JPH02202855A - Production of secondary amine - Google Patents

Abstract

PURPOSE:To obtain a secondary amine in high yield by reacting an alcohol or aldehyde with a primary amine in the presence of a catalyst consisting of copper-group VIII platinum group element-alkali or alkaline earth metal element while removing formed water. CONSTITUTION:An alcohol or aldehyde is reacted with a primary amine in the presence of a catalyst consisting of three components of copper-group VIII platinum group element (Pt, Pd, Ru or Rh)-alkali or alkaline earth metal (Li, Na, K, Rb, Cs, Mg, Ca, Sr or Ba) at 150-250 deg.C under atmospheric pressure or <=100atm pressure applied thereto while removing water formed by the reaction to afford the objective substance. The catalyst composition is (1:0.0001)-(1:0.1) molar ratio of the copper to the platinum group element and 0.001-1 molar ratio of the alkali or alkaline earth metal based on the total amount of the copper and platinum group element. The aliphatic secondary amine is useful as an intermediate for rust preventing agents, surfactants, germicides, dyeing assistants for fiber, softening bases, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a corresponding secondary amine by reacting an alcohol or aldehyde with a primary amine.

Aliphatic secondary amines are used as rust inhibitors, surfactants, bactericides,
As a dyeing aid for fibers and as an intermediate such as a soft base,
It is an industrially important substance.

[Conventional technology]

BACKGROUND ART Conventionally, methods have been known for producing corresponding secondary amines by reacting alcohols or aldehydes with primary amines. For example, JP-A-62-149648 (
There is a report on a copper-nisochelium-platinum group element catalyst). This is an excellent method and is also versatile.

However, this method also does not work when reacting highly reactive linear alcohols or linear aldehydes with primary amines.
It has the disadvantage of producing many side reaction products and reducing selectivity. Further, the copper-platinum group element catalyst, which has shown high selectivity in the production of secondary amines using linear alcohols or linear aldehydes as raw materials, is not necessarily a satisfactory method in terms of activity.

[Problem to be solved by the invention]

Therefore, catalyst properties are required that exhibit high activity and selectivity to selectively give secondary amines regardless of whether the raw alcohol is branched or linear.

[Means to solve the problem]

Therefore, as a result of intensive studies to solve these problems, the present inventors developed a new catalyst in which a tertiary component metal was added to a binary metal consisting of copper with a small amount of Group 8 platinum group element added. developed and were able to solve these problems all at once. That is, in producing a secondary amine by the reaction of an alcohol or aldehyde with a primary amine, the present inventors aimed to achieve higher activity and selectivity so that the secondary amine is selectively produced. The aim was to explore new functions and properties through intermetallic composites of copper, Group 8 platinum group elements, and various tertiary component metal species.

As a result, the present inventors found that copper and VIII as the catalyst metal composition.
Group platinum group elements and alkali metals or alkaline earth metals 3
Due to the combined effect of the component metals, we discovered a new function that shows high activity and high selectivity even in small amounts.

That is, among the Group 8 platinum group elements, especially platinum, palladium, ruthenium, and rhodium, and among the alkali metals and alkaline earth metals, lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and barium. It has been found that this compound exhibits extremely effective functions for the reaction of the present invention.

That is, the present invention uses a copper-Group 8 platinum element-alkali metal or alkaline earth metal catalyst when producing a secondary amine by reacting an alcohol or aldehyde with a primary amine. In the presence of a catalyst, the reaction is carried out at atmospheric pressure or below 100 atm (gauge pressure) at a temperature of 150°C to 250°C, while water produced by the reaction is removed continuously or intermittently from the reaction system. The present invention provides a method for producing secondary amines in high yield.

In order to obtain a high yield of secondary amine during the reaction, the reaction must be carried out in such a way that the primary amine is always present in the system in an amount greater than the consumption amount of alcohol or aldehyde per unit time. is preferred.

In other words, there is a method of continuously or intermittently adding a primary amine under certain conditions so that the amount of alcohol or aldehyde present in the system is equal to or greater than that consumed per unit time. Essentially, under the reaction conditions (reaction temperature, amount of catalyst, pressure), it is sufficient to have a primary amine present in the system in an amount greater than the amount that alcohol or aldehyde is consumed per unit time. . Although it is possible to carry out the reaction by adding the primary amine in an amount less than this amount (for example, adding it continuously in small amounts), it is necessary to is not desirable.

In the reaction using the catalyst of the present invention, the activity and selectivity of the catalyst are excellent, so even if there is an excess of primary amine in the reaction system, its decomposition is unlikely to occur, and the generated secondary amine It exhibits high selectivity in that the reaction between amines and alcohols or aldehydes is suppressed.

In terms of reaction conditions, a pressurized system of 100 kg/cm"G or higher is also possible, but atmospheric pressure to 100 kg/cm"
2G is sufficient to achieve the purpose.

In addition, the copper-Group 8 platinum group element-alkali metal or alkaline earth metal catalyst has excellent durability and has the characteristic that there is almost no decrease in catalyst activity even if it is collected and reused several to more than ten times. There is.

The catalyst of the present invention exhibits extremely high activity and selectivity compared to conventional catalysts, so it is possible to react at low temperatures and at normal pressure, reducing the amount of catalyst required and improving reaction selectivity. As a result, high-yield and high-quality secondary amines can be obtained from branched aliphatic alcohols or aldehydes, from which conventional techniques have not been able to obtain the corresponding secondary amines in high yields. became possible to manufacture. Also, -
It has become possible to produce corresponding secondary amines in extremely high yields even from polyhydric alcohols and linear alcohols, which are difficult to produce due to the yield and quality of secondary amines due to the tendency of side reactions in boat fishing.

In the catalyst used in the present invention, the ratio of copper to platinum group elements and alkali metals or alkaline earth metals in the catalyst metal composition used can be set arbitrarily, but the amount of platinum group elements added to copper is 0. A range (molar ratio) of 0001 to 0.1 is preferred. Further, the amount of the alkali metal or alkaline earth metal element added to the total of copper and platinum group elements is preferably in the range of 0.001 to 1 (molar ratio),
More preferably, it is 0.01 to 1.

The three components of the catalyst metal composition are copper, a platinum group element, and an alkali metal or alkaline earth metal element, but the catalyst suitable for the present invention can be selected from various forms.

That is, in the present invention, the three components of copper, a platinum group element, and an alkali metal or alkaline earth metal element are used as a catalyst composition.
When present in the reaction system, the effect of the interaction between these three components is exhibited for the first time, and this three-component composition has an essential catalytic function, and in making alcohol and amine react, Catalytic activity is first expressed by reducing each metal component in a hydrogen atmosphere. Therefore, the difference in the form of the metal before the reduction operation and the state in the system after the reduction operation is not particularly limited in the present invention. Any form may be used as long as the interaction between group elements and alkali metals or alkaline earth metals is exhibited.

Therefore, the forms of metals that are compatible with the method of the present invention include: 1) Forms that can be dispersed in the reaction medium, such as these metals, their oxides or hydroxides, and mixtures thereof; 2) Or a mixture of copper, a platinum group element, an alkali metal or an alkaline earth metal element each supported on a suitable carrier, or a mixture of copper, a platinum group element, an alkali metal or an alkaline earth metal element, 3) in a form that is uniformly supported on the same support and dispersed in the reaction medium; 3) or as aliphatic carboxylates of these metals or complexes stabilized by suitable ligands. 4) Those in the form of a metal colloid in the reaction medium and become homogeneous, 4) Those in the form of a dispersion in the reaction medium as in 1) to 2), and the reaction medium as in 3) It may be a mixture with a substance that is in a uniform form in the water, or a substance that is in a dispersed form before hydrogen reduction and becomes a uniform form after hydrogen reduction, and the essence of the present invention is that It is sufficient if the interaction between the three component metals is brought about by reduction operation in a hydrogen atmosphere.

In the method of the present invention, more preferable forms of the catalyst include stabilization of the catalyst metal, that is, immobilization of the active surface;
In addition, from the viewpoint of durability against catalyst poisoning substances, it is preferable to have these three component metals uniformly supported on a suitable carrier.

When the three component metals of the present invention, copper, platinum group elements, and alkali metals or alkaline earth metals, are supported on a carrier, suitable carriers include those commonly used as catalyst carriers, such as alumina, silica alumina, Diatomaceous earth, silica, activated carbon, natural and artificial zeolites, etc. can be used. Although the amount of catalyst metal supported on the support can be arbitrarily determined, it is usually in the range of 5 to 70%.

Various methods can be selected for supporting these three component metals on the carrier surface. In this case, as the form of the catalyst raw metal, oxides or hydroxides of copper, platinum group elements, alkali metals or alkaline earth metal elements, or various metal salts thereof can be used. For example, chlorides, sulfates, nitrates, acetate aliphatic carboxylates of copper, platinum group elements and alkali metals or alkaline earth metals, or complexes of these metals, such as acetylacetone complexes and dimethyl glycol of copper, platinum group elements. Oxime complexes and the like can also be used, as well as carbonyl complexes, amine complexes, phosphine complexes and the like for platinum group elements. When producing a catalyst by supporting on a carrier using these metal raw materials, for example, the carrier is placed in a solution of copper, a platinum group element, and an appropriate salt of an alkali metal or alkaline earth metal element, and the A method of impregnating and then drying and firing (impregnation method) and carrier
A carrier is placed in an aqueous solution of an appropriate salt of a platinum group element, such as an aqueous solution of copper nitrate and a chloride of a platinum group element, and the mixture is thoroughly mixed. Then, an alkaline aqueous solution such as sodium carbonate, sodium hydroxide, or aqueous ammonia is added to place the metal salt on the carrier. There are two methods: precipitating it in aqueous solution of an alkali metal or alkaline earth metal salt, impregnating it, and then drying and calcining it (a combination of coprecipitation method and impregnation method); Any conventionally known method may be used, such as a method of ion-exchanging copper or platinum group elements (ion-exchange method). In the case of an impregnation method or a coprecipitation method, after the metal is deposited, the metal is thoroughly washed with water, dried at around 100°C, and then calcined at 300°C to 700°C to obtain a catalyst.

More preferably, the catalyst form is such that the three components are uniformly supported on the same carrier.

The alcohol or aldehyde that is the raw material used in the present invention is a linear or branched urea having a number of 8 to 36
saturated or unsaturated aliphatic alcohols or aldehydes, such as 2-ethylhexyl alcohol, octyl alcohol, lauryl alcohol, myristyl alcohol, stearyl alcohol, behenyl alcohol, oleyl alcohol, etc. and mixed alcohols thereof, also obtained by the Ziegler process Alcohols having a branched chain such as Ziegler alcohol, oxo alcohol obtained by oxo synthesis, and Guerbet alcohol, and examples of the aldehyde include lauryl aldehyde, oxo aldehyde, and other aliphatic aldehydes corresponding to the above alcohols.

Various polyhydric alcohols can also be used.

Examples include 1,3-butanediol, 1,4-butanediol, 1.5-bentanediol, 1.6-hexanediol, and polyhydric alcohols such as diethylene glycol, triethylene glycol, and propylene glycol. Other alcohols include aromatic alcohols such as benzyl alcohol, polyoxyether alcohols such as ethylene oxide or propylene oxide adducts of aliphatic alcohols, and amino alcohols such as ethanolamine and jetanolamine.

The alcohol or aldehyde is particularly an aliphatic alcohol or aldehyde selected from saturated or unsaturated linear or branched aliphatic alcohols or aldehydes having 8 to 36 carbon atoms, and aliphatic glycols having 2 to 12 carbon atoms. is preferred. The amines to be reacted with these alcohols or aldehydes include saturated or unsaturated linear or branched aliphatic primary amines having 4 to 36 carbon atoms, such as butylamine, 2 - A wide variety of primary amines include ethylhexylamine, octylamine, laurylamine, oleylamine, stearylamine, and behenylamine.

In the present invention, the alcohol or aldehyde and the first
It is an essential requirement to take out of the reaction system the water produced by the reaction with the amine, and if the produced water is not taken out of the system, the catalyst performance of the present invention cannot be fully exhibited. That is, the catalyst activity and selectivity are reduced, and secondary amines cannot be easily obtained in high yield. Removal of water may be carried out intermittently or continuously, as long as the produced water does not exist in the reaction system for a long time and is removed as appropriate. It is desirable to remove it. Specifically, hydrogen gas can be recycled by introducing an appropriate amount of hydrogen gas into the reaction system during the reaction and condensing and separating the produced water in a condenser. It is also possible to add a suitable solvent to the reaction system and remove the produced water by azeotropic distillation with this solvent.

In the method of the present invention, a catalyst that has been reduced in advance with hydrogen gas may be used, but the catalyst before reduction is placed in a reactor together with the reaction raw material alcohol, aldehyde, or primary amine, and the hydrogen gas is Alternatively, reduction is carried out by raising the temperature to the reaction temperature while introducing a mixed gas of hydrogen gas and a small amount of gaseous amine. That is, the copper of the present invention
The Group 8 platinum group-alkali metal or alkaline earth metal element catalyst has a remarkable feature in that it has a low reduction temperature and can be reduced during the process of heating up to the reaction temperature.

Embodiments of the method of the present invention will be briefly described.

Alcohol or aldehyde as raw materials and a catalyst are charged into a reaction vessel equipped with a tube for introducing hydrogen and amine, alcohol, or aldehyde, and a condenser and separator for condensing and separating water produced by the reaction. Although the catalyst can be charged in any amount, it is usually in the range of 0.1% to 2% by weight based on the alcohol or aldehyde charged. After replacing the inside of the system with nitrogen gas, temperature rise is started without introducing hydrogen gas. The reaction temperature is usually 180-2
The reaction is carried out at a temperature of about 30°C, but temperatures outside this range can be used depending on the type of reaction. During this temperature rise, the catalyst is reduced and becomes an active catalyst. After reaching a predetermined temperature, the amine is introduced to start the reaction. Either gaseous or liquid amines can be used, and they may be introduced into the system continuously, intermittently, or all at once (in the case of liquid amines).

During the reaction, water produced is discharged from the reaction system together with gaseous substances and a small amount of oily substances, and is separated from the oily substances through a condenser and a separator. The separated oil is returned to the reactor. In addition, as a result of analyzing gaseous substances, it was found that most of these gaseous substances contained byproducts (e.g., hydrocarbons, amine byproducts generated by disproportionation of raw material amine, etc.).
It was proved that the catalyst of the present invention has high selectivity, and it was found that by using a circulator, these gaseous substances can be reused without a special purification step. By directly distilling or filtering the reaction product after the reaction is complete, the secondary amine can be obtained in extremely pure form.

The primary amine used may be equimolar to the alcohol or aldehyde, or may be in excess or in deficiency. That is, an extremely high-quality secondary amine can be obtained simply by removing unreacted primary amine in the former case, and unreacted alcohol or aldehyde in the latter case, as the first distillation fraction.

[Example] The present invention will be described in detail with reference to the following Examples and Comparative Examples, but the present invention is not limited thereto.

Application -1 and Ratio -1 to 2 A three-way catalyst of copper-platinum group element alkali metal or alkaline earth metal element supported on synthetic zeolite was prepared by coprecipitation method. After filtering the precipitate, washing with water, and drying, 500'
C. to obtain a catalyst.

Next, using this catalyst, a reaction was carried out using Guerbet alcohol as a branched chain alcohol and lauryl amine as a primary amine. For comparison, a similar reaction was carried out in the same manner using a catalyst consisting of three components: copper-nisochelone-platinum group element, and a catalyst consisting of two components: copper-platinum group element.

Add 300 g of oxo alcohol (12 to 14 carbon atoms) to 11 flasks equipped with a condenser to separate the water produced by the reaction.
3.0 g (1.0% based on alcohol) of the above-mentioned catalyst were charged, and while stirring, the inside of the system was purged with nitrogen and the temperature was started to rise.

As the oxo alcohol, Dopanol 23 (branching rate about 80%) manufactured by Mitsubishi Yuka was used.

When the temperature reaches 100℃, use a flow meter to supply hydrogen gas at 101/h.
The mixture was blown into the system at a flow rate of 1, and the temperature was raised to 190°C. At this temperature, 25% laurylamine (equimolar to alcohol)
It was introduced into the reaction system under atmospheric pressure at a flow rate of mole%/h·l mole of alcohol, and the reaction was monitored using the amine value and gas chromatography.

The results are shown in Table-1.

*Catalyst: Supported amount 50% **Others: Unreacted primary amine, alcohol, by-product 3
Grade amines, etc. ll-2 and -3 to 4 Next, the same test as in Example 1 was conducted using these three types of catalysts and changing the raw alcohol from oxo alcohol to stearyl alcohol.

The results are shown in Table-2.

In contrast, the catalyst system of the present invention (Example-1 and reaction temperature =
190℃ *Catalyst: Supported amount 50% **Others: Unreacted primary amine, alcohol, by-product 3
As a result, in the copper-platinum group element catalyst of Comparative Example 2, the reaction activity between the branched chain alcohol and the primary amine was extremely low, and the yield of the secondary amine was poor. In addition, the copper-Nisoker-platinum group element catalyst of Comparative Example 3 had low selectivity between linear alcohol and primary amine, and the yield of secondary amine was poor.

The reaction with a primary amine (having 14 to 18 carbon atoms) derived from a fatty acid was carried out in the same manner as in Example 1, and various combinations of platinum group elements and alkali metals or alkaline earth metals were used in the catalyst. Instead, we investigated its effects.

The results are shown in Table-3.

table It was found that secondary amines can be produced using this method.

On the other hand, in a system in which Fe+Cr or the like was added instead of the platinum group element, the reaction activity and secondary amine selectivity were extremely low, and it was found that the three components of the present invention are essential.

Reaction temperature: 200°C Primary amine addition: 20 mole%/h to alcohol 11 lole equimolar addition Catalyst: Cu/platinum group element/alkali metal or alkaline earth metal element -110,0110,01 (molar ratio) As a result, the three-component catalyst system of copper-platinum group element-alkali metal or alkaline earth metal element of the present invention has extremely high activity and high selectivity (after applying the catalyst of the present invention to one side). The reaction of various alcohols or aldehydes with various primary amines was carried out in the same manner as in Example-1.

The results are shown in Table 4.

Table-4 *2 Molecular weight 400 **Others: unreacted primary amine, alcohol, by-product tertiary amine, etc. Reaction temperature: 190°C, reaction time 6 hours, catalyst amount: 1% by weight vs. alcohol, primary Amine: 1.1 times the mole of alcohol/aldehyde Cu/platinum group element/alkali metal or alkaline earth metal = 110.0110.01 (molar ratio) From the above results, the copper-platinum group element-alkali of the present invention By using a metal or alkaline earth metal element catalyst, a corresponding secondary amine can be produced from a linear or branched alcohol or aldehyde or polyhydric alcohol and a primary amine with high activity and high selectivity. It turns out that it can be manufactured.

After the reaction in Example 1 was completed, the catalyst was collected and the amination reaction was repeatedly carried out under the same conditions.

The results are shown in Table-5.

*Others: unreacted primary amine, alcohol, by-product tertiary
The above results revealed that the catalyst of the present invention can be repeatedly reused.

Claims (1)

[Claims] 1. Alcohol or aldehyde and primary amine,
In the presence of a catalyst consisting of three components: copper - Group 8 platinum group element - alkali metal or alkaline earth metal, while removing the water produced by the reaction, under atmospheric pressure or under pressure of 100 atmospheres (gauge pressure) or less. , a method for producing a secondary amine, characterized in that the reaction is carried out at a temperature of 150°C to 250°C. 2. The method for producing a secondary amine according to claim 1, wherein the Group 8 platinum group element is one or more selected from platinum, palladium, ruthenium, and rhodium. 3. The alkali metal or alkaline earth metal is lithium,
2. The method for producing a secondary amine according to claim 1, wherein the amine is one or more selected from sodium, potassium, rubidium, cesium, magnesium, calcium, strontium, and barium. 4. The molar ratio of copper to the metal atom of the Group 8 platinum group element in the ternary catalyst of copper-Group 8 platinum group element-alkali metal or alkaline earth metal is 1:0.0001 to 1:0.1 and the alkali metal or alkaline earth metal has a molar ratio of metal atoms of 0 to the total of copper and Group 8 platinum group elements.
．． 4. The method for producing a secondary amine according to claim 1, wherein the secondary amine is 001 to 1. 5. A claim characterized in that, in the reaction between alcohol or aldehyde and primary amine, the reaction is carried out in such a way that the primary amine is present in the system in an amount greater than the consumption amount of alcohol or aldehyde per unit time. 1 or 2
The method for producing the secondary amine described above.