starting material and Gederler G-49A as the catalyst to obtain homopiperazine in a yield of only 32.4% (J.org.chem.,1961,26(1): 131-. The synthetic route is as follows:

the process has the advantages of short reaction time, less by-products, large pressure, explosive gas as a medium, difficult control of operation, strict equipment requirement and lower yield.

And (III) taking propylene diamine as a raw material: in 2006, japanese patent JP2006306790 discloses a method for obtaining high piperazine with a yield of 23.5% by using 1, 3-propanediamine and ethylene glycol as raw materials and performing high-pressure hydrogenation in a fixed bed reactor by using NKHD24 as a catalyst. The synthetic route is as follows:

the raw materials of the method are simple and easy to obtain, but the reaction temperature is as high as 150-400 ℃, and the yield is only 21%.

(IV) taking N- (2-aminoethyl) -1, 3-propane diamine as a raw material: in 1962, Ichikawa F.Y et al reported two routes for synthesizing homopiperazine from N- (2' -aminoethyl) propanediamine (US 3040029):

the first is to remove one molecule of ammonia through the intramolecular cyclization of imine to form unsaturated compound, and the unsaturated compound is reduced into homopiperazine through catalytic hydrogenation, the reaction temperature is 130 ℃, the reaction pressure is 4.5 MPa-6.6 MPa, and the yield is 32%. The synthetic route is as follows:

the second is that imine forms an amino-substituted homopiperazine compound through cyclization, and then the homopiperazine is formed through hydrogenolysis of the amino-substituted homopiperazine compound. The catalyst is Raney nickel, and the yield is only 4.8%. The synthetic route is as follows:

the two methods have simple process and low cost, but have high raw material consumption, more byproducts, low yield and serious equipment corrosion.

Taking N- (beta-hydroxy) -1, 3-propane diamine as a raw material: 2006In the year, the chemical industry institute of Tianjin university develops a new process for synthesizing homopiperazine by taking N- (beta-hydroxy) -1, 3-propane diamine as a raw material, and the catalyst is Cu-Cr-Ba-Al₂O₃The conversion rate of raw materials is more than 93.2 percent, and the high piperazine yield can reach 90 percent (Reaction Kinetics and Catalysis letters.2006,89(2): 201-. The synthetic route is as follows:

however, the synthetic route reported in the literature seems to be irreproducible and the effectiveness thereof cannot be demonstrated.

The existing high piperazine synthesis process has many problems, so that the development of a new method for industrial production of high piperazine, which has the advantages of simple synthesis route, environmental protection, safety, reliability, low cost, high quality and high yield, is of great significance.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide an industrial production method which has the advantages of simple route, safety, environmental protection, simple and convenient operation and low cost and can continuously synthesize homopiperazine, the method generates catalytic amination reaction of intramolecular alcohol in N- (beta-hydroxyl) -1, 3-propane diamine solution under the action of heterogeneous noble metal catalyst, and the homopiperazine is separated after the reaction.

According to one aspect of the present invention, it is an object of the present invention to provide a process for the synthesis of homopiperazine by catalytic one-step, which is carried out as follows:

mixing the N- (beta-hydroxyl) -1, 3-propane diamine solution with hydrogen or the mixed gas of the hydrogen and ammonia gas, introducing the mixture into a continuous reactor filled with a catalyst for reaction, collecting reaction products, and separating to obtain a high piperazine product.

Preferably, the continuous reactor used in the synthesis process according to the invention can be any reactor capable of carrying out continuous reactions, including but not limited to fixed bed reactors, fluidized bed reactors, moving bed reactors, trickle bed reactors, microchannel reactors; preferably a fixed bed reactor; further preferred is a single tube or tubular fixed bed reactor to remove the heat of reaction quickly and reduce the polymerization reaction.

Preferably, the N- (β -hydroxy) -1, 3-propanediamine solution is a solution in which N- (β -hydroxy) -1, 3-propanediamine is dissolved in a solvent selected from at least one of water, methanol, ethanol, propanol, butanol, tetrahydrofuran, 1, 4-dioxane, and at a mass percentage concentration of 5 wt% to 30 wt%; more preferably, it may be at least one of water, methanol, tetrahydrofuran, 1, 4-dioxane; most preferably water.

Further preferably, the concentration of the N- (β -hydroxy) -1, 3-propanediamine solution is 10 wt% to 25 wt%, more preferably 20 wt%.

When the reactor is a fixed bed reactor:

preferably, the gas pressure in the fixed bed reactor is 0.1-5.0 MPa, and further preferably 0.1-2 MPa.

Preferably, the hydrogen gas volume percentage content in the mixed gas of hydrogen gas and ammonia gas is 5% to 100%, more preferably 30% to 100%, more preferably 60% to 100%, and when the hydrogen gas volume percentage content is 100%, the hydrogen gas is pure and no ammonia gas is contained.

Preferably, the molar ratio of N- (β -hydroxy) -1, 3-propanediamine to hydrogen in the synthesis process according to the invention is preferably from 1:1 to 1:100, more preferably from 1:30 to 1:80, most preferably 1: 50.

Preferably, the empty speed ratio of the feeding in the synthetic method is 0.2-30000 h^-1More preferably 0.8 to 30 hours^-1。

Preferably, the temperature in the synthesis method is 100-400 ℃, and further preferably 150-350 ℃.

The catalyst in the synthesis method according to the invention consists of a carrier and an active component loaded on the carrier.

The active component of the catalyst consists of a main catalyst component and an auxiliary catalyst component.

The main catalyst active component is selected from at least one of simple substances of ruthenium (Ru), platinum (Pt), rhodium (Rh) and gold (Au) or oxides thereof, preferably one of simple substances of platinum or ruthenium and oxides thereof, and most preferably ruthenium.

The promoter component is selected from at least one of the simple substances of chromium, rhenium, barium, iron, manganese, cerium and lanthanum or oxides thereof. Preferably at least one of the elements of chromium, rhenium, barium, iron, manganese and oxides thereof, and most preferably rhenium or manganese and oxides thereof.

Preferably, the catalyst comprises the following components in percentage by mass: the content of the main catalyst component accounts for 2-30% of the catalyst, the content of the auxiliary catalyst component accounts for 0.5-20% of the catalyst, and the content of the carrier accounts for 50-98.5% of the catalyst.

Preferably, the carrier can be one or more of activated carbon, zirconia, magnesia, titania, alumina, molecular sieve, silica gel and diatomite; preferably, the support is selected from zirconia and/or titania.

Preferably, the shape of the catalyst can be granular, rod-shaped, spherical, chip-shaped, disk-shaped, circular ring-shaped, wheel-shaped or honeycomb monolithic catalyst, which can be selected according to the conditions of the reactor.

Preferably, the catalyst is in the form of particles or rods.

The preparation method of the catalyst can be a precipitation method, an impregnation method, a blending method and a sol-gel method; precipitation and impregnation are preferred.

Preferably, the preparation method of the catalyst is carried out as follows:

1) weighing the carrier components, and vacuum degassing at 150 ℃ for 12h for later use;

2) dissolving the salt of the main catalyst component in water to form a main catalyst component precursor solution, heating the main catalyst component precursor solution, adjusting the pH of the system to acidity by using an alkali solution, adding a standby carrier, and stirring and dipping;

3) dissolving the salt of the cocatalyst component in water to form a cocatalyst component precursor solution, then adding the slurry obtained in the step 2), continuously adjusting the pH of the system to be alkaline (12) by using alkali, and fully stirring, pulping and aging;

4) filtering and washing the slurry after aging until the filtrate is neutral, adding molding aid sesbania powder into the slurry, then carrying out extrusion molding on a strip extruding machine, drying at 80-120 ℃ for 6-24 hours, and then roasting at 300-600 ℃ to constant weight.

The reaction type of the method provided by the invention can be a gas-solid two-phase reaction in which the reaction materials are completely gasified, or a gas-liquid-solid three-phase reaction in which the reaction raw materials are partially gasified or not gasified, and a suitable reaction type can be selected according to the reactor, preferably, the reaction type is the gas-solid two-phase reaction, and further preferably, the gas-solid heterogeneous catalytic reaction.

Advantageous effects

Compared with the prior art, the invention has the advantages that:

the invention uses N- (beta-hydroxyl) -1, 3-propane diamine as raw material, adopts heterogeneous noble catalyst, has simple process, long service life of the catalyst and stable process, is safe and reliable, and is suitable for industrial continuous production; compared with the Cu-based catalyst reported in the prior art (Wang, H., Chen, L., Luan, D.et al.A. continuous process for the synthesis of homopterazine catalyzed by Cu-based catalysts, React kinetic catalyst Lett 89, 201-208 (2006)), the Cu-based catalyst has obvious effects and service life advantages. In the reaction of the Cu-based catalyst, Cu is easy to deactivate, even Cu particles are aggregated and grown, or polymers and the like are easy to form to block a reaction pipeline. The catalyst used in the invention has the advantages of easily available raw materials, simple preparation, stable activity, long service life and good catalytic effect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a TEM photograph of the catalyst prepared in preparation example 1;

FIG. 2 is a transmission electron micrograph of a catalyst prepared in preparation example 2;

FIG. 3 is a graph showing the effect of catalytic evaluation of the catalyst of example 1.

Detailed Description

Hereinafter, the present invention will be described in detail. Before the description is made, it should be understood that the terms used in the present specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the present invention on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Accordingly, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the invention, so it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the invention.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to specific embodiments. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the application of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the concepts of the present invention.

The one-step synthesis method of homopiperazine according to the present invention, the principle of which is represented by the following reaction formula 1, comprises the following steps:

wherein:

step 1), removing one molecule of hydrogen from hydroxyl in raw material N- (beta-hydroxyl) -1, 3-propane diamine under the action of a multifunctional catalyst of dehydrogenation-hydrogenation to generate aldehyde group;

step 2), performing a reaction between amino and aldehyde groups to close rings, and then dehydrating to form Schiff base;

and 3) finally, hydrogenating under the action of a catalyst to obtain the homopiperazine.

In the method for synthesizing homopiperazine by one step, the steps are sequentially carried out under the synergistic catalysis of the same catalyst, so that the continuous production of the homopiperazine can be realized.

Specifically, the one-step synthesis of homopiperazine according to the invention proceeds as follows:

1) dissolving N- (beta-hydroxy) -1, 3-propane diamine in a solvent to form a solution with the mass percentage concentration of 5 wt% to 30 wt%, wherein the solvent is selected from at least one of water, methanol, ethanol, propanol, butanol, tetrahydrofuran and 1, 4-dioxane, and preferably at least one of water, methanol, tetrahydrofuran and 1, 4-dioxane; most preferably water. The solution of the invention is overall more economical, since it allows the use of water compared to the technical routes of the prior art, without the risk of water poisoning the catalyst or side effects on the reaction.

Preferably, the mass percent concentration of the N- (beta-hydroxy) -1, 3-propanediamine solution is 10 wt% to 25 wt%, more preferably 20 wt%. When the mass percent concentration of the N- (beta-hydroxy) -1, 3-propane diamine solution is less than 5 wt%, the reaction efficiency is low and the method is not economical; if the mass percent concentration of the N- (beta-hydroxy) -1, 3-propane diamine solution is more than 30 wt%, although the reaction efficiency can be improved, the side reaction products are obviously increased, and the total yield is reduced.

2) Mixing the N- (beta-hydroxy) -1, 3-propane diamine solution with pure hydrogen or a mixed gas of hydrogen and ammonia gas, introducing the mixture into a continuous fixed bed reactor filled with a catalyst for reaction, collecting a reaction product, and separating to obtain a high piperazine product. The gas pressure in the fixed bed reactor is maintained at 0.1 to 5.0MPa, and preferably 0.1 to 2 MPa.

Wherein the hydrogen gas volume percentage content in the mixed gas of hydrogen gas and ammonia gas is 5% to 100%, more preferably 30% to 100%, more preferably 60% to 100%, when the hydrogen gas volume percentage content is 100%, the hydrogen gas is pure hydrogen gas, and no ammonia gas is contained. The ammonia gas is added to prevent the deamination of the raw materials under the action of the catalyst.

Because N- (beta-hydroxy) -1, 3-propane diamine is easy to generate hydrogenolysis to generate deamination reaction or intermolecular N-N coupling reaction under the action of a catalyst and hydrogen, the addition of ammonia gas can not only effectively inhibit the deamination reaction in the process, but also greatly reduce the intermolecular N-N coupling reaction. But at the same time, the addition of ammonia gas partially reduces the reaction efficiency, so that it is very important to reasonably control the ammonia gas addition ratio.

Preferably, the molar ratio of the N- (β -hydroxy) -1, 3-propanediamine to hydrogen is preferably from 1:1 to 1:100, more preferably from 1:30 to 1:80, most preferably 1: 50. In general, since there is a large phase interface due to the gas-liquid reaction, the amount of hydrogen should be kept in a suitable excess amount in order to increase the reaction of the material, but if the amount is too large, excessive hydrogenation reduction is easily caused, which increases the content of by-products, and at the same time, the pressure of the reactor is too high, which affects the safe operation of the equipment, so it is very important to keep a suitable ratio of hydrogen and a suitable pressure range of the reactor.

The catalyst in the one-step synthesis method according to the invention is a supported catalyst, wherein the active component consists of a main catalyst component and a cocatalyst component.

Preferably, the shape of the catalyst can be granular, rod-shaped, spherical, chip-shaped, disk-shaped, circular ring-shaped, wheel-shaped or honeycomb monolithic catalyst, which can be reasonably selected according to the conditions of the reactor used.

Preferably, the catalyst is in the form of particles or rods.

Preferably, the preparation method of the catalyst is carried out as follows: dissolving catalyst active component precursor metal hydrochloride or nitrate (selected from ruthenium (Ru), platinum (Pt) and rhodium (Rh)) or sulfate or nitrate of gold (Au) in water or alcohol to form a solution, dropwise adding an alkaline solution at 20-80 ℃ in the forward direction to deposit and precipitate the active component, when the pH value of the system reaches 2-5, adding carrier powder, then adding a second active component metal solution (such as ammonium perrhenate, manganese acetate and the like), controlling the concentration of the second active component solution to be 0.05-0.5mol/L, continuously titrating the alkaline solution until the pH value of the system reaches 12-13, fully stirring, pulping and aging for 3-12 hours, filtering and washing the slurry until the filtrate becomes neutral, adding a forming assistant pseudo-boehmite or sesbania powder into the slurry, extruding the slurry into 3mm round bars on a bar extruder, cutting the round bars into 3-5mm lengths, drying the prepared material at 105 ℃ for 12 hours, transferring the dried material to 500 ℃ and roasting to constant weight, then transferring the mixture to a catalyst evaluation fixed bed for evaluation, and before introducing raw materials, firstly putting the catalyst in H₂Reducing at 350-550 ℃ for 6 hours under flowing to obtain the catalyst.

It is to be noted that, whether the raw materials for preparing the catalyst are selected from nitrates, organic salts of sulfates or other metal double salts, the final existing form of the active components of the catalyst is simple substance or oxide.

It should also be noted that when a micro-flow reactor is used, the active ingredients of the catalyst can be directly supported on the tube walls of the reaction channels.

The following examples are given by way of illustration of embodiments of the invention and are not to be construed as limiting the invention, as those skilled in the art will appreciate that various modifications may be made without departing from the spirit and scope of the invention. Unless otherwise specified, reagents and equipment used in the following examples are commercially available products.

Examples

Preparation example 15 wt% Ru-1 wt% ReOx/TiO₂The preparation of (1):

100g of TiO2(P25, Woundplastoxi, Germany) were weighed out at 150 ℃ for 12h in vacuo and kept ready for use. Dissolving 13.5g of ruthenium trichloride hydrate (Ru content 37.5%, national drug group chemical reagent Co., Ltd.) in 50ml of water to form a catalyst precursor solution, heating the catalyst precursor solution to 40 ℃, adding 10% ammonia water in a forward dropwise manner to make the pH value of the system reach 2.5, adding catalyst carrier powder, and stirring and soaking for 3 hours; dissolving 1.5g ammonium perrhenate (purchased from Beijing Bailingwei science and technology Co., Ltd.) in 20ml water, adding the slurry, continuously titrating 10% ammonia water until the pH value of the system is 12, fully stirring, pulping and aging for 12 hours, filtering and washing the slurry after aging until the filtrate is neutral, adding the forming aid sesbania powder into the slurry, extruding the slurry into 3mm round strips on a strip extruding machine, cutting the round strips into 3-5mm lengths, drying the prepared material at 105 ℃ for 12 hours, then transferring the dried material to 500 ℃ for roasting to constant weight, then transferring the material to a catalyst evaluation fixed bed for evaluation, and before introducing the raw material, firstly, adding the catalyst to H, then, adding the catalyst to H, and then, adding the catalyst to a solvent, and then, adding the solvent, stirring, drying, and then, drying, and then, drying, and carrying out the catalyst to obtain the product₂Reduced at 450 ℃ for 6 hours under flow, and the catalyst prepared according to this method is labeled 5 wt% Ru-1 wt% ReOx/TiO₂(the loading is expressed herein as the percentage of Ru or Re metal used on the catalyst support, as follows.) FIG. 1 is a TEM image of the catalyst prepared in this preparation example.

Preparation example 25 wt% Ru-10 wt% ReOx/TiO₂Preparation of

The procedure was as in catalyst preparation example 1, except that the amount of ammonium perrhenate was increased to 15 g. The catalyst prepared according to this method is labeled 5 wt% Ru-10 wt% ReOx/TiO₂。

Preparation example 3: 5 wt% Ru-10 wt% MnOx/TiO₂Preparation of

100g of TiO are weighed₂(P25, Woundengdiosai, Germany) vacuum at 150 ℃Degassing for 12h and reserving. Dissolving 13.5g of ruthenium trichloride hydrate (Ru content 37.5%, national drug group chemical reagent Co., Ltd.) in 50ml of water to form a catalyst precursor solution, heating the catalyst precursor solution to 50 ℃, adding 10% ammonia water in a forward dropwise manner to make the pH value of the system reach 2.5, adding catalyst carrier powder, and stirring and soaking for 3 hours; 36g of manganese (II) chloride tetrahydrate are dissolved in 200ml of water, the above slurry is added and titration of 10% Na is continued₂CO₃The solution is stirred fully until the pH value of the system is 12, pulping and aging are carried out for 12 hours, the slurry is filtered and washed after aging until the filtrate is neutral, the molding aid sesbania powder is added into the slurry, then the slurry is extruded into 3mm round strips on a strip extruding machine and is cut into 3-5mm lengths, the prepared material is dried for 12 hours at 105 ℃, then is transferred to 500 ℃ to be roasted to constant weight, and then is transferred to a catalyst evaluation fixed bed for evaluation, before the raw material is introduced, the catalyst is firstly put into a H-shaped reactor to be evaluated₂Reduced at 350 ℃ for 6 hours under flow, and the catalyst prepared according to this method is labeled 5 wt% Ru-10 wt% MnO_x/TiO₂(the loading is expressed as the percentage of the Ru or Mn metal used by weight of the catalyst support). FIG. 2 is a TEM photograph of the catalyst prepared in this preparation example.

Preparation example 4: 5 wt% Ru-10 wt% ReO_x/ZrO₂Preparation of

The preparation method is the same as that of catalyst preparation example 2, except that TiO is added₂Conversion of support to ZrO₂. In which ZrO of high specific surface area₂Preparation was performed by the precipitation-aging method reported in CHUAH (G, JAENICKE S. the prediction of high surface area antibiotic in fluorescence of prediction agent and differentiation [ J]Applied Catal systems A, General,1997,163(12):261 and 273). Measuring ZrOCl with a certain volume concentration of 0.4mol/L₂And transferring the solution into a dropping funnel with scales, fixing the dropping funnel on an iron support, measuring a certain amount of ammonia water, and diluting the ammonia water by three times to form an ammonia solution with the concentration of about 5 mol/L. Under continuous stirring, the zirconium oxychloride solution is slowly added dropwise into the ammonia water solution, and the pH value of the solution changes: from 11.91 (start of titration) to 9.52 (end of titration), stirring was stopped; transferring the obtained white precipitate into 100 deg.C oil bath, aging for 60 hr, cooling to room temperature, and suction-filtering and washing with deionized waterWashed to Cl free^-(with 0.1M AgNO)₃Checking), the eluate is neutral; and drying the filter cake in a 110 ℃ forced air drying oven for 24 hours to obtain a white solid. Namely Zr (OH)₄·xH₂And O. The obtained precursor Zr (OH)₄·xH₂O is roasted for 5 hours at 500 ℃ to prepare ZrO with high specific surface area₂. Nitrogen adsorption test shows that the synthesized ZrO₂The BET specific surface area is up to 223m²(ii) in terms of/g. The catalyst prepared according to this method was labeled 5 wt% Ru-10 wt% ReO_x/ZrO₂

Example 1

The reactor is a self-made single-tube fixed bed reactor, the inner diameter of the reaction tube is 15mm, and the length of the reaction tube is 500 mm. 30g of a catalyst having a composition of 5 wt% Ru-1 wt% ReOx/TiO was charged into a reaction tube₂(preparation example 1). The packing height of the catalyst layer was about 200 mm. The catalyst was made active by reduction at 280 ℃ for 5 hours. After the reduction, the temperature was lowered and maintained at 210 ℃ and 30% hydrogen/ammonia gas was introduced at a flow rate of 40mL/min and a flow rate of 2mL/min (space velocity of the reaction raw material: 1.2 h)^-1) Introducing a solution of 20 wt% N- (beta-hydroxy) -1, 3-propane diamine in 1, 4-dioxane, wherein the solvent is dioxane. And (3) enabling a reaction product to flow out from the lower end of the fixed bed reactor, cooling, and carrying out gas-liquid separation to obtain a product mixed solution, wherein the mixed solution is subjected to gas chromatography analysis.

The analysis was performed on a gas chromatograph of Shimadzu 2010PLUS equipped with an autosampler AOC-20. Quantitative conditions of gas chromatography: the chromatographic column adopts HP-5(25m multiplied by 0.25mm multiplied by 0.2 mu m); the vaporization chamber temperature is 280 ℃ (split ratio is 1: 50); the temperature of the FID detector is 300 ℃; keeping the temperature of the column incubator at 60 ℃ for 1min, then increasing the temperature to 270 ℃ at the speed of 20 ℃/min and keeping the temperature for 10 min; gas circuit control: n is a radical of₂ 1mL/min(column)，H₂30mL/min, 300mL/min air, and blowing N229 mL/min.

The result shows that the conversion rate of the raw material is 100%, the selectivity of the high piperazine is 84.2%, and long-term operation data shows that the activity of the catalyst is basically kept unchanged and the selectivity of the product is kept above 80% within 400 hours of operation of the catalyst. Fig. 3 is a graph of the catalytic evaluation effect of the catalyst of this example, and it can be seen from the graph that the conversion rate and the selectivity of the synthesis method according to the present invention using the catalyst prepared in preparation example 1 are kept at high levels in the process of running for nearly 500 hours, and the synthesis method has good industrial application value.

Example 2

30g of catalyst is filled in a single-tube fixed bed reactor with the inner diameter of 15mm and the length of 500mm, and the catalyst composition is 5wt percent of Ru to 10wt percent of ReOx/TiO₂(preparation example 2). The packing height of the catalyst layer was about 200 mm. The catalyst in the reactor is kept in a hydrogen state and hydrogen flows through the reactor, and the temperature is kept at 350 ℃ for 5 hours of reduction, so that the catalyst has activity. After the reduction is finished, the temperature is reduced to 260 ℃, and the pressure of hydrogen is increased to 1.5 MPa. At a flow rate of 2mL/min (space velocity of the reaction raw material: 1.2 h)^-1) Introducing 20 wt% N- (beta-hydroxy) -1, 3-propane diamine solution with water as solvent. The reaction product flows out from the lower end of the fixed bed reactor, and a product mixed solution is obtained after cooling and gas-liquid separation, and the mixed solution is analyzed by gas chromatography: the conversion of the starting material was 96.8% and the high piperazine selectivity was 42.1%.

Example 3: the procedure is as in example 2, except that the reaction solvent is changed to tetrahydrofuran, and the other conditions are maintained, the conversion of the starting material is 98% and the selectivity to homopiperazine is 69.5%.

Example 4: the procedure is as in example 2, except that the reaction solvent is replaced by 1, 4-dioxane, and the feed rate is adjusted to 1.2ml/min (space velocity of the reaction feed: 0.72 h)^-1) And other conditions are kept unchanged, the conversion rate of the raw material is 100 percent, and the selectivity of the high piperazine is 88.9 percent.

Example 5

26g of a catalyst having a composition of 5 wt% Ru to 10 wt% MnO was packed in a single-tube fixed bed reactor having an inner diameter of 15mm and a length of 500mm_x/TiO₂(preparation example 3). The packing height of the catalyst layer was about 200 mm. The catalyst in the reactor is kept in a hydrogen state and hydrogen flows through the reactor, and the temperature is maintained at 350 ℃ for reduction for 5 hours, so that the catalyst has activity. After the reduction is finished, the temperature is reduced to 220 ℃, and the hydrogen pressure is increased to 2 MPa. At the speed of 2mL/min (space velocity of reaction raw material: 1.2 h)^-1) A20 wt% solution of N- (. beta. -hydroxy) -1, 3-propanediamine in methanol was introduced at the flow rate of (2). And (3) enabling a reaction product to flow out from the lower end of the fixed bed reactor, cooling, and performing gas-liquid separation to obtain a product mixed solution, wherein the mixed solution is subjected to gas chromatography analysis: the conversion of the raw material was 97.9% and the selectivity for high piperazine was 58.3%.

Example 6

31g of a catalyst consisting of 5 wt% Ru to 10 wt% ReO was packed in a single-tube fixed bed reactor having an inner diameter of 15mm and a length of 500mm_x/ZrO₂(preparation example 4). The packing height of the catalyst layer was about 200 mm. The catalyst in the reactor is kept in a hydrogen state and hydrogen flows through the reactor, and the temperature is maintained at 350 ℃ for reduction for 5 hours, so that the catalyst has activity. After the reduction is finished, the temperature is reduced to 250 ℃, and the pressure of hydrogen is increased to 1.5 MPa. At the speed of 2mL/min (space velocity of reaction raw material: 1.2 h)^-1) A 20 wt% solution of N- (. beta. -hydroxy) -1, 3-propanediamine in 1, 4-dioxane as solvent was introduced at the flow rate of (2). The reaction product flows out from the lower end of the fixed bed reactor, and a product mixed solution is obtained after cooling and gas-liquid separation, and the mixed solution is analyzed by gas chromatography: the conversion of the starting material was 98.8% and the high piperazine selectivity was 56.4%.

Comparative example 1:

Cu-Cr-Ba-Al was prepared according to the precipitation method reported by Wang et Al (Wang, H., Chen, L., Luan, D.et Al. A continuous process for the synthesis of Cu-based catalysts, React kinetic Cat 89, 201-208 (2006))₂O₃The catalyst is extruded into strips with the length of 2-3mm by a strip extruder and is reduced for 4 hours at 350 ℃ in a hydrogen atmosphere before use. 20 wt% of N- (. beta. -hydroxy) -1, 3-propanediamine in 1, 4-dioxane was pumped at a rate of 2mL/min (space velocity of the reaction feed: 1.2 h) using a plunger pump^-1) The conversion rate of the raw materials is 100 percent and the selectivity of the high piperazine is 36.5 percent after the materials are fed and discharged through chromatographic detection, and the product is obtainedThe product contained more black tarry substances. After the fixed bed runs for 45 hours, the system pressure is increased, and feeding cannot be carried out, which indicates that more serious carbon deposition or raw material polymerization phenomenon exists.

Comparative example 2: Cu-Cr catalyst:

the commercial Cu-Cr catalyst is loaded into a fixed bed and reduced for 4h at 350 ℃ in a hydrogen atmosphere. A20 wt% solution of N- (. beta. -hydroxy) -1, 3-propanediamine in 1, 4-dioxane was pumped with a plunger pump at 0.5mL/min (space velocity of the reaction feed: 0.3 h)^-1) Feeding at a speed, and discharging through chromatographic detection, wherein the conversion rate of the raw material is 100%, the selectivity of the high piperazine is 45%, and the product also contains more black tarry substances. The feed rate was adjusted to 2ml/min, the feed conversion was 42% and the high piperazine selectivity was 75%.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A process for the synthesis of homopiperazine in one catalytic step, which is carried out by:

mixing the N- (beta-hydroxy) -1, 3-propane diamine solution with hydrogen or the mixture of hydrogen and ammonia gas, introducing the mixture into a continuous reactor filled with a catalyst for reaction, collecting reaction products, and separating to obtain a high piperazine product.

2. The one-step process for the synthesis of homopiperazine according to claim 1, characterized in that the continuous reactor comprises a fixed bed reactor, a fluidized bed reactor, a moving bed reactor, a trickle bed reactor, a microchannel reactor; preferably a fixed bed reactor; more preferably a single tube or a tubular fixed bed reactor.

3. The one-step synthesis method of homopiperazine according to claim 1, characterized in that the N- (β -hydroxy) -1, 3-propanediamine solution is a solution of N- (β -hydroxy) -1, 3-propanediamine dissolved in a solvent selected from at least one of water, methanol, ethanol, propanol, butanol, tetrahydrofuran, 1, 4-dioxane and having a mass percent concentration of 5 wt% to 30 wt%; more preferably at least one of water, methanol, tetrahydrofuran and 1, 4-dioxane; most preferably water.

4. The one-step synthesis method of homopiperazine according to claim 1, characterized in that the concentration of the N- (β -hydroxy) -1, 3-propanediamine solution by mass percentage is 10 wt% to 25 wt%, more preferably 20 wt%.

5. The one-step synthesis method of homopiperazine according to claim 1, characterized in that, when the reactor is a fixed bed reactor, the gas pressure in the fixed bed reactor is 0.1-5.0 MPa, preferably 0.1-2 MPa.

6. The one-step synthesis method of homopiperazine according to claim 1, characterized in that the hydrogen gas and ammonia gas mixture contains 5% to 100% by volume of hydrogen gas, more preferably 30% to 100% by volume of hydrogen gas, more preferably 60% to 100% by volume of hydrogen gas, and when the hydrogen gas content is 100% by volume, the mixture represents pure hydrogen gas and does not contain ammonia gas;

preferably, the molar ratio of the N- (β -hydroxy) -1, 3-propanediamine to hydrogen is preferably from 1:1 to 1:100, more preferably from 1:30 to 1:80, most preferably 1: 50.

7. The method for synthesizing homopiperazine according to claim 1, characterized in that the air speed ratio of the feeding material in the method for synthesizing homopiperazine is 0.2-30000 h^-1More preferably 0.8 to 30 hours^-1；

Preferably, the temperature in the one-step synthesis method of homopiperazine is 100-400 ℃, and more preferably 150-350 ℃.

8. The one-step synthesis method of homopiperazine according to claim 1, characterized in that, the reaction type is gas-solid two-phase reaction of complete gasification of reaction materials, or gas-liquid-solid three-phase reaction of partial gasification or non-gasification of reaction raw materials; the preferred type of reaction is a gas-solid two-phase reaction, and more preferably a gas-solid heterogeneous catalytic reaction.

9. The one-step synthesis method of homopiperazine according to claim 1, characterized in that, the catalyst is composed of a carrier and an active component loaded on the carrier;

the active component of the catalyst consists of a main catalyst component and an auxiliary catalyst component;

the main catalyst active component is selected from at least one of simple substances of ruthenium (Ru), platinum (Pt), rhodium (Rh) and gold (Au) or oxides thereof, preferably one of simple substances of platinum or ruthenium and oxides thereof, and most preferably ruthenium;

the promoter component is selected from at least one of the simple substances of chromium, rhenium, barium, iron, manganese, cerium and lanthanum or oxides thereof; preferably at least one of the simple substances of chromium, rhenium, barium, iron and manganese and oxides thereof, and most preferably the simple substance of rhenium or manganese and the oxide thereof;

preferably, the catalyst comprises the following components in percentage by mass: the content of the main catalyst component accounts for 2-30% of the catalyst, the content of the auxiliary catalyst component accounts for 0.5-20% of the catalyst, and the content of the carrier accounts for 50-98.5% of the catalyst;

preferably, the carrier is one or more of activated carbon, zirconia, magnesia, titania, alumina, molecular sieve, silica gel and diatomite; preferably, the support is selected from zirconia and/or titania;

preferably, the catalyst is in the shape of a granular, rod, sphere, chip, disk, ring, wheel, or honeycomb monolith catalyst; more preferably, the catalyst is in the form of particles or rods;

10. The one-step synthesis method of homopiperazine according to claim 9, characterized in that, the preparation method of the catalyst is as follows:

4) filtering and washing the slurry after aging until the filtrate is neutral, adding the molding aid sesbania powder into the slurry, then carrying out extrusion molding on a strip extrusion machine, drying at the temperature of 80-120 ℃ for 6-24 hours, and then transferring to 300-600 ℃ for roasting to constant weight.