SU330623A1 - METHOD OF OBTAINING AZINS AND IZOHYDRAZO ^ MP ^^^ S-TigSH '^' KArfI - Google Patents

Description

The invention relates to an improved process for the preparation of azines and isohydrazones, which are intermediate products in the synthesis of hydrazine and its salts.

Methods for the preparation of azines are widely described in the literature. In particular, a method for producing azines or isohydrazones is known, involving the interaction of chlorine with an excess of ammonia and a carbonyl compound in the gas phase in the presence of a strong base, for example caustic soda. The yield of the target product is about 70%.

In order to increase the yield of the final product, a method for the production of azines or isohydrazones is proposed, namely, chlorine is reacted with an excess of gaseous ammonia to form chloramine, which is then reacted with carbonyl compound in the presence of aqueous ammonia in the second stage. The resulting product is purely azine if the second stage of the reaction is carried out in the presence of a strong base; if the second stage is carried out in the absence of a strong base, the product is a mixture of a. azine and isohydrazone.

chloramine, ketone and aqueous ammonia developed. This is the main difference between the proposed method and the known one, according to KOTopOMV, the ketone is introduced into the reaction in the gas phase. This difference makes it possible to increase the yield of the target product, and at the same time the hydrazine obtained on its basis.

Example 1. Chlorine (0.2 mol / h) is continuously mixed with ammonia gas (5 mol / h) in a double liquid nozzle. After a short residence time, the gases are passed at 25 ° C for 1 hour into a stirred reaction mixture containing methyl ethyl ketone (0.6 mol), saturated hydroxide

ammonium (400 ml) and gelatin (1 ml of 1% solution), to which 0.4 mol / h of sodium hydroxide (30% aqueous solution) is added. The yield of methyl ethyl ketazine is 95%. Methyl ethyl ketazine is distilled off from the aqueous p (the reaction solution is dissolved in water and fed to a distillation column under pressure, then npii 180 ° C is distilled under a pressure of 10 kg / cm. Methyl ethyl ketone is taken at the top of the column and at the bottom of the column.

Example 2. Chlorine (0.2 mol / h) is continuously mixed with ammonia gas (0.4 mol / h) in a double liquid nozzle immersed in the reaction liquid at

concentric nozzles. Ammonia is supplied through the external, and chlorine through the internal nozzle. The reaction liquid consists of acetone (0.6 mol), a saturated solution of ammonium hydroxide (500 ml) and gelatin (1 ml of a 1% solution). 0.4 mol / h of a 30% aqueous solution of sodium hydroxide is added to the liquid. After 1 hour, the yield of acetazine is 95%.

Sulfuric acid is added to the reaction product (to obtain a final pH of 1-2); the solution is cooled and the precipitated monohydrazine sulfate is filtered off.

Example 3. Chlorine (0.2 mol / h) is continuously mixed with ammonia gas (0.4 mol / h) in a double liquid nozzle. The dual fluid nozzle consists of concentric nozzles; ammonia is fed through the outer nozzle and chlorine through the inner. A double liquid nozzle is immersed in a reaction liquid with a temperature of 45 ° C, containing methyl ethyl ketone (0.4 mol), a saturated solution of ammonium hydroxide (500 ml) and gelatin (1 ml of a 1% solution), into which a 30% solution is fed sodium hydroxide at such a rate that the pH is maintained at 13.0. The feed rate of caustic soda is 0.4 mol / h.

After one hour, the yield of methyl ethyl ketazine is 95%.

Example 4. Chlorine (0.2 mol / h) is continuously mixed with ammonia gas (0.4 mol / h) in a double liquid nozzle immersed in a reaction liquid with a temperature of 35 ° C. The reaction liquid consists of methyl ethyl ketone (0.4 mol), a saturated solution of ammonium hydroxide (500 ml) and gelatin (1 ml of 1% solution), and sodium hydroxide solution is added to it at such a rate that the pH of the reaction solution is maintained equal to 12.5. The amount of added caustic soda corresponds to 0.38 mol / h.

After one hour, the yield of methyl ethyl ketazine is 89% and the yield of methyl ethyl ketone isohydrazone is 8%.

Example 5. Chlorine (0.2 mol / h) is continuously mixed with ammonia gas (0.4 mol / h) in a double liquid nozzle immersed in a reaction liquid with a temperature of 35 ° C. The reaction liquid consists of methyl ethyl ketone (0.4 mol), a saturated solution of ammonium hydroxide (500 ml) and gelatin (1 ml of a 1% solution). After 1 hour, the hydrazine yield as a mixture of 30% and 80% isohydrazone is 97%. The reaction product is extracted with methyl ethyl ketone in a liquid extractor, the organic phase is separated, and freed from ammonia by degassing under pressure. The resulting solution is mixed with an equal volume of water and heated to boiling point.

sulfonated polystyiol resin, crosslinked with divinylbenzene (commercially available as Zeo-Karb 225), in an amount of 40 parts per 1 mole of hydrazine and then cooled. The resin is filtered off, washed with water and hydrazine is eluted with aqueous ammonia as an aqueous solution of hydrazine hydrate.

Subject invention

Claims (2)

1. A method of producing azines and isohydrazones by the interaction of chlorine, ammonia and carbonyl compound, characterized in that, in order to increase the yield of the target product, the interaction of chlorine and ammonia is carried out in the gas phase, and the resulting chloramine is reacted with carbonyl compound the liquid phase in the presence of an aqueous solution of ammonia. 2. A method according to claim 1, characterized in that the process is carried out in the presence of a strong base, which leads to the formation of azine.