DE2702631A1 - Hydroxy-aminopropane-di:phosphonic acids prepn. - from beta-alanine or poly-beta-alanine and phosphorous acid-phosphorus oxychloride - Google Patents

Abstract

Prepn. of 1-hydroxy-3-amino-propane-1:1-diphosphoric acids comprises reacting body-beta-alanine or beta-alanine, where the amino gps. may be opt. substd. by lower alkyl gps., with a mixture of phosphorous acid and phosphorus oxychloride, and hydrolysing the reaction product, e.g. with water. The POCl3 may be partially replaced by P2O5. Prods. are used as complexants, effective in amts. of below stoichiometric, e.g. in water purification. The prodn. of yellow-red by-products comprising the readily flammable P-O cpds. is obviated.

Description

Process for the preparation of 1-hydroxy-5-aminopropane

1, 1 -diphosphonic acids "The invention is an improved Process for the preparation of 1-hydroxy -) - aminopropane-l, l-diphosphonic acids, wherein the amino group can be substituted by lower alkyl radicals.

It is known from German Patent 2 1) 0 794 to use 1-hydroxy-3-aminopropane-1,1-diphosphonic acid by reacting ß-alanine or poly-ß-alanine with a mixture of phosphorus trichloride and phosphorous acid in the presence or absence of an organic diluent to manufacture. It is preferably used in the presence of an organic diluent how chlorobenzene worked to avoid difficulty stirring the reaction mixture to avoid. During the conversion, however, yellow-red by-products are formed of amorphous phosphorus-oxygen compounds of unknown structure, their separation is very expensive, especially in the presence of chlorobenzene. When making larger ones Quantities must be taken into account that these phosphorus compounds are dangerous, easily represent flammable by-products.

It has now been found that these disadvantages can be avoided if follow the procedure described below for the preparation of 1-hydroxy-3-aminopropane-1,1-diphosphonic acids served. The new process is characterized in that one poly-ß-alanine or ß-alanine, the amino group being replaced by lower Substituted alkyl radicals can be, with a mixture of phosphorous acid and POS1 »and the reaction mixture then hydrolyzed.

Poly-ß-alanine, which is formed from acrylonitrile and formic acid, is hydrolyzed in this reaction to ß-alanine, which is then further to 1-hydroxy -) - amino-propane-1, 1-diphosphonic acid reacts.

In addition to ß-alanine, such ß-alanines can also be used as starting products whose hydrogen atoms located on the amino group are wholly or partially are replaced by lower alkyl radicals such as methyl, ethyl or propyl groups.

Expediently, 0.5 to 2 moles, preferably, are per mole of β-alanine 1 - 2 mol, phosphorous acid and 0.5 to 2 mol, preferably 1 - 2 mol, POCl) used. It has been shown that POC13 partially, i. H. about up to halfway can be replaced by P205.

If desired, diluents such as chlorobenzene, tetrachloroethane, Tetrachlorethylene, trichlorethylene or carbon tetrachloride are used, however, preference is given to working without a diluent.

The reaction generally takes place at temperatures between 80 and 1300 c. The reaction mixture is then hydrolyzed by adding water.

The 3-amino-1-hydroxypropane-1,1-diphosphonic acids crystallize out of the aqueous solution the end. The yield can still be achieved by separating off the mother liquor and adding it Increase alcohol or acetone.

The resulting 1-hydroxy-3-aminopropane-1, 1 -diphosphonic acids are good complexing agents that are also effective in sub-stoichiometric amounts. she can therefore be used in detergents or water treatment agents.

Example 1 In a mixture of 82.8 g (1 mol) of 99.0 phosphorous Acid and 153.5 g (1 mol) of phosphoryl chloride slowly became 89.1 g (0.5 mol) of 81.4 g Entered diethylaminopropionic acid, the temperature rising to a maximum of 40 ° C. After the addition, the mixture was gradually heated to 1000 C and the reaction mixture was 4 Leave at this temperature for hours. During this time the product grew more viscous and finally solid; however, no yellow "phosphorus polymers" were formed.

After cooling, 300 ml of water were added for hydrolysis and the solution boiled down to a total volume of approx. 250 ml. By instilling the Solution in ethyl alcohol, the diphosphonic acid was precipitated. There were 8) .1 g = 57.1 ffi) diethylamino-1-hydroxypropane-1,1-diphosphonic acid.

Molecular weight according to pH titration = 289.1; cal. 291 Melting point: 2020 C found C 28.80 H 6.44 N 4.99 P 21.27 calc. 28.87 6.5) 4.81 21.31 Example 2 Mixtures of ß-alanine with H »PO) and POCl3 (and possibly P205), which are in different order can be combined, were given in the table below Molar ratios, times and temperatures implemented. The reaction product was then hydrolyzed with a sufficient amount of water in the heat Cooling to -5 to +100 C, the crystallized diphosphonic acid was separated off. By treating the mother liquor with precipitants such as alcohol and acetone leaves the yield increase noticeably. The yields given in the table have been obtained without precipitation.

Tabel MV ß-alanine: H3PO3: POCl3: P2O5 reaction tempe yield duration (std) rature% ° C 1: 1: 1: 0 5 100 48 1: 1: 1: 0 2 100 1: 2: 2: 0) 90 47 1.5: 1: 1: 0 4 105 45 1: 1: 0.5: 0.5 4 120

Claims (2)

Claims 9 errahren for the production of 1-hydroxy -) - amino-propane, l-diphosphonic acids, characterized in that one polybeta-alanine or ß-alanine, where the amino group may be substituted by lower alkyl radicals, with a mixture of phosphorous Reacts acid and phosphorus oxychloride and then hydrolyzes the reaction product. 2. The method according to claim 1, characterized in that phosphorus oxychloride is partially replaced by P205.