SU40987A1 - The method of obtaining aminoxyphanyl acid - Google Patents

Description

The literature describes the following methods for the reduction of nitro-hydroxyphenylarsinic acid: 1) Reduction with sodium amalgam B. jY 45757, Rus. pref. No. 22716, 2) Restoration of germs hydrosulfite. pat 224953 and Russian. pref. No. 2271 b, 3) Recovery by electrolysis in soda solution germs. pat La 270568. 4) E glucose recovery by the US patent Cli. Z. Vol. IV, p. 723 (1923), 3) Reduction with iron sulfate and alkali.

When checking the UKGZANNY. The above methods failed to get good results.

The authors of the present invention propose a method of reducing nitroxy - phenylacetic acid with iron using a small amount of hydrochloric acid or using an excess of it.

When carrying out the reduction with the use of a small amount of HC, the resulting mixture of iron oxide, hydrochloric acid, and amidooxyphenylarsinic acid was treated with a large excess of sodium hydroxide in solution (neither soda nor

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ammonia is not strong enough to destroy the compound of iron with amidooxyphenylarsinic acid and does not remove it from this mixture). The dissolved amido-oxiphenyl sodium acid was aspirated from iron oxide and the acid acid precipitated from it.

In the reduction reaction, hydrochloric acid was used, replacing it with acetic acid gave the worst yield.

Due to the long-term presence of amido-oxyacid in a warm alkaline solution, it was obtained by isolating a rather dark one with a yield near the theory.

Reduction with excess acid: hydrochloric acid took an excess against the amido-oxyphenylarsonic acid required for the dissolution of iron and the formation of the hydrochloric acid salt, so that everything went into solution. The solution, sucked from contamination, was salted out warm, and the salt of the amidooxy salt was obtained in the form of crystals. After cooling, the latter was aspirated and washed off the iron chloride remaining in the solution of ferric chloride.

salt. The output of crude salt reaches 83, theory.

Cleaning was carried out according to the method described in Amer. Ch. Soc. 42 No. 2402 and B. No. 45 p. 757, i.e. by dissolving the hydrochloric acid salt in the hydrochloric acid, owing to hydrolytic cleavage, is completely insoluble in water; this splitting is aided by the formation of an internal, difficultly soluble salt by insisting on cold, with charcoal, filtering from the latter and precipitating with deficiency rather than an excess solution of sodium acetic acid, as indicated in the literature, in order not to isolate iron.

During the cleaning process, about the solubility of amidooxy in the water is lost, so that the yield from nitroxy reaches 75 / o of the theory of an almost chemically pure preparation.

Example 1. 500 g of fine cast iron sawdust, 5 liters of water and 50 Of technical hydrochloric acid (or 50 80dz-acetic acid) boil for 10 minutes. Bleeding, while moving, 263 g (1 mol) of nitroxyphenylarsinic acid is gradually introduced and boiled until the discoloration has resulted on filter paper. 200 g of sodium hydroxide are added to 2000 cm of water, heated to boiling and the solution is sucked off from iron oxide. Amidooxyphenylarsenic acid is precipitated from the solution by adding 300 cm of hydrochloric acid to 17.5 ° Be and then to 60 cm 80 of hydrochloric acid acetic acid. After cooling, the crystals are sucked off, washed with water and dried. Output 140 g 60% of theory.

Example 11. To a suspension of nitroxyphenylarsinic acid 263 g in 1880 with 5-normal hydrochloric acid with good stirring and a temperature of about 40 ° gradually 170 g of iron shavings are introduced. Finally, the temperature is allowed to rise to 55-60. After all the nitroxide is dissolved, it is filtered warm and 250 g of sodium chloride is added to the solution with stirring. After cooling, the precipitated crystals are sucked off and well washed up with a concentrated solution of sodium chloride (about V .; liter). Exit 80-85:, j theory.

The product obtained according to Example 11 was dissolved in B of 1.5 liters of water heated to 40 ° and 340 cm of 5-normal hydrochloric acid, 10 g of animal charcoal was added, and after 2-3 hours it was filtered. The filtrate is precipitated with concentrated solution of acetic acid sodium at about 750 cm- (2.3 standards) until the violet reaction to Congo. After 2-3 hours, the precipitated crystals are sucked off, washed with water and dried. The output of 1 mol. nitroxy about 174 theories.

The subject matter of the invention.

The method of obtaining amino-para-hydroxyphenylarsenic acid by reduction of the corresponding nitroxyphenylarsinic acid with iron, characterized in that methods of reduction of iron (for example, in the form of cast-iron sawdust) with acids or by reacting usually are used for this reaction using a small amount of acid, and upon termination of reduction, the translation with the aid of caustic alkali results in the formation of the amino-hydroxy-phenylarsinic acid I in solution in the form of salt and, after filtration, isolating it from the solution in free form by acidification, or when I used to restore acid I in excess against the amount needed to dissolve all the iron and form the salt of the resulting amino compound, and after the reduction and filtration is completed, salivating the amino-hydroxy-phenylarsinic acid salt by conventional methods.