SU790698A1 - Method of preparing alkaline salts of oxyethylidenediphosphonic acid complexes with second group metals - Google Patents

Description

the mixture for 0.5-1.5 h, followed by neutralization of the obtained product with an alkali at a molar ratio of hydroxyethylidene diphosphonic acid, oxide or metal hydroxide and alkali, equal to I: 0.9 1.0: 2.0 2.1.

The described method allows to obtain the desired products with yields of 90- 99%. Products obtained directly from the reaction mass have a crystalline structure, are easily filtered, pressed, quickly dry and have a constant composition.

A significant role in this method, in contrast to Lime, is the following sequence of operations: metal oxide (hydroxide) was added to a solution of hydroxyethylidene diphosphonic acid (HEDP), allowed to hold for 0.5-1.5 hours, and then alkali was added ( caustic soda, caustic potassium) in the form of finely divided powder or solution in alcohol.

Violation of the order of introduction of reagents leads to contamination of the target products or to the impossibility of obtaining them in crystalline form. For example, the addition of alkali to a solution of hydroxyethylidene diphosphonic acid leads to the formation of disubstituted alkaline solp HEDP, which drops out as sticky lumps, unable to fully interact further with powdered metal oxides, which envelop the lumps from the surface.

The need for aging after the addition of metal oxides to HEDP is dictated by the following: immediately after the addition of the metal oxide to HEDP, a metastable complex is formed that is soluble in an organic solvent. In the acidic medium () in the presence of a solvent, after a period of 0.5-1.5 hours, the disubstituted HEDP complex with the corresponding metal falls out, which then forms an end product upon reaction with alkali. If the alkali solution (or solid alkali) is introduced into the solution of the metastable complex, without giving rise, then due to the increase in the pH of the medium, it will partially transform into a water-insoluble tetrasubstituted metal complex that pollutes the target product.

After separation of the target products, the mother liquors can be repeatedly and repeatedly used in the synthesis without additional purification and distillation, which makes the process practically wasteless.

The method is carried out as follows.

To a solution of 1 mole of o-xylethylenediphosphonic acid in alcohol or dimethylformamide, 0.9-I, O mole of metal oxide (hydroxide) was added, transfer the mass within 0.5-1.5 hours, and a solution of 2.0 -

2.1 moles of alkali in alcohol or finely crushed alkali is added, allowed to stand for 1-2 hours and the precipitate is filtered off. After drying in air, the desired product is obtained with a yield of 90-99%.

Example 1. To a solution of 10.6 g of hydroxyethylidene diphosphonic acid in 200 ml of ethyl alcohol are added in portions 4.0 g of zinc oxide. The reaction mass is transferred at room temperature for 30 minutes, during which a creamy suspension is formed, to which a solution of 6.4 g of 87% caustic potash in 100 ml of alcohol is poured from a dropping funnel. The mixture is stirred for 2 hours at room temperature. Then the precipitate is filtered, well squeezed and dried in a vacuum desiccator. 18.8 g (98.5%) of the dipotassium salt of the zinc complex of hydroxyethylidene diphosphonic acid are obtained.

Found,%: Zn - 16.71;

C2H4K207P2Zn. 2H20.

Calculated,%: Zn - 17.1.

40 g of product are dissolved in 100 ml of water.

Example 2. To a solution of 10.6 g of hydroxyethylidene diphosphonic acid in 200 ml of alcohol was added 2.8 g of calcium oxide. After soaking for 1.5 hours, a solution of 6.4 g of potassium hydroxide in 100 ml of alcohol was added to the reaction mass. Upon completion of the addition, the alkali is allowed to stand at room temperature for 2 hours. After separating and treating the precipitate, as described in Example 1, 18.6 g (99%) of dicalyl salt of the calcium complex of hydroxyethylidene diphosphonic acid are obtained.

Found,%: Sa - 10.3;

С2Н4К2О7Р2Са - ЗНзО.

Calculated,%: Sa - 10.7.

More than 30 g of product is dissolved in 100 ml of water.

Example 3. To a solution of 10.6 g of hydroxyethylidene diphosphonic acid in 200 ml of alcohol was added. 2.0 g of magnesium oxide, allowed to stand for 1.5 h and a solution of 6.4 g of caustic potash in 100 ml of alcohol was added. After soaking the reaction (mass for 1.5 hours, separating the precipitate and drying it) in air, 17.9 g (99.8%) of the dipotassium salt of the magnesium complex of hydroxyethylidene diferaphone insulin are obtained.

Found,%: Mg - 6.02;

C2H4K207P2Mg. ЗН2О.

 Calculated,%: Mg - 6.77.

20 g of product are dissolved in 100 ml of water.

Example 4. To a solution of 10.6 th, xyethylidene, phoofonic acid of yours in 200 ml of alcohol, add 4.0 g of zinc oxide to lorschians. The reaction was stirred at room temperature for 1 hour, after which a solution of 4.1 g of sodium hydroxide (98%) in 160 ml of alcohol was added dropwise from a dropping funnel. The mixture is stirred

Claims (1)

Claim The method of obtaining alkali salts of hydroxyethylidene diphosphonic acid complexes with Group II metals by reacting hydroxyethylidene diphosphonic acid with a metal-containing compound: in a solvent medium followed by neutralization of the obtained product with an alkali, which, in order to simplify the process and improve the quality of the product, use oxide or metal hydroxide, alcohol or dimethylformamide as solvent and hydroxyethylidene diphosphonic acid, metal oxide or hydroxide la and alkali are taken in a molar ratio of 1: 0.9 = 1.0: 2.0 = 2.1 and the obtained product is kept for 0.5-1.5 hours before neutralization.