CS252897B1 - Process for the production of technical 2-isopropylamino-4-ethylamino-6-chloro-s-triazine - Google Patents

Abstract

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

Description

I 3 4 252897

The present invention provides a process for the preparation of technical 2-isopropylamino-4-ethylamino-6-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.

The most well-known and most widely produced s-triazinating herbicides include 2-isopropylamino-4-ethylamino-6-chloro-s-triazine (atracin). 227. The preparation of atrazine by the reaction of cyanuric chloride, ethylamine, isopropylamine and sodium hydroxide in an aqueous chlorofenene medium is described in U.S. Pat. No. 110,352. used ammonia, describes Swiss patent 508 640. The product obtained contains 92% of atrazine. The influence of the pH on the yield of atrazine is described in the German Patent Specifications. According to GDR pat. 51646, the best yield is obtained when, in the first reaction stage, i.e. after the addition of the first amine and alkali metal hydroxide, a pH of 6-8 is maintained in the second reaction stage, i.e., the pH is adjusted to 8 after addition of the second amine and alkali metal hydroxide. 5 to 9. The atrazine yield is 96%. In German Patent No. 2,032,861, the pH value in the first stage is 6.5 to 10. In the case of pH. No. 3,328,399 and 3,586,679 describe the preparation of atrazine from cyanuric chloride, ethyl amine, isopropylamine in an anhydrous medium at 120 DEG-170 DEG C. with distillation of the resulting hydrogen chloride. The advantage of the process is that the problem of mineral salts is eliminated. Swiss Patent 546,247 describes an adiabatic process for the preparation of atrazine in a water-soluble solvent by reaction of ethylamine, isopropylamine, alkali hydroxide and cyanuric chloride. In French Patent No. 2,296,628, Romanian Patent No. 68,016, Patent 131,592 (1977), the first isopropylamine is dosed in the dosage of amines in the manufacture of amidrazine. BanksC. a spol. J. Am. Chem. Soc. 66, 1771 (1944) and Friedheim, E., J. Am. Chem. Soc. 66, 1725 (1944) recommend at a first reaction stage of atrazine production a temperature of about 0 ° C and a second reactive stage at temperatures of 30-50 ° C. In the first reaction step, the reaction medium is a mixture of water and water, water, and an organic solvent. The disadvantage of the above-mentioned features is that the condensation overheats in the presence of an organic solvent which must be separated off after the condensation has ended.

The cyanuric chloride used as reaction, as well as the technical atrazine formed, is partially hydrophobic, which may make the reaction of cyanuric chloride with amine solutions difficult, as well as reduce the reaction rate of the reaction itself.

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

By the process of preparing the technical atrazine according to the invention, a better wetting of the cyanuric chloride and the resulting atrazine is achieved by using the tensile agent, thereby improving the reaction conditions in the manufacture of atrazine. Example 1

Water (250 mL) was added to the reaction flask. After cooling to 5 ° C, 30 g cyanuric chloride was added to the water. To the mixture was added 0.1 ml of ethylene oxide / propylene oxide copolymer known under the trade name SlovanilkT 610. Then, 50 ml of 20.2 percent by weight were added sequentially. isopropylamine aqueous solution and after 30 min. 55 ml 10.0 wt. aqueous sodium hydroxide solution. The temperature was maintained at 5-10 ° C. After 50 min, 21.5 mL of 39 wt. aqueous solution of ethylamine and 50 ml of 10.1 wt. aqueous sodium hydroxide solution. The mixture was left for 50 min. doreago-vať. Then the technical atrazine was filtered through a Buchner funnel, washed with 200 ml of water and dried at 105 eC. 33.1 g of technical atrazine with a content of 97.1% oatrazine, 1.6% by weight were obtained. % of simazine and 0.9 wt. p-ropazine. Example 2

As described in Example 1, a 250 ml 10% w / w solution was added instead of water. chloride solution. 33.6 kg of technicalatrazine were obtained with a content of 97.3% by weight. % of atrazine, 1.2 wt. % of simazine and 1.3 wt. propasin. Example 3

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

The invention finds application in the production of technical atrazine, which is used in the agricultural alcohol industry.

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.