JPH0366660A - Production of n,n-bis(hydroxyalkyl)aminoethylsulfonate - Google Patents

Abstract

PURPOSE:To efficiently and readily obtain a compound useful as a raw material for surfactants, intermediate for medicines, organic chemicals, etc., in high purity by reacting a taurine salt with a lower alkylene oxide at a specific molar ratio. CONSTITUTION:A salt of 2-aminoethylsulfonic acid (referred to as taurine) is reacted with a lower alkylene oxide in water medium at 30-80 deg.C to afford N,N-bis(hydroxyalkyl)aminoethylsulfonate. The reaction is carried out under conditions of >=2 to <=3mol alkylene oxide based on 1mol taurine salt. An alkali metal salt or ammonium salt is preferably used as the taurine salt and ethylene oxide is preferably used as the lower alkylene oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to N,N-bis(hydroxyalkyl)aminoethyl sulfonate (hereinafter referred to as , BHES).

"Prior art" As a method for producing N,N-bisalkyl taurine salt, which is one of the salt derivatives of aminoethylsulfonic acid (generally called taurine, hereinafter this compound is abbreviated as taurine), ■Applicable It is known that it can be produced by a method of adding alkanolamines to a vinyl sulfonate, and a method of condensing the corresponding 2-halogenated taurine salt with alkanolazines. The preparation of BHES, a taurine salt substituted with an alkyl group, is not disclosed.

Furthermore, as a method easily analogous to those skilled in the art, BHES
Although a method for producing the same can be mentioned, there is no example disclosed regarding this method either.

"Problems to be Solved by the Invention" Considering the above-mentioned circumstances, the present inventors have conducted intensive studies on the method of addition of alkylene oxide described above, and have found that using water as a solvent and under specific reaction conditions. The inventors have discovered that if this process is carried out, highly pure B)IEs can be produced efficiently and easily, and the present invention has been achieved.

``Means for Solving Problems J'' That is, the present invention provides 1 mol of 2-aminoethylsulfonate and a lower alkylene oxide in an aqueous medium at a temperature of 30°C to 80°C. This is a method for producing BHES, characterized in that the reaction is carried out under conditions of 2 moles or more and 3 moles or less of alkylene oxide per reaction.

One of the characteristics of the method of the present invention is that water is used as a reaction medium, and the ratio of taurine salt to water is preferably 0.4 or more and 2.0 by weight. If the amount used is less than 0.4 weight ratio, not only will the reaction efficiency be poor, but also a large amount of reaction by-product acid will be produced from water and alkylene oxide, which is undesirable. The solubility may be close to or exceed the solubility of taurine salt, which is undesirable because not only the reaction may become non-uniform, but also the reaction system becomes viscous, making it difficult for the reaction to proceed smoothly.

The lower alkylene oxide, which is one of the raw materials used in the present invention, means an alkylene oxide having 2 to 4 carbon atoms, preferably ethylene oxide or propylene oxide. In particular, when ethylene oxide is used, the characteristics of the method of the present invention becomes more prominent.

As the taurine salt, which is another raw material, any inorganic salt of taurine can be used, but in consideration of solubility in water, an alkali metal salt or an ammonium salt is preferable.

As mentioned above, it is preferred that the reaction proceed within the range of 30 to 80°C. At temperatures below 30°C, the reaction becomes extremely slow, and at temperatures above 80°C, side reactions between water and alkylene oxide become noticeable as described above, both of which are unfavorable.

The molar ratio of the raw material alkylene oxide to taurine salt used in the method of the present invention needs to be 2 moles or more in order to efficiently obtain the desired BHES, and if it is less than 2 moles, by-products such as monohydroxy compounds may be produced. This is not preferable because it increases the amount of BHES and requires purification of BHES. Further, if the amount used is 3 moles or more, the so-called Hofmann decomposition reaction, which is produced via the quaternary ammonium salt produced from the amine and alkylene oxide in addition to BHES, becomes significant, which is not preferable.

The method of the present invention does not particularly require a catalyst, but known catalysts used in alkylene oxide addition reactions such as tertiary amines and alkali hydroxides may be used.

To describe an embodiment of the method of the present invention, first, the above-mentioned taurine salt is added to a predetermined amount of water as a medium, and an alkylene oxide is added continuously or intermittently at a predetermined reaction temperature. There is no particular limit to the reaction pressure during this time, but it is usually 5 kg.
1 cTIl-G or less is sufficient. The reaction time varies depending on the type of raw materials used and the reaction temperature, but is approximately 1 to 5 hours, including the reaction time after the reaction pressure generated by addition of the alkylene oxide returns to atmospheric pressure.

The reaction is thus terminated, and if unreacted alkylene oxide remains, it is removed by reducing the pressure of the reaction system to obtain BHES. If this BHES is required as an aqueous solution, it can be left as is; if it is required as a solid, the above aqueous solution should be concentrated or the BHES
The ES may be isolated by pouring it into a water-soluble solvent with low solubility, and then dried to obtain a product.

"Example The present invention will be explained in more detail with reference to Examples below.

Example 1 After putting 74 g of taurine sodium salt and 150 g of water in a metal autoclave and sealing the autoclave, 46.0 g of ethylene oxide was added over 1 hour while maintaining the temperature at 45 to 50°C to carry out a reaction. During this time, the pressure was maintained below 2.0 atmospheres. After the addition of ethylene oxide was completed, an aging reaction was further carried out at the same temperature for 30 minutes.

Since 0.8 g of unreacted ethylene oxide remained in the reaction system, the pressure of the system was reduced to remove this.

There was 116 g of solid material in the reaction mixture, and when it was analyzed, it was confirmed from the infrared absorption spectrum that it was N,N-bis(2- and droxyethyl) taurine sodium salt, and the purity calculated from the hydroxyl value was 99.0%,
The yield based on the taurine sodium salt used was 98.0%.
Met.

Example 2 The method described in Example 1 was repeated using 82 g of taurine potassium salt, 140 g of water and 46 g of ethylene oxide.

The yield of the obtained N,N-bis(2-hydroxyethyl)taurine potassium salt was 123 g, and the yield was 97.6% based on the taurine potassium salt used. Further, the purity estimated from the hydroxyl value was 99.1%.

Example 3 71g of taurine ammonium salt in a metal autoclave
After adding 140 g of water and sealing the container, 69.0 g of propylene oxide was added over 1 hour while maintaining the temperature at 50 to 65° C. to conduct a reaction. During this time, the pressure was maintained below 3.0 atmospheres. After the addition of propylene oxide was completed, an aging reaction was further carried out at the same temperature for 40 minutes.

Since 2.0 g of unreacted propylene oxide remained in the reaction system, the pressure of the system was reduced to remove this.

There was 123g of solid material in the reaction mixture, and when it was analyzed, it was confirmed from the infrared absorption spectrum that it was N,N-bis(2-hydroxypropyl)taurine ammonium salt, and the purity estimated from the hydroxyl value was The yield is 98.9%, and the yield is 94% based on the taurine ammonium salt used.
．． It was 9%.

"Effect of the invention"

Claims (1)

[Claims] 1. 2-aminoethylsulfonate and lower alkylene oxide in an aqueous medium at a temperature of 30°C to 80°C.
1. A method for producing N,N-bis(hydroxyalkyl)aminoethyl sulfonate, characterized in that the reaction is carried out under conditions of 2 mol or more and 3 mol or less of alkylene oxide per 1 mol of aminoethyl sulfonate. 2. The manufacturing method according to claim 1, wherein the 2-aminoethylsulfonate is an alkali metal salt or an ammonium salt. 3. The manufacturing method according to claim 1 or 2, wherein the lower alkylene oxide is ethylene oxide or propylene oxide. 4. The manufacturing method according to claims 1 to 3, wherein the 2-aminoethylsulfonate is a sodium salt, and the alkylene oxide is ethylene oxide.