EP0000930B1 - N-carboxyalkane-aminoalkane-diphosphonic acids, n-carboxyalkane-azacycloalkane-diphosphonic acids and n-carboxyalkane-aminoarylkane diphosphonic acids, process for their preparation and their use as sequestering agents - Google Patents

Description

The present invention relates to N-carboxyalkane-aminoalkane-diphosphonic acids, N-carboxyalkane-azacyloalkane-diphosphonic acids and N-carboxyalkane-aminoarylalkane-diphosphonic acids, and a process for their preparation.

DT-PS 23 18 416 discloses N-carboxymethylaminoalkane diphosphonic acids and N-carboxymethylaminoarylalkane diphosphonic acids, which are obtained by reacting aminoalkane or aminoarylalkane diphosphonic acids in an alkaline medium with formaldehyde and alkali metal cyanide while heating to 70 ° C. 150 ° C.

This process has the disadvantage that very great caution is required when working with alkali metal cyanides, especially on an industrial scale, and therefore extensive safety precautions are essential.

Surprisingly, it has now been found that both the compounds known from German Patent 23 18 416 and new N-carboxyalkane-aminoalkane-diphosphonic acids, N-carboxyalkane-azacycloalkane-diphosphonic acids and N-carboxyalkane-aminoarylaican-diphosphonic acids can be prepared under more favorable working conditions, if one of aminoalkane, azacycloalkane or aminoarylalkane diphosphonic acids of the general formula II

bildet, mit gerad- oder verzweigt-kettigen Halogenalkanmonocarbonsäuren mit 2 bis 12 KohlenstoffAtomen oder mit Halogenalkandicarbonsäuren bzw. deren Alkalisalzen oder Estern bei Temperaturen von 50-160°C im Molverhältnis von 1:1 bis 1:3 in wäßrigem Medium umsetzt.In which R _{1 is} a hydrogen atom, or an alkyl radical of the formula - (CH ₂ ) _x CH ₃ with x = 0 to 10, or a lower hydroxyalkyl radical, or a lower carboxyalkyl radical, or an aryl radical, or an N, N-bis- ( carboxyalkyl) aminoalkyl radical, or a lower alkylphosphonic acid radical, or R, together with the substituent R _{2 is} an alkylene group having 3 to 5 carbon atoms and forms an azacycloalkane ring and R _{4 is} a hydrogen atom, or a lower alkyl radical or R ₄ together with the substituent R is an alkylene group with 3 to 5 carbon atoms and an azacyloalkane ring with the grouping

forms, with straight or branched-chain haloalkane monocarboxylic acids with 2 to 12 carbon atoms or with haloalkanedicarboxylic acids or their alkali metal salts or esters at temperatures of 50-160 ° C in a molar ratio of 1: 1 to 1: 3 in an aqueous medium.

in der R, wie vorstehend bei Formel II definiert ist, während R₂ ein Wasserstoffatom, oder ein niedriger Alkylrest, oder der gleiche Rest wie R₃, oder R₂ zusammen mit dem Substituenten R₁ eine Alkylengruppe mit 3 bis 5 C-Atomen ist und einen Azacycloalkanring mit der Gruppierung

bildet, und R₃ ein carboxylsubstituierter unverzweigter oder verzweigter Alkylrest, oder ein dicarboxylsubstituierter Alkylrest ist.In this way, compounds of general formula I are obtained

in which R is as defined above for formula II, while R _{2 is} a hydrogen atom or a lower alkyl radical, or the same radical as R ₃ or R ₂ together with the substituent R _{1 is} an alkylene group having 3 to 5 carbon atoms and an azacycloalkane ring with the moiety

forms, and R _{3 is} a carboxyl-substituted unbranched or branched alkyl radical, or a dicarboxyl-substituted alkyl radical.

New compounds of this type are N-carboxymethane-azacycloheptane-2,2-diphosphonic acid, N-carboxypentane-1-aminoethane-1,1-diphosphonic acid, N-carboxyethane-1-aminoethane-1,1-diphosphonic acid, N-carboxy-2 , 2-dimethylpropane aminomethane diphosphonic acid, N-10-carboxydekanamino methane-diphosphonic acid, N, N-bis-10-carboxydecane-aminomethane-diphosphonic acid and N- (1,1-diphosphonoprop-1-yl) -DL-aminosuccinic acid.

Suitable compounds for the carboxylation of aminoalkanoic, aminoarylalkane or azacycloalkane diphosphonic acids are, for example, monochloro- or bromoacetic acid, 6-bromohexanoic acid, 3-chloropropionic acid, 3-chloro-2,2-dimethylpropionic acid (ß-chloropivalic acid), 11 -Bromundekansäure, and as dicarboxylic acid bromosuccinic acid.

To produce the substances according to the invention, it is possible to dissolve the aminodiphosphonic acid in excess alkali metal hydroxide solution and then to enter the halocarboxylic acid in such a way that the pH does not fall below 4. The process can be carried out much more elegantly if only as much alkali metal hydroxide solution is introduced as is required for the desired pH between 4 and 12, preferably 7 and 9. The further dosing of alkali and halocarboxylic acid is then controlled depending on the pH.

In some cases, the diphosphonic acid and halocarboxylic acid are advantageously suspended in water and completely or partially neutralized with alkali metal hydroxide. The reaction time and temperature are taking advantage of the neutralization _t iönswärme from 0.5 to 3 hours and at 50-160 ° C, advantageously at 60 to 110 ° C.

In this way, completely or partially neutralized salts are obtained as reaction products, which can be converted into the free acids by means of cation exchangers.

It is also readily possible to use alkali hydroxide, e.g. Alkali carbonate or, for special purposes, alkali and alkaline earth hydroxides together, e.g. Sodium or calcium hydroxide or alkali heavy metal hydroxides, e.g. Use sodium aluminate, sodium zincate or sodium stannate.

Products manufactured in this way are particularly suitable for corrosion protection agents and for products in the treatment of service water.

Depending on the properties or the desired application, the solutions are used directly, the salts crystallized or naci. Ion exchange the acid obtained by methods known per se, such as evaporation concentration or precipitation or extraction with organic solvents.

The carboxylation gives, depending on the molar ratios used and the aminodiphosphonic acid used, single or multiple carboxyalkylated products. With a molar ratio of the reactants of 1: 1, N-carboxyalkane-aminoalkane-diphosphonic acids are preferably obtained. A molar ratio of the reactants of aminodiphosphonic acid: halocarboxylic acid of 1: 2 to 1: 3 preferably gives N, N-bis-carboxyalkanaminoalkane-diphosphonic acids.

The substances obtained according to the present invention can be used wherever a good complex binding capacity with respect to divalent and polyvalent metal ions is required. They are particularly characterized by their resistance to hydrolysis at high temperatures. They can be used in all media in which the hardness constituents of the water interfere or in which all influences of polyvalent metal ions are to be eliminated. The treatment of hard water, textile treatment baths, paper production, photographic processing baths, electroplating baths and tanning can be mentioned here in detail. These diphosphonic acids are also suitable for stabilizing the water hardness in substoichiometric amounts. They can also serve as stabilizers for dispersions and suspensions.

Since the products according to the invention have the properties of phosphonic acids and aminocarboxylic acids, they offer application technology advantages over the phosphonic acids or aminocarboxylic acids alone, which go beyond the sum of the properties of the individual components.

Example 1:

6.72 kg of 50% strength potassium hydroxide solution are placed in a stirred vessel with a thermometer and reflux condenser, and 2.05 kg of 1-aminoethane-1,1-diphosphonic acid are added so that the bottom temperature does not exceed 60.degree. A solution of 1.89 kg of monochloroacetic acid in 2.2 kg of water is then added dropwise in the course of one hour, and the mixture is then heated to 100 ° C. for three hours.

After desalting an aliquot of the reaction product using a strongly acidic cation exchanger and concentrating the solution, the N, N-bis-carboxymethane-1-aminoethane-1,1-diphosphonic acid could be crystallized with methanol / ethanol in a yield of 91.3% Theory can be gained.

The product shows the following analysis:

Example 2:

28 g of potassium hydroxide are dissolved in 100 ml of water and 20.5 g of 1-aminoethane-1,1- diphosphonic acid entered. Then 13.9 g of bromoacetic acid are added and the mixture is refluxed for three hours.

The reaction product is treated with an acidic exchanger (Lewatit S 100) and the solution is concentrated. The result is a light yellow, viscous oil which is crystallized with methanol / ethanol. After drying in a water-jet vacuum at 80 ° C., 25.4 g of N-carboxymethane-1-aminoethane-1,1-diphosphonic acid are obtained, which corresponds to a yield of 96.6% of theory.

Example 3:

47.8 g of aminomethane diphosphonic acid are dissolved in 148 g of 50% potassium hydroxide solution at 60 ° C. and a solution of 99.4 g of the potassium salt of monochloroacetic acid in 250 ml of water is added. The mixture is then heated to 80-90 ° C for three hours.

After working up the reaction solution as described in the previous example, 75.2 g of the N, N-bis-carboxymethane-aminomethane-diphosphonic acid are obtained.

Example 4:

95.5 g of aminomethane diphosphonic acid are dissolved in 224 g of 50% potassium hydroxide solution at 60 ° C., 300 ml of water and 54.3 g of methyl chloroacetate are added. After refluxing for 3 hours, the mixture is allowed to cool.

After working up the solution with an acid exchanger, concentrating, crystallizing and drying, 115 g of N-carboxymethane-aminomethane-diphosphonic acid are obtained, which corresponds to a yield of 92.3% of theory.

Example 5:

13.4 g of phenylaminomethane diphosphonic acid are dissolved in a solution of 8 g of NaOH in 100 ml of water so that the temperature does not exceed 60 ° C., and 4.8 g of monochloroacetic acid are then added. The reaction solution is then kept at 110 ° C. for three hours, allowed to cool and treated with a strongly acidic exchanger.

15 g of crystalline N-carboxymethanophenylaminomethane-diphosphonic acid are obtained from the concentrated solution with methanol.

Example 6:

54.8 g of 1-aminopropane-1,1-diphosphonic acid are stirred into 200 ml of water and 14.6 g of basic zinc carbonate are slowly added. After the evolution of gas has ceased, 140 g of 50% potassium hydroxide solution are added and, after cooling to 50 ° C., 47.3 g of monochloroacetic acid are added in portions.

After two hours of refluxing, a clear, slightly yellow colored solution of the potassium zinc salt of N, N-bis-carboxymethane-1-aminopropane-1,1-diphosphonic acid is obtained. Thin-layer chromatographic studies show a minimum conversion of 90% of theory. Part of the solution is worked up as described in the previous examples.

Example 7:

90 g of potassium hydroxide are dissolved in 250 ml of distilled water and 103.6 g of aza-cycloheptane-2,2-diphosphonic acid are introduced into this solution in such a way that the temperature does not exceed 60.degree. After adding 38 g of monochloroacetic acid, the mixture is heated to 110 ° C. for 2 1/2 hours. Allow to cool and then obtains 102.5 g of N-carboxymethane-aza-cycloheptane-2,2-diphosphonic acid from the solution by the method described in Example 1.

Example 8:

41 g of 1-aminoethane-1,1-diphosphonic acid are dissolved in 187 g of 30% strength potassium hydroxide solution with stirring and 39 g of 6-bromohexanoic acid are added at 60.degree. To complete the reaction, the mixture is slowly heated to 100 ° C. and left at this temperature for three hours. After working up according to Example 1, N-carboxypentane-1-aminoethane-1,1-diphosphonic acid is obtained.

A conversion of 73.4% of theory was determined by determining the free amino groups using the Van Slyke method.

Example 9:

In a mixture of 51 g of 1-aminoethane-1,1-diphosphonic acid, 27.2 g of 3-chloropropionic acid and 150 ml of water, 140 g of 50% strength potassium hydroxide solution are added dropwise with stirring at 70.degree. C. and then the clear solution two Cooked at reflux for hours.

After working up the solution, 57.5 g of N-carboxyethane-1-aminoethane-1,1-diphosphonic acid are obtained.

Example 10:

34.6 g of 3-chloro-2,2-dimethylpropionic acid (β-chloropivalic acid) are added to a solution of 47.8 g of aminomethane-diphosphonic acid in 288 g of 30% strength potassium hydroxide solution. The solution is heated to boiling within one hour and kept at this temperature for two hours. After working up, N-2-carboxy-2,2-dimethylethane-aminomethane-diphosphonic acid was obtained.

A conversion of 73.5% of theory could be determined by determining the primary amino groups in the solution.

Example 11:

54.7 g of 1-aminopropane-1,1-diphosphonic acid are dissolved in 150 g of 40% sodium hydroxide solution and 49.5 DL-bromosuccinic acid are introduced at 60 ° C. To complete the reaction, the mixture is boiled under reflux for a further two hours.

In the solution, 21 g of 1-aminopropane-1,1-diphosphonic acid and 51.4 g of N- (1,1-diphosphonoprop-1-yi) -DL-aminosuccinic acid were detected by quantitative thin-layer chromatography.

Example 12:

47.8 g of aminomethane-diphosphonic acid are dissolved in 150 g of 50% potassium hydroxide solution and 88.8 g of 11-bromundecanoic acid are introduced into this solution at 80.degree. After refluxing for 2 hours and cooling the solution, approx. 30% aminomethane-diphosphonic acid, approx. 60% N-10-carboxydecane-aminomethane-diphosphonic acid and approx. 10% N, N-bis-10-carboxydecane were able to be determined by thin-layer chromatography -aminomethane-diphosphonic acid can be detected.

Example 13:

127.7 kg of 1-amino-ethane-1,1-diphosphonic acid are placed in 292.2 kg of water and 69.8 kg of 50% potassium hydroxide solution in 292.2 kg of water and 69.8 kg of 50% potassium hydroxide solution in a 1 m ³ stirred tank with reflux condenser, heating, built-in pH combination electrode and two dropping funnels solved. Using the heat of neutralization, the solution is heated to 80 ° C. and 147.7 kg of 80% monochloroacetic acid solution and about 362 kg of 50% potassium hydroxide solution are metered in from the two templates. The addition is controlled so that the pH in the reaction medium is between 8.0 and 8.5. The reaction mixture can keep the reaction mixture at 80 to 90 ° C. After the end of the feed, the pH is adjusted to 8.5 with potassium hydroxide solution and the solution is stirred at 90-100 ° C. for one hour.

The resulting solution has a content of about 20% N, N-bis-carboxymethylene-1-aminoethane-1,1-diphosphonic acid.

Example 14:

58.7 g of 3-hydroxy-1-aminopropane-1,1-diphosphonic acid are introduced into a solution of 84 g of KOH in 300 ml of water. The solution is heated to 60 ° C and with vigorous stirring, 56 g 3-chloropropionic acid entered so that the temperature slowly rises to 80 ° C. After boiling under reflux for 3 hours, a pale yellow solution results.

After working up the solution using a strongly acidic ion exchanger, concentrating, crystallizing and drying, 81 g of slightly yellowish hygroscopic crystals are obtained. The thin-layer chromatographic analysis shows a content of about 20% N-carboxyethane-3-hydroxy-l-aminopropane-1,1-diphosphonic acid and about 80% N, N-bis-carboxyethane-3-hydroxy-1-aminopropane -1,1- diphosphonic acid.

Example 15:

24.9 g of 2-carboxy-1-aminoethane-1,1-diphosphonic acid are dissolved in 119 ml of 30% strength potassium hydroxide solution at 50 ° C. while stirring, and 19 g of 5-bromovaleric acid are introduced at this temperature. The mixture is boiled under reflux for 3 1/2 hours, cooled, the solution is treated with a cation exchanger, the acid solution is evaporated almost to dryness and fractionated with mixtures of methanol, ethanol and acetone. The yield of 2-carboxy-1,1-diphosphono-ethane-1-aminopentanoic acid is 24.5 g.

Example 16:

_{6, 9} g 1-Aminododekan-1,1-diphosphonic are dissolved in 56 g of 10% igerKalilauge, at 60 ° C 2.8 g of 3-chloro-2,2-dimethylpropionic acid was added and boiled for three hours under reflux. After working up the reaction solution using an acidic cation exchanger, filtering and concentrating the acid solution, 6 g of N-2-carboxy-2,2-dimethyl-ethane-1-aminododecane-1,1-diphosphonic acid are obtained by crystallization with methanol / water.

Claims (13)

1. Process for the production of N-carboxyalkane-aminoalkane diphosphonic acids, N-carboxyalkane-azacycloalkane-diphosphonic acids and N-carboxyalkane-aminoaryl-diphosphonic acids of the general Formula I

wherein R¹ is a hydrogen atom, or an alkyl radical of formula -(CH₂)_xCH₃ with x = 0 to 10, or a hydroxy ethyl radical, or a carboxy methyl radical, or a phenyl radical, or an N,N-bis-(carboxyalkyl)-aminoalkyl radical, or a methyl- or ethyl-phosphonic acid radical, or R¹ together with R² is an alkylene group with 3 to 5 C-atoms and forms an azacycloalkane ring with the grouping

R² is a hydrogen atom, or a methyl radical, or the same radical as R³, or R² together with R¹ is an alkylene group with 3 to 5 C-atoms and forms an azacycloalkane ring with the grouping

R³ is a carboxy-substituted unbranched alkyl radical with the formula (CH₂)_mCOOH in which m = 1 to 12, or a 2-carboxy-2,2-dimethyl ethyl radical, or a 1,2-dicarboxy-ethyl radical, characterised in that an amino alkane, azacyclo alkane or aminoaryl alkane diphosphonic acid of the general Formula II

wherein R¹ is defined as stated in Formula I and R⁴ is a hydrogen atom, or a methyl radical, or R⁴ together with R¹ is an alkylene group with 3 to 5 C-atoms and forms an azacyclo alkane ring with the grouping

is heated with a corresponding unbranched or branched halogen alkane carboxylic acid or halogen succinic acid, its alkali salts, earth alkali salts or alkali-heavy metal salts or its esters in a molar ratio of 1:1 to 1:3 in aqueous medium at a temperature between 50 and 160°C and at a pH value between 4.0 and 12.0 until the reaction is concluded.

2. Process according to Claim 1, characterised in that the pH value is kept between 7.0 and 9.0 during the reaction.

3. Process according to Claim 1, characterised in that the reaction is carried out in a temperature range of 60 to 110°C.

4. An N-carboxyalkane-aminoalkane-diphosphonic acid of the general Formula I

in which the radicals R¹ and R² are as defined in Claim 1 and R³ is a carboxy-substituted unbranched alkyl radical with the formula (CH₂)_mCOOH in which m = 2 to 12, a carboxy-substituted branched alkyl radical or a dicarboxy-substituted alkyl radical, characterised in that it is produced by a process according to one of Claims 1 to 3.

5. Compound according to Claim 4, wherein R¹ together with R² is an alkylene group with 5 C-atoms and forms an azacycloheptane ring with the grouping

R³ is a carboxy methyl group and thus the compound is N-carboxymethane-azacycloheptane-2,2- diphosphonic acid.

6. Compound according to Claim 4, wherein R¹ is a methyl radical, R² is a hydrogen atom, R³ is a carboxy pentyl radical and thus the compound is N-carboxypentane-1-amino-ethane-1,1-diphosphonic acid.

7. Compound according to Claim 4, wherein R¹ is a hydrogen atom, R² is a hydrogen atom, R³ is a 2-carboxy-2,2-dimethyl ethyl radical and thus the compound is N-(2-carboxy-2,2-dimethyl ethane)-aminomethane-diphosphonic acid.

8. Compound according to Claim 4, wherein R¹ is an ethyl radical, R² is a hydrogen atom, R³ is a group with the formula

and thus the compound is N-(1,1-diphosphonoprop-1-yl)-D,L-amino-succinic acid.

9. Compound according to Claim 4, wherein R¹ is a hydrogen atom, R² and R³ are carboxydecyl groups and thus the compound is N,N-bis-(10-carboxydecane)-aminomethane-diphosphonic acid.

10. Compound according to Claim 4, wherein R¹ is a carboxy methyl group, R² is a hydrogen atom, R³ is a pentane carboxylic acid radical and thus the compound is 2-carboxy-1,1-diphosphono- ethane-1-aminopentane carboxylic acid.

11. Compound according to Claim 4, wherein R¹ is an undecyl radical, R² is a hydrogen atom, R³ is a 2-carboxy-2,2-dimethyl ethyl group and thus the compound is N-(2-carboxy-2,2-dimethyl ethane)-1-aminododecane-1,1-diphosphonic acid.

12. Compound according to Claim 4, wherein R¹ is a hydroxyethyl radical, R² is a carboxyethyl group, R³ is likewise a carboxyethyl group and thus the compound is N,N-bis-(carboxyethane)-3-hydroxy-1-aminopropane-1,1-diphosphonic acid.

13. Use of the compounds according to Claim 4 in stoichiometric or sub-stoichiometric quantities for the treatment of aqueous systems.