CS252897B1 - Method of technical 2-isopropylamino-4-ethylamino-6-chloro-s-triazine production - Google Patents

Abstract

The production of atrazine by the reaction of cyanuric chloride is solved with ethylamine, isopropylamine and sodium hydroxide. The reaction overhears in an aqueous environment or in an aqueous medium alkaline chloride solution in the presence surfactant. Atrazine is used as a herbicide in agriculture.

Description

The present invention provides a process for the preparation of technical S-isopropylamino-1-ethylamino-S-chloro-s-triazine by reacting cyanuric chloride with aqueous solutions of ethylamine, isopropylamine, sodium hydroxide in an aqueous medium in the presence of a surfactant.

Among the best known and most widely produced s-triazine herbicides are 2-isopropylamino-4-ethylamino-6-chloro-s-triazine (atracin). Herlbicidal effects of cane discovered in 1954 in Switzerland and described in Swiss Patent 229 227. Preparation of atrazine by reaction of cyanuric chloride, ethylamine, isopropylamine and sodium hydroxide in aqueous chlorobenzene medium is described in Czechoslovak patent 110,352. a perfect organic solvent using anhydrous ammonia to bind the resulting hydrogen chloride is described in Swiss patent 508,640. The product obtained contains 92% atrazine. The effect of pH on atrazine yield is described in the patents NDR and NSR. GDR Stage Pat. 51 646, the best yield is obtained if in the first reaction stage, ie after the addition of the first amine and alkali hydroxide (the metal is maintained at pH 6-8, in the second reaction stage, ie after the addition of the second amine and alkali hydroxide, the pH is maintained The yield of atrazine is 96%, and in U.S. Pat. No. 2,032,861 the pH of the first step is 6.5 to 10. In U.S. Pat. Nos. 3,328,399 and 3,586,679, a process for preparing atrazine from cyanuric chloride is described. The advantage of the method is that the problem of waste water containing mineral salts is avoided, Swiss patent 546 247 describes an adiabatic process for the production of atrazine in a water-insoluble solvent by reaction of ethyl, ethylamine, isopropylamine in an anhydrous isopropylamine, alkali hydroxide and cyanuric chloride In French Patent No. 2 296 628, Romanian Patent 68 016, Japanese Patent 131 592 (1977), it is recommended that the first isopropylamine be metered in amine dosing for atrazine production. Banks C. et al. f. Am. Chem. Soc. 66, 1771 (1944) and Friedheim E., J. Am. Chem. Soc. 66, 1725 (1944) recommend at a temperature of about 0 ° C for the first reaction stage of atrazine production, and a second reaction stage at temperatures of 30 to 50 ^° C. In the first reaction stage water / ice is used as the reaction medium. ad and organic solvent. A disadvantage of the above processes is that the condensation takes place in the presence of an organic solvent which must be separated from the product after the condensation has been completed.

The cyanuric chloride used for the reaction, as well as the technical atrazine formed, are partially hydrophobic, which may complicate the reaction of the cyanuric chloride with the amine solution as well as reduce the reaction rate of the reaction itself.

The above-mentioned drawbacks are alleviated by the process for the production of technical 2-isopropylamino-4-ethylamino-6-chloro-s-triazine, which consists in reacting cyanuric chloride with aqueous solutions of ethylamine, isopropylamine and sodium hydroxide in an aqueous medium or in aqueous medium. an aqueous solution of an alkali metal chloride. The reaction is carried out in the presence of a surfactant.

According to the process for the production of technical atrazine according to the invention, the wetting of the cyanuric chloride and the resulting atrazine is improved by using a surfactant, thereby improving the reaction conditions in the atrazine production.

Example 1

250 ml of water was added to the reaction flask. After cooling to 5 ° C, 30 g of cyanuric chloride were added to water. 0.1 ml of a copolymer of ethylene oxide and propylene oxide known under the trade name Slovanilk T 610 was added to the mixture. Then 50 ml of 20.2 percent by weight were added successively. aqueous isopropylamine solution and after 30 min. 55 ml 10.0 wt. aqueous sodium hydroxide solution. The temperature was maintained between 5 and 10 ° C. After 50 minutes, 21.5 mL of 39 wt. of aqueous ethylamine solution and after 40 minutes, 50 ml of 10.1 wt. aqueous sodium hydroxide solution. The mixture was left for 50 min. to complete the reaction. The atrazine technical Bucihnerovom lieviiku the filtered, washed with 200 ml of water and dried at 105 ^{& C.} Yield 33.1 g of technical atrazine content of 97.1 ° / o of atrazine, 1.6% by weight. % simazine and 0.9 wt. propazine.

Example 2

The procedure of Example 1 was followed except that 250 ml of 10 ¹ wt. sodium chloride solution. 33.6 kg of technical atrazine with a content of 97.3% by weight were obtained. atrazine,

1.2 wt. % simazine and 1.3 wt. propazine.

Example 3

The procedure of Example 1 was followed except that 250 ml of 5 wt. potassium chloride solution and 0.1 ml of an aqueous solution of sodium dodecylbenzenesulfonic acid known under the trade name Abeson NAM was added instead of Slavic T 610. 33.9 g of technical atrazine were obtained with a content of 96.8 percent by weight. atrazine, 1.3 wt. % simazine and 1.8 wt. propazine.

The invention finds application in the production of technical atrazine, which uses an alcohol herbicide in agriculture.

Claims (1)

Process for the preparation of technical 2-isopropylamino-4-ethylamino-6-chloro-s-triazine by reaction of cyanuric chloride with aqueous solutions of ethylamine, isopropylamine and sodium hydroxide INVENTED in an aqueous medium or in an aqueous solution of an alkali metal chloride, characterized in that in the presence of a surfactant.