SU1049494A1 - Process for preparing tris-(2,3-dibromopropyl)phosphate - Google Patents

Description

four

four;

with

"4 The invention relates to the chemistry of organophosphorus compounds, namely to a method for producing tris- (2, 3 Dibromopropyl phosphate of the formula O P (OCH 2 SIV p CHjBn) J which is used in the national economy as a flame retardant in elastomeric compositions, rubbers and textile There is a known method of producing Tris-fZ, Zdibromopropyl) phosphate by reacting phosphorus oxychloride with 2,3 dibromopropanol in the presence of lithium catalizer at a molar ratio of reagents of 1.0: 3.15. : 0.022. The reaction is carried out in benzene at 80 ° C. The theoretical amount of hydrogen chloride is released after 7 hours. The product is washed with 5 N, ammonia solution (with the addition of 2% hydrogen peroxide to improve color), separated from benzene by distillation under vacuum. The yield of tris (2, 3-dibromopropyl) phosphate is 95%, purity is 97 °. The disadvantages of the method are the need to use an inert solvent and its subsequent regeneration, washing the target portion with an ammonia solution with the addition of hydrogen peroxide and then. drying the product is long process. Tris- (2, 3-Dibromopropyl) phosphate obtained by this method is noticeably colored. The closest to the invention to the technical essence and the achieved results is the method of obtaining Tris- (2, 3-dibromopropyl) phosphate by the interaction of phosphorus oxychloride with 2, 3 dibromopropanol in the presence of Friedl Crafts catalysts (aluminum halides, titanium tin, iron, zinc) in organic solvent at SO-UO Yield of tris- (2, 3 Dibromopropyl) phosphate and 93-9. Reaction time 2.33-, 5 h. The target product is washed twice with a 5Ni solution of hydrochloric acid, then twice with BN. ammonia solution, water .. In the case of use as catalyst for aluminum trichloride, the process is carried out at a primol ratio of phosphorus oxychloride, 2, 3-dibromopropanol and aluminum trichloride, equal to 1.0: 3.09: 0.309. The disadvantage of this method is the complexity its technology, associated with the use of a solvent, a significant amount of catalyst, the need for its hydrolysis with hydrochloric acid and ammonia solution, the need for a target product with water and the formation of large amounts of wastewater. In addition to TorOj, tris- (2, 3-Dibrompro-) saws the phosphate obtained in this way is noticeably colored in a dark yellow color. The aim of the invention is to simplify the process and improve the quality of the target product. This aim is achieved according to the method for producing tris (2, 3-dibromopropyl) phosphate provided comprising in that phosphorus oxychloride is reacted with 2, 3-dibromopropanol in the presence of a catalyst - a complex compound triethylbenzylammonium chloride, tetrabutyl ammonium iodide or trifenilbenzil phosphonium chloride or bromide with a metal chloride General formula h MeSBh, where Me - zinc, cadmium, iron or tin; integer from 1 to 3J P an integer of 2 or 3, X is carried out at a temperature of 60 of the SO-C process and a molar ratio of oxychloride (1x spectrum, 2, 3 of Dibromopropanol and catalyst, equal to 1, 0: 3,, 5:: 0.01 The proposed method allows to simplify the process of obtaining tris- (2, 3-dibromopropyl) phosphate for the estimates of reducing the elimination of the use of a solvent, a significant decrease in the amount of catalyst, the absence of a stage of hydrolysis of the catalyst, the elimination of washing the target product and the associated absence of washing. waters. In addition, the proposed method allows It is necessary to obtain colorless tris- (2,3-dibromopropyl) phosphate, which is necessary to obtain non-combustible polymer compositions without changing their color, with a high yield (). The method is carried out as follows. To a solution of the catalyst in 2, 3d bromopropanol at 80 ° C is added dropwise phosphorus oxychloride .. Hydrogen chloride formed is absorbed by an aqueous solution of alkali. The reaction is carried out to the 100% conversion of phosphorus oxychloride. The molar ratio of the components of POCl 2, 3-Dibromopropanol catalyst is 1.0: 3.0 - +, 5 110 - 1-10 . The reaction time is 2 hours. The yield of tris- (2, 3-dibr-propyl) phosphate is theoretically. The desired product is not colored; an excess of 2, 3 dibromopropanol is distilled off from the reaction mixture under vacuum of an oil pump under a nitrogen atmosphere. Example. In a three-necked flask with a capacity of 0.25 l, 78.6 g (o, 36 mol) of 2, 3-dibromopropanol and 0.0939 g (110 mol) of the complex catalyst () C1x X are placed. With stirring and the temperature of the water bath, 9.15 ml (0.1 mol) of phosphorus oxychloride are added from the dropping funnel. The reaction is carried out under a nitrogen atmosphere. The hydrogen chloride that forms is absorbed by the titrated aqueous solution of the alkali conversion (phosphorus oxychloride is reached after 2.5 h. The excess of 2, 3-dibromopropanol is distilled off under nitrogen in a vacuum of an oil pump at 10-15 hours) (-5 mm Hg. 1. 65.8t g (9, 2%) Tris- (2, W-Dibromopropyl phosphate, PH5705. Found D: Bri67,9; 68,2. Calculated,%: BV 68 , 75 Example 2 -. In a three-necked flask with a capacity of 0.25 l, h4 was placed in 26.1 g (0.12 mol of 2,3-Dibromopropanol and 0.168 g (3.3-10 mol) of the complex catalyst (C Hollj 3 X ZnClg. With stirring and temperature 3.05 ml (3.3102 mol) of phosphorus oxychloride are added dropwise in one bath. The conversion of phosphorus oxychloride is achieved in 2 hours. After distilling off the excess of 2, 3-Dibromopropanol, 22.0 g are obtained (9.9% L tris- (2, 3-Dibromopropyl) phosphate; 1.571 A. Found: 3 ;: Brg68, A5. Calculated,%: Br 68.75. Application — rH. 78.6 g (about, 36 mol 2) are placed in a three-neck flask with a capacity of 0.25 l. , 3-Dibropropanol and 0.501 g (l-.10 mol) of the complex catalyst () C1 x x2 Z and Cl2. With the stirring and the temperature of the 8 ° C water bath, 9.15 ml (0.1 mol) of phosphorus oxychloride are added dropwise. The reaction mass is flushed with nitrogen for 3 hours to convert the phosphorus oxychloride to 100%. The excess of 2, 3-dibromopropanol is distilled off under nitrogen in a vacuum of an oil pump. 67.3 g (96.52) tris-2, 3-dibromopropyl phosphate 1.5701 are obtained. Found: B (- 68.7. Calculated ,:, 75. Data on the reactions of 2, 3-dibromopropanol with phosphorus oxychloride in the presence of complex catalysts of different composition are given in Table 1. I. T a l and c a one

(C H5 PCH C6H5 Cl-CdC 210 () PCH2SbN5 C1-GeSC 10 (C, H5) zP CH2C, H5 Cl-SnCl2 Q212 9it, 61.5688, 91.5718, 21.5704 Tables 2 and 3 present the data illustrating the effect of temperature, as well as the ratio of reagents and kata. Continuation of table 6

I 1,5706 Table 3 of the lysing composition (C2H5) NCH2C H5l C1x 2ZnCl2 on the reaction rate, yield and purity of tris- (2,3-dibromopropyl) phosphate,

EZZI lI ZIZZIIZXI ± I 1,0: 3,6: 0,01178 1,0: i, 5: 0,01170 1,0: 3,6: 0,001217

Continued table. 3 1.5701 9b, 5 1.5712 97.2 1.5700 96.3

Claims (2)

2. England patent N ’1098637, cl. C 2 C, published. 1968 (prototype). (541 S'GAB OBTAINING TRIS- <2, 3-DIBROMPROPYL) PHOSPHATE of the formula 0 = R., (basic ₂ snvp CH ₉ Vn) _{3 by the} interaction of phosphorus oxychloride with 2, 3 “Dibromopropanol in the presence of a catalyst at elevated temperature, which consists in that, in order to simplify the process and improving the quality of the target product, a complex compound of triethylbenzylammonium chloride, tetrabutylammonium iodide or triphenylbenzylphosphonium chloride, or bromide with a metal chloride of the general formula is used as a catalyst c. MeC6 _k , where Me is zinc, cadmium, iron or tin; P is an integer from 1 to 3, X is an integer from 2 or 3, and the process is carried out at a temperature of 6080 ° C and a molar ratio of phosphorus oxychloride, 2, 3 Dibromopropanol and catalyst equal to 1.0: 3.0-4.5:: 0.01-0.0001.