DE2203340C3 - Process for the preparation of 1-aminoethane-l-diphosphonic acid and derivatives thereof substituted on the nitrogen - Google Patents

Description

resulting water calculated ^l / _A - converts up to 2 times the stoichiometric amount of phosphorus trxide.

The present invention is a Ver 35 For the production of Aminoäthan-l.l-diphosphon-

drive for the production of l-aminoethane-l-diphos acid according to the present invention are

Phonic acid, optionally with substituted amino, preferably acetamide, phosphorous acid and

group, put together from acetamide or phosphorus pentoxide in the cold and substituted on nitrogen

tem acetamide. then stir the mixture up in an oil bath

It i; it already known, 1-Aminoäthan-ll-diphosphonic 30120-200 ⁰ C, preferably 160 to 190 ⁰ C, for about 1 to

Phonic acid from alkyl nitriles and phosphorus trihalogeni- heated for 2 hours. When the reaction

the, such as phosphorus dichloride or phosphorus tribromide, solution, optionally after dilution with a little

to produce- !. In this process the yield is water, the l-aminoethane-l.l-diphos-

but very bad, especially in the implementation of phonic acid.

with phosphorus trichloride, but also with phosphorus trichloride. But you can also proceed in such a way that you first

bromide are no satisfactory results ER phosphorous acid in an oil bath at 100 to 14O ⁰ C

keep. heated, for this purpose acetamide with stirring and then

It is also known to add l-aminoalkane-l-diphos- ßend phosphorus pentoxide and to the above

Phonic acids by reacting acid amides with the specified manner.

Phosphorus trichloride or a mixture of phosphorus 40 However, any other order is also possible,

phosphorus trichloride and phosphorous acid and then with the restriction that you never have one

Bender hydrolysis of the intermediate to produce. Mixture of phosphorous acid and phosphorus pent-

The aminoalkane-1.l-diphosphonic acids are only allowed to heat after oxide, otherwise the already mentioned

the hydrolysis from the reaction solution by a stormy reaction with the development of phosphine

narrow or by precipitation with organic solution 45 takes place.

obtained by means of acetone. As noted, however, in addition to acetamide, nitrogen-substituted

was, this process is used for the production of acetamides such as methylacetamide, dimethylacet-

Aminoethane-l, l-diphosphonic acid less suitable because amide is suitable. Even with these amides it is preserved

here in contrast to other acid amides such. B. one according to the invention in good yield the corresponding

Formamide, only poor yields are obtained. 5 ° corresponding derivatives of l-aminoethane-l-diphosphonic

In contrast, the invention relates to a process acid.

for the production of l-aminoethane-l.l-diphosiphon- The l-aminoethane-l, l-diphosphonic acid and its

acid and its derivatives substituted on nitrogen have good derivatives substituted on nitrogen

by converting acetamide or complexing properties on nitrogen and are also suitable

substituted acetamide with phosphorus trihalide, 55 in substoichiometric amounts, so-called

which is characterized by the fact that, instead of "vaccination amounts", it is excellent for

Phosphorus trihalide uses phosphorous acid and prevents stone-forming deposits in water

the reaction in the presence of phosphorus pentoxide in rigen systems.
Temperatures between 120 and 200 ^° C., preferably

160 bic 190 ⁰ C. 60 Example 1

According to the method according to the invention, 1-

Aminoethane-l, l-diphosphonic acid in up to 80% strength 492 g phosphorous acid (6 mol), 180 g acetamide

Yield obtained in crystalline form. In contrast (3.05 mol) and 200 g of phosphorus pentoxide are used in

the free room temperature is added directly to the known method, within

Acid and not a first intermediate, which is heated to 65 45 minutes in an oil bath at 190 to 200 ⁰ C.

the free acid must be hydrolyzed. Stirring also crystal and 1 hour at this temperature,

According to the process according to the invention, the internal Dk temperature is 175 during this time

l * Aminoethane-l, l-diphosphonic acid from the reac- to 189 ° C. The reaction mass turns pale yellow.

203

The reaction product is cooled, with about 500 ml Diluted water and overnight to clear out kept. After suction filtration and drying, 46Og = 74% pure l-amino & than-l, l-diphosphonic acid are obtained,

For analysis, a sample was dissolved in boiling water, bandaged with some animal charcoal and filtered while hot. After standing overnight in the refrigerator, the 1-Aminoätban-lJ-diphosphonic acid is suctioned off, with Washed with water and alcohol and cooked at 100 ° C dries.

Found .N 6.78, P 30.5%;

calculated N 6.85, P 30.2%.

Example 2

82 g of phosphorous acid (1.0 mole) are heated to 120 ⁰ C, then 29.5 g of acetamide (0.5 mol) and 35 g Pbosphorpentoxid under stirring. Subsequently, the bath temperature is raised within 40 minutes at 19O ⁰ C to obtain a crystal slurry formed. After a total reaction time of one hour, it is cooled to room temperature, suction filtered and washed with a little water.
Yield: 80.5 g = 78%.

Example 3

164 g phospborige acid (2 moles), 59 g of acetamide (1 mole) and 47 g of phosphorus pentoxide are added together at room temperature, hitzt in an oil bath with stirring at 200 ⁰ C e? And 1 hour at this temperature nachgerühit After cooling and diluting with 100 ml 1-Amiaoethane-l, l-diphosphonic acid crystallizes out in water.

Yield: 69 g = 68%.

Claims (2)

tion solution, if necessary after diluting with a little Patent address; Water out without a cumbersome narrowing of the Reaction solution or precipitation with organic h process for the production of l-Aminoitban solvents is required, which is another important 1,1-djphosphonic acid and its nitrogen sub- 5 term advantage of the process according to the invention against »Statuted derivatives by converting acetamide via the known method. or, on the nitrogen-substituted acetamide with As experiments have shown, takes place between acetamide and PbosphortrihaJogenjd, characterized by phosphorous acid alone no reaction takes place. Also draws that instead of phosphorus it was found that phosphorus acid and phosphorus trihalide pbospborige acid used and the io phorpentoxid in the absence of acid amide on a Reaction in the presence of phosphorus pentoxide must react with each other in a completely different way, since Temperatures between 120 and 200 ^° C., preferably even when the two substances are only slightly heated wise 160 to 190 ⁰ C, carries out. on the water bath with development of phosphine 2. The method according to claim 1, characterized in that a very stormy reaction takes place, whereby it shows that the acetamide can even cause spontaneous combustion with the phospho- 15. It was Rigen acid in a molar ratio of 1: 2 therefore surprising and not to be expected from up to 1: 1 in the presence of the resulting acetamide and phosphorous acid in the presence of Water calculated Y ₄ - up to 2 times stoichioraetri- phosphorus pentoxide in such good yield i-amino- amount of phosphorus pentoxide converts. Ethane-l, l-diphosphonic acid is formed. ao It has proven to be useful that the acid amide with phosphorous acid in a molar Ratio from 1: 2 to 1: 1 in the presence of the