SU1456416A1 - Method of extracting 2,2ъ-dihydroxy-3,3ъ,5,5ъ-tetrachlorodiphenylsulfide - Google Patents

Abstract

The invention relates to organic sulfur compounds, in particular, the method for the separation of 2,2-d-idroxy-3,3, 5, 5-tetrachloro-diphenyl sulfide from the reaction mixture, when it is prepared, which is used to treat ruminants from parathystasia. The goal is to simplify and improve the safety of the process, increasing the yield of the target product. Synthesis of the target substance is carried out by reaction of 2,4-dichloro phenol with sulfur monochloride in the presence of AlCl3 in the medium of organochlorine solvent at 45-55 C. The reaction mass is filtered. The precipitate is treated with an aqueous solution of NaOH to pH 11-13, filtered, the filtrate is acidified with mineral acid to pH 1-2 at 50-80 C. The precipitated target product is washed with water and dried. The method allows to increase the yield of the target product from 50 to 79%, to exclude the recrystallization stage using a flammable solvent, to separate the completely elemental sulfur from the raw product. 1 tab.

Description

This invention relates to an improved method for separating 2,2-dihydroxy-3.3, 5.5-tetrachloro-diphenylsulfide from the reaction mass when it is prepared, which is an effective treatment for ruminants from parathysthomatosis.

The aim of the invention is to simplify and enhance the safety of the process and increase the yield of the target product, which is achieved by treating the precipitate obtained after filtering the reaction mass with an aqueous solution of sodium hydroxide to pH 11-13, filtering, acidifying the filtrate with mineral acid to pH 1-2 at 50-80 ° C, washing with water and drying the precipitated thus precipitated target product.

Example. In a round bottom flask equipped with a stirrer, a reflux condenser, and an addition funnel, 163 g (1 mol) of 2,4-dichlorophenol and 250 ml of an organochlorine solvent are charged. After dissolving dichlorophenol, 6 g of anhydrous aluminum chloride are added as a catalyst. 72 g (0.53 mol) of sulfur monochloride are added during 1 hour. Move another 3 hours, raise the temperature to 65-70 ° C and heat another 1 hour. The reaction is considered complete when the content of 2,4-dichlorophenol in the mixture drops below 1%. Then cooled, the precipitate filtered

ABOUT

Wash, washed with 50 ml of solvent. The precipitate is placed in a beaker, a solution of 50 g of NaOH in 450 g of water is added, and the pH is 12.3. The sulfur precipitate is filtered off, the filtrate, which is a solution of monon: trisulfate 2,2-dihydroxy-3,3, 5,5-β-tetrachlorophenyl sulfide, acidified with hydrochloric acid to pH 1.0 and maintained at 50 ° C , 5 hours

the precipitate is filtered off, washed with hot water (), dried with hot air. 124.0 g (70%) of 2,2-dihydroxy-3,3,5,5-tetrachlorobiphenyl sulfide are obtained, m.p. 182-4 ° C.

Found,%: S 9.05.

Calculated,%: S 9.0.

The results of the experiments are given in the table (the content of 2,4-dichlorophenol 163 g, sulfur monochloride 72 g).

 Produt but vvvstzhg it udo lvtv tue U.

Thanks to the elimination of the re-technology stage and increased safety

the pigtalization of the raw product from the op process.

 solvent, excellent when treating the product sludge with

OG called at the stage of synthesis, a gray solution of alkali occurs them,

there is no need for regeneration complete separation, due to the transition

One toxic, highly flammable product in a water-soluble, natrically active solvent and solvent, simplifies the ev salt. Sulfur under these conditions

practically insoluble and easily removed by filtration. As a result, product losses occurring during recrystallization are eliminated, and its yield increases to 79%, against 50%, the amount of organic waste is reduced.

The proposed method can be implemented on an industrial scale. The elemental sulfur formed as a by-product is obtained sufficiently pure and can be directed to the production of carbon dioxide. Thus, the proposed method for the preparation of 2,2-dihydroxy-3,3,5,5-tetrachlorodiphenylsulfide is low-waste and meets modern requirements for newly created processes in terms of resource saving and environmental protection.

Claims (1)

Claims of Invention A method for separating 2,2-dihydroxy-3.3, 5.5-tetrachlorobiphenyl sulfide from the reaction mass obtained by reacting 2,4-dichlorophenol with sulfur monochloride in an environment of an organochlorine solvent in the presence of aluminum chloride as a catalyst 45-55 ° C, using mineral acid, washing with water and heating, characterized in that, in order to simplify and increase the safety of the process and increase the yield of the target product, the precipitate obtained after filtering the reaction mixture is treated with m sodium hydroxide until pH 11-13 is filtered off, the filtrate was acidified with mineral acid to pH 1-2 at 50-80 C, and the precipitated title product was washed with water and suschat.