JPH06192209A - Method for purifying taurine - Google Patents

Abstract

PURPOSE:To separate or remove impurities and obtain high-purity taurine having wide uses as a medicine such as a therapeutic agent for hepatopathy, an antidote or an anticonvulsant agent or a food additive in high yield simply by treating the taurine in an alcoholic solution. CONSTITUTION:Crude taurine (2-aminoethylsulfonic acid) obtained especially by a method for reacting 2-chloroethylamine hydrochloride with sodium sulfite, etc., is treated in an alcoholic solution to separate or remove impurities. Methanol and ethanol are preferred as the alcohol to be used. The final concentration of the alcohol in carrying out this treatment is >=20wt.%, preferably >=35wt.%. The crystallization temperature is preferably <=10 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for purifying taurine (2-aminoethylsulfonic acid). More specifically,
The present invention relates to a method for purifying taurine, which comprises treating with an alcohol solution when purifying taurine obtained through a manufacturing process.

[0002]

BACKGROUND OF THE INVENTION Taurine is widely known as a drug such as a drug for treating liver diseases, an antidote, an anticonvulsant, and a food additive.

As a method for producing taurine, extraction from aquatic products and a plurality of organic synthesis methods are already known, but taurine must be purified to a high degree of purity in order to be used in the above applications. Further, industrially, it is important to obtain taurine in a high yield.

As a means for purifying taurine in a high yield, a technique of adding alcohol for crystallization has been known. That is, when purifying taurine from a hot water or hot water extraction solution of natural products (aquatic products, etc.) or a synthetic reaction completed solution, crystals of taurine are precipitated in an aqueous alcohol solution, and final taurine crystals are obtained by filtration and drying. Is the way.

However, in the case of purifying taurine from natural products, a large number of unspecified impurities are present,
Coprecipitation of impurities during alcohol treatment cannot be avoided. Therefore, it is necessary to remove impurities to some extent before crystallization by performing electrodialysis treatment or ion exchange resin treatment in advance.

On the other hand, in the case of purifying taurine obtained through the manufacturing process, the types and amounts of impurities present are limited, so that purification can be performed by crystallization focused on the removal of specific impurities. It is possible.

Several types of organic synthesis methods for producing taurine have been known, and a typical example thereof is a method for producing taurine by reacting 2-chloroethylamine hydrochloride with sodium sulfite. (JP-A-60-23360, JP-A-60-2)
3361, JP-A-63-48258, JP-A-63-48
259).

In the case of this method, when taurine is produced, 2
Since a double molar amount of sodium chloride is by-produced, sodium chloride having almost the same weight concentration as that of taurine is present in the reaction completed solution (hereinafter referred to as the reaction solution). Further, sodium sulfate contained in the raw material sodium sulfite and sodium sulfate by-produced by the oxidation of sodium sulfite are also contained in the reaction liquid. Furthermore, the raw material 2-
Chlorethylamine (hereinafter, CEA), 2-aminoethanol (hereinafter, MEA) that is a raw material of CEA, N- (2-aminoethyl) -taurine (hereinafter, AET) produced by the reaction of CEA or MEA and taurine, Impurities such as oxybis-aminoethane (hereinafter, OBAE) produced by dehydration condensation of two MEA molecules are present.

Here, alcohol, especially lower alcohol optionally mixed with water, is a solvent that is highly versatile and widely used in industry. One of the reasons is that the physical properties of individual compounds represented by the solubility change in the aqueous solution and the aqueous alcohol solution. The inventors of the present invention considered that the behavior of the above impurities might change in an alcohol solution, and conducted studies and completed the present invention.

[0010]

[Means for Solving the Problems] The present inventors investigated the solubility of the above impurity groups in an alcohol solution. As a result, like taurine, sodium chloride / sodium sulfite / sodium sulfate / AET has a significantly reduced saturated solubility when the alcohol concentration is high, whereas CEA / MEA / OBAE has a very low saturated solubility in the alcohol concentration. Turned out to be independent. Furthermore, CEA / MEA / OBAE was found to have a property that when taurine was crystallized in an alcohol solution, entrainment in taurine crystals was reduced. Therefore, the present invention was completed by utilizing the difference in behavior between each impurity and taurine in the alcohol solution.

That is, the present invention is a method for purifying taurine, which comprises treating taurine obtained through a manufacturing process with an alcohol solution to separate or remove impurities. Furthermore, when such a manufacturing process is a reaction of 2-chloroethylamine hydrochloride and sodium sulfite, it is a particularly effective purification method.

The method for carrying out the present invention will be described in detail below. The production process of taurine of the present invention is not particularly limited, but it is a particularly effective method when it is produced according to the organic synthesis method described below, because the above-mentioned impurities are present in the reaction solution. B) A method of producing by reacting 2-chloroethylamine hydrochloride with sodium sulfite (Ind. Eng. Che
m. , Vol. 39, 1947, JP-B-63-4825
8, Japanese Patent Publication No. 63-48259). B) A method for producing by reacting 2-bromoethylamine hydrobromide with sodium sulfite (J. Am. Che
m. Soc. , Vol. 58, 1936). C) A method of reacting 2-aminoethanol sulfate with sodium sulfite to produce (J. Chem. So.
c. , Vol. 4,1943, Japanese Examined Patent Publication 4-1046
7). D) A method for producing a 2,2-2 substituted thiazolidine by oxidation (JP-A-57-26654).

The present invention is specifically achieved by adding alcohol to the above reaction solution to crystallize taurine and separating the crystals by means such as filtration. At this time, CE
Impurities such as A, MEA, and OBAE are less likely to be trapped in the taurine crystal, and thus can be efficiently separated from taurine. Further, this property is not limited at all with respect to the concentration of alcohol during the treatment, but it is effective to carry out it at a concentration of preferably 20% by weight or more. Further, there is no limitation on the type of alcohol and the crystallization temperature.

Industrially, it is important to obtain taurine from the reaction solution in good yield. Therefore, the final concentration of alcohol when the treatment of the present invention is performed is preferably 20% by weight or more, preferably 35% by weight or more, and the crystallization temperature is preferably 20 ° C. or lower, preferably 10 ° C. or lower. The alcohol is not particularly limited as long as it is freely miscible with water, but methanol or ethanol is particularly desirable.

When the taurine crystal separated from impurities such as CEA / MEA / OBAE contains impurities such as sodium chloride / sodium sulfite / sodium sulfate / AET whose solubility depends on the alcohol concentration, an aqueous solution or Recrystallization or sludging or the like is performed in an alcohol aqueous solution of less than 20% by weight to finally separate these compounds from taurine.

Here, the effects of the present invention will be specifically described by using Examples and Comparative Examples. In the examples, before performing the final reconstitution, two crystallizations in methanol solution
Specific impurities in the reaction solution (MEA, CEA, OBAE)
Have been removed. On the other hand, in the comparative example, the impurities that could be removed in the examples cannot be completely removed, and the impurity content is relatively large.

When the secondary crystal of the example and the primary crystal of the comparative example are compared, the yield of the comparative example is lower than that of the example, which affects the final yield.

[0018]

【Example】

Example Purification was carried out using 400.0 g of a taurine reaction solution synthesized by the method disclosed in JP-A-63-48259.
The amount of each compound in this solution was as follows. Taurine 76.0 g Sodium chloride 71.0 g Sodium sulfate 6.2 g AET 2.73 g MEA 2.79 g CEA 0.67 g OBEA 3.12 g The reaction solution was once heated to 70 ° C. to completely dissolve taurine and the like. After cooling to room temperature, 267.0 g of methanol
Is gradually added (methanol concentration 40.0% by weight), and 0
The mixture was stirred at ℃ for 2 hours to precipitate taurine crystals and filtered.
Separation and drying gave 101.1 g of primary crystals. The amount of the compound in the primary crystal was as follows (in parentheses:
Yield from reaction solution) Taurine 71.3 g (93.8%) Sodium chloride 26.2 g (36.9%) Sodium sulfate 2.8 g (44.4%) AET 0.27 g (9.9%) MEA 0.02 g (0.7%) CEA non-detection (0.0%) OBEA non-detection (0.0%) Subsequently, 127.1 g of water was added to the primary crystal and the mixture was heated to 80 ° C. to form the primary crystal. It was completely dissolved. After cooling to room temperature,
Slowly add 57.0 g of methanol (methanol concentration 2
0.0 wt%, taurine concentration 25.0 wt%), then 10
The mixture was stirred at ℃ for 2 hours to precipitate taurine crystals, which were filtered, separated and dried to obtain 66.4 g of secondary crystals. The amount of the compound in the secondary crystal was as follows (in parentheses, the total yield from the reaction solution). Taurine 65.5 g (86.2%) Sodium chloride 0.76 g (1.1%) Sodium sulfate 0.03 g (0.5%) AET 0.04 g (1.4%) MEA undetected (0.0% Further, 159.6 g of water was added to the secondary crystal and heated to 80 ° C. to completely dissolve the secondary crystal (taurine concentration 29.0).
w%). The mixture was stirred at 10 ° C. for 2 hours to precipitate taurine crystals, which was filtered, separated and dried to obtain 53.5 g of tertiary crystals.
AET was not contained in this tertiary crystal. In addition, it was a product that passed the Japanese Pharmacopoeia (8th revision) (taurine purity 99.7%). The total yield from the reaction solution is 70.4.
%Met. In both the examples and comparative examples, taurine
Quantitative analysis of MEA / CEA / AET / OBAE was performed using high performance liquid chromatography under the following analysis method and conditions. Column: Inersitol ODS-2 Carrier: 10v% methanol-30mM phosphoric acid aqueous solution (pH 3.0) (however, containing 0.6% by weight 1-heptanesulfonic acid) Flow rate: 1.0ml / min Column temperature: 40 ° C Detection method : Fluorescence method with o-phthalaldehyde (EX = 3
(65 nm, EM = 455 nm) Detection limit: 1 ppm Further, the quantitative analysis of sodium chloride and sodium sulfate was carried out by measuring D for chlorine ion and sulfate ion, respectively.
It was performed using an ion chromatography device series 2000i (column: AS4A) manufactured by IONEX.

Comparative Example 400.0 g of the same solution as in Example 1 was used to purify taurine. The reaction solution was once heated to 70 ° C. to completely dissolve taurine and the like. After cooling to room temperature, stirring at 10 ° C for 2 hours to precipitate taurine crystals, filtration, separation,
By drying, 54.2 g of primary crystals were obtained. The amount of the compound in the primary crystal was as follows (in parentheses, the yield from the crystallization mother liquor) Taurine 51.8 g (68.2%) Sodium chloride 1.6 g (2.3%) Sulfuric acid Sodium 0.18g (2.9%) AET 0.11g (4.0%) MEA 0.17g (6.1%) CEA 0.04 (6.0%) OBEA 0.12 (3.8%) Subsequently, 124.4 g of water was added to the primary crystal and heated to 80 ° C. to completely dissolve the primary crystal (taurine concentration 29.0).
weight%). After cooling to room temperature, the mixture was stirred at 10 ° C. for 2 hours to precipitate taurine crystals, and filtered, separated and dried to obtain 42.3 g of secondary crystals. This secondary crystal was a product that passed the Japanese Pharmacopoeia (eighth revision) (taurine purity 99.7%).
The overall yield from the reaction solution was 55.7%.

[0020]

According to the method of the present invention, when purifying taurine obtained through the production process, it is possible to efficiently separate impurities by-produced in the production process and obtain taurine in a high yield.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuhiro Fukuhara 30 Asamu-cho, Omuta-shi, Fukuoka Mitsui Toatsu Chemical Co., Ltd.

Claims (4)

[Claims] 1. Taurine obtained through the manufacturing process,
Method for purifying taurine, characterized by treatment in alcoholic solution to separate or remove impurities 2. The purification method according to claim 1, wherein the production step is a reaction of 2-chloroethylamine hydrochloride with sodium sulfite. 3. The final concentration of the alcohol solution to be treated is 2
The purification method according to claim 1 or 2, which is 0% by weight or more. 4. The purification method according to claim 1, 2 or 3, wherein the alcohol used for the treatment is methanol or ethanol.