JP2014214152A - Method for producing asymmetric dialkylamine compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially suitable method for producing an asymmetric dialkylamine compound, which provides an asymmetric dialkylamine compound (a target) by a simple method without performing complicated operations in a high yield while suppressing generation of by-products as much as possible.SOLUTION: The method for producing an asymmetric dialkylamine compound comprises: (A) a step of producing a reaction mixture containing an asymmetric dialkylamine compound by mixing an arylmethylideneamine compound and an organic solvent and, thereafter, adding 0.90 to 1.20 mole of an alkylating agent to 1 mole of an arylmethylideneamine compound while maintaining the mixture at 75 to 110°C; (B) a step where water is added to the reaction mixture which is stirred, an organic layer is separated, and subsequently an aqueous layer is mixed with an aromatic hydrocarbon and a basic aqueous solution, an organic layer is separated; and (C) a step of contacting the organic layer with a molecular sieve, followed by filtration and distillation to obtain the asymmetric dialkylamine compound.

Description

  The present invention relates to a method for producing an asymmetric dialkylamine compound. Asymmetric dialkylamine compounds are useful compounds as, for example, aminoacetamide derivatives as organic pharmaceutical intermediates, organic dye raw materials, epoxy resin curing retarder raw materials, olefin polymerization catalyst raw materials, and ligands for film forming materials. (For example, see Patent Documents 1 to 4).

Conventionally, as a method for producing an asymmetric dialkylamine compound, for example,
(1) A method of producing ethylmethylamine in a yield of 81.7% by reacting an N-ethylbenzylideneamine derivative and dimethyl sulfate at 40 to 50 ° C. (see, for example, Patent Document 1),
(2) A method for producing t-butylethylamine in a yield of 77% by reacting t-butylamine and ethanol in a gas phase at 250 ° C. in the presence of copper oxide-zinc oxide (see, for example, Patent Document 5) )
It has been known.

JP-A-8-151354 JP 2005-049635 A International Publication No. 2006/129773 Japanese Patent Application No. 2011-241025 (unpublished) JP 2011-26214 A

However, in the method (1), the remaining dimethyl sulfate or methyl sulfate / sodium salt may further methylate the target amine to produce a tertiary amine as a by-product. No attention has been paid to not generating or removing them.
On the other hand, the method (2) has a problem that the reaction conditions are extremely strict and a special catalyst must be used. Therefore, the above method is not desirable as an industrial production method.
Furthermore, in the method of Patent Document 4, although an effective method for producing an asymmetric dialkylamine compound is described, a proposal for an asymmetric dialkylamine compound with higher purity (impurities reduced) has been demanded.

  The inventors of the present invention have a higher purity (impurities) by removing the monoalkyl sulfate (by-product resulting from the alkylating agent) by-produced in the reaction of the present invention from the reaction liquid at an early stage. It was recognized that this was an asymmetric dialkylamine compound with a reduced number of), and this was studied as an issue.

  An object of the present invention is to solve the above-mentioned problems and to obtain an asymmetric dialkylamine compound (target product) in a high yield while reducing the generation of by-products as much as possible without complicated operations. It is another object to provide a method for producing a suitable asymmetric dialkylamine compound.

  The subject of this invention is (A) General formula (1).

(In the formula, Ar represents an aryl group. R ¹ , R ² and R ³ represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. In addition, R ¹ , R ² and R ³ may be bonded to each other to form a ring, provided that two or more of R ¹ , R ² and R ³ do not simultaneously become hydrogen atoms.)
After mixing the arylmethylideneamine compound represented by the formula (1) with an organic solvent, 0.90 to 1.20 mol alkylating agent is added to 1 mol of the arylmethylideneamine compound while maintaining the mixture at 75 to 110 ° C. In addition, by reacting, the general formula (2)

(In the formula, R is a linear alkyl group having 1 to 6 carbon atoms, and R ¹ , R ² and R ³ are as defined above.)
A step of producing a reaction solution containing an asymmetric dialkylamine compound represented by:
(B) A step of separating the organic layer after adding and mixing water to the reaction solution, and then separating the organic layer after mixing the obtained aqueous layer, the aromatic hydrocarbon, and the basic aqueous solution; And (C) the organic layer is brought into contact with a molecular sieve and then filtered and distilled to obtain an asymmetric dialkylamine compound, which is solved by the method for producing an asymmetric dialkylamine compound.

  INDUSTRIAL APPLICABILITY According to the present invention, an industrially suitable method for producing an asymmetric dialkylamine compound that obtains an asymmetric dialkylamine compound in high yield without complicated operations can be provided.

  The reaction of the present invention comprises the following two steps.

  (A) General formula (1)

(In the formula, Ar, R ¹ , R ² and R ³ are as defined above.)
After the arylmethylideneamine compound represented by formula (1) and an organic solvent are mixed, the mixture is maintained at 75 to 110 ° C., preferably 0.90 to 1.20 mol with respect to 1 mol of the arylmethylideneamine compound. The reaction is carried out by adding an alkylating agent of general formula (2)

(In the formula, R is a linear alkyl group having 1 to 6 carbon atoms, and R ¹ , R ² and R ³ are as defined above.)
And (B) separating the organic layer after adding water to the reaction solution and mixing, and then separating the organic layer and the aromatic hydrocarbon And a step of separating the organic layer after mixing the basic aqueous solution; and (C) a step of bringing the organic layer into contact with a molecular sieve and then filtering and distilling to obtain an asymmetric dialkylamine compound.

(A) A step of producing a reaction solution containing an asymmetric dialkylamine compound (hereinafter, also referred to as step A)
The arylmethylideneamine compound used in step A of the present invention is represented by the general formula (1). In the general formula (1), Ar is an aryl group. Specifically, for example, carbon such as phenyl group, tolyl group, methoxyphenyl group, fluorophenyl group, chlorophenyl group, mesityl group, naphthyl group, anthryl group, etc. An aryl group having 6 to 14 atoms is shown, and a phenyl group and a tolyl group are preferable.

R ¹ , R ² and R ³ represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, and as a linear or branched alkyl group having 1 to 6 carbon atoms, Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group, with a methyl group and an ethyl group being preferred. These groups include various isomers, and R ¹ , R ² and R ³ may be bonded to each other to form a ring. However, two or more of R ¹ , R ² and R ³ are not simultaneously hydrogen atoms.

The group constituted by R ¹ , R ² and R ³ is preferably a secondary or tertiary group. Specifically, R ¹ , R ² and R ³ are all methyl groups. It is preferable that t-butyl group is formed, or that R ¹ is a hydrogen atom, R ² and R ³ are methyl groups, and an isopropyl group is formed. At this time, the group constituted by R ¹ , R ² and R ³ is not the same as R described later.

  The organic solvent used in Step A of the present invention is selected from the group consisting of aliphatic hydrocarbons (including alicyclic hydrocarbons), halogenated aliphatic hydrocarbons, aromatic hydrocarbons and halogenated aromatic hydrocarbons. At least one organic solvent, specifically, aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, cycloheptane; methylene chloride, chloroform, carbon tetrachloride, 1, Halogenated aliphatic hydrocarbons such as 2-dichloroethane; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; and halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene.

  The amount of the organic solvent to be used is preferably 0.10 to 0.80 mol, more preferably 0.20 to 0.50 mol, relative to 1 mol of the arylmethylideneamine compound. By setting it as this range, solidification of the reaction solution can be prevented while maintaining a high reaction rate.

  Specific examples of the alkylating agent used in Step A of the present invention include, for example, dialkyl sulfates such as dimethyl sulfate and diethyl sulfate; alkyl halides such as methyl iodide; diazoalkanes such as diazomethane; dimethyl carbonate, Examples include alkyl esters such as dimethyl acid, but dialkyl sulfate is preferably used. In addition, the alkyl group of this alkylating agent is R in the general formula (2).

  The amount of the alkylating agent to be used is preferably 0.90 to 1.20 mol, more preferably 0.95 to 1.05 mol, per 1 mol of the arylmethylideneamine compound. By setting it within this range, it is possible to facilitate the treatment of the unreacted alkylating agent and the by-product after alkylation from the reaction solution after the reaction while maintaining a high reaction rate.

  In Step A of the present invention, after the arylmethylideneamine compound and the organic solvent are mixed, the mixture is maintained at 75 to 110 ° C., and 0.90 to 1.20 relative to 1 mol of the arylmethylideneamine compound. Mole alkylating agent is added and the reaction is carried out at the same temperature (75 to 110 ° C.). The reaction pressure at that time is not particularly limited.

  The reaction solution obtained in Step A contains an asymmetric dialkylamine, but can be used as it is in the next step without any particular treatment.

  The arylmethylideneamine compound used in Step A of the present invention is represented by the general formula (3)

（式中、Ｒ^１、Ｒ^２及びＲ^３は水素原子、炭素原子数１〜６の直鎖状又は分岐状のアルキル基を示す。なお、Ｒ^１、Ｒ^２及びＲ^３は互いに結合して環を形成していても良い。但し、Ｒ^１、Ｒ^２及びＲ^３のうち２つ以上が同時に水素原子となることはない。）
で示されるモノアルキルアミンと一般式（４）

(In the formula, R ¹ , R ² and R ³ represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. In addition, R ¹ , R ² and R ³ are bonded to each other. A ring may be formed, provided that two or more of R ¹ , R ² and R ³ do not simultaneously become hydrogen atoms.)
And a general formula (4)

（式中、Ａｒはアリール基である。）
で示されるアリールアルデヒドとを反応させて得ることができる（後述の参考例１参照）。

(In the formula, Ar is an aryl group.)
It can obtain by making it react with the aryl aldehyde shown by (refer the below-mentioned reference example 1).

(B) The process of isolate | separating the organic layer containing an asymmetrical dialkylamine compound (henceforth process B)
In the step B of the present invention, the asymmetric dialkylamine compound present in the reaction solution is not impaired by the side reaction or the sequential reaction from the reaction solution obtained in the step A and is not accompanied by a by-product. This is a step of separating an organic layer containing an amine compound. The method is performed according to the flow shown by the following formula.

  Hereinafter, operations in each stage will be described in order.

  In step B of the present invention, water is first added to the reaction solution and mixed, and then the aqueous layer is separated. The amount of water used at that time is preferably 1 to 20 mol, more preferably 2 to 10 mol, per 1 mol of the arylmethylideneamine compound. By setting the amount of water within this range, the by-product resulting from the alkylating agent in the reaction solution obtained in Step A (for example, a salt of methyl sulfate when the alkylating agent is dimethyl sulfate) Decomposition proceeds promptly and separation from the organic layer is facilitated. The aqueous layer may contain a salt that does not participate in the target product.

  Next, the aqueous layer containing the target asymmetric dialkylamine compound is separated, and the separation operation can be separated by a usual method such as a separatory funnel. The obtained aqueous layer may be washed with a hydrophobic solvent as necessary. Examples of the hydrophobic solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, and cycloheptane; halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, and 1,2-dichloroethane. Aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene are used.

  Next, the aqueous layer obtained by separation, the aromatic hydrocarbon, and the basic aqueous solution are mixed. Examples of the aromatic hydrocarbon include xylene, toluene, benzene, ethylbenzene, mesitylene, styrene, and anisole. Is mentioned. Examples of the basic aqueous solution include a sodium hydroxide aqueous solution, a potassium hydroxide aqueous solution, a calcium hydroxide aqueous solution, and an ammonium hydroxide aqueous solution. In addition, these aromatic hydrocarbons may be used alone or in combination of two or more, and basic aqueous solutions may also be used alone or in combination of two or more.

  The amount of the base used in the basic aqueous solution used at that time is preferably 1.00 to 5.00 mol, more preferably 1.85 to 2.20 mol, relative to 1 mol of the arylmethylideneamine compound. . By setting the amount of the base within this range, the decomposition of the by-product caused by the alkylating agent (for example, when the alkylating agent is dimethyl sulfate, the salt of methyl sulfate) proceeds quickly, and the purpose is It is possible to prevent migration and loss of the asymmetric dialkylamine compound of the product to the aqueous layer. Furthermore, since the separation operation from the aqueous layer containing the residue of the alkylating agent that causes side reactions and sequential reactions becomes easy, loss of the asymmetric dialkylamine compound due to the reaction can be prevented.

  Moreover, the density | concentration of basic aqueous solution becomes like this. Preferably it is 15-48 mass%, More preferably, it is 25-40 mass%. By setting the concentration within this range, by-products derived from the alkylating agent (for example, a methyl sulfate salt when the alkylating agent is dimethyl sulfate) can be removed to the aqueous layer, It is possible to prevent loss of the asymmetric dialkylamine compound of the product to the aqueous layer. Furthermore, since the separation operation from the aqueous layer containing the residue of the alkylating agent that causes side reactions and sequential reactions becomes easy, loss of the asymmetric dialkylamine compound due to the reaction can be prevented.

  Next, the organic layer containing the target asymmetric dialkylamine compound is separated, and the separation operation can be separated using a usual method, for example, a separatory funnel.

(C) Step of obtaining an asymmetric dialkylamine compound (hereinafter also referred to as Step C)
Step C of the present invention is a step of obtaining an asymmetric dialkylamine compound by bringing the organic layer obtained in Step B into contact with a molecular sieve, followed by filtration and distillation.

  The molecular sieve is preferably a molecular sieve having an effective pore size of 1 to 10 mm (angstrom), more preferably at least one molecular sieve selected from the group selected from natural zeolite and synthetic zeolite, specifically For example, zeolite and molecular sieves are used.

  In this step, the organic layer can be contacted with a molecular sieve and then filtered and distilled to obtain an asymmetric dialkylamine compound.

  The distillation method can be appropriately selected depending on the melting point, boiling point, etc. of the target product. For example, by-product such as tertiary amine and water is reduced by distillation under normal pressure, reduced pressure, or increased pressure. can do. The distillation conditions are not particularly limited. However, when a compound that causes a side reaction or a sequential reaction (for example, an alkylating agent or its residue) is mixed, the distillation temperature is set to 25 to 90 ° C., for example. It is desirable to carry out in a short time under various conditions.

  An asymmetric dialkylamine can be obtained by the above step C. This is because the content ratio of the trialkylamine is less than 0.1%, the content ratio of the monoalkylamine that is a decomposition product of the raw material is less than 1.0%, and An asymmetric dialkylamine raw material composition for producing tri (asymmetric dialkylamido) aluminum having a content ratio of an alkyl alcohol as a by-product of an alkylating agent of less than 0.1% and a water content of less than 300 ppm by mass. is there.

  Examples of tri (asymmetric dialkylamido) aluminum include, for example, the general formula (5)

(In the formula, R ¹ , R ² and R ³ represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. In addition, R ¹ , R ² and R ³ are bonded to each other. A ring may be formed, provided that two or more of R ¹ , R ² and R ³ do not simultaneously become hydrogen atoms.)
The compound shown by these is mentioned.

In the general formula (5), R is a linear alkyl having 1 to 6 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. R ¹ , R ² and R ³ are hydrogen atoms, methyl groups, ethyl groups, n-propyl groups, isopropyl groups, t-butyl groups, t-pentyl groups, neopentyl groups, etc. (Wherein R, R ¹ , R ² and R ³ may be bonded to each other to form a ring, provided that R ¹ , R ² and R ³ Except when two or more of them simultaneously become hydrogen atoms). In addition, some or all of the three dialkylamide ligands may be different from each other.

  Next, the present invention will be specifically described with reference to examples, but the scope of the present invention is not limited thereto.

Reference Example 1 (Synthesis of N-benzylidene-t-butylamine)

攪拌装置、温度計及び滴下漏斗を備えた内容積２０００ｍｌのフラスコに、ベンズアルデヒド５３０．８５ｇ（５．００ｍｏｌ）を加えた。次いで、水浴下、液温を２５℃に保ちながら、ｔ−ブチルアミン３６７．５０ｇ（５．０２ｍｏｌ）を滴下した。滴下後、攪拌しながら２５℃で１５時間反応させた。反応終了後、反応混合物を分液し、得られた有機層を減圧下（２５℃、１３．３Ｐa）で２時間還流させ、Ｎ−ベンジリデン−ｔ−ブチルアミン７８８．９１ｇを得た（単離収率；９８％）。

530.85 g (5.00 mol) of benzaldehyde was added to a flask having an internal volume of 2000 ml equipped with a stirrer, a thermometer and a dropping funnel. Subsequently, 367.50 g (5.02 mol) of t-butylamine was added dropwise while keeping the liquid temperature at 25 ° C. in a water bath. After dropping, the mixture was reacted at 25 ° C. for 15 hours with stirring. After completion of the reaction, the reaction mixture was separated, and the obtained organic layer was refluxed under reduced pressure (25 ° C., 13.3 Pa) for 2 hours to obtain 788.91 g of N-benzylidene-t-butylamine (isolated product). Rate; 98%).

Example 1 (Synthesis of t-butyl (methyl) amine)

(Process A)
In an argon atmosphere, 63.96 g (0.397 mol) of N-benzylidene-t-butylamine obtained in the same manner as in Reference Example 1 was added to a 300-ml flask equipped with a stirrer, a thermometer and a dropping funnel. 14.78 g (0.139 mol) of xylene was added. Next, 50.79 g (0.403 mol) of dimethyl sulfate was gently dropped while maintaining the mixed solution at 85 to 90 ° C. After the dropping, the mixture was reacted at 85 to 90 ° C. for 4 hours while stirring.
(Process B)
After completion of the reaction, 34.75 g (1.928 mol) of water was slowly dropped while keeping the reaction solution at 85 to 90 ° C., and the reaction solution was separated at room temperature to obtain an aqueous layer. The resulting layer was washed with xylene. Next, to the flask having an internal volume of 300 ml equipped with a stirrer, a thermometer, and a dropping funnel, the previously obtained aqueous layer and 87.30 g (0.822 mol) of xylene were added, and the liquid temperature was maintained at 10 to 15 ° C. Then, 88.22 g (0.794 mol) of a 36 mass% sodium hydroxide aqueous solution was gently added dropwise, and then the reaction solution was separated.
(Process C)
42.46 g of molecular sieves was added to the separated organic layer and immersed for 48 hours. Thereafter, filtration was performed, and the obtained filtrate was distilled (68 to 71 ° C.) under normal pressure to obtain 26.64 g of t-butyl (methyl) amine (isolation yield: 77%).
In addition, the composition of the obtained t-butyl (methyl) amine is the target product t-butyl (methyl) amine, t-butyl (dimethyl) amine (byproduct), t-butylamine (raw material decomposition product). The content ratio of methanol (by-product) is 99.3: 0: 0.23: 0, the water content is 58 ppm by mass, and the amount of by-products, residual raw materials, solvent used, and water is extremely mixed. There were few.

Comparative Examples 1-2
In Example 1, the reaction and post-treatment were performed in the same manner as in Example 1 except that the presence or absence of xylene addition in Step B and the presence or absence of molecular sieve treatment in Step C were changed. The processing conditions (Steps B and C) are shown in Table 1, and the composition ratio in the target product after the Step C operation is shown in Table 2.

(Storage stability test)
In Example 1 and Comparative Example 2, the organic layer obtained in Step B (before Step C) was allowed to stand at room temperature, and the storage stability of t-butyl (methyl) amine in the organic layer was observed. Table 3 shows the results of the storage stability test of t-butyl (methyl) amine obtained in Example 1, and Table 4 shows the results of the storage stability test of t-butyl (methyl) amine obtained in Comparative Example 2. Indicated.

  From the above results, in the method of the present invention (Example 1), since t-butyl (methyl) amine in the organic layer obtained in Step B does not decompose (because of excellent storage stability), Step C is performed. It turns out that there is no need to do it immediately.

Example 2 (Synthesis of tris (methyl-t-butylamido) aluminum)
526.0 g (1.29 mol) of a 15.66% butyllithium / hexane solution was added to a flask having an internal volume of 1 L equipped with a stirrer, a thermometer and a dropping funnel and cooled. 119.2 g (1.37 mol) of t-butyl (methyl) amine obtained in Example 1 was slowly added dropwise thereto so that the internal temperature became 5 to 10 ° C. Subsequently, 60 ml of cyclopentyl methyl ether was added, and the mixture was stirred at room temperature for 30 minutes and then concentrated. To this, 180 ml of cyclopentyl methyl ether was added, and then 55.76 g (0.418 mol) of anhydrous aluminum chloride dissolved in 240 ml of cyclopentyl methyl ether was slowly added dropwise under water cooling and reacted at room temperature for 30 minutes.
After completion of the reaction, the obtained reaction solution was heated at 96 to 97 ° C. for 2 hours. This was cooled and pressure filtered for 5 minutes. The filter residue was washed with hexane and all filtrates were concentrated. The concentrate was distilled under reduced pressure (110 ° C., 89 Pa) to obtain 109.5 g of tris (methyl-t-butylamido) aluminum as a white solid (isolated yield; 91.7%).
Tris (methyl-t-butylamido) aluminum is a novel compound represented by the following physical property values.

¹ H-NMR (C ₆ H ₆ , δ (ppm)); 1.22 (27H, s), 2.58 (9H, s)
Melting point: 45-50 ° C
Spontaneous ignition (temperature 22 ° C, humidity 50% in air); no pyrophoric vapor pressure (80 ° C); 1.1 torr

Comparative Example 3 (Synthesis of tris (methyl-t-butylamido) aluminum)
697.3 g (1.63 mol) of a 15.00% butyllithium / hexane solution was added to a flask having an internal volume of 2 L equipped with a stirrer, a thermometer and a dropping funnel and cooled. Methyl-t-butylamine 144.6g (1.66mol) was dripped here gently so that internal temperature might be -18--15 degreeC. Subsequently, the mixture was stirred at room temperature for 30 minutes and then concentrated. To this was added 500 ml of diethyl ether, and then 69.77 g (0.52 mol) of anhydrous aluminum chloride dissolved in 500 ml of diethyl ether was slowly added dropwise under water cooling to react at room temperature for 30 minutes. The reaction mixture was concentrated after completion of the reaction, and the concentrate was distilled under reduced pressure (110 ° C., 53 Pa) to obtain 32.8 g of tris (methyl-t-butylamido) aluminum as a white solid (isolated yield; 22.0%).

Comparative Example 4 (Synthesis of tris (methyl-t-butylamido) aluminum)
In Example 2, the reaction was performed in the same manner as in Example 2 except that t-butyl (methyl) amine produced in Comparative Example 2 was used.
As a result, the isolation yield was low as in Comparative Example 3.

  As a result, a large number of undesired aluminum compounds coordinated with t-butyl (dimethyl) amine or t-butylamine were obtained. Therefore, it is possible to synthesize (tris (methyl-t-butylamido) aluminum in high yield by using a high-purity asymmetric dialkylamine compound (target product) while reducing the generation of by-products as much as possible. Yes, the usefulness was confirmed.

  From the above, it is considered that the asymmetric dialkylamine compound of the present invention is suitable for the production of tri (asymmetric dialkylamido) aluminum.

  The present invention relates to a method for producing an asymmetric dialkylamine compound. Asymmetric dialkylamine compounds are useful compounds as, for example, aminoacetamide derivatives as organic pharmaceutical intermediates, organic dye raw materials, epoxy resin curing retarder raw materials, olefin polymerization catalyst raw materials, and ligands for film forming materials. .

Claims (9)

(A) General formula (1)

(In the formula, Ar represents an aryl group. R ¹ , R ² and R ³ represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. In addition, R ¹ , R ² and R ³ may be bonded to each other to form a ring, provided that two or more of R ¹ , R ² and R ³ do not simultaneously become hydrogen atoms.)
After mixing the arylmethylideneamine compound represented by the formula (1) with an organic solvent, 0.90 to 1.20 mol alkylating agent is added to 1 mol of the arylmethylideneamine compound while maintaining the mixture at 75 to 110 ° C. In addition, by reacting, the general formula (2)

(In the formula, R is a linear alkyl group having 1 to 6 carbon atoms, and R ¹ , R ² and R ³ are as defined above.)
A step of producing a reaction solution containing an asymmetric dialkylamine compound represented by:
(B) A step of separating the organic layer after adding and mixing water to the reaction solution, and then separating the organic layer after mixing the obtained aqueous layer, the aromatic hydrocarbon, and the basic aqueous solution; And (C) a method of producing an asymmetric dialkylamine compound, comprising the step of bringing the organic layer into contact with a molecular sieve and then filtering and distilling to obtain the asymmetric dialkylamine compound.   The method for producing an asymmetric dialkylamine compound according to claim 1, wherein the organic solvent is used in an amount of 0.10 to 0.80 mol per mol of the arylmethylideneamine compound.   The organic solvent is at least one organic solvent selected from the group consisting of aliphatic hydrocarbons, halogenated aliphatic hydrocarbons, aromatic hydrocarbons and halogenated aromatic hydrocarbons. A process for producing an asymmetric dialkylamine compound as described in 1.   The method for producing an asymmetric dialkylamine compound according to any one of claims 1 to 2, wherein the alkylating agent is dialkyl sulfate.   The method for producing an asymmetric dialkylamine compound according to claim 1, wherein the amount of the base used in the basic aqueous solution is 1.85 to 2.20 mol per 1 mol of the arylmethylideneamine compound.   The method for producing an asymmetric dialkylamine compound according to claim 1, wherein the basic aqueous solution is an alkali metal hydroxide. The arylmethylideneamine compound has the general formula (3)

(In the formula, R ¹ , R ² and R ³ represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. In addition, R ¹ , R ² and R ³ are bonded to each other. A ring may be formed, provided that two or more of R ¹ , R ² and R ³ do not simultaneously become hydrogen atoms.)
And a general formula (4)

(In the formula, Ar is an aryl group.)
The manufacturing method of the asymmetrical dialkylamine compound of Claim 1 obtained by making it react with the aryl aldehyde shown by these.   The content ratio of the trialkylamine is less than 0.1%, the content ratio of the monoalkylamine that is a decomposition product of the raw material is less than 1.0%, and the content ratio of the alkyl alcohol that is a byproduct of the alkylating agent is 0.1 % Asymmetric dialkylamine raw material composition for producing tri (asymmetric dialkylamido) aluminum having a water content of less than 300 ppm by mass. Tri (asymmetric dialkylamido) aluminum has the general formula (5)

(In the formula, R ¹ , R ² and R ³ represent a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms. In addition, R ¹ , R ² and R ³ are bonded to each other. A ring may be formed, provided that two or more of R ¹ , R ² and R ³ do not simultaneously become hydrogen atoms.)
The asymmetrical dialkylamine raw material composition of Claim 8 which is a compound shown by these.