DE4211713A1 - New amino di:carboxylic-N,N-di:acetic acid deriv., useful as complexing agents - is prepd. from amino di:carboxylic acids, formaldehyde and hydrocyanic acid, or alkali metal cyanide, with amino di:carboxylic acid-N,N-di:acetonitrile as intermediate - Google Patents

Abstract

New aminodicarboxylic acid-N,N-diacetic acids of formula (I) are prepd. by reacting aminodicarboxylic acids of formula XOOC-(CH2)n-CH-COOX (II), in water and/or an organic solvent, with 2-2.6 mols of HCHO and 2-2.3 mols of liq. HCN at 0-150 deg. C., or with 2-2.3 moles of alkali metal cyanide at 40-100 deg. C., and hydrolysing amide or CN gps. formed, in presence of an acid or a base. Aminodicarboxylic acid-N,N-diacetonitriles of formula XOOC- (CH2)n-CH (N(CH2CN)2 COOX (III), formed as intermediates, are also claimed. In the formulae, X = H, alkali metal, NH4 or ammonium gp. substd. with 1-4C alkyl or hydroxyalkyl; and n = 1-4. USE/ADVANTAGE - (I) are prepd. in high purity and good yield, from easily available cpds., by a simple, efficient process applicable on the large scale and giving almost no loading with inorganic salt. (I) can be used in alkaline media, overcoming corrosion problems. (I) are complex-formers, esp. for alkaline earth and heavy metal ions, and can be used in washing compsns. and solns. to control the content of free heavy metal ions, as bleach stabilisers, e.g. for NaBO3, as builders, and in bleaching textiles, cellulose or paper pulp, to prevent destruction of the bleach system, enzymes, optical bleaches and perfumes by heavy metal ions.

Description

The present invention relates to a new method for Production of aminodicarboxylic acid-N, N-diacetic acids and ih ren salts. The invention further relates to aminodicarbon acid-N, N-diacetonitrile as an intermediate for the Her position of the aminodicarboxylic acid N, N-diacetic acids or their Salts.

DE-A 37 12 329 (1) describes a process for the production of serine-N, N-diacetic acid and derivatives thereof, for the serine with formaldehyde and liquid hydrocyanic acid Temperatures from 0 to 45 ° C or alkali metal cyanide at tem temperatures of 40 to 100 ° C is implemented and, if necessary existing amide and nitrile groups then hydroly be settled.

US-A 2 500 019 (2) relates to a method of manufacture tion of polycarboxylamino acids by reacting α-ami no acids with formaldehyde and alkali metal cyanide in strongly al Kalische aqueous solution at temperatures from 30 to 100 ° C. If glutamic acid is used as the α-amino acid, decarboxylated the γ-carboxyl group under the strongly alkaline conditions partially and you get a mixture of Glu taminic acid-N, N-diacetic acid and α-aminobutyric acid-N, N- diacetic acid.

The object of the present invention was to provide a simple and efficient process for the production of aminodicarbon acid-N, N-diacetic acids by reaction with formaldehyde and Provide hydrocyanic acid or alkali metal cyanide, the one by-product-free end product.

Accordingly, a process for the preparation of aminodicar bonic acid-N, N-diacetic acids of the general formula I

in the
X independently of one another represents hydrogen, alkali metal, ammonium or ammonium substituted by C ₁ to C ₄ alkyl groups or C ₁ to C ₄ hydroxyalkyl groups and n denotes a number from 1 to 4,
found, which is characterized in that amino dicarboxylic acids of the general formula II

in water, an organic solvent or a Mi from this with 2 to 2.6 mol, in particular 2 to 2.2 mol Formaldehyde and 2 to 2.3 mol, in particular 2 to 2.1 mol liquid hydrocyanic acid at temperatures from 0 to 150 ° C or 2 up to 2.3 mol, in particular 2 to 2.1 mol, of alkali metal cyanide at temperatures of 40 to 100 ° C and at Um settlement of any amide and nitrile groups formed hydrolyzed in the presence of an acid or base.

In a preferred embodiment, aminodicar is used bonic acids II in water, an organic solvent or a mixture thereof with 2 to 2.6 mol, in particular 2 to 2.2 mol of formaldehyde and 2 to 2.3 mol, in particular 2 to 2.1 mol of liquid hydrocyanic acid at temperatures from 0 to 150 ° C um and hydrolyzed ent if necessary during the reaction standing amide and nitrile groups in the presence of an acid or base.

If x does not stand for hydrogen, salts are corresponding the carboxylic acids. In particular, the variable means x then especially sodium, potassium, ammonium or trial  alkyl or trihydroxyalkyl ammonium. As the tri-substituted Bases based on ammonium cations come mainly from tertiary amines trimethylamine, triethylamine, triethanolamine and triisopropanolamine. The connections of the Formula I can be completely or partially neutralized ter form and also different cations X ent hold. As a rule, however, according to the invention the completely neutralized connection gene received.

The variable n preferably represents the number 1 or 2, especially for 1. In the case of n = 1 there is an aspartic acid Derivative I, in the case of n = 2, a glutamic acid derivative I before.

The implementation takes place in a conventional manner according to type ei ner Strecker synthesis, cf. Houben-Weyl, Vol. 11/2, Pp. 408 ff. (1958), Thieme-Verlag Stuttgart.

Water is preferably used as the solvent, but also other water-miscible organic solvents tel such as methanol, ethanol, n-propanol, iso-propanol, ter tertiary butanol, dioxane or tetrahydrofuran or mixtures these organic solvents with each other or their Mi Water mixtures can be used. With watery Mixtures expediently become the weight of the water Given 10 to 70 wt .-% organic solvent.

The concentration of the starting compounds II in each Solvent is advantageously 10 to 80 wt .-%, preferably as 20 to 70 wt .-%.

In a preferred reaction procedure, an aminodicar bonic acid II in acidic form or its di-sodium or di-Ka lium salt in one of the solvents or solutions mentioned medium mixtures with the formaldehyde in the form of its aqueous approx. 30% by weight solution and the liquid hydrocyanic acid in the preferred temperatures of 5 to 100 ° C, especially 15 up to 80 ° C, especially 20 to 60 ° C, implemented at normal pressure. At temperatures above 100 ° C one works in closed Equipment under autogenous pressure.  

The reaction with alkali metal cyanide, especially Na trium- or potassium cyanide, instead of the liquid hydrocyanic acid is preferably carried out at 70 to 90 ° C.

Appropriate come for the reaction with liquid hydrocyanic acid some pH ranges from 0 to 11, preferably 3 to 9, in Consider being turned on with an acid or base can be put.

Appropriate come for the reaction with alkali metal cyanide occasionally pH ranges from 3 to 14, preferably 5 to 13, in Consider that also with an acid or Base can be adjusted.

In a further preferred embodiment, the the reaction formed as an intermediate aminodicarbon Acid-N, N-diacetonitrile of the general formula III

in which X and n have the meanings given above, iso giert, cleaned if necessary and on to the final product I implemented.

The present application also relates to amino dicarboxylic acid-N, N-diacetonitrile II as an intermediate for the preparation of the aminodicarboxylic acid N, N-diacetic acids I or their salts. The compounds I are in the literature not yet described.

Usually follows the implementation of the verbin tion II with formaldehyde and hydrocyanic acid or alkali metal cya nid for existing nitrile groups and possibly existing amide groups a hydrolysis or saponification to carbon acid in a conventional manner in an aqueous reaction mixture, if necessary after adding water, in the presence of alkalis, such as sodium or potassium hydroxide, or of Acid such as sulfuric or hydrochloric acid. This hydrolysis  is expediently at temperatures of 20 to 110 ° C, preferably 40 to 100 ° C performed.

According to the reaction conditions, the free aminodicarboxylic acid N, N-diacetic acid I or an alkali metal salt obtained therefrom. Then you can without wide res salts with other cations. If he did required, can conversely from the acid obtained in übli a salt can be produced.

The compounds I can in pure without difficulty Shape be isolated. For free acid and salts especially spray or freeze drying, crystal lization or precipitation. It can be beneficial to the fallen solution directly to a technical use to lead.

The manufacturing method according to the invention compared to be Known processes the advantage that practically no inorganic salt load. Because of the easy availability the input materials and the implementation partner become an exception neatly inexpensive large-scale process ready poses. The compounds I can be of high purity and be produced in very good yields.

As is known, the compounds I are suitable as a complex formers, especially for alkaline earth and heavy metal ions, for a wide variety of technical applications. So DE-OS 23 39 888 (3) relates to a method of manufacture non-toxic, non-contaminating, biological degradable sequestrant composition with a derivative egg ner L- or D, L-N, N-dicarboxymethyl amino acid, where mono chloroacetic acid with the disodium salt of dicarboxyamino acid in an aqueous medium with fixation of two carboxyme thyl groups on the nitrogen atom of the amino group of the amino acid is implemented. For the implementation of this procedure who recommended especially glutamic acid and aspartic acid.

They have proven to be particularly suitable complexing agents enantiomerically pure or largely enantiomerically pure L-Ami nodicarboxylic acid-N, N-diacetic acids I highlighted their biodegradability is that of racemic D, L-aminodicarboxylic acid-N, N-diacetic acids I usually  clearly outperform. So shows L-aspartic acid-N, N-diesdig acid in the Zahn-Wellens test under standard conditions biodegradability of <95% (28 days value), whereas the racemic D, L-aspartic acid-N, N-diacetic acid below equal conditions gives the value of 55%. After he Processes according to the invention can be the L-aminodicarbon produce acid-N, N-diacetic acids I particularly advantageously, because when using enantiomerically pure L-aminodicarbon acid II as a starting material during the reaction none Racemization occurs.

In the following technical fields the aminodicarboxylic acid N, N-diacetic acids I, especially in the enantiomerically pure or largely enantiomerically pure L-form, advantageously be set.

In detergents and cleaning agents, the compounds I are used to determine the content of free heavy metal ions in the detergents themselves and in the washing solutions troll. The amount used as a complexing agent is expediently 0.1 to 2% by weight, based on the total weight of detergent ingredients.

Their beneficial effects also lie in a bleach stabilization, for example for sodium perborate, in Detergents and in the bleaching of textiles, cellulose or paper stock. Traces of heavy metals such as iron, copper Fer and manganese come in the washing powder itself, in the water and in the textile and catalyze the decomposition of the natri umperborates. The complex image produced according to the invention These bind metal ions and prevent the unwanted Decomposition of the bleaching system during storage and in the Wash liquor. This increases the efficiency of the bleaching system stems and fiber damage are suppressed.

In addition, enzymes, optical brighteners and fragrances before heavy metal catalyzed oxidative decomposition protects.  

In liquid detergent formulations, the compounds gen I as a preservative, useful in a quantity from 0.05 to 1% by weight, based on the total weight of the wa detergent formulation can be used.

In soaps, the compounds I prevent me, for example metal-catalyzed oxidative decomposition.

Furthermore, they serve as Ge in detergents and cleaning agents builders (builders) to precipitate and incrustate to prevent the tissue.

You can advantageously be used anywhere there where, in technical processes, precipitation of Ca, Mg and heavy metal salts interfere and should be prevented len, for example to prevent deposits and Incrustations in boilers, pipes, on spray cans or generally on smooth surfaces.

They can be used to stabilize phosphates in alkaline Degreasing baths and prevention of lime precipitation soaps serve and prevent the "tarnishing" of Non-ferrous surfaces and extend the service life of al calic cleaning baths.

They can be used as a complexing agent in alkaline rust removal and Descaling baths are used as well as in galvanic ones Baths instead of cyanides to mask impurities ren.

The cooling water treatment with the compounds I prevented Deposits or dissolve existing ones. A The advantage is the applicability in alkaline medium and there with the removal of corrosion problems.

When polymerizing rubber, they can be used to manufacture development of the redox catalysts used the. They also prevent the loss of iron hydro xid in an alkaline polymerization environment.

In the photographic industry, the compounds I in developer fixing baths, which are mixed with hard water are used to make the precipitate less soluble  To prevent Ca and Mg salts. The precipitates lead to Gray veils on films and images as well as deposits in the tanks, which can thus advantageously be avoided. Iron III complexing agent solutions can be advantageous in Bleach-fix baths are used where they are made from ecological hexacyanoferrate solutions can put.

In the textile industry they can be used to remove heavy traces of metal during the manufacturing or dyeing process of natural and synthetic fibers. Thereby there are many defects such as dirt stains and streaks the textile goods, loss of gloss, poor wettability, prevents uneven coloring and color errors.

In the paper industry, they can be used to eliminate Cal cium ions used in resin sizing with alum and sodium re sinate, form insoluble salts, and heavy tall, mainly iron ions, can be used. The Deposition of iron on paper leads to "hot spots", where the oxidative catalytic destruction of cellulose begins.

Applications come in as further applications, for example Pharmaceuticals, cosmetics and food are considered to be e.g. B. the metal-catalyzed oxidation of olefinic dop bonds and thus the rancidity of the products prevent.

In plant nutrition are used to remove heavy matter tall deficit Cu, Fe, Mn and Zn complexes used. The Heavy metals are added as chelates to prevent the precipitation prevention as biologically inactive, insoluble salts other.

Further areas of application for the compounds I are flue gas scrubbing, namely the removal of NO _x from Rauchga sen, H ₂ S oxidation, metal extraction and use as catalysts for organic syntheses, for. As the air oxidation of paraffins or the hydroformylation of olefins to alcohols.

example 1 Production of L-aspartic acid-N, N-diacetonitrile

A suspension of 133.2 g (1.0 mol) of L-aspartic acid was added placed in 300 g of water and were within one hour at 20 to 25 ° C simultaneously 200 g (2.0 mol) 30 wt .-% aqueous formaldehyde solution and 54 g (2.0 mol) of hydrocyanic acid drips. After the one-hour reaction was at 70 ° C no starting material can be verified and is therefore complete implementation achieved.

There were 687 g of an approximately 30 wt .-% solution of L-Aspara ginsäure-N, N-diacetonitrile (corresponding to a yield of 97%) received. After removing the water and washing the Residue with methanol gave a colorless crystal powder.

The characterization was based on the ¹³ C-NMR and IR spectra.

¹³ C spectrum (D ₂ O, pH = 7): 41.8 (CH ₂ CO ₂ ), 42.7 (CH ₂ -CN), 68.0 (CH-CO ₂ ), 119.7 (2XCN) , 180.4 and 181.7 ppm (each -CO ₂ ). IR (KBr): 2245 cm ^-1 (CN).

Example 2 Production of L-aspartic acid-N, N-diacetic acid-tetra sodium salt

To 406 g (4.06 mol) of a 30% by weight aqueous sodium hydroxide solution was the aqueous solution of L-Aspa obtained in Example 1 ragic acid-N, N-diacetonitrile within one hour 40 ° C added dropwise. During the reaction time of 4 hours the temperature was raised to 100 ° C. After that there was none Ammonia development more detectable.

The result was 1024 g (corresponding to a yield of 94%) of a clear, yellow, 30% by weight aqueous solution of L-aspartic acid-N, N-diacetic acid tetrasodium salt.

The melting point of the isolated salt was over 300 ° C.  

Example 3 Production of free L-aspartic acid-N, N-diacetic acid

The aqueous solution of L-Aspara prepared in Example 2 Ginsäure-N, N-diacetic acid tetrasodium salt was removed under ver reduced pressure to a content of approx. 50% by weight centered. With concentrated hydrochloric acid a pH was reached set by 2. The solution was then on the 5 times the amount of methanol dropped. The fancy colorless Precipitation was filtered off and again with methanol to wash. The purity of the free L-aspartic acid obtained re-N, N-diacetic acid was <98%.

Example 4 Production of L-aspartic acid-N, N-diacetic acid without Ni tril intermediate

To the solution of 177.1 g (1.0 mol) of L-aspartic acid dina trium salt in 400 g of water was added dropwise under reduced pressure 200 g pressure at 85 ° C within 4 hours (2.0 mol) 30% by weight aqueous formaldehyde solution and 327 g (2.0 mol) 30% by weight aqueous sodium cyanide solution. Soon Water distilled off early with the ammonia was during the reaction replaced.

This gave 1104 g of a solution containing 25.3% by weight of L-aspartic acid-N, N-diacetic acid-tetrasodium salt (corresponding to a yield of 83%).

Claims (4)

1. Process for the preparation of aminodicarboxylic acid N, N-diacetic acids of the general formula I. in the
X independently of one another represents hydrogen, alkali metal, ammonium or ammonium substituted by C ₁ to C ₄ alkyl groups or C ₁ to C ₄ hydroxyalkyl groups and
n denotes a number from 1 to 4,
characterized in that aminodicarboxylic acids of the general formula II in water, an organic solvent or a mixture thereof with 2 to 2.6 mol formaldehyde and 2 to 2.3 mol liquid hydrocyanic acid at temperatures from 0 to 150 ° C or 2 to 2.3 mol alkali metal cyanide at temperatures from 40 to 100 ° C implemented and hydrolyzed in the implementation of any resulting amide and nitrile groups in the presence of an acid or base. 2. Process for the preparation of aminodicarboxylic acid N, N-diacetic acids I according to claim 1, characterized records that aminodicarboxylic acids II in water, egg nem organic solvent or a mixture here with 2 to 2.6 mol of formaldehyde and 2 to 2.3 mol liquid hydrocyanic acid at temperatures from 0 to 150 ° C sets and any resulting during the implementation Amide and nitrile groups in the presence of an acid or Base hydrolyzed. 3. A process for the preparation of aminodicarboxylic acid N, N-diacetic acids I according to claim 1 or 2, characterized in that the aminodicarboxylic acid-N, N-diacetonitrile formed in the reaction as an intermediate product of the general formula III in which x and n have the meanings given above, isolated, cleaned if desired and further converted to the end product I. 4. Aminodicarboxylic acid-N, N-diacetonitrile III according to An saying 3 as an intermediate.