JPH0665166A - Separation of alpha-@(3754/24)m-nitrophenyl)alkylamine and alpha-@(3754/24)p-nitrophenyl)alkylamine and production of alpha-@(3754/24)m-aminophenyl)alkylamine and alpha-@(3754/24)p-aminophenyl) alkylamines using the same - Google Patents

Abstract

PURPOSE:To separate the subject compound useful as a polyimide, etc., efficiently and in high yield by converting a mixture containing m-derivative and p- derivative of a specific alpha-nitrophenylalkylamine into a sulfate and crystallizing the p-derivative. CONSTITUTION:A mixture containing at least m-derivative and p-derivative of an alpha-(nitrophenyl)alkylamine of the formula (R is H or 1-5C lower alkyl; nitro group is in m-position or p-position) is converted into a sulfate, the p- derivative is preferentially crystallized to separate the p-derivative from the m-derivative. The prepared alpha-(m-nitrophenyl)alkylamine or alpha-(p-nitrophenyl) alkylamine (sulfate) is catalytically reduced in particular to give an alpha-(m- aminophenyl)alkylamine or an alpha-(p-aminophenyl)alkylamine.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a mixture of at least m- and p-forms of α- (nitrophenyl) alkylamines obtained by nitrating α-phenylalkylamines, both of which are converted into sulfates. Regarding the method of separating each. Furthermore, m-form or p- obtained by separation
The present invention relates to a method for producing α- (m-aminophenyl) alkylamines and α- (p-aminophenyl) alkylamines by catalytically reducing the body.

[0002] α- (Nitrophenyl) alkylamine is not only a useful intermediate as a precursor of diamines, but also diamines obtained by catalytic reduction of diamines are
For example, polyimide, polyamide, polyamideimide,
It is a compound useful as a starting material for bismaleimide, diisocyanate, epoxy resin curing agent and the like.

[0003]

2. Description of the Related Art In recent years, research and development of highly functional polymer materials has become more and more active, and accordingly, synthesis of intermediates having highly reactive functional groups is required. In particular, among high-performance polymer materials, polyimide, polyamide and the like have excellent heat resistance and dimensional stability, and are expected to be widely used in a wide range of fields.

The inventors of the present invention have previously proposed Japanese Patent Laid-Open No. 61-
No. 10539 discloses a method for producing aminobenzylamines. This method is a method for producing an aminobenzylamine mixture using a mineral salt of a nitrobenzylamine mixture containing an isomer obtained by nitrating benzylamine. Further, Japanese Patent Laid-Open No. 3-200748 proposes a method for producing alkyldiamines. This method is also a production method using isomer-containing DL-α-nitrophenylalkylamines obtained by nitrating DL-α-phenylalkylamines or a mineral acid salt thereof. As described above, in the known production method, the diamines are obtained by using the ortho-, meta-, para-isomer mixture formed by the nitration. Furthermore, it was very difficult to isolate any nitration product from the mixture containing the isomers (m: p = 1: 1) as described above.

On the other hand, a method for directly nitrating benzylamine to produce m-nitrobenzylamine (Journal, Chemical, Society, 1811 (1925)).
Is also known. In this method, benzylamine was inserted into 95% nitric acid at -10 ° C for 2 hours, reacted at the same temperature for 1 hour, then discharged into ice water, and the precipitated crystals were left for a while and filtered. By doing so, m-nitrobenzylamine nitrate was obtained (yield not described).
Furthermore, after the m-nitrobenzylamine contained in the filtrate is removed, the p-form is once acetylated and the like to obtain the desired product. Thus, conventionally, a method of directly nitrating α-phenylalkylamines to efficiently separate m-form and p-form from a mixture containing isomers has not been known.

[0006]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above problems, the present inventors have found that α- (nitrophenyl) alkylamines obtained by nitrating α-phenylalkylamines At least m-body and p-
By adjusting the sulfuric acid concentration of the mixture containing the body to 70 to 30%, the p-nitro body is converted to the m-nitro body due to the difference in solubility between the sulfate of the m-nitro body and the sulfate of the p-nitro body. By taking advantage of the preferential crystallization as a poorly soluble salt, α- (m-nitrophenyl) alkylamine and α- (m-nitrophenyl) alkylamine
It has been found that (p-nitrophenyl) alkylamines can be separated. Furthermore, those sulfates are left as salt,
Alternatively, it was found that α- (m-aminophenyl) alkylamines and α- (p-aminophenyl) alkylamines can be easily obtained by neutralizing the salt and then catalytically reducing the respective compounds, thus completing the present invention. Came to let.

That is, the present invention is based on the general formula (1)

[0008]

[Chemical 4] (In the formula, R represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and the nitro group of the phenyl group is located at the m-position or the p-position.)- (Nitrophenyl) alkylamines at least m-form and p
In the method for separating the m-form and the p-form from a mixture containing the -form, both are made into a sulfate and then the p-form is preferentially crystallized to separate the p-form and the m-form. Separation method, a method of separating the m-form by crystallization as a sulfate from the mother liquor mainly containing the m-form obtained by separating the p-form, the sulfuric acid concentration of the above mixture, or Sulfuric acid concentration is adjusted to 70 to 30 wt% and separated into p- form and m-
A method for separating a body, wherein the mixture containing at least the m-body and the p-body of the α- (nitrophenyl) alkylamines is the α-phenyl represented by the following general formula (2) A method which is obtained by nitrating alkylamines,

[0009]

[Chemical 5] (In the formula, R represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms.) [Alpha]-(m-nitrophenyl) alkylamine or [alpha]-(p-nitro obtained by separating by the above-mentioned methods. [Alpha]-(m-aminophenyl) alkylamine or [alpha]-(p represented by the general formula (3) (Chemical Formula 6), which is characterized by performing catalytic reduction of phenyl) alkylamines or their sulfates. -Aminophenyl) alkylamines.

[0010]

[Chemical 6] (In the formula, R has the same meaning as in formula (1), and the amino group of the phenyl group is located at the m-position or the p-position.) Α- (nitrophenyl) alkyl of the present invention In the method of separating a mixture containing at least m- and p-amines, the sulfuric acid concentration of the mixture is 70 to 30 wt%.
The p-form is preferentially crystallized to separate the p-form and the m-form due to the difference in solubility between the p-form and the m-form sulfate. Regarding the adjustment of the sulfuric acid concentration, the mixture is a slightly viscous solution obtained by nitrating α-phenylalkylamines, and is adjusted by adding water to it or discharging it into water. And adjust. Here, when the sulfuric acid concentration is 70% or more, the separation yield of the p-form decreases, and
When it is 0% or less, not only the volume efficiency is lowered, but also the amount of the inorganic salt added is increased, which is not economically preferable. The solution whose sulfuric acid concentration was adjusted was further cooled at a temperature of 40 ° C. or lower, and stirred for several hours. Due to the difference in solubility between the p-nitro-form sulfate and the m-nitro-form sulfate, The p-nitro form is preferentially crystallized as a salt that is less soluble than the m-nitro form.

In the separation method of the present invention, when the sulfuric acid concentration is adjusted, an inorganic salt is added and salted out to improve the recovery rate of the sulfate. As the inorganic salt to be added, for example, sodium chloride, sodium sulfate, ammonium sulfate, magnesium sulfate, magnesium sulfate and the like are used. The amount of these inorganic salts used may be 10 to 25 parts by weight based on the water used for adjusting the sulfuric acid concentration of the mixture. In the method of the present invention, instead of adding the above-mentioned inorganic salt, a part of the used sulfuric acid may be neutralized with an alkali and the resulting inorganic salt may be crystallized. In this case, 20 to 40% by weight of the sulfuric acid used may be neutralized.
Even if it exceeds 40% by weight, there is no problem in isolation, but the amount of inorganic salt mixed in increases.

After the p-form crystallized as above is separated by filtration, the filtrate (mother liquor) is partially neutralized or salted out to crystallize the m-form as a sulfate to give the m-form. Can be separated.

In the method of the present invention, the mixture containing at least m- and p-forms of α- (nitrophenyl) alkylamines is obtained by nitrating α-phenylalkylamines represented by the general formula (2). Of the α-phenylalkylamines, benzylamine is produced in good yield by, for example, a method in which benzaldehyde is catalytically reduced with Raney nickel in the presence of ammonia in alcohol (Experimental Chemistry Lecture, Vol, 20). , 460. Journal, American, Chemical, Society (J,
Am, Chem, Soc) 61, 3566 (193).
9)). Examples of α-phenylalkylamines include α-phenylethylamine, α-phenylpropylamine, α-phenylbutylamine, α-phenylpentylamine, α-phenylhexylamine and the like. These can be produced, for example, by reductive amination of the carbonyl group of alkylphenyl ketones in the presence of ammonia (Japanese Patent Application No. 53-95).
No. 63, Chemical, And, Pharmaceutical, Bulletin (Chem, Pharm, BULL, Vol, 11
3, 277 (1963)).

The amount of sulfuric acid used in the nitration of the present invention is 1 to 8 times that of the raw material α-phenylalkylamine. Even if the amount used exceeds 8 times, there is no problem in the reaction, but not only the volume efficiency is lowered, but also waste acid treatment cost and the like are economically unfavorable. It is preferably in the range of 2 to 4 times. Further, the amount of nitric acid used in the nitration of the present invention is 0.95 to 1.2 equivalents relative to 1 equivalent of α-phenylalkylamine. There is no problem in reaction even if it exceeds 1.2 equivalents,
It is not preferable in terms of waste acid treatment cost. The nitric acid used in this case may have a concentration of 60 to 98%.

An inert organic solvent may be used in combination in the nitration reaction of the present invention. The amount of sulfuric acid can be reduced by using an organic solvent together. For example, when ethylene chloride is used, the α-phenylalkylamines are initially dissolved in an organic solvent, but upon contact with sulfuric acid, the α-phenylalkylamines form a sulfate and move to the sulfuric acid layer. After the reaction, it has two layers, so after standing still,
The lower sulfuric acid layer may be discharged into ice water. Moreover, the ethylene chloride in the upper layer can be recovered and recycled as it is.

Specific examples of the organic solvent that can be used in combination include methylene chloride, chloroform, carbon tetrachloride, 1,1-dichloroethane, ethylene chloride, 1,1,
Halogenated hydrocarbons such as 1-trichloroethane, 1,1,2-trichloroethane and 1,1,1,2-tetrachloroethane are used. When the organic solvent as described above is used in combination, it is used in a range of 1 to 9 times the amount of the raw material α-phenylalkylamine.

In the present invention, the reaction temperature for nitration is −
It is carried out in the range of 20 to 25 ° C, preferably -10 to 15
It is carried out in the range of ° C. At -20 ° C or lower, there is no problem in the reaction, but an efficient device such as cooling equipment is required. Further, at a temperature of 25 ° C. or higher, by-products tend to increase with the oxidation of nitrates. The reaction time depends on the amount of sulfuric acid and the sulfuric acid concentration, but is in the range of about 1 to 8 hours, and about 2 to 5 hours is sufficient.

As a general embodiment of the nitration reaction of the present invention, for example, after cooling α-phenylalkylamines, a mixed acid is charged, or sulfuric acid is charged with α-phenylalkylamines. After the addition, any method such as dropping a mixed acid or nitric acid at 25 ° C. or lower may be used.

At least m-form and p-form of α- (nitrophenyl) alkylamines obtained by the above nitration reaction.
From the mixture containing the body, the m-body and the p-body are prepared by the method of the present invention.
The product separated as a sulfate is subjected to a method of reducing or neutralizing the salt, and then reducing the product, to obtain an α- (m-aminophenyl) alkylamine or α- (p represented by the general formula (3). -Aminophenyl) alkylamines can be prepared. The reduction method is not particularly limited, and usually,
Although a method of reducing a nitro group to an amino group can be applied, catalytic reduction is industrially preferable.

In the case of catalytic reduction, the reduction catalyst used may be a metal catalyst generally used for catalytic reduction, such as nickel, palladium, platinum, rhodium, ruthenium, cobalt or copper. It is industrially preferable to use a palladium catalyst. These catalysts are also used in a metal state, but usually, carbon, barium sulfate, silica gel, alumina, or used by being supported on the surface of a simple substance such as Celite, nickel,
It is also used as a Raney catalyst for cobalt and copper.

The amount of the catalyst used in the method of the present invention is not particularly limited, but the raw material α- (nitrophenyl) is used.
The amount of the metal is 0.01 to 10% by weight with respect to the m- or p-form of the alkylamine, and usually 2 to 8% by weight when used in the metal state, which is supported on the carrier. In some cases, it is in the range of 0.1 to 5% by weight. The reaction solvent is not particularly limited as long as it is inert to the reaction, and examples thereof include water or an organic solvent, specifically, alcohols such as methanol, ethanol and isopropyl alcohol, ethylene glycol and propylene. Glycols such as glycols, ethers such as dioxane, tetrahydrofuran and methyl cellosolve, aliphatic hydrocarbons such as hexane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, esters such as ethyl acetate and butyl acetate. , Halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethane and N,
N-dimethylformamide and the like can also be used. When an organic solvent is used as the reaction solvent, the target product is obtained by recovering the solvent and then distilling under reduced pressure. When water is used, the desired product may be extracted with an inert organic solvent and then the solvent may be recovered. The amount of these solvents used is sufficient to suspend or completely dissolve the raw materials, and is not particularly limited, but is usually 0.5 to 0.5 with respect to the raw materials.
It is carried out 10 times by weight.

The reaction temperature is not particularly limited, but is generally in the range of 5 to 100 ° C, preferably 20 to 100 ° C.

In the separation method of the present invention, the salt in the ortho-, meta-, para-isomer mixture conventionally produced by nitration is
It was found that there is a difference in solubility with respect to a specific sulfuric acid concentration, and an intermediate useful as a precursor of a diamine can be isolated, which is extremely industrially advantageous and expected to be used in a wide range of applications.

[0024]

EXAMPLES The present invention will now be described in more detail with reference to examples. The analysis was carried out by gas chromatography. Example 1 [α- (m-nitrophenyl) ethylamine and α-
Isolation of (p-nitrophenyl) ethylamine sulfate] A container equipped with a stirrer was charged with 363.6 g of 98% sulfuric acid (3 times amount / α-phenylethylamine), cooled to 0 ° C., and then charged. Α-phenylethylamine 121.
8 g (1.0 mol) were charged in 2 hours. Then -5
After cooling to ℃, mixed acid 1 consisting of 121.8 g of 98% sulfuric acid and 67.5 g (1.05 mol) of 98% nitric acid at the same temperature 1
89.3 g was charged in 6 hours. After reacting for 2 hours at the same temperature, the reaction solution was analyzed by gas chromatography. As a result, o-form: m-form: p-form = 7.6: 36.9: 55.5
(Area ratio), and no raw material was detected. The reaction liquid was discharged into a container having 446 g of ice water and 66.9 g of sodium chloride (adjusted to a sulfuric acid concentration of 50%) at 0 to 30 ° C. 10-1
After cooling to 5 ° C. and stirring at the same temperature for 2 hours, the pale yellow crystals were filtered. The filter cake was washed with 122 ml of a saturated saline solution twice, to obtain 139.1 g of a white sulphate of α- (p-nitrophenyl) ethylamine as a wet body. Purity 4
7.8% Yield 66.5 g (free) Yield 40.0% / α-phenylethylamine The wet body obtained here was recrystallized with water. Melting point 266.2
[Deg.] C- (decomposition) 700 g of the filtrate was charged at a temperature of 10 to 15 [deg.] C with 88.9 g (1.0 mol) of 45% sodium hydroxide in 2 hours. After stirring at the same temperature for 2 hours, the pale yellow crystals were filtered. The filter cake was washed twice with 122 ml of saturated saline solution twice to obtain 132.1 g of a wet product of pale yellow α- (m-nitrophenyl) ethylamine 1/2 sulfate. Purity 44.1% Yield 58.3 g (free) Yield 35.1% / α-phenylethylamine The wet body obtained here was recrystallized from water. Melting point 220.6
~ 222.4 ° C

Example 2 [Isolation of α- (p-nitrophenyl) ethylamine and synthesis of α- (p-aminophenyl) ethylamine] The α- (obtained in Example 1 was placed in a container equipped with a stirrer. p-
69.5 g of wet body of nitrophenyl) ethylamine sulfate
(0.2 mol), water 104.3 g and toluene 99.
After charging 7 g, 28% ammonia water at 25 ° C or below 3
0.4 g (0.5 mol) was neutralized in 2 hours (pH 9.
0). After separating the upper toluene layer, the aqueous layer was further extracted with 33 g of toluene 3 times. The obtained toluene extract (200 g) was washed with 33 g of saturated saline solution × 3 times. Then, the toluene extract was concentrated at 50 ° C. or lower to recover toluene. 33 g of the concentrated liquid was divided into two equal parts. 16.5 g of the concentrated liquid was distilled under reduced pressure at 101 ° C./2-1 mmHg to obtain α- (p-nitrophenyl) ethylamine. Yield 15.3 g Yield 92.2% / α- (p-nitrophenyl) ethylamine 1/2 sulphate Concentrated solution 16.5 in catalytic hydrogenation margen for 100 ml.
g and 49.5 g of toluene, and then 5 under a nitrogen stream.
% Pd-C (50 wt%) 0.33 g was charged, and the system was replaced with hydrogen. 6.7 liters of hydrogen were absorbed at 25-30 ° C. for 7 hours. After the reaction, the system was replaced with nitrogen, and the catalyst was filtered off. After 70.0 g of the filtrate was recovered at 50 ° C. or lower, the toluene was recovered at 102 ° C./1 to 2 mmHg.
Distillation under reduced pressure gave α- (p-aminophenyl) ethylamine. Yield 15.4 g Yield 92.7% / α- (p-nitrophenyl) ethylamine

Example 3 [Isolation of α- (m-nitrophenyl) ethylamine and synthesis of α- (m-aminophenyl) ethylamine] The α- (obtained in Example 1 was placed in a container equipped with a stirrer. m-
Wet form of nitrophenyl) ethylamine sulfate 75.4 g
(0.2 mol), water 113.1 g and toluene 99.
After charging 7 g, 28% ammonia water at 25 ° C or below 3
0.4 g (0.5 mol) was neutralized in 2 hours (pH 9.
0). After separating the upper toluene layer, the aqueous layer was further extracted with 33 g of toluene 3 times. The obtained toluene extract (201 g) was washed with 33 g of saturated saline solution × 3 times. Then, the toluene extract was concentrated at 50 ° C. or lower to recover toluene. 34 g of the concentrated liquid was divided into two equal parts. The concentrated solution (17.0 g) was distilled under reduced pressure at 106 ° C./1-2 mmHg to obtain α- (m-nitrophenyl) ethylamine. Yield 15.2 g Yield 91.5% / α- (m-nitrophenyl) ethylamine 1/2 sulfate The elemental analysis results of the α- (m-nitrophenyl) ethylamine obtained here were as follows. . Concentrated liquid 17.0 in catalytic hydrogenation margen for 100 ml
g and toluene (51.0 g) were charged, and then 5
% Pd-C (50 wt%) 0.34 g was charged, and the system was replaced with hydrogen. Hydrogen at 25 to 30 ° C. and 7 hours 6.
Absorbed 7 liters. After the reaction, the system was replaced with nitrogen, and the catalyst was filtered off. After recovering toluene at 50 ° C. or lower, 75.8 g of the filtrate was distilled under reduced pressure at 101 ° C./1-2 mmHg to obtain α- (m-aminophenyl) ethylamine. Yield 15.6 g Yield 94.0% / α- (m-nitrophenyl) ethylamine 1/2 sulfate An elemental analysis result of the α- (m-aminophenyl) ethylamine obtained here was as follows. .

Example 4 [Isolation of m-nitrobenzylamine and p-nitrobenzylamine sulfate] 98% in a container equipped with a stirrer.
321.0 g of sulfuric acid (3 times amount / benzylamine) was charged, and after cooling to 0 ° C., benzylamine 10 was added at the same temperature.
7.2 g (1.0 mol) were charged in 3 hours. Next-
After cooling to 5 ° C, 107.2 g of 98% sulfuric acid at the same temperature
And 174.7 g of a mixed acid consisting of 67.5 g (1.05 mol) of 98% nitric acid and 6 hours were charged. The reaction was carried out at the same temperature for 2 hours. As a result of analyzing this reaction liquid by gas chromatography, o-form: m-form: p-form = 2.0: 45.
It was 0: 53.0 (area ratio), and the raw material was not detected. This reaction solution was discharged into 984 g of ice water (adjusted to a sulfuric acid concentration of 30%) at 0 to 30 ° C. After cooling to 20 to 25 ° C, the mixture was stirred at the same temperature for 2 hours, and then pale yellow crystals were filtered. The filter cake was washed with 107 ml of a saturated saline solution twice and washed with a wet body of a pale yellow p-nitrobenzylamine sulfate salt 119.
1 g was obtained. The purity of free p-nitrobenzylamine in the wet body obtained here was 47.4%. Also, m
-Nitrobenzilamine was not detected. Yield 56.5 g (free) Yield 37.1% / benzylamine After cooling 1400 g of the filtrate to 10 to 15 ° C. and stirring at the same temperature for 2 hours, the precipitated crystals were filtered. The filter cake was washed with 107 ml of saturated saline solution twice, to obtain 125.5 g of a wet product of pale yellow m-nitrobenzylamine sulfate.
The purity of free p-nitrobenzylamine in the wet body obtained here was 44.1%. In addition, p-nitrobenzylamine was not detected. Purity 42.5% Yield 53.3 g (free) Yield 35.1% / benzylamine

Example 5 [α- (m-nitrophenyl) propylamine and α
-Isolation of (p-nitrophenyl) propylamine sulfate] In a container equipped with a stirrer, 405.6 g of 98% sulfuric acid
Charge (3 times amount / α-phenylpropylamine) and
After cooling to ° C, 135.2 g (1.0 mol) of α-phenylpropylamine was charged at the same temperature for 3 hours. Next, after cooling to −5 ° C., 98% sulfuric acid 1
202.7 g of a mixed acid consisting of 35.2 g and 67.5 g (1.05 mol) of 98% nitric acid was charged in 6 hours. The reaction was carried out at the same temperature for 2 hours. As a result of analyzing this reaction liquid by gas chromatography, o-form: m-form: p-form = 7.
The ratio was 6: 41.9: 50.5 (area ratio), and no raw material was detected. This reaction liquid was mixed with 450 g of ice water and 90.
It was discharged to 0 g (adjusted to a sulfuric acid concentration of 50%) at 0 to 30 ° C.
After cooling to 10 to 15 ° C, the mixture was stirred at the same temperature for 2 hours, and then pale yellow crystals were filtered. Filter cake is saturated saline 135m
White α- (p-nitrophenyl) after washing 1 × 2 times
143.3 g of a wet body of propylamine sulfate was obtained. Purity 50.3% Yield 72.1 g (free) Yield 40.0% / α-phenylpropylamine 1100 g of filtrate at a temperature of 10 to 15 ° C. and 88.9 g (1.0 mol) of 45% sodium hydroxide for 2 hours I charged it in need. After stirring at the same temperature for 2 hours, the pale yellow crystals were filtered. The filter cake was washed with 135 ml of saturated saline solution twice to obtain 136.2 g of a wet product of a pale yellow α- (m-nitrophenyl) propylamine sulfate. Purity 43.7% Yield 59.5 g (free) Yield 33.0% / α-phenylpropylamine

Example 6 [Synthesis of α- (m-aminophenyl) ethylamine] 5
After the catalytic hydrogenation margen for 00 ml was charged with 75.4 g (wet 33.2 g, 0.2 mol) of a wet body of α- (m-nitrophenyl) ethylamine sulfate and 226 g of water,
0.66 g of 5% Pd-C (50 wt%) was charged under a nitrogen stream, and the system was replaced with hydrogen. 13.5 liters of hydrogen was absorbed at 25 to 30 ° C. for 7 hours. After the reaction, the system was replaced with nitrogen, and the catalyst was filtered off. After charging 66.4 g of toluene to this reaction solution (315 g), 15
Neutralized at -20 ° C with 17.8 g of 45% sodium hydroxide. After separating the toluene layer, add more toluene 3
The water layer was extracted with 3.2 g. This extract (10
After recovering 0 g of toluene, 101 ° C./1 to 2 mm
Distillation under reduced pressure under Hg gave α- (m-aminophenyl) ethylamine. Yield 25.9 g Yield 95.1% / α- (m-nitrophenyl) ethylamine

Example 7 [Synthesis of α- (p-aminophenyl) ethylamine] 5
After the catalytic hydrogenation margen for 00 ml was charged with 69.5 g of a wet body of α- (p-nitrophenyl) ethylamine sulfate (free 33.2 g, 0.2 mol) and 209 g of water,
0.66 g of 5% Pd-C (50 wt%) was charged under a nitrogen stream, and the system was replaced with hydrogen. 13.5 liters of hydrogen was absorbed at 25 to 30 ° C. for 7 hours. After the reaction, the system was replaced with nitrogen, and the catalyst was filtered off. After charging 66.4 g of toluene to this reaction solution (279 g), 15
Neutralized at -20 ° C with 17.8 g of 45% sodium hydroxide. After separating the toluene layer, add more toluene 3
The water layer was extracted with 3.2 g. This extract (100
After recovering toluene from g), 101 ° C / 1-2 mm
Distillation under reduced pressure under Hg gave α- (p-aminophenyl) ethylamine. Yield 26.2 g Yield 96.2% / α- (p-nitrophenyl) ethylamine

Example 8 [α- (m-nitrophenyl) ethylamine and α-
Isolation of (p-nitrophenyl) ethylamine sulfate]
In a container equipped with a stirrer, ethylene chloride 609.0 (5
Double amount / α-phenylethylamine) was charged, and after cooling to 0 ° C., α-phenylethylamine 12 was added at the same temperature.
1.8 g (1.0 mol) was charged in 1 hour. Next, after cooling to -5 ° C, at the same temperature, 98% sulfuric acid 242.0
g and 309.5 g of a mixed acid consisting of 67.5 g (1.05 mol) of 98% nitric acid were charged in 6 hours. The reaction was carried out at the same temperature for 2 hours. After the reaction, the mixture was allowed to stand at 20 to 25 ° C. for 2 hours, and then the lower layer of sulfuric acid was discharged into 213 g of ice water and 32.0 g of sodium chloride (adjusted to a sulfuric acid concentration of 50%) at 0 to 30 ° C. 10-1
After cooling to 5 ° C. and stirring at the same temperature for 2 hours, the pale yellow crystals were filtered. The filter cake was washed with 122 ml of saturated saline solution twice, to obtain 159.1 g of a white α- (p-nitrophenyl) ethylamine sulfate salt wet body. Purity 47.0% Yield 74.8 g (free) Yield 45.0% / α-phenylethylamine 650 g of filtrate requires 45% sodium hydroxide 88.9 g (1.0 mol) at a temperature of 10 to 15 ° C. for 2 hours. I charged it. After stirring at the same temperature for 2 hours, the pale yellow crystals were filtered. The filter cake was washed with 122 ml of saturated saline solution twice, to obtain 155.6 g of a wet product of a pale yellow α- (m-nitrophenyl) ethylamine sulfate. Purity 45.0% Yield 70.0 g (free) Yield 42.1% / α-phenylethylamine

Example 9 [α- (m-nitrophenyl) ethylamine and α-
Isolation of (p-nitrophenyl) ethylamine sulfate]
In a container equipped with a stirrer, 363.6 g (3% of 98% sulfuric acid) was added.
(Double amount / α-phenylethylamine) was charged, and after cooling to 0 ° C., α-phenylethylamine 1 was added at 0 to 10 ° C.
21.8 g (1.0 mol) were charged in 2 hours. At the same temperature, 99.0 g (1.10 mol) of 70% nitric acid was charged for 6 hours. The reaction was carried out at the same temperature for 2 hours. As a result of analyzing this reaction solution by gas chromatography, the o-form:
m-body: p-body = 5.6: 43.4: 51.0 (area ratio), and no raw material was detected. 301 g of ice water and 46.5 g of salt (adjusted to a sulfuric acid concentration of 50%)
It was discharged at 0-30 ° C. After cooling to 10 to 15 ° C, the mixture was stirred at the same temperature for 2 hours, and then pale yellow crystals were filtered. The filter cake was washed with 122 ml of a saturated saline solution twice, to obtain 146.2 g of a white salt of α- (p-nitrophenyl) ethylamine sulfate as a wet body. Purity 48.9% Yield 71.5 g (free) Yield 43.0% / α-phenylethylamine The filtrate is 45% sodium hydroxide 8 at a temperature of 10 to 15 ° C.
8.9 g (1.0 mol) were charged in 2 hours. After stirring at the same temperature for 2 hours, the pale yellow crystals were filtered. The filter cake was washed with 122 ml of saturated saline solution twice and washed with a pale yellow α-
Wet form of sulfate of (m-nitrophenyl) ethylamine 1
42.0 g was obtained. Purity 45.7% Yield 64.9 g (free) Yield 39.0% / α-phenylethylamine

[0033]

INDUSTRIAL APPLICABILITY According to the present invention, the sulfuric acid concentration of a mixture containing at least m- and p-forms of α- (nitrophenyl) alkylamines obtained by nitrating α-phenylalkylamines is adjusted. By utilizing the difference in solubility between the m-nitro sulfate and the p-nitro sulfate, α- (m-nitrophenyl) ethylamine and α-
It is intended to provide a method capable of efficiently separating (p-nitrophenyl) ethylamines. Further, the obtained nitro compound can be obtained in good yield by directly reducing the salt or by neutralizing the salt and then catalytically reducing the salt.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Ryuji Haseyama 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemicals, Inc. (54) [Title of Invention] α- (m-nitrophenyl) alkylamine and α Method for separating-(p-nitrophenyl) alkylamine, and method for producing α- (m-aminophenyl) alkylamine and α- (p-aminophenyl) alkylamines using the same

Claims (6)

[Claims] 1. General formula (1) (Chemical formula 1) (In the formula, R represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and the nitro group of the phenyl group is located at the m-position or the p-position.)- (Nitrophenyl) alkylamines at least m-form and p
In the method for separating the m-form and the p-form from a mixture containing the -form, both are made into a sulfate and then the p-form is preferentially crystallized to separate the p-form and the m-form. Separation method. 2. The m obtained by separating the p-form according to claim 1.
-A method of crystallizing and separating the m-form as a sulfate from the mother liquor mainly containing the -form. 3. The method according to claim 1, wherein the sulfuric acid concentration of the mixture is adjusted to 70 to 30 wt% for separation. 4. The method according to claim 2, wherein the mother liquor is separated by adjusting the sulfuric acid concentration to 70 to 30 wt%. 5. The α- (nitrophenyl) according to claim 1.
A mixture containing at least m- and p-forms of alkylamines is obtained by nitrating α-phenylalkylamines represented by the following general formula (2) (formula 2). The method according to any one of to 4. [Chemical 2] (In the formula, R represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms.) 6. An α- (m-nitrophenyl) alkylamine or an α- (p-nitrophenyl) alkylamine or a sulfate thereof obtained by the separation according to any one of claims 1 to 5. Is particularly catalytically reduced, and α- (m represented by the following general formula (3)
A method for producing -aminophenyl) alkylamine or α- (p-aminophenyl) alkylamines. [Chemical 3] (In the formula, R has the same meaning as in formula (1), and the amino group of the phenyl group is located at the m-position or the p-position.)