JP2001151733A - Method for producing n,n-dimethyl-n-alkylamine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an N,N-dimethyl-N-alkylamine of a high purity in a high yield. SOLUTION: This method for producing the N,N-dimethyl-N-alkylamine is provided by heating a higher alcohol and dimethylamine (a) in the presence of a catalyst of copper-a 4th period transition metal element (except for Cr) which may contain the 8th group platinum group element, (b) under an atmospheric pressure or 9.8 MPa, (c) at 100-250 deg.C in a reaction system, (d) introducing dimethylamine and hydrogen into the reaction system and removing the produced water to the outside of the system, (e) setting the amount of dimethylamine in the exhausted gas discharged to the outside of the reaction system after removing the produced water as 0.5-50 vol.%, (based on the exhaust gas) (f) also stopping the introduction of dimethylamine gas into the reaction system at a time point that the molar ratio of the higher alcohol/N-methyl-N-alkyl or alkenylamine produced as byproducts becomes 1-1.5 and reacting while continuing the introduction of hydrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to N, N-dimethyl-
The present invention relates to a method for producing N-alkylamine.

[0002] Aliphatic amines derived from beef tallow, coconut oil, palm oil and the like are important intermediates in the domestic and industrial fields. In particular, N, N-dimethyl-N-alkylamine is derived from a quaternary ammonium salt and the like, and is used in a wide range of applications such as a fabric softener, an antistatic agent, and a rinse base.

[0003]

2. Description of the Related Art N, N
As a method for producing -dimethyl-N-alkylamine, there is known a method in which a higher alcohol and dimethylamine are directly aminated in the presence of an amination catalyst (JP-A-61-1586).
No. 5, JP-A-62-149646, etc.). However, in these methods, N-methyl-N-alkylamine which is a reaction by-product is present in the product, and the quality and yield of N, N-dimethyl-N-alkylamine are reduced. Therefore, as a method of reducing N-methyl-N-alkylamine, a method of reducing the amount of exhausted excess dimethylamine gas has been performed. However, even with this method, reduction of N-methyl-N-alkylamine is not possible. Was enough.

The problem to be solved by the present invention is to reduce N-methyl-N-alkylamine as a reaction by-product,
An object of the present invention is to provide a method for producing a high-quality N, N-dimethyl-N-alkylamine with high yield.

[0005]

Means for Solving the Problems The present inventors have found that the above problems can be solved by reacting a higher alcohol with dimethylamine under specific conditions.

That is, the present invention relates to a method of reacting a higher alcohol with dimethylamine under the conditions satisfying all of the following (a) to (f) to form an N, N-dimethyl-N-alkyl or alkenylamine. Provide a recipe. Condition (a) The reaction is carried out in the presence of a copper-fourth transition metal element (excluding Cr) catalyst which may contain a Group 8 platinum group element. (b) The reaction is performed at a pressure of a reaction system (hereinafter, referred to as a reaction system) between the higher alcohol and dimethylamine at atmospheric pressure to 9.8 MPa. (c) The reaction is carried out at a temperature of the reaction system of 100 ° C to 250 ° C. (d) Dimethylamine and hydrogen are introduced into the reaction system, and the reaction is performed while removing water produced by the reaction outside the reaction system. (e) Gas excluding generated water exhausted to the outside of the reaction system (hereinafter, referred to as
The reaction is carried out while the amount of dimethylamine in the exhaust gas is 0.5 to 50% by volume (to the exhaust gas). (f) When the molar ratio of higher alcohol and N-methyl-N-alkyl or alkenylamine by-produced in the reaction system becomes higher alcohol / N-methyl-N-alkyl or alkenylamine = 1 to 1.5, The introduction of dimethylamine gas into the reaction system is stopped, and the reaction is carried out while continuing the introduction of hydrogen.

The catalyst used in the present invention is a catalyst comprising a copper-fourth transition metal element (excluding Cr) which may contain a Group 8 platinum group element. Here, the fourth period transition metal element is preferably nickel, cobalt,
One or more selected from zinc, particularly preferably zinc. The Group 8 platinum group element is preferably at least one selected from platinum, palladium, and ruthenium, and particularly preferably palladium or ruthenium.

In the catalyst of the present invention, the weight ratio of metal atoms is copper / the fourth transition metal element (excluding Cr) / eighth.
Platinum group elements = 0.1 to 10/1/0 to 0.5 are preferred, and N, N-
Efficient production of dimethyl-N-alkyl or alkenylamine is not achieved.

Various forms can be selected for the catalyst according to the present invention. That is, in the present invention, two or three components of copper and the fourth-period transition metal element (except for Cr) or copper and the fourth-period transition metal element (except for Cr) and the Group 8 platinum group element are used. When present in the reaction system as a catalyst composition, the effect of the interaction between these components is exhibited only for the first time, and these compositions have an essential catalytic function,
In the reaction between higher alcohol, dimethylamine and hydrogen, catalytic activity is first manifested by an activation operation. Therefore, the difference between the form of the metal before the activation operation and the state in the system after the activation operation is not particularly limited in the present invention, and copper and the fourth period transition metal element (however, Cr ) Or a form in which the catalytic action of copper, the fourth transition metal element (except for Cr) and the platinum group VIII element is exerted.

Accordingly, the forms of the metals suitable for the method of the present invention are 1) those metals or their oxides or hydroxides and the like, which are dispersed in a reaction medium such as a mixture thereof; A mixture of those on each of which a copper, a fourth period transition metal element (except for Cr) and a Group 8 platinum group element are supported, or copper or a fourth period transition metal element (but excluding Cr) , 2 of the group 8 platinum group elements
Or a form in which three components are uniformly supported on the same carrier and dispersed in a reaction medium. 3) An aliphatic carboxylate of these metals or a complex stabilized by a suitable ligand In the form of a metal colloid in the reaction medium to form a homogeneous system, 4) in the form of dispersion in the reaction medium as in 1) to 2), and in the reaction medium as in 3) In any case, such as a mixture with the one having a uniform form in the above, or a dispersed form before the activation operation and a uniform form after the activation operation, etc., which is the essence of the present invention, 2 to 3 It suffices that the component metal exhibits a catalytic action by the activation operation. In the method of the present invention, a more preferable form of the catalyst is to stably support the catalyst metal, that is, to immobilize the active surface, and to uniformly support these component metals on a suitable carrier from the viewpoint of durability against catalyst poisoning substances. What was done is good.

When the carrier of the present invention supports two or three components of copper, the fourth period transition metal element (excluding Cr), and a platinum group element of Group VIII, a suitable carrier is a general catalyst carrier. What is used, for example, alumina, silica alumina, magnesia, titania, diatomaceous earth, silica, activated carbon, natural and artificial zeolites and the like can be used. The amount of the catalyst metal supported on the carrier can be arbitrarily determined, but is usually in the range of 5 to 70% by weight (based on the carrier).

Various methods for supporting these two or three component metals on the carrier surface can also be selected. in this case,
As the form of the catalyst raw material metal, copper, a fourth-period transition metal element (excluding Cr), oxides, hydroxides or various metal salts of a Group VIII platinum group element can be used. For example,
Copper, the fourth period transition metal element (except for Cr), chloride, sulfate, nitrate, acetate, aliphatic carboxylate of the Group 8 platinum group element, or a metal complex thereof, for example, copper,
Fourth transition metal elements (excluding Cr), acetylacetone complexes and dimethylglyoxime complexes of platinum group 8 elements, and carbonyl complexes, amine complexes, phosphine complexes and the like for the group 8 platinum group elements. Can be used. In addition, as a method of supporting on a carrier using these raw material species, for example, copper, a fourth period transition metal element (excluding Cr), and a carrier in a suitable salt solution of a Group 8 platinum group element are used. And then thoroughly impregnated, and then dried and fired. The carrier was thoroughly mixed with an aqueous solution of copper, a fourth transition metal element (excluding Cr), and an appropriate salt of a Group VIII platinum group element. Thereafter, an alkali aqueous solution such as sodium carbonate, sodium hydroxide, or aqueous ammonia is added to precipitate a metal salt on the carrier, or, in a carrier slurry, copper, a fourth transition metal element (excluding Cr), An aqueous solution of an appropriate salt of a platinum group element of Group VIII and an aqueous solution of an alkali such as sodium carbonate, sodium hydroxide or aqueous ammonia are simultaneously added so that the slurry has a constant pH (eg, pH 7), and the metal salt is precipitated on the carrier. Dry・ After firing, copper-fourth transition metal element (excluding Cr) catalyst or copper-fourth transition metal element
A periodic transition metal element (excluding Cr) -Group 8 platinum group element catalyst is prepared.

Further, only copper or only copper and the fourth period transition metal element (except for Cr) are supported on a carrier by such a method, and before carrying out the reaction, the copper of the Group VIII platinum group element is supported. It is also effective to add a substance, an aliphatic carboxylate, or a complex to combine copper with a fourth-period transition metal element (excluding Cr) and a Group VIII platinum group element. More preferably, the catalyst form is such that two or three components are uniformly supported on the same carrier. In the present invention, the copper, the fourth period transition metal element (except for Cr), and the second group 8 platinum group elements
Or three components are essentially essential.

The operation for activating the catalyst in the present invention includes a reduction operation using a reducing agent such as hydrogen gas, formalin, sodium borohydride or the like. In the present invention, the amount of the catalyst used is 0.1 to 10% by weight (based on higher alcohol).

The raw material higher alcohol used in the present invention is a straight or branched chain saturated or unsaturated aliphatic alcohol having 8 to 36 carbon atoms, such as octyl alcohol, lauryl alcohol, myristyl alcohol, stearyl alcohol, and the like. Behenyl alcohol, oleyl alcohol and the like, and mixed alcohols thereof, and alcohols having a branched chain, for example, fine oxocol 180, 180N (manufactured by Nissan Chemical Industries, Ltd.), Diadol 18G
(Manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) and Dovanol 231 (manufactured by Mitsubishi Yuka Co., Ltd.).

In the present invention, it is necessary to carry out the reaction while introducing hydrogen into the reaction system and removing water generated in the reaction outside the reaction system. The method of removing water from the reaction system may be intermittent or continuous.

In the present invention, a catalyst which has been separately reduced in advance with hydrogen gas or the like may be used, but the catalyst before reduction is put into a reactor together with a higher alcohol which is a reaction raw material, and the reaction is carried out while introducing hydrogen gas. The reduction may be performed by raising the temperature to the temperature. The amount of hydrogen to be introduced is 1 to 100 cm ³ / hr with respect to 1 g of higher alcohol used as a raw material.
More preferably, it is 10 to 50 cm ³ / hr.

In the present invention, the amount of dimethylamine in a gas (hereinafter referred to as an exhaust gas) excluding produced water exhausted to the outside of the reaction system is 0.5 to 50% by volume (to the exhaust gas),
Preferably 5 to 30% by volume, particularly preferably 10 to 30% by volume
Is important, otherwise the desired object of the present invention cannot be achieved.

Further, in the present invention, it is necessary to carry out the reaction at a pressure in the reaction system from atmospheric pressure to 9.8 MPa and a temperature in the reaction system from 100 ° C. to 250 ° C. If the pressure and temperature are outside the above ranges, the object of the present invention cannot be achieved.

Further, in the present invention, the molar ratio of higher alcohol to N-methyl-N-alkyl or alkenylamine by-produced in the reaction system is higher alcohol /
N-methyl-N-alkyl or alkenylamine =
When the pressure becomes 1 to 1.5, it is necessary to stop the introduction of dimethylamine gas into the reaction system and perform an operation while continuing the introduction of hydrogen. Without this, N, N-dimethyl-N-alkyl or alkenylamine cannot be obtained with high purity and high yield.

An example of a preferred embodiment of the method of the present invention will be described. A higher alcohol as a raw material and a catalyst are charged into a reaction vessel equipped with a tube for introducing hydrogen or nitrogen and a rectification column. The catalyst can be charged in any amount, but is usually in the range of 0.1 to 10% by weight based on the charged alcohol.
When performing catalytic reduction in the reaction system, the inside of the reaction system is replaced with nitrogen gas, and then the temperature is raised to a reduction temperature while introducing hydrogen, and this temperature is maintained for 0.5 to 3 hours. Reduction is usually 160
Perform at ~ 250 ° C. After the catalyst is reduced, the reaction temperature and pressure are set to predetermined values. The reaction temperature is from 100 to 250 ° C., and the reaction pressure is from atmospheric pressure to 9.8 MPa. Thereafter, hydrogen is introduced at a constant flow rate. The amount of hydrogen introduced is 1 to 1 g of higher alcohol.
100100 cm ³ / hr.

Next, dimethylamine is introduced to start the reaction. Dimethylamine is introduced in such a manner that the amount of dimethylamine in the exhaust gas is 5 to 50% by volume. The reaction was followed by gas chromatography, and the molar ratio of the higher alcohol as a raw material to the by-produced N-methyl-N-alkyl or alkenylamine was changed to higher alcohol / N-
Methyl-N-alkyl or alkenylamine = 1 to 1
At 1.5, the introduction of dimethylamine was stopped and only hydrogen was introduced, and the point at which N-methyl-N-alkyl or alkenylamine disappeared was taken as the reaction end point. After the completion of the reaction, the catalyst was removed by filtration and purified by distillation to obtain N, N-
This gives dimethyl-N-alkyl or alkenylamine.

[0023]

EXAMPLES The preparation methods of the catalysts used in the examples are summarized below. <Preparation of Catalyst> A copper-nickel catalyst (catalyst A), a copper-nickel-ruthenium catalyst (catalyst B) and a copper-zinc-ruthenium catalyst (catalyst C) supported on a synthetic zeolite were prepared as follows.

(1) Catalyst A A synthetic zeolite was charged into a one liter flask, and then copper nitrate and nickel nitrate were mixed at a weight ratio of each metal atom of Cu: Ni =
The mixture was dissolved in water so as to have a ratio of 4: 1, and the temperature was raised while stirring. At 90 ° C., a 10% aqueous solution of Na ₂ CO ₃ was gradually added dropwise. After aging for 1 hour, the precipitate was filtered, washed with water, dried at 100 ° C for 10 hours, and calcined at 600 ° C for 3 hours. The supported amount of the obtained metal oxide on the carrier is 50% by weight.

(2) Catalyst B Titania is charged into a 1 liter flask, and then copper nitrate, nickel nitrate and ruthenium chloride are added so that the weight ratio of each metal atom is Cu: Ni: Ru = 5: 1: 0.02. It was dissolved in water and heated with stirring. At 90 ° C., a 10% aqueous solution of Na ₂ CO ₃ was gradually added dropwise. After aging for 1 hour, the precipitate was filtered, washed with water, dried at 100 ° C for 10 hours, and calcined at 600 ° C for 3 hours.
The supported amount of the obtained metal oxide on the carrier is 50% by weight.

(3) Catalyst C A synthetic zeolite is charged into a 1 liter flask, and then copper nitrate, zinc nitrate and ruthenium chloride are mixed so that the weight ratio of each metal atom is Cu: Zn: Ru = 8: 2: 0.01. Was dissolved in water and heated with stirring. At 90 ° C., a 10% aqueous solution of Na ₂ CO ₃ was gradually added dropwise. After aging for 1 hour, the precipitate was filtered, washed with water, dried at 100 ° C. for 9 hours, and calcined at 600 ° C. for 1 hour. The supported amount of the obtained metal oxide on the carrier is 50% by weight.

Examples 1-3, Comparative Example 1 A 2-liter separable flask was charged with 1200 g of stearyl alcohol (Kalcohl-80, manufactured by Kao Corporation) and 6 g of catalyst A, B or C (0.5% by weight of the starting alcohol). The system was replaced with nitrogen while stirring, and the temperature was raised. 100 ℃
Was reached, hydrogen gas was blown into the system at a flow rate of 20 L / hr using a flow meter, and kept at 180 ° C. for 0.5 hour to activate the reduction of the catalyst. Thereafter, a dimethylamine gas was introduced at this temperature so that dimethylamine in the exhaust gas became 20% by volume, and the reaction was started. The reaction pressure is normal pressure,
Water generated by the reaction was continuously removed from the rectification column to the outside of the system. During the reaction, the amount of dimethylamine in the exhaust gas was controlled so as to be 5 to 30%. After that, the reaction was traced by gas chromatography,
When the conversion of the alcohol is 95% (the molar ratio of stearyl alcohol / N-methylstearylamine at this time =
In 1.1), the introduction of dimethylamine gas was stopped, and only hydrogen was introduced for about one hour (this introduction of only hydrogen is hereinafter referred to as hydrogen treatment). Thereafter, the mixture was cooled to 100 ° C. under a nitrogen atmosphere, and the catalyst was removed by filtration. The filtrate is vacuumed at 0.67 kPa
And the composition was determined. The conversion of alcohol and the composition of the product after the reaction were analyzed by gas chromatography.

As Comparative Example 1, a catalyst A was used and reacted up to an alcohol conversion rate of 99% without performing a hydrogen treatment, followed by cooling and catalyst filtration. The results after distillation are shown in Table 1.

[0029]

[Table 1]

As a result, it is understood that the production method according to the present invention can produce N, N-dimethyl-N-alkyl or alkenylamine of high purity and high quality in high yield.

[0031]

According to the production method of the present invention, by-product N
-Methyl-N-alkyl or alkenylamine can be reduced, and N, N-dimethyl-N-alkyl or alkenylamine of high purity and high quality can be obtained in high yield.

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Claims (4)

[Claims] 1. A higher alcohol and dimethylamine are reacted under the conditions satisfying all of the following (a) to (f):
A method for producing N, N-dimethyl-N-alkyl or alkenylamine. Condition (a) The reaction is carried out in the presence of a copper-fourth transition metal element (excluding Cr) catalyst which may contain a Group 8 platinum group element. (b) The reaction is performed at a pressure of a reaction system (hereinafter, referred to as a reaction system) between the higher alcohol and dimethylamine at atmospheric pressure to 9.8 MPa. (c) The reaction is carried out at a temperature of the reaction system of 100 ° C to 250 ° C. (d) Dimethylamine and hydrogen are introduced into the reaction system, and the reaction is performed while removing water produced by the reaction outside the reaction system. (e) Gas excluding generated water exhausted to the outside of the reaction system (hereinafter, referred to as
The reaction is carried out while the amount of dimethylamine in the exhaust gas is 0.5 to 50% by volume (to the exhaust gas). (f) When the molar ratio of higher alcohol and N-methyl-N-alkyl or alkenylamine by-produced in the reaction system becomes higher alcohol / N-methyl-N-alkyl or alkenylamine = 1 to 1.5, The introduction of dimethylamine gas into the reaction system is stopped, and the reaction is carried out while continuing the introduction of hydrogen. 2. The catalyst of the condition (a) is such that the weight ratio of metal atoms to copper / the fourth period transition metal element (excluding Cr) / Group 8 platinum group element = 0.1 to 10/1/0. 2. A process for producing N, N-dimethyl-N-alkyl or alkenylamine according to claim 1, which is a catalyst of from 0.5 to 0.5. 3. The fourth period transition metal element is at least one selected from nickel, cobalt and zinc,
The N, N group according to claim 1 or 2, wherein the platinum group element is at least one selected from platinum, ruthenium and palladium.
A method for producing N-dimethyl-N-alkyl or alkenylamine. 4. The N, N-dimethyl-form according to claim 1, wherein the amount of hydrogen introduced into the reaction system is 1 to 100 cm ³ / hr based on 1 g of the higher alcohol used as a raw material. N
-Preparation of alkyl or alkenyl amines.