CS232643B1 - Method of purifying 2-isopropylamino-4-ethylamino-6-chloro-s-triazine - Google Patents

Abstract

The invention solves the purification of 2-isopropylamino-4-ethylamino-6-chloro-s-triazm contaminated with organic and inorganic substances. The impure 2-isopropylamino-4-ethylamino-6-chloro-s-triazine is dissolved and/or melted in a water-insoluble organic solvent at the boiling temperature of the mixture, the insoluble impurities are separated, and the solvent is steam distilled from the 2-isopropylamino-4-ethylamino-6-chloro-s-triazine. Filtration or sedimentation is used for separation. The rust is preferably separated magnetically. The invention can be used in the purification of 2-isopropylamino-4-ethylamino-6-chloro-s-triazine, the contamination of which reduces its quality. 2-isopropylamino-4-ethylamino-6-chloro-s-triazine is used as a herbicide in agriculture, especially in cornfields.

Description

232643

The present invention relates to the purification of 2-isopropylamino-4-ethylamino-6-chloro-s-triazine contaminated with organic and inorganic substances.

The most well-known and most widely produced s-triazine herbicides include 2-isopropylamino-4-ethylamino-6-chloro-s-triazine (atrazine). Herbicidal effects have been discovered in 1954 in Switzerland and described in Swiss Patent 229,227. the reaction of cyanuric chloride, ethylamine, isopropylamine and sodium hydroxide in the aqueous chlorobenzene medium is described in U.S. Pat. pat. The preparation of atrazine by reaction of cyanuric chloride with ethylamine, isopropylamine in an anhydrous organic solvent, using anhydrous ammonia for binding of the resulting hydrogen chloride, is described in U.S. Pat. No. 508,640. The product obtained contains 92% of atrazine. The effect of pH on atrazine is described in the patent specifications of NDR and NSR. According to GDR pat. In the second reaction stage, i.e. in the first reaction stage, i.e. after the addition of the first amine and the alkali metal hydroxide, a better yield is obtained in the first reaction stage, i.e. after the first amine and alkali metal hydroxide have been added. after addition of the second amine and hydroxyalcalic metal, the pH is maintained at 8.5 to 9. The atrazine yield is 96%. NSR Pat. No. 2,032,861 discloses a pH in the first stage of 6.5 to 10. U.S. Pat. No. 3,328,393 and 3,586,679 disclose the preparation of atrazine from cyanuric chloride, ethylamine, isopropyl amine in anhydrous medium at 120 DEG-170 DEG C. by distilling off the resulting hydrogen chloride. The advantage of the process is that the wastewater problem is eliminated by the content of mineral salts. Swiss Patent No. 546,247 describes an adiabatic process for the preparation of atrazine in a water-soluble solvent by reacting ethylamine, isopropylamine, an alkali hydroxide with cyanuric chloride. pat. 2 296 628, rum. pat. 60 016, jap. pat. 131 592 (1977), the addition of amines in the manufacture of atrazine is recommended to meter the first isopropylamine. Banks C. et al., J. Am. Chem. Soc. 66, 1771 (1944) and Friedheim E., J. Am. Chem. Soc. B6, 1725 (1944) recommends at a first reaction step to produce atrazine a temperature of about 0 ° C and a second reaction step at temperatures of 30 to 50 ° C. For the reaction stage, a mixture of water and ice, or, respectively, an organic solvent is used as the reaction medium. Reference is not made in the literature to the purification of the strong contaminated waste and the atrazine produced during its production.

The aforementioned drawbacks are eliminated by the method of purifying 2-isopropylamino-4-ethyl-amino-6-chloro-s-triazine, the essence of which is that 2-isopropylamino-4-ethyl-amino-6-chloro-s-triazine contaminated with organic organic or insoluble organic solvents, dissolves and / or melts in organic water-soluble solvents such as aliphatic, aromatic hydrocarbons, or derivatives thereof, preferably at the temperature of the solvent, with insoluble impurities separating from the solution and / or emulsion 2-isopropylamino-4-ethylamino-6-chloro-s-triazine in an organic solvent. The organic water-insoluble solvent is removed by distillation. It is preferred to use steam distillation. The impurities are preferably separated from the solution or emulsion by filtration, whereby filtration through fine sieve can be used. Inorganic compounds can be separated by sedimentation. Impurities that contain lesion can be separated magnetically. Purification of 2-isopropylamino-4-ethylamino-6-chloro-s-triazine can be carried out with a water-insoluble organic solvent in the presence of water.

According to the present invention, the purification of contaminated 2-isopropylamino-4-ethylamino-6-chloro-s-triazine and an increase in its quality is achieved. Pollution must be caused by organic insoluble solvents. The solubility of 2-iso, pro, pyridin-4-ethylamino-6-chloro-s-triazine is strongly temperature-dependent in most solvents. At the boiling point of the solvent, a portion of the 2-isopropylamino-4-ethylamino-6-chloro-s-triazine melts and causes the mixture to become opaque. Fine filtration is sufficient to separate most of the impurities. Larger inorganic particles can be separated by sedimentation, which can be done with a simple device. The fine iron-containing particles are preferably separated from the magnesium. Since the solubility of 2-isopropylamino-4-ethylamino-6-chloro-s-triazine is most prominent in the water-soluble solvent at the boiling point of the mixture, at a higher temperature it exerts a prominent Brown particle movement that prevents them from sedimenting. In the case of ferromagnetic particles, the advantage is eliminated with a magnet. Purification can be carried out in the presence of water, whereby a wet material can be used for cleaning, which does not need to be dried before cleaning. Example 1

The flask was charged with 200 ml of technical chlorobenzene and 100 g of impure 2-isopropyl-amino-4-ethylamino-6-chloro-s-triazine, containing 52.1% by weight. of technical 2-isopropylamino-4-ethylamino-6-chloro-s-triazine, 0.6 wt. of polypropylene fibers by filtration, 0.4 wt. rust expressed as FezOs and 0.9% sand. The flask was mounted on an electromagnetic stirrer and heated to boiling temperature and passed through a 0.355 x 0.355 mm sieve made of stainless steel. The threads seized and the larger inorganic

Claims (5)

1. A process for the purification of 2-isopropylamino-4-ethylamino-6-chloro-s-triazine contaminated with organic or inorganic substances such as sand, rust, characterized in that the contaminated 2-isopropylamino-4-ethylamino-6-chloro-s -triazine is dissolved and / or melted in a water-insoluble organic solvent, preferably at the boiling point of the mixture, where the insoluble impurities are separated and the solvent is distilled off from the 2-isopropylamino-4-ethylamino-6-chloro-s-triazine-steam . We claim: 2. The method according to claim 1, characterized in that the impurities are separated by filtration. 3. A process according to claim 1, characterized in that the inorganic impurities are separated by sedimentation. 4. Method according to claim 1, characterized in that the rust is separated magnetically or electromagnetically. 5. The method according to items 1 to 4, characterized by. that purification takes place in the presence of water.