JP2000128839A - Production of crystal (s,s)-ethylenediamine-n,n-disuccinic acid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject succinic acid, useful as a builder for detergents, in satisfactory yield within a practical time by optimizing power for agitation of the reaction system to accelerate the reaction. SOLUTION: This method reacts (A) L-aspartic acid with (B) a dihaloethane (preferably 1,2dichloroethane or 1,2-dibromoethane) in an aqueous solvent under a basic condition, while agitating the reaction system by power of 0.3 to 1.5 kW/m3. It is preferable that the reaction is effected under the conditions of reaction solution pH: 9 to 13, reaction temperature: 80 to 1 20 deg.C, and concentration of the component A in the reaction solution: 5 to 40 wt.%. It is recommended to use methanol or the like as the solvent, and make the reaction solution basic with sodium hydroxide or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound represented by the following structural formula (I):
(S, S) -ethylenediamine-N, N'-
The present invention relates to a method for producing disuccinic acid (hereinafter, ethylenediamine-N, N'-disuccinic acid may be abbreviated as EDDS).

[0002]

Embedded image

Specifically, L-aspartic acid and dihaloethane are reacted in an aqueous solvent under basic conditions (S,
The present invention relates to an improvement in a method for producing S) -EDDS. (S,
S) -EDDS has both practical chelating power and biodegradability, has no toxicity, and is used for, for example, detergent builders and photographs.

[0004]

2. Description of the Related Art Among the well-known chelating compounds, sodium tripolyphosphate has been used as a detergent builder for a long time because of its excellent chelating ability. It is a cause of eutrophication and has been discontinued at present. However, the zeolite used as a substitute has weak chelating power, has no biodegradability because it is an inorganic substance, and is insoluble in water.

On the other hand, ethylenediaminetetraacetic acid (EDT)
A) Chelating compounds such as nitrilotriacetic acid (NTA) have extremely stable chelating power. For example, when EDTA is poorly biodegradable and is released into the environment, it solubilizes heavy metals harmful to living organisms. Therefore, there is a concern that heavy metals may be accumulated in living bodies. Also N
Although TA is biodegradable, its use is cautious due to concerns about its toxicity. Compared to these chelate compounds, EDDS has practical chelating ability, biodegradability and no toxicity, and is expected to increase demand in the future. EDDS
Has two asymmetric carbons and three optical isomers. Among these isomers, the S and S isomers have excellent biodegradability, but the R and R isomers are poorly biodegradable and have EDTA.
Similar to the above, there is a concern about environmental problems, and the R and S-forms are slower in biodegradation than the S and S-forms, and cannot be said to be easily biodegradable compounds.

Various proposals have been made for a method of manufacturing an EDDS. For example, as a method of producing a racemic EDDS, a method of adding maleic acid to ethylenediamine (Zhurn Obshche)
i Khinii. , 49, 659 (1978)). As a method for producing S, S-EDDS, a method of adding L-aspartic acid to dibromoethane (Inorg. Chem., 7, 2405 (196)
8)), a method of adding L-aspartic acid to dichloroethane (Chem. Zvesti., 20, 414 (1)
966)) or dicarbonyl compound (glyoxal)
A method for producing a Schiff base from carboxylic acid and aminocarboxylic acid (L-aspartic acid) followed by a reduction reaction (W
O96 / 32371) and the like. These methods generally have a low yield, and particularly when a dihaloethane such as 1,2-dibromoethane or 1,2-dichloroethane is to be reacted with L-aspartic acid in an aqueous solvent, the reaction rate is low. There is a problem that the reaction is slow and requires a long time. In order to increase this reaction rate, WO9
No. 6,35,662 proposes a method of adding a hydrophilic organic solvent to a reaction system.

[0007]

However, if such solvents are not used in the same amount with respect to water, the effect is low. As a result, the size of the reactor becomes large, and lower alcohols such as methanol and ethanol are used. When using, there is a problem that the reaction pressure rises and that it is recovered. An object of the present invention is to significantly shorten the conventional long reaction time in the production of (S, S) -EDDS by the reaction of L-aspartic acid and dihaloethane, and to obtain the desired product in a practical time. It is to provide a method.

[0008]

Means for Solving the Problems The present inventors have made intensive studies in view of the above circumstances, and as a result, by optimizing the stirring power in the reaction system, the reaction speed was improved, and the reaction speed was satisfactory within a practical time. To obtain the desired product yield,
The present invention has been completed.

That is, the gist of the present invention is to react L-aspartic acid and dihaloethane in an aqueous solvent under basic conditions with stirring at a stirring power of 0.3 to 1.5 kW / m ^3. (S, S) -ethylenediamine-N, N'-disuccinic acid.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
One of the starting materials in the production method of the present invention, L-
The method for producing aspartic acid is not particularly limited. For example, aspartic acid can be produced from a microorganism having aspartase activity from fumaric acid and ammonia by an enzymatic reaction, and then L-aspartic acid obtained by acid crystallization is used. it can. Further, an alkali metal L-aspartate obtained by adding a specified amount of an alkali metal hydroxide to ammonium L-aspartate produced by an enzymatic reaction and deammonating and distilling can also be used.

As the dihaloethane, 1,2-dichloroethane and 1,2-dibromoethane can be preferably used, but 1,2-dichloroethane is preferable in terms of cost and toxicity. Dihaloethane is generally used in an amount of 0.3 to 1.0 mol, preferably 0.5 to 0.7 mol, per 1 mol of L-aspartic acid.
Mole, more preferably 0.5 to 0.6 mole. If the amount is less than the above range, L during purification of EDDS
-Since the residual amount of aspartic acid is increased, the purification efficiency is remarkably reduced, and if it exceeds the above range, it leads to an increase in by-products and an increase in cost.

As the aqueous solvent, water is usually used, but water-soluble organic solvents such as methanol, ethanol and ethylene glycol can be used in combination. However, even if the reaction rate is slightly increased by the addition of these alcohols, there are problems such as an increase in the amount of the reaction solution, an increase in the reaction pressure, and recovery thereof. The amount of the aqueous solvent used is such that the concentration of L-aspartic acid or a salt thereof in the reaction solution is usually 5 to 50% by weight, preferably 5 to 40% by weight. If the concentration is lower than 5% by weight, the production efficiency is poor and impractical. If the concentration is higher than 50% by weight, the reaction rate may decrease due to the precipitation of the product and the decrease in the solubility of dihaloethane. is there.

The reaction system is made basic, that is, when the pH is 9-13.
The alkali compound used to maintain the range is preferably an alkali metal hydroxide, an alkaline earth hydroxide, more specifically sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide or These mixtures are mentioned. When L-aspartic acid is used as a raw material, an alkali metal hydroxide is selected from the solubility of the alkali compound, and preferably 2 to 4 mol, more preferably 2.2, per 1 mol of L-aspartic acid.
Approximately 2.6 mol is added, and the mixture reacts as an alkali metal L-aspartate. When an alkali metal L-aspartate is produced from an enzyme reaction solution, the pH is measured, and an alkali compound may be added as necessary. As for the method of adding an alkali compound necessary for maintaining the pH during the reaction, calcium hydroxide and magnesium hydroxide, which are hardly soluble in water, may be added all at once before the start of the reaction. If potassium hydroxide is added in excess, it promotes the decomposition of dihaloethane, so it is preferable to add potassium hydroxide sequentially.

[0014] The reaction temperature is usually in the range of 50 to 140 ° C, preferably 80 to 120 ° C, more preferably 90 to 110 ° C. At a temperature lower than 50 ° C., the reaction rate significantly decreases, and at a temperature higher than 140 ° C., the selectivity decreases.
Racemization of L-aspartic acid is also a concern. Although the reaction pressure depends on the temperature, the reaction is carried out at normal pressure or under pressure. The reaction time depends on other conditions, but is usually in the range of 0.5 to 12 hours.

The feature of the present invention is that the stirring power is 0.3 to 1.5.
kW / m ³ , more preferably 0.4 to 1.2 kW / m ³
Under strong stirring conditions. 0.3 kW / m ³ stirring power is low, the reaction rate than is significantly reduced, not obtained satisfactory EDDS yield was within a practical reaction time the present inventors have considered, higher than 1.5 kW / m ³ Also has no effect on the required power. By selecting such strong stirring conditions, it is possible to improve the desired reaction rate and shorten the reaction time.
In the case of batch mixing of liquids, the stirring power is strictly affected by the type of liquid to be mixed, but as a general guide, water-kerosene (80:20) -low viscosity liquid- In this case, if 0.2 kW / m ^3, dispersion control would not be performed. Realize Co., Ltd., edited by Koji Hatai, stirring, mixing, kneading, dispersing [Technical Integration], 71-72
Page (November 29, 1991) and the like. Energy required for stirring when stirring the reaction tank (stirring power)
Is described in detail in Chemical Engineering Association Handbook (Revised 5th Edition), pages 891-900 (March 18, 1988), published by Maruzen Co., Ltd. Were calculated using Nagata et al.'S estimation formulas (20 · 13) to (20 · 18) commonly used by those skilled in the art.

The type of the stirring blade is not particularly limited as long as the stirring power can be achieved. Examples thereof include a propeller type, a flat blade type, and a Faudler type. Frequently used stirring blades such as a max blend type and a full zone type can also be used. After completion of the reaction, the produced target product (S, S) -EDDS is isolated by crystallization. First, unreacted dihaloethane is recovered in the reaction solution.
The recovery method is generally to recover by heating under normal pressure or reduced pressure. The recovered dihaloethane can be used again as a raw material for producing EDDS.

An inorganic acid is added to the reaction solution after the recovery of the dihaloethane, and crystallization is performed to recover the precipitated EDDS crystals. At this time, water may be added to the reaction solution to adjust the EDDS concentration. The EDDS concentration at this time is preferably from 3 to 30% by weight. If the EDDS concentration is lower than this, the efficiency is poor, and if it is higher, operations such as stirring become difficult due to the precipitated EDDS. As the inorganic acid to be used, hydrochloric acid or sulfuric acid is preferable, and it is added to the reaction solution little by little. It is preferable to use an acid diluted with water to about 3 to 50% by weight from the viewpoint of preventing excessive heat generation. The crystallization temperature is not particularly limited.
There is no problem if carried out at about 80 to 80 ° C, preferably 20 to 60 ° C, usually around room temperature. Heat is generated by the addition of the acid. In this case, the rate of addition of the acid can be adjusted, and the acid may be added while cooling. The acid addition time is usually in the range of 0.1 to 30 hours, and aging may be performed after the addition. In the crystallization, an acid is added while checking the pH, but crystals are precipitated around pH 3 to 5. Thereafter, a small amount of an acid is added to maintain the pH, and the operation is continued until the pH does not increase. Precipitated crystals, if necessary, filtration under pressure, filtration under reduced pressure, centrifugation, etc.
The filtration is performed by a usual filtration method. By washing the obtained cake several times with water, the incorporation of inorganic substances and the like can be almost completely prevented.

[0018]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the examples unless it exceeds the gist thereof. Example 1 To 35 g of water was added and dissolved 8.3 g (0.2 mol) of 96% sodium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.), and then L-aspartic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 13 .
3 g (0.1 mol) was added to produce disodium L-aspartate, which was charged into a 100 cc autoclave. 4.95 g (0.05 mol) of 1,2-dichloroethane (manufactured by Wako Pure Chemical Industries, Ltd.) was also charged into the autoclave, and the mixture was stirred and reacted at 100 ° C. and 930 rpm. The stirring blade of the used autoclave had a blade width of 15 mm and a blade diameter of 10
mm, quadruple 90 degree paddle type, without baffle. The liquid density was calculated as 1250 kg / m ³ , and the stirring power was about 0.1 kg.
It became 4 kW / m ³ .

One hour after the reaction, the reaction solution was cooled and partly extracted, and the conversion of L-aspartic acid, (S, S) -EDDS
The yield was determined by high performance liquid chromatography. As a result, the conversion of L-aspartic acid was 13.0%, (S,
S) -EDDS yield was 11.2%. Thereafter, the reaction was conducted again for 3 hours (total 4 hours). After cooling, a part of the reaction solution was taken out and measured by the same method as described above. The L-aspartic acid conversion was 44.2% (S, S) -EDDS yield 3
It was 4.9%. Since the pH of the reaction solution decreased with the progress of the reaction and was 9.4, a 20% by weight aqueous sodium hydroxide solution was added to adjust the pH to 12.0. Thereafter, the reaction was carried out again for 4 hours (total 8 hours), and the reaction solution was cooled and analyzed. As a result, the conversion of L-aspartic acid was 78.0% (S, S) -EDDS yield was 55.8%.
Met. From the recovered reaction solution, trace amounts of unreacted 1,2-
Dichloroethane was collected under reduced pressure, the residual liquid was taken in a beaker, and a 40% by weight aqueous sulfuric acid solution was added under stirring at room temperature. As a result, white crystals were precipitated at pH 4.2. Thereafter, a 40% by weight aqueous solution of sulfuric acid was added little by little, and the pH was maintained at 3.5 to 4.2, and crystallization was continued. After the rise in pH was stopped, the mixture was further stirred for 30 minutes, and then the precipitated crystals were isolated by filtration under reduced pressure. The obtained crystals were washed three times with 30 ml of pure water and then dried under reduced pressure. The recovered crystals weighed 8.59 g, and when analyzed by high performance liquid chromatography, contained 7.97 g (92.8% by weight, yield 54.6%) of (S, S) -EDDS, and other L-aspartic acid. It contained 0.06 g and 0.67 g of water and a trace amount of inorganic substances.

Comparative Example 1 The same raw materials as in Example 1 were charged into an autoclave and reacted by stirring at 100 ° C. and 450 rpm with the same stirring blade.
The liquid density was calculated as 1250 kg / m ³ , and the stirring power was 0.1 kg.
It became 05 kW / m ³ . One hour after the reaction, a part of the reaction solution was withdrawn and measured in the same manner as in Example 1.
Aspartic acid conversion was 6.1%, (S, S) -EDD
The S yield was 5.5%. Thereafter, the reaction was carried out again for 3 hours (total 4 hours) and analyzed. As a result, the conversion of L-aspartic acid was 20.3% and the yield of (S, S) -EDDS was 16.6%.
Met. At this time, the pH of the reaction solution was 10.5.
Was adjusted. After the reaction for 4 hours (total 8 hours), the conversion of L-aspartic acid was 41.9%, (S,
The yield of S) -EDDS was 31.8%, the conversion of L-aspartic acid after 16 hours was 73.6%, and the yield of (S, S) -EDDS was 50.4%. As compared with Example 1, twice the reaction time was used, and almost the same conversion was obtained.

[0021]

According to the present invention, L-aspartic acid and dihaloethane are heated and stirred in a water solvent under basic conditions to obtain (S, S) -ED.
When producing DS, the stirring power is set to 0.3 to 1.5 kW /
When the reaction is performed within the range of m ³ , the reaction rate can be improved, and as a result, the desired product can be obtained in a practical reaction time.

Continuation of the front page (72) Inventor Masako Yoshitake 8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture Tsukuba Research Laboratory, Mitsubishi Chemical Corporation (72) Inventor Hiroshi Iwane 8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Prefecture No. Within the Tsukuba Research Laboratory, Mitsubishi Chemical Corporation (72) Inventor Tadashi Okura 1 Tohocho, Yokkaichi City, Mie Prefecture F term (reference) 4H006 AA02 AB70 AB76 AC24 AC52 AD15 BA02 BA06 BA29 BA92 BB47 BB47 BC10 BC16 BC18 BC34 BC35 BC51 BS10 BU32 NB10

Claims (5)

[Claims] 1. A method according to claim 1, wherein L-aspartic acid and dihaloethane are mixed in an aqueous solvent under basic conditions with a stirring power of 0.3 to 1.5 k.
Characterized in that the reaction is performed while stirring at a range of ^{W / m 3 (S, S} ) - ethylenediamine -N, manufacturing method of N'- disuccinic acid. 2. The (S, S) -ethylenediamine-N, according to claim 1, wherein the dihaloethane is 1,2-dichloroethane or 1,2-dibromoethane.
A method for producing N'-disuccinic acid. 3. The method for producing (S, S) -ethylenediamine-N, N′-disuccinic acid according to claim 1, wherein the pH of the reaction solution is 9 to 13. 4. The method according to claim 1, wherein the reaction temperature is 80 to 120 ° C.
A method for producing S) -ethylenediamine-N, N'-disuccinic acid. 5. The (S, S) -ethylenediamine according to claim 1, wherein a concentration of L-aspartic acid or a salt thereof in the reaction solution is 5 to 40% by weight. A method for producing N, N'-disuccinic acid.