JP2000080063A - Method for producing dihydroxyamino compound - Google Patents

Abstract

(57) [Problem] To provide a method for producing a dihydroxyamino compound in which coloring is prevented with a high yield. SOLUTION: When a dihydroxyamino compound represented by the following formula (1) is produced from an epoxy compound represented by the following formula (2) and an amino compound represented by the following formula (3), a batch reactor is used. A method for producing a dihydroxyamino compound, characterized by sequentially adding an epoxy compound (2) after supplying an amino compound (3). Embedded image Embedded image Embedded image

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a dihydroxyamino compound, and more particularly, to a method of preparing a dihydroxyamino compound, in a reaction step in a production step, specifying a charging order of reaction raw materials,
In the process for producing a dihydroxyamino compound with reduced by-produced impurities, and in the process of distilling a product dihydroxyamino compound in a purification process to separate high-boiling impurities in addition to the method of charging the raw materials (product production process), The present invention relates to an improved method for producing a dihydroxyamino compound, which prevents a decrease in the yield of a dihydroxyamino compound due to deterioration of the compound.

[0002]

2. Description of the Related Art Dihydroxyamino compounds are industrially important compounds. For example, 1-amino-2,3-propanediol and the like have attracted attention as useful raw material compounds for X-ray contrast agents, which have been growing in demand in recent years. Methods for producing dihydroxyamino compounds are well known. Among them, for example, in a method for producing 1-amino-2,3-propanediol, glycidol represented by the following reaction formula (1) is reacted with ammonia. There is a way.

[0003]

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A method for producing a dihydroxyamino compound from such an epoxy compound and an amino compound is described in, for example, L. Knorr et al. (Der. Deutsch. Che
m. Ges. Vol. 32.750.1899);
Baum et al. (J. Org. Chem. Vol. 27.2).
331.1962) and disclosed in JP-A-56-
JP-A-161355, JP-A-56-161356, JP-A-56-161357, JP-A-3-41
056, JP-A-3-41057, JP-A-3-41057
-63251, JP-A-3-86851 and the like. This reaction mechanism is considered to be such that the amino compound nucleophilically attacks the electron-deficient carbon atom of the epoxy ring of the epoxy compound to cause a ring-opening addition reaction. As a side reaction, for example, high-boiling impurities such as bis (2,3-dihydroxypropyl) amine obtained by reaction of glycidol and 1-amino-2,3-propanediol shown in the following reaction formula (2) are generated. Therefore, in the methods described in the above publications, a large excess of the amino compound is used in order to improve the yield of the dihydroxyamino compound.

[0005]

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JP-A-56-16135, JP-A-56-16136, JP-A-56-16137, JP-A-3-41056, JP-A-3-410
No. 57 does not describe the hue of the obtained dihydroxyamino compound at all. JP-A-3-8
No. 6851 only describes a hue. The method described in this publication proposes to improve the hue of the dihydroxyamino compound as a product by limiting the bottom temperature and the residence time in the evaporator in the vacuum distillation step for purification to within 1 hour. In the method (1), purification conditions are restricted, and it is difficult to obtain a sufficient yield. Under these circumstances, it has been desired to develop a method for producing a colorless dihydroxyamino compound from a crude low-boiling liquid obtained by removing unreacted amino compounds and low-boiling components from the crude reaction liquid in good yield.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a dihydroxyamino compound in a high yield while preventing coloring. Usually, a value of 50 or less in APHA is important as a guide for coloring.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, have specified the order of charging raw materials when producing a dihydroxyamino compound from an epoxy compound and an amino compound. As a result, it has been found that generation of impurities can be reduced, and a dihydroxyamino compound in which coloring is prevented can be obtained with good yield, and the present invention has been completed.

That is, in producing a dihydroxyamino compound represented by the following formula (1) from an epoxy compound represented by the following formula (2) and an amino compound represented by the following formula (3), a batch reactor is used. A method for producing a dihydroxyamino compound, characterized by sequentially adding an epoxy compound (2) after supplying an amino compound (3). In the above invention, the unreacted amino compound and low-boiling impurities in the reaction crude liquid containing the dihydroxy compound (1) are removed to obtain a low-boiling crude liquid, and the dihydroxyamino compound is removed from the de-boiling crude liquid by distillation. In the step of separating and purifying the boiling point impurities, the high boiling point impurities are removed in a low concentration state so that the dihydroxy compound concentration of the bottoms becomes 20% by weight or more, and then the bottoms are removed using an evaporator. Provided is a method for producing a dihydroxyamino compound, which comprises recovering the contained dihydroxyamino compound by evaporation. Further, in the above invention, the amino compound (3) is ammonia, the epoxy compound (2)
Is glycidol or epichlorohydrin, and the dihydroxyamino compound (1) is 1-amino-2,3-propanediol.
And the amino compound (3) is monomethylamine, the epoxy compound (2) is glycidol or epichlorohydrin, and the dihydroxyamino compound (1)
Is a method for producing a dihydroxyamino compound (1), which is 1-monomethylamino-2,3-propanediol.

[0010]

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[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the method for producing a dihydroxyamino compound of the present invention, an amino compound represented by the above formula (3) as a reaction raw material is charged into a batch reactor, and an epoxy compound represented by the above formula (2) as another raw material is added thereto. It consists of adding the compounds sequentially. A raw material that can be used in the method for producing a dihydroxyamino compound of the present invention is an epoxy compound represented by the formula (2), wherein R ¹ , R ² , R ³ , R ⁴ , R
⁵ is a hydrogen atom or a substituent of any one of an alkyl group, an alkenyl group and an alkoxy group. Each substituent preferably has 1 to 10 carbon atoms, and particularly preferably 1 to 10 carbon atoms.
-8. R ⁶ is a substituent of either a hydroxyl group or a halogen group.

Specifically, glycidol, 1,2-epoxy-3-butanol, 2,3-epoxy-1-butanol, 1,2-epoxy-3-pentanol, 1,2-
Epoxy-3-hexanol, 1,2-epoxy-3-
Heptanol, 3,4-epoxy-2-pentanol,
3,4-epoxy-4-methyl-2-pentanol,
R ¹ , R ² such as 1,2-epoxy-3-decanol,
Compounds in which R ³ , R ⁴ and R ⁵ are each a hydrogen atom or an alkyl group, 4,5-epoxy-3-hydroxy-1-pentene, 5,6-epoxy-4-hydroxy-2-heptene, 5,6 -Epoxy-4-hydroxy-6-methyl-
2-heptene, 5,6-epoxy-4-hydroxy-6
A compound in which any one of R ¹ , R ² , R ³ , R ⁴ and R ⁵ contains an alkenyl group, such as -methyl-2-decene, 4-methoxy-
R ¹ , R ² , R ³ such as 1,2-epoxy-3-hydroxybutane, 4-ethoxy-1,2-epoxy-3-hydroxybutane, 6-ethoxy-3,4-epoxy-5-hydroxypentane , R ⁴ and R ⁵ include a compound containing an alkoxy group, or a compound such as epichlorohydrin, wherein R ⁸ contains a halogen.

When epichlorohydrin is used, as shown in the following reaction formula (3), the epoxy group of epichlorohydrin is opened with water to form 3-chloro-1,2-propanediol, which is removed. Glycidol is obtained by cyclization by HCL. A dihydroxyamino compound is formed by adding an amino compound to the compound. Therefore,
Since 3-chloro-1,2-propanediol is formed and cyclized by hydrolysis of epichlorohydrin, it is considered that the reaction proceeds basically by the same route as glycidol.

[0014]

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The other reaction raw material used in the method for producing a dihydroxyamino compound of the present invention is an amino compound represented by the formula (3), wherein R ⁶ and R ⁷ are each a hydrogen atom or an alkyl group, It is a substituent of either an alkenyl group or an alkoxy group. The carbon number of each substituent is
It is preferably from 1 to 10, particularly from 1 to 8. Specifically, primary amine compounds such as ammonia, monomethylamine, monoethylamine, mono-n-propylamine, monoisopropylamine and monobutylamine, dimethylamine, diethylamine, di-n-propylamine, N-ethylmethyl Amines, secondary amino compounds such as N-butylethylamine, amino compounds containing alkenyl groups such as N-ethyl-2-methylallylamine,
Amino compounds containing an alkoxy group such as monomethoxyamine, methylethoxyamine, ethylbutoxyamine, dimethoxyamine and dibutoxyamine are exemplified. For example, when ammonia is used as an amino compound and glycidol is used as an epoxy compound, the above-mentioned 1-amino-2,3-propanediol is obtained as a dihydroxyamino compound.

In the present invention, it is necessary to charge an amino compound into a batch reactor and then sequentially add an epoxy compound. At the time of the reaction, the molar ratio of the epoxy compound to the amino compound is preferably 2 to 100 mol, more preferably 3 to 50 mol, per 1 mol of the epoxy compound. If the amount is less than 2 mol, the yield of the dihydroxyamino compound is undesirably low. On the other hand, if it exceeds 100 moles, the amount of the crude reaction solution is increased and the space-time yield is decreased, and the yield of the dihydroxyamino compound is not improved with respect to the added amount of the amino compound.

As a preferred example, for example, when an aqueous ammonia solution is used as an amine compound and glycidol is used as an epoxy compound, if the aqueous ammonia solution is charged at a molar ratio of 15 times the amount of glycidol to a batch reactor, 1- produced is obtained. Amino-2,3-propanediol accounts for about 3 to 10% by weight in the crude reaction liquid, and unreacted ammonia and water are present as low boiling components, and bis (2,3-dihydroxypropyl) is present as a high boiling component. ) Amine and the like are generated.

The amount of the dihydroxyamino compound contained in the crude low-boiling liquid obtained by removing excess amine compounds and low-boiling components from the reaction crude liquid is preferably 5 to 99% by weight, more preferably 10 to 70% by weight. %. Within this range, coloring components and the like can be removed while preventing decomposition of the dihydroxyamino compound. For example, when the dihydroxyamino compound is 1-amino-2,3-propanediol, 1-amino-2,3 contained in the crude liquid having a low boiling point is removed.
-The propanediol concentration is preferably 30 to 99% by weight, and the low-boiling crude liquid contains other high-boiling components such as bis (2,3-dihydroxypropyl) amine and a small amount of low-boiling components. It is. When the concentration of the dihydroxyamino compound contained in the crude liquid having a low boiling point is lower than the above range, it can be concentrated by distillation or the like in advance and used in the subsequent steps.

The present inventors have studied the mechanism of coloring in the step of commercializing a dihydroxyamino compound. As a result, for example, in the production method of 1-amino-2,3-propanediol, the production process has been carried out in a dehydration step. A high boiling component such as bis (2,3-dihydroxypropyl) amine is present in a distillation apparatus that distills a crude boiling liquid and separates and purifies a dihydroxyamino compound in a distillate and a high boiling component in a bottom. As a result, the product 1-amino-2,3-propanediol and the high-boiling component bis (2,3-dihydroxypropyl) amine and the like are decomposed in the main body of the distillation column or the reboiler thereof, thereby generating a low-boiling coloring component, It was found that the product 1-amino-2,3-propanediol was colored.

In the present invention, the process of separating and purifying a dihydroxyamino compound and a high boiling point impurity from a crude liquid having a low boiling point by distillation and obtaining a dihydroxyamino compound as a product is referred to as a commercialization process. Hereinafter, the case where the dihydroxyamino compound is 1-amino-2,3-propanediol will be described as an example. When a distillation apparatus including an evaporator (evaporator) and a distillation column is used to separate and purify the low-boiling point crude liquid by distillation into a dihydroxyamino compound and high-boiling impurities as products, the evaporator (evaporator) Temperature in the can) is 60 to 200 ° C, especially 70 to 190 ° C
It is preferred that If the temperature in the evaporating section is lower than 60 ° C., the viscosity of the reaction crude liquid is high, which may make the distillation operation difficult. On the other hand, when the temperature is higher than 200 ° C., the product fraction is undesirably deteriorated by heat and easily colored, and a high-temperature heating source is required. The pressure in the evaporator is 0.1 to 50 Torr, especially 0.5 to 50 Torr.
Preferably, it is 40 Torr. Pressure is 0.1 To
If it is less than rr, expensive equipment is required to maintain the ultra-vacuum, which is not very practical. On the other hand, 50 Torr
If the pressure exceeds the above, the pressure in the evaporating section is increased due to high pressure, and the dihydroxyamino compound is liable to be thermally degraded, and coloring due to decomposition is promoted. In the present invention,
There is no particular limitation on the distillation apparatus that can be used for distilling the product dihydroxyamino compound to separate impurities having a high boiling point, and generally, an apparatus including an evaporator and a distillation column can be used. The operating conditions must be such that the concentration of the dihydroxyamino compound in the bottoms discharged by this distillation is at least 20% by weight, preferably at least 40% by weight.

The bottom liquid discharged by distillation of the crude liquid having a low boiling point is distilled as a vapor containing 1-amino-2,3-propanediol using an evaporator. The vapor condensate is recycled to the crude reaction liquid or to a crude low-boiling liquid obtained by removing unreacted amino compounds and low-boiling components from the crude reaction liquid, thereby reducing the loss of 1-amino-2,3-propanediol. It becomes possible to reduce. As the recycle destination, a crude low-boiling liquid obtained by removing unreacted amino compounds and low-boiling components from the crude reaction liquid is preferable. This is because 1-amino-2,3-propanediol distilled in the evaporator has solubility in water, but does not dissolve instantaneously due to its high viscosity. This is because 1-amino-2,3-propanediol is liable to form two layers without dissolving in the reaction crude liquid when circulating through the liquid. Further, the amount of bis (2,3-dihydroxypropyl) amine contained in the vapor condensate is extremely small, and little accumulation in the product tower is recognized. Since the impurities can be efficiently separated by this evaporator, the coloring of the product including the low concentration of 1-amino-2,3-propanediol in the bottoms in the commercialization process is performed. Prevention and improvement in yield. The dihydroxyamino compound obtained by the production method of the present invention preferably has a hue of not more than 50, more preferably not more than 45, particularly preferably not more than 40 in terms of APHA in terms of coloring degree.
This is advantageous in improving the yield in the next step when used industrially.

In the case of concentrating a low-concentration high-boiling component of the bottoms discharged from the evaporator in the production step, for example, a dihydroxyamino compound is recovered using a distillation apparatus provided with a rectification column. The recovered liquid was colored or the recovery rate was reduced, and was not practically usable. On the other hand, the recovery and concentration using an evaporator, preferably an evaporator without a rectifying section, can greatly improve the coloration and yield of the product, and at the same time, concentrate the high boiling components to a high concentration. It turned out to be possible.

[0023]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples. (Example 1) Into a 5-liter glass separable reactor equipped with a stirrer and a jacket, 2200 g of a 28% by weight aqueous ammonia solution were charged, and 182 g of glycidol was charged over 6 hours and aged for 3 hours. Reaction temperature is 15
° C. The concentration of 1-amino-2,3-propanediol in the reaction crude liquid thus obtained was 6.5% by weight.

The crude reaction solution was subjected to a distillation apparatus equipped with a demister above the falling film evaporator made of stainless steel (distillation unit:
40mmφ × 1200mmH) using 1600g /
H, heated at a temperature of 106 ° C., and the top pressure was 760.
Distillation was performed in Torr to distill ammonia and water, and the bottoms were placed on a stainless steel falling film evaporator at the top of a regular packing (“Sluzer Lab Packing” manufactured by Sumitomo Heavy Industries, Ltd .: specific surface area = 1700 m). ² / m ³ ) was charged into a distillation apparatus equipped with a vacuum jacket-type packed tower (50 mmφ × 110 mmH) packed therein, and distilled at a temperature of an evaporator of 152 ° C. and a top pressure of 20 Torr to further remove excess water and ammonia. did. The composition of the crude liquid obtained by removing low boiling point (removing low boiling point crude liquid) is 12.0% by weight of 1-amino-2,3-propanediol, 0.9% by weight of water and other components. 27.1% by weight.

Next, a stirred liquid film type evaporator having a steam heating part of a stainless steel jacket is filled with a regular packing ("Surzer Lab Packing" manufactured by Sumitomo Heavy Industries, Ltd .: specific surface area = 1700 m ² / m ³ ). In a distillation apparatus equipped with a vacuum jacket-type packed tower (50 mmφ × 385 mmH), 300 g /
The evaporator was charged at a rate of H and the distillation was carried out at a constant evaporator temperature of 2 Torr and a reflux ratio of 1 so that the 1-amino-2,3-propanediol concentration of the bottoms became 40% by weight. The bottom liquid is charged into a stirred liquid film type evaporator having a steam heating section of a stainless steel jacket at a rate of 135.5 g / H, and 53 g of a distillate containing 90% by weight of 1-amino-2,3-propanediol is charged. / H. A low-boiling-point crude liquid obtained by removing excess ammonia and water from the reaction crude liquid: this crude liquid was mixed at a ratio of 300: 53, and again the upper part of a stirred liquid film type evaporator having a steam heating section of a stainless steel jacket. Was charged to a distillation apparatus (product tower) equipped with a demister at a rate of 353 g / H of crude liquid, and 1
-Amino-2,3-propanediol concentration of 40% by weight
The temperature of the evaporator is kept constant so that
Distillation was carried out at orr, reflux ratio = 1. The APHA of the product of the distillate thus obtained was 40, and the loss rate in the commercialization step was 3%.

Reference Example 1 The same procedure as in Example 1 was carried out to remove the low boiling point, and in the production process, 1-amino-
The same operation as in Example 1 was performed except that the 2,3-propanediol concentration was reduced to 7% by weight, and the bottom product was not distilled again. The quality obtained is described in Table 1. 1APD in the table represents 1-amino-2,3-propanediol.

(Reference Example 2) The same procedure as in Example 1 was carried out up to the treatment for removing the low boiling point.
The same operation as in Example 1 was performed except that the 2,3-propanediol concentration was adjusted to 15% by weight, and the bottom product was not distilled again. Table 1 shows the obtained qualities.

[0028]

[Table 1]

[0029]

According to the method for producing a dihydroxyamino compound of the present invention, coloring of a product can be prevented.

Claims (4)

[Claims] 1. A batch reactor for producing a dihydroxyamino compound represented by the following formula (1) from an epoxy compound represented by the following formula (2) and an amino compound represented by the following formula (3): A method for producing a dihydroxyamino compound, characterized in that an amino compound (3) is supplied to an epoxy resin and an epoxy compound (2) is sequentially added. Embedded image Embedded image Embedded image 2. The crude reaction mixture containing the dihydroxy compound (1) is freed from unreacted amino compounds and low-boiling impurities to obtain a low-boiling crude liquid, and the dihydroxyamino compound and the high-boiling point are distilled from the low-boiling crude liquid. In the step of separating and purifying impurities, high-boiling impurities are removed in a low-concentration state so that the dihydroxy compound concentration of the bottoms becomes 20% by weight or more, and then contained in the bottoms using an evaporator. The method for producing a dihydroxyamino compound according to claim 1, wherein the recovered dihydroxyamino compound is recovered by evaporation. 3. The amino compound (3) is ammonia, the epoxy compound (2) is glycidol or epichlorohydrin, and the dihydroxyamino compound (1) is 1-amino-2,3-propanediol. Or 2
3. The method for producing a dihydroxyamino compound (1) according to item 1. 4. The amino compound (3) is monomethylamine, the epoxy compound (2) is glycidol or epichlorohydrin, and the dihydroxyamino compound (1)
Is 1-monomethylamino-2,3-propanediol. The method for producing a dihydroxyamino compound (1) according to claim 1 or 2.