CS260767B1 - Method of 4-phenol sodium sulfonate insulation from waste water during 4-amino-1-phenyl-5-chloro-6-oxo-1h-pyridazine production - Google Patents

Abstract

The solution relates to a method for isolating 4-phenol sulfonate sodium from wastewater in production 4-amino-l-phenyl-5-chloro-6-oxo-pyridazine containing sodium chloride, 4-phenolsulfonate sodium and other organic impurities. The 0.5 to 1.2 moles of hydroxide are added to the waste water sodium per mole of chloride present % ammonium, 0.05 to 0.8 wt. adsorbent against waste water, the mixture is concentrated to 20 to 50% of the flood volume and temperature 60 to 100 ° C is filtered, the filtrate is cooled at -10 to +30 ° C and solid 4-phenylsulfonate the sodium is isolated or the filtrate containing Sodium 4-phenolsulfonate is used directly into the reaction. The solution can be used in chemical industry.

Description

The present invention relates to a process for the isolation of sodium 4-phenol sulfonate from waste water in the production of 4-amino-1-phenyl-5-chloro-6-oxo-1H-pyridazine containing sodium chloride, sodium 4-phenol sulfonate and other organic impurities. 0.5 to 1.2 moles of sodium hydroxide per mole of ammonium chloride present, 0.05 to 0.8 wt. adsorbent to waste water, the mixture is concentrated to 20 to 50% flood volume and filtered at 60 to 100 ° C, the filtrate is cooled to -10 to +30 ° C and solid sodium 4-phenylsulfonate is collected or the filtrate containing 4 sodium phenol sulfonate is used directly in the reaction.

The solution can be used in the chemical industry.

The present invention relates to a process for the isolation of sodium 4-phenol sulfonate from waste water for the production of 4-amino-1-phenyl-5-chloro-6-pho-1H-pyridazine. Sodium 4-phenol sulfonate is used as a catalyst in this process.

4-Amino-1-phenyl-5-chloro-6-oxo-1H-pyridazine is a herbicide intended primarily for the selective control of weeds in sugar beet (Burex, Pyramine) and in its preparation according to Art. AO 226 250 uses sodium 4-phenol sulfonate as a catalyst to achieve high purity of the technical product. Sodium 4-phosulphonate, which is dissolved in the reaction mixture, after filtering off the technical product, leaves with other inorganic and organic impurities as waste water into the chemical sewer.

[0003] The processes known to date for the isolation of phenolsulfonic acids and the like are known. their alkali salts consist in extracting their solutions with aromatic petroleum solvents, possibly by inorganic solar extraction. Said isolations are carried out from the reaction mixture after their previous preparation, possibly from their pure high concentration solutions.

Japanese Patent 7,015,019 discloses, for example, the preparation of 4-phenol sulfonic acid sodium salt by reaction of phenol and 96% sulfuric acid. After completion of the reaction from the reaction mixture, the sodium salt of 4-phenol sulfonic acid is salted out by adding 30% aqueous sodium chloride solution. The isolated sodium 4-phenol sulfonate can be further purified by crystallization from sodium chloride solution.

It has now been found a process for the isolation of sodium 4-phenolsulfonate from waste water after the preparation of 4-amino-1-phenyl-5-chloro-6-oxo-1H-pyridazine according to the invention.

SUMMARY OF THE INVENTION The present invention consists in adding to the waste water containing ammonium chloride, sodium 4-phenolsulfonate and other organic impurities in a molar ratio to 0.05 to 1.2 to 1 ammonium chloride present and 0.05 to 0.8. % wt. adsorbent to waste water. As the adsorbent, bleaching clay, activated carbon and the like can be used. The mixture is then concentrated to 20 to 50% of the original volume and filtered at 60 to 100 ° C to remove the adsorbent with organic impurities and some of the inorganic salts. The sodium 4-phenol sulfonate filtrate is used or directly reacted, or after cooling to -10 to +30 degrees Celsius, solid sodium 4-phenol sulfonate is isolated, which, after washing with aqueous sodium chloride solution, is obtained in high purity.

An advantage of the invention is that a simple process with minimal energy consumption isolates a valuable catalyst, i. j. Sodium 4-phenolsufonate from waste water, which would no longer be of practical use. It should also be pointed out that reducing the content of sodium 4-phenolsulfonate to waste water to a minimum is of no significant importance in environmental protection.

The following example illustrates but does not limit the scope of the invention.

Example

A 1000 ml flask was charged with 500 g of waste water from the production of 4-amino-1-phenyl-5-chloro-6-oxo-1H-pyridazine containing 9 wt. % ammonium chloride, 4.94 wt. sodium phenolsulfonate and other organic impurities. To the present waste water was added 1 g of bleaching clay and 84.1 g of a 40% aqueous sodium hydroxide solution. While stirring, 410 g of water were distilled off at atmospheric pressure while ammonia escaping was collected in water in an absorption column. The mixture was then filtered at 95 ° C. After cooling the filtrate to 10 ° C, the sodium 4-phenol sulfonate that was drawn out was isolated and washed with 25 ml of 5% aqueous sodium chloride solution at 5 ° C.

After drying the product at 140 ° C, 21.3 g of sodium 4-phenolsulfonate with a purity of 95.4% by weight were obtained. The yield was 82.3% by weight, based on sodium 4-phenol sulfonate in the present waste water. . ’,

Claims (1)

SUBJECT A process for the isolation of sodium 4-phenolsulfonate from waste water in the production of 4-amino-1-phenyl-5-chloro-6-oxo-1H-pyridazine containing sodium chloride, sodium 4-phenolsulfonate and other organic impurities, characterized in that 0.5 to 1.2 moles of sodium hydroxide per mole of ammonium chloride present, 0.05 to 0.8 wt. adsorbents to waste water, the mixture concentrated to 20 to 50% of the original volume is filtered at 60 to 100 ° C, the filtrate containing sodium 4-phenolsulfonate is used in the reaction or from the filtrate after cooling to -10 to +30 ° C solid sodium 4-phenolsulfonate is isolated.