KR840001033B1 - Process for producing aziridine-2-carboxylic acid or its salt - Google Patents

Abstract

α-halo-β-aminopropionic acids and esters, and their mineral acid salts, were treated with alkali and alk. earth hydroxides and NH3 to yield metal and ammonium 2-aziridine carboxylates. Thus, aq. NaOH was added to H2NCH2CHClCOOHHCl in water, and the mixt. was kept 24 hr at room temp. to give Na 2-aziridinecarboxylate.

Description

Aziridine-2-carboxylic acid or salt thereof preparation method

The present invention relates to a process for preparing aziridine-2-carboxylic acid or a salt thereof useful as an intermediate for preparing agrochemical α-amino acids.

Several methods of preparing aziridine-2-carboxylate have been known. For example, a method of preparing aziridine-2-carboxylic acid sodium may be prepared by using α-croro-β-alanine hydrochloride in aqueous sodium hydroxide solution. Neutralizing and simultaneously heating the neutralizing product to reflux, and adding 1N sodium hydroxide solution dropwise so that the pH of the aqueous solution is maintained in the range of 7 to 7.5 (1) [KD Gundermann, Chem. Ber., 93 '1640 (1 960)] and aziridine-2-carboxylic acid isopropyl obtained by the reaction of α, β-dibromopropionic acid isopropyl with liquid ammonia and a mixed solvent of eger, ethanol and water. Hydrolysis with sodium ethoxide in water (2) [E. Kyburz, Hev. Chim. Acta, 49 , 368 (1966)], and as a method for preparing lithium aziridine-2-carboxylic acid, ethyl ester produced by treating α-chloro-β-alanine ethyl ester with triethanol amine in ethanol is used. Characterized by hydrolysis with lithium hydroxide in a mixed solvent of ethanol and water. (3) [KD Gundermann, Chem. Ber., 93 , 1639 (1960). However, in the method of (1), there is a drawback that the reaction must be carried out while keeping the concentration of α-chloro-β-alanine hydrochloride as a starting material in the reaction system as low as about 1% by weight, and (2) and (3) In this method, the synthesis operation of aziridine-2-carboxylic acid ester is complicated, and the yield of the target object is low. Therefore, in the industrial practice, the above known methods are not satisfactory at all.

It is therefore an object of the present invention to provide a process which can industrially advantageously produce aziridine-2-carboxylic acid and its salts.

The present inventors have conducted extensive research to achieve the above object, and accordingly, an aqueous solution of α-halogeno-β-aminopropionitrile or an inorganic acid salt thereof or a hydrous organic solvent solution is appropriately heated with alkali or alkaline earth metal hydroxides. It came to find a method characterized by. According to the method of the present invention, the nitrile group undergoes hydrolysis and intramolecular dehydrochlorination (cyclization), almost no by-products are generated, and almost selectively of alkali or alkaline earth metal salts of aziridine-2-tarboxyl.

In the process of the invention, the α-halogeno aminopropionitrile or its inorganic acid salt used as starting material is α-halogeno acrylonitrile or α, β-dihalogeno propionitrile and ammonia in water or in an organic solvent. It can be obtained easily by making it react in the inside.

In particular, according to a preferred embodiment of the present invention α-halogeno-β-aminopropionitrile or α, β-dihalogenopro obtained by reacting α-halogeno acrylonitrile and ammonia in water and or an organic solvent Α-halogeno-β-aminopropionitrile obtained by reacting pionitrile with ammonia in water and / or an organic solvent can be used as a raw material without isolating from the reaction system. That is, hydroxides of alkali metals or alkaline earth metals are added to the reaction solution containing α-halogeno-β-aminopropionitrile as prepared in the above in the form of an aqueous solution, a water suspension or a solid, and heated as necessary. Aziridine-2-carboxylic acid can be manufactured.

Thus, according to the present invention, it can be easily and inexpensively prepared by halogenation of acrylonitrile and dehydrohalogenation, and industrially by halogenation of α-halogeno acrylonitrile or acrylonitrile. And aziridine-2-carboxylic acid can be industrially advantageously prepared from low-cost α, β-dihalogeno propionitrile and then α-halogeno-β-aminopropionitrile. have.

The process of the present invention can be prepared inexpensively and easily, the reaction operation is simple, the operations are very simple, and the desired aziridine_2_carboxylic acid can be obtained in high yield. It has several advantages over the methods. Thus, the method of the present invention is very advantageously used industrially.

Examples of α-halogeno-β-aminopropionitrile or inorganic acid salts thereof used in the method of the present invention include α-chloro-β-aminopropionitrile, α-bromo-β-aminopropionitrile, α And -chloro-β-aminopropionitrile hydrochloride and sulfate, and α-bromo-β-aminopropionitrile hydrochloride and sulfate.

α-halogeno-β-aminopropionitrile or an inorganic acid salt thereof is obtained by reacting α, β-dihalogeno-propionitrile or α-halogenoacrylonitrile with ammonia in water or in an organic solvent. The free α-halogeno-β-aminopropionitrile is obtained by distilling under reduced pressure on an extract obtained by extracting a reaction product of the reaction mixture or the reaction mixture described above with an organic solvent which is not mixed with water. When hydrochloric acid or sulfate is applied to the reaction mixture, α-halogeno-β-aminopropionitrile hydrochloride or sulfate is obtained. For example, α-chloro-β-aminopropionitrile hydrochloride is added dropwise α-chloroacrylonitrile at about 0 ° C. to an ammonia solution such as isopropanol, reacted at this temperature for 2-4 hours, and then isopropanol solution of hydrogen chloride It can be isolated in a yield of 80% or more by supplying.

As an aqueous solution or aqueous organic solution containing α-halogeno-β-aminopropionitrile or an inorganic acid salt thereof used in the method of the present invention, α, β-dihalogenopropionitrile (1) or α-halogeno A reaction mixture containing α-halogeno-β-aminopropionitrile obtained by reacting acrylonitrile (2) with ammonia may be used. This reaction mixture will be described in more detail below.

(1) First, a reaction mixture containing α-halogeno-β-aminopropionitrile obtained by reacting α, β-dihalogenopropionitrile with ammonia in water and / or an organic solvent will be described. As the starting materials α, β-dihalogenopropionitrile, chlorine, bromine, oxo and fluorine derivatives may be used, but α, β-dichloropropionitrile, α, β-dichloropropionitrile and α, β Dibromopropionitrile is preferred, and α, β-dihalogenopropionitrile can be easily prepared by halogenating acrylonitrile.

As ammonia used for the production of α-halogeno-β-aminopropionitrile, aqueous ammonia or a solution in which ammonia gas or aqueous ammonia is dissolved in an organic solvent is used. This reaction can also be carried out while introducing ammonia gas into the reaction system. The organic solvent used for the reaction means an organic solvent having ammonia dissolving power, and generally, lower grades such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, methylcellosolve or cellosolve Use alcohol. These organic solvents may be used by mixing two or more thereof or by mixing with water.

The amount of α, β-dihalogenopropionitrile and ammonia used is 2 mol or more, preferably 2.2 mol or more, with respect to 1 mol of α, β-dihalogenopropionitrile. When the reaction is carried out in aqueous ammonia, ammonia is used as a 5 to 30% by weight solution, and when it is carried out in an organic solvent or a hydrous organic solvent, a solution having a concentration of 2 to 25% by weight ammonia is used.

Although the method and order of addition of the starting material and the solvent in the production reaction of α-halogeno-β-aminopropionitrile are not specified, the α, β-dihalogenopropionyl is usually slowly added in water or an aqueous organic solvent. It is preferable to add, and it may add after diluting (alpha), (beta)-dihalogeno propionitrile with an organic solvent.

The reaction temperature is -40 to 30 ° C, preferably -20 to 20 ° C, and the reaction time is 0.5 to 20 hours, preferably 1 to 15 hours. The present reaction may be carried out in an air atmosphere, but the reaction is preferably carried out in an inert gas such as nitrogen gas because the side reaction can be suppressed while the reaction is performed in an inert gas.

The end point of the reaction between α, β-dihalogentopropionitrile and ammonia can be easily confirmed by gas chromatography, high performance liquid chromatography, or the like.

(2) A reaction mixture containing α-halogeno-βaminopropionitrile obtained by reacting α-halogenoacrylonitrile with ammonia in water and / or an organic solvent will be described in detail below.

In general, α-chloroacrylonitrile and α-bromoacrylonitrile are used as α-halogenoacrylonitrile.

Ammonia uses aqueous ammonia or ammonia gas or a solution form in which aqueous ammonia is dissolved in an organic solvent. The reaction of α-halogenoacrylonitrile with ammonia can be carried out in water and / or in an organic solvent. When the reaction is carried out in an organic solvent, an organic solvent having no ammonia solubility is used. Examples of suitable organic solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, and methyl cell. Lower alcohols, such as a solve and a cellosolve, can be enumerated, These solvent can be used individually or in mixture of 2 or more, and can also be used in mixture with water.

The amount of α-halogenoacrylonitrile and ammonia used is 1 mol or more, preferably 1.2 mol or more, with respect to 1 mol of α-halogenoacrylonitrile. When the reaction is carried out in aqueous ammonia, a solution having an ammonia concentration of 5 to 30% by weight is used, and when the reaction is carried out in an organic solvent, a solution having a concentration of 2 to 25% by weight is used.

In the reaction of α-halogenoacrylonitrile with ammonia, the method and order of addition of the starting materials and the solvent are not specified, but are usually added in water and / or ammonia-containing organic solvent, and preferably α-halogenoacryl. Nitrile can be added after dilution with an organic solvent.

The reaction temperature is -40 to 30 ° C, preferably -20 to 20 ° C, and the reaction time is 0.5 to 20 hours, preferably 1 to 15 hours. The reaction may be carried out in an open or inert gas atmosphere. However, since the side reaction can be suppressed in an inert gas atmosphere, the reaction is preferably carried out in an inert gas atmosphere such as nitrogen atmosphere or nitrogen vapor. The reaction end point can be confirmed quickly and easily by gas chromatography, high performance liquid chromatography, or the like.

Examples of the alkali or alkaline earth metal hydroxide used in the present invention include alkali metal hydroxides such as lithium, sodium, potassium, and rubidium, and alkali alkali earth metal hydroxides such as beryllium, magnesium, calcium, strontium, and barium. Examples include lithium hydroxide, sodium hydroxide, potassium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide and barium hydroxide. In general, sodium hydroxide, potassium hydroxide and calcium hydroxide are preferred.

In the method of the present invention, when the amount of alkali or alkali metal hydroxide is used as starting material, free α-halogeno-β-aminopropionitrile is used in an amount of 2 equivalent or more relative to the starting material, and as starting material, α-halogeno- If an inorganic acid salt of β-aminonopropionitrile is used, it is used in an amount of at least 3 equivalents based on the starting material. Although it is not characterized by the upper limit of the amount of hydroxide used, it is not necessary to use a large amount, and a maximum of 5 equivalents is sufficient.

2, or more, preferably 2.2 or more, of α, β-dihalogenopropionitril or α-halogenoacrylonitrile or relative to α-halogenoacrylonitrile. The upper limit of the amount of alkali or alkaline earth metal used is not specified, but it is not necessary to use it in excess, and usually up to 5 equivalents is sufficient.

The process of the invention is carried out in water or in an aqueous organic solvent. In other words, this reaction is carried out in an aqueous solution or a mixture of water and a water miscible organic solution.

Illustrative water miscible organic solvents include methanol, ethanol, n-propanol, isopropanol, t-butanol, cellosolve, methylcellosolve, acetone, dioxane, tetrahydruroran, N, N-dimethylformamide, N, N-diethylformamide, dimethyl sulfoxide, etc. can be mentioned. When mixing water and an organic solvent, the ratio of water to an organic solvent may be arbitrarily selected. The solvent is used in an amount of 3 to 200 times, preferably 5 to 100 times with respect to the starting material α-halogeno-β-aminopropionitrile or an inorganic acid salt thereof.

In carrying out the process of the present invention, the method and order of addition of starting materials, alkalis and reaction solvents are not limited. Usually, a predetermined amount of alkali or alkaline alkali metal hydroxide is used as an aqueous solution or suspension to form α-halogeno-. β-aminopropionitrile or a salt thereof is added to a solution dissolved in water and / or in a water-miscible organic solvent at a desired concentration, or a solution containing α-halogeno-βaminopropionitrile is alkali or alkaline earth metal You may add in aqueous solution or suspension of hydroxide. Reaction in water and / or organic solvent when using a reaction mixture containing α-halogeno-β-aminopropionitrile derived from α, β-dihalogenopropionitrile or α-halogenoacrylonitrile The solution in which the mixture is dissolved may be treated with hydroxide in the same manner as described above.

Alkali or alkaline earth metal hydroxides may be added in a solid phase.

When ammonium chloride precipitates as a by-product from the reaction mixture containing α-halogeno-β-aminopropionitrile, ammonium chloride is separated and the reaction mixture is hydrolyzed. When the production reaction of α-halogeno-β-aminopropionitrile is carried out in an organic solvent, water must be added for subsequent hydrolysis and cyclization reaction. Although the addition amount of water is not specified, the ratio of an organic solvent and water can be selected as needed.

The reaction temperature is 0 to 100 ° C, preferably 20 to 80 ° C, but the reaction is usually carried out at atmospheric pressure, and may be carried out under reduced pressure or normal pressure, if necessary. The reaction time depends on various reaction conditions, but is usually 0.5 to 50 hours, preferably 2.0 to 30 hours. The end point of the reaction can be easily and quickly confirmed by thin layer chromatography.

In the process of the invention, the aziridine-2-carboxylic acid is produced with an alkali or alkaline earth metal salt corresponding to the alkali used in the reaction. If necessary, the organic solvent can be removed under reduced pressure from the product to obtain the product in the form of an aqueous solution.

The present invention will be described in more detail with reference to the following examples.

As a standard sample used in the Example, ariridine-2-carboxylic acid lithium was synthesized as follows. Analysis by liquid chromatography therein was performed under the following conditions.

(a) Preparation of aziridine-2-carboxylic acid lithium

10 g of α-chloro-β-aminopropionate was dissolved in 100 ml of dehydrated ethanol, 20 g of triethanolamine was added, and the mixture was reacted at 60 ° C to 70 ° C for 5 hours while stirring. Precipitated triethanolamine hydrochloride was filtered off and washed with a small amount of ethanol. The filtrate and washings were combined, 55 ml of a 1N aqueous lithium hydroxide solution was slowly added while cooling, and then left in a cold dark for 24 hours. The reaction mixture was concentrated under reduced pressure, and 30 ml of benzene was added to the residue (syrup material) to completely remove water by azeotropic distillation. Then hot ethanol was added and the mixture was cooled to form a precipitate. 100 ml of ether was added to completely precipitate the crystals. The precipitate was filtered off and washed with ether to obtain 1.0 g of ariridine-2-carboxylic acid lithium.

Melting Point: 260 ~ 268 ℃ (Decomposition)

Elemental Analysis (%) C ₃ H ₄ NO ₂ Li:

Found (%): C 37.86, H 4.22, N 14.71, Li 7.40

Calculated Value (%): 38.74, 4.33, 15.06, 7.46

The purity of the produced aziridine-2-carboxylic acid lithium lithium measured by proton NMR spectroscopy (measurement solvent; D ₂ O, measurement temperature: room temperature) using dioxane as an internal standard was 97%.

(b) Analytical conditions by high performance liquid chromatography

Column: Shodex OH Pak B-804 (from Showa Denko)

Detector: Cirring Refractometer RI-2 (manufactured by Nippon Boraxe Industrial Co., Ltd.)

Mobile phase: H ₃ PO ₄ aqueous solution (1 × 10 ^-3 mol / liter)

Flow rate: 1.3 ml / min

Measurement temperature: room temperature

Under the conditions described above, the retention time of aziridine-2-carboxylic acid was 16.5 to 16.8 minutes.

Example 1

28.2 g of α-chloro-β-aminopropionitrile hydrochloride was dissolved in 80 g of water, and then, an aqueous solution in which 25.6 g of sodium hydroxide was dissolved in 84 g of water was added dropwise with stirring, followed by reaction at room temperature for 24 hours. The reaction mixture was analyzed by high performance liquid chromatography using aziridine-2-carboxylic acid lithium as an internal standard. As a result, the yield of production of aziridine-2-carboxylic acid lithium was α-chloro-β-aminopropio. 95.5% relative to nitrile hydrochloride.

Analysis of the resulting reaction mixture by proton NMR spectroscopy showed a signal attributable to the methylene proton of aziridine-2-carboxylic acid at δ = 1.79 ppm (q., 2H) and a signal attributable to methine protons. This δ = 2.35 ppm (q., 1H) was shown, and this signal model was the same as in the aziridine-2-carboxylic acid lithium, synthesized as a standard sample.

Example 2

14.1 g of α-chloro-β-aminopropionitrile hydrochloride was dissolved in 160 g of water, and an aqueous solution in which 22.4 g of potassium hydroxide was dissolved in 90 g of water was added dropwise while stirring. Next, the reaction mixture was heated to 60 ° C. and reacted at 60 to 65 ° C. for 4 hours. As a result of analyzing the reaction mixture by high performance liquid chromatography in the same manner as in Example 1, the yield of aziridine-2-lithium carboxylate was 92.3%.

Example 3

Example 2 operation, except that 10.5 g of free α-chloro-β-aminopropionitrile instead of α-chloro-β-aminopropionitrile hydrochloride and 13 g of lithium hydroxide in place of potassium hydroxide were used. Was repeated to produce aziridine-2-lithium carbonate in a yield of 90.8%.

Example 4

The procedure of Example 2 was repeated except that 15.3 g of α-chloro-β-aminopropionitrile sulfate was used in place of the α-chloro-β-aminopropionitrile hydrochloride, and the aziridine-2- Lithium carboxylate was produced in 94.2% yield.

Example 5

14.1 g of α-chloro-β-aminopropionitrile hydrochloride was dissolved in 160 g of water, and 12 g of calcium hydroxide was slowly added while stirring, and the reaction mixture was heated to 60 ° C. and reacted at 60 to 65 ° C. for 8 hours. After completion of the reaction, excess calcium hydroxide was filtered off, and the residue was analyzed by high performance liquid chromatography in the same manner as in Example 1, whereby aziridine-2-carboxylic acid calcium was produced in 92.5% yield.

Example 6

14.1 g of α-chloro-β-aminopropionitrile hydrochloride was dissolved in 150 g of methanol, and an aqueous solution in which 12.8 g of sodium hydroxide was dissolved in 75 g of water was added dropwise while stirring. Next, the reaction mixture was heated to 60 ° C. and reacted at this temperature for 10 hours, after which the residue obtained by distilling off the methanol in the reaction mixture under reduced pressure was analyzed by high performance liquid chromatography. As a result, aziridine-2-carboxyl was analyzed. Sodium acid was produced in 89.2% yield.

Example 7

The same procedure was repeated except that 150 g of isopropanol was used instead of methanol in Example 6 to obtain sodium aziridine-2-carboxylic acid in a yield of 93.5%.

Example 8

20.8 g of α, β-dichloropropionitrile was added dropwise over about 2 hours while maintaining 60.8 g of concentrated aqueous ammonia (28 wt% concentration) at 0 ° C. and slowly stirring under a nitrogen stream. The reaction was further performed at 0 to 5 ° C. for 3 hours, and then an aqueous solution of 25.6 g of sodium hydroxide dissolved in 150 g of water was added dropwise over about 30 minutes, followed by another 30 minutes at room temperature. As a result of analyzing the reaction mixture by high performance liquid chromatography, sodium aziridine-2-carboxylic acid was produced in a yield of 80.1% relative to α, β-dichloropropionitrile. The reaction time was 16.5 minutes.

When the reaction mixture was subjected to proton NMR spectrum (measurement temperature; room temperature), a signal was observed only at δ = 1.79 ppm (q., 2H) and δ = 2.35 ppm (q., 1H). These signals were identical to those of lithium aziridine-2-carboxylic acid in standard time in aqueous solution.

Example 9

225 g of isopropanol solution dissolved in a concentration of 6.8% of ammonia gas was maintained at 0 ° C., and 24.8 g of α, β-dichloropropionitrile was added dropwise over about 2 hours while slowly stirring under a stream of nitrogen. The reaction was carried out at 占 폚 for 3 hours to produce α-chloro-β-aminopropionitrile. The reaction mixture was externally cooled and an aqueous solution in which 25.6 g of sodium hydroxide was dissolved in 230 g of water was slowly added dropwise. The solution was heated to 50 ° C. and reacted at 50 to 55 ° C. for 7 hours. Next, the reaction mixture was distilled off under reduced pressure to distill the isopropanol and the residue was analyzed by high-performance etch chromatography in the same manner as in Example 9, whereby the aziridine-2-carboxylic acid sodium was α, β-dichloropro It was produced in 90.8% yield relative to pionenitrile.

[Examples 10-13]

Aqueous solution of aziridine-2-carboxylic acid alkali or alkaline earth metal corresponding to each alkali used in the same operation as in Example 9, except that each alkali shown in Table 1 below was used instead of sodium hydroxide. Got. The yield of the resultant target is shown in Table 1 below.

[Table 1]

[Examples 14-16]

The same operation was carried out except that the respective solvents listed in Table 2 below were used in place of isopropanol to obtain sodium aziridine-2-carboxylic acid in the yields described in Table 2 below.

[Table 2]

Example 17

Except that the reaction of α, β-dichloropropionitrile and ammonia was carried out at 15 to 20 ° C. in Example 9, the same operation was carried out to give an aqueous solution of sodium aziridine-2-carboxylic acid to α, β-dichloroprop It was obtained in a yield of 91.3% with respect to the pionitrile.

Example 18

A solution obtained by dissolving 17 g of ammonia gas in 200 g of hydrous ethanol containing 20% by weight of water was cooled to 0 ° C., and 24.8 g of α, β-dichloropropionitrile was added dropwise while stirring was slowly under a nitrogen gas stream. The reaction was also performed at 0-5 [deg.] C. for 4 hours to produce [alpha] -chloro- [beta] -aminopropionitrile. Next, the reaction mixture was added dropwise while performing external cooling in a solution in which 25.6 g of sodium hydroxide was dissolved in 200 g of water, and heated to 60 ° C. for 5 hours at 60 to 65 ° C .. The reaction mixture was distilled off under reduced pressure to remove ethanol and the residue obtained was analyzed by high performance liquid chromatography in the same manner as in Example 1, whereupon sodium aziridine-2-carboxylic acid was α, β-dichloropropionitrile. For 86.7% yield.

Example 19

60.8 g of aquatic ammonia (28% concentration) was maintained at 0 ° C., and 17.5 g of α-acrylonitrile was added dropwise over about 2 hours while slowly stirring under a stream of nitrogen gas, followed by 4 hours at 0 to 50 ° C. Reaction was carried out. An aqueous solution in which 17.6 g of sodium hydroxide was dissolved in 120 g of water was added dropwise over about 30 minutes, and the reaction was carried out at room temperature for another 30 hours. The reaction mixture was analyzed by high performance liquid chromatography, and as a result, sodium aziridine-2-carboxylic acid was produced in a yield of 78.6% relative to α-chloroacrylonitrile.

The reaction mixture was observed by proton NMR spectrum (measurement temperature; room temperature) and the signal was found only at δ = 1.79 ppm (q., 2H) and δ = 2.35 ppm (q., 1H). These signals were the same as in the standard sample aziridine-2-carboxylic acid ritum in aqueous solution.

Example 20

200 g of isopropanol solution in which ammonia gas was dissolved at a concentration of 6.8% by weight was kept at 0 ° C., and 17.5 g of α-chloroacrylonitrile was slowly added dropwise over about 1.5 hours while slowly stirring under a nitrogen gas stream. Next, the reaction was carried out at 0 to 5 ° C. to produce α-chloro-β-aminopropionitrile. Next, while externally cooling the reaction mixture, a solution of 17.6 g of sodium hydroxide dissolved in 200 g of water was slowly added dropwise. The solution was heated to 50 ° C. and reacted at 50 to 60 ° C. for 8 hours.

The reaction mixture was distilled off under reduced pressure to remove isopropanol, and the residue was analyzed by high performance liquid chromatography. As a result, sodium aziridine-2-carboxylic acid was obtained in a yield of 88% relative to α-chloroacrylonitrile.

[Examples 21-23]

The same procedure was followed for the same procedure as in Example 20, except that each of the alkalis listed in Table 3 was used instead of sodium hydroxide to give the corresponding alkalis of aziridine-2-carboxylic acid alkali or alkaline earth metal salts. The aqueous solution was obtained in the yield described in the following table.

TABLE 3

Example 24

The same operation was repeated except that methanol was used instead of isopropanol in Example 20 to obtain an aqueous solution of sodium aziridine-2-carboxylic acid in a yield of 85.1%.

Example 25

The same procedure was followed as in Example 20, except that the reaction of α-chloroacrylonitrile with ammonia was carried out at 15 to 20 ° C. to give an aqueous solution of sodium aziridine-2-carboxylic acid in a yield of 90.4%. Got it.

Claims (1)

A process for producing aziridine-2-carboxylic acid or a salt thereof, wherein α-halogeno-β-aminopropionitrile or an inorganic acid salt thereof is treated with an alkali or alkaline earth metal hydroxide in water or in an aqueous organic solvent.