SU1006433A1 - Process for preparing 1,3,5-tris-(2,3-dibromopropyl)-isocyanurate - Google Patents

Abstract

METHOD OF OBTAINING I, 3, 5-TRIS-

Description

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This invention relates to an improved process for the preparation of 1,3,5-tris (2,3-dibromopropyl) isocyanurate, which is a flame retardant additive for polymers, in particular polyurethanes.

A known method for producing 1,3,5-tris (2,3-dibromopropsh1) -isocyanurate under bromination of trilyl isocyanurate (TAIC) in an inert organic solvent at fe sf 5О С; As an inert solvent, according to the experiment, methylene hydrodide (t, kip. si 4 O C) is used, the mass ratio of TAIC: methylene chloride is 1: O, 9. The use of solvents such as carbon tetrachloride or chloroform raises the reaction temperature above 5 ° C to greatly reduce the yield of the target product, therefore their use is not recommended. The yield of the target product 90-95% from

C theory, ..

The disadvantage of the method is the difficulty of processing the regeneration mixture after the termination of the synthesis: the viscous reaction mass is mixed with petroleum ether, rehearsed with stirring for 51 hours (up to 12 hours) for off; White colored fine powder, then the resulting precipitate is treated with methyl acetate. alcohol.

The aim of the invention is to simplify the process, allowing in one stage to obtain a crystalline product with a yield close to stoichiometric, without additional treatment with solvents,.

The goal is achieved according to the method of obtaining 1 | 3,5-tris- {2.3 dibromopropyl) -isozzanurate; bromination of triallylionic inurate in carbon tetrachloride during mass production of triple cyanthiocyanate and four-porous carbon 1: (B-7) with gradual increase; to the teosherature boiling of the reaction mixture ..

When conducting the interaction between trilyl isocyanurate and bromine, it was unexpectedly found that the implementation of this process in a carbon tetrachloride medium, taken at a mass ratio to the trilyl isocyanurate, 1: (5 27) and temperatures of 20-75 C., followed by cooling at a pH of 10% of crystalline A white precipitate is presented in parts 1, 3, 5-tris- {2,3dibropropyl) -Ircyanurate. target product 95-98%.

The indicated mass ratios between carbon tetrachloride and trial lily isocyanurate are chosen based on the fact that with a smaller amount of carbon chloride, the reaction products are viscous, slow (Crystallizing:, mass that cannot be separated by filtration.

The ratio of carbon tetrachloride: trilyl isocyanurate above 7: 1 is not technologically feasible, since it leads to an increase in the volume of recycled solvent, not the best process.

Example I. 5O g (0.2 mol) TAITS and 25 O g carbon tetrachloride (TAIC: carbon tetrachloride mass ratio 1: 5) mark an 8 round bottom flask equipped with an addition funnel, stirrer and reverse column. 96.4 g of bromine (O, 6 mol) are loaded into a dropping funnel. 55 g of bromine are added dropwise over 30 minutes without heating. The temperature due to the heat of reaction increased from room temperature () to. Then the heating is turned on and the rest of the bromine is added dropwise while heating the reaction mass to 75 s per minute. After dropping the entire amount of bromine, the reaction mixture is kept at / h / 75 C for 1 h. During this time, the solution mixture turns a pale straw color. Then the reaction mixture is cooled with stirring. At 20-25 C ira the reaction mixture a white fine precipitate falls out. The precipitate is filtered off, washed with distilled water, dried at 75-80 ° C. The yield of the desired product is 14 O g (96% of theoretical), melting point is 10 10 -10 0 ° C.

PRI me R. 2. With a mass ratio of trilyl isocyanurate:, carbon tetrachloride 1: 7, at loading of 5O g TAITS, 35O g of carbon tetrachloride is taken. The synthesis is carried out as in Example I. The total dropping time of bromine is 30 min. The duration of provision and cooling does not vary. The precipitate disappears when the reaction mass is cooled to 35 ° C. The yield of the desired product is 132 g (90% of the theoretical), so pl. 106-110 C.

PRI me R 3. Exodus from 50 g triallloshoshtsotsianurata, ZOO g mother liquor chetyz

310064334

re} cx of the peroxide carbon separated 142 g (98% of the theoretical

Example 2, and 96.4 g of bromine, carried out 1,3,5-tris- (2,3-dibromopropl) -extraction as in examples t and, 2, nurata, mn. tt) 6-tlO C.

Claims (1)

METHOD FOR PRODUCING I, 3, 5-TRIS- (2,3-DIBROMPROPYL) ISOPIANURATE. bromination of triallylisocyanurate in a medium of “chlorinated hydrocarbon with a gradual increase in temperature from room temperature to the boiling point of the reaction mixture, characterized in that, in order to simplify the process, carbon tetrachloride is used as a chlorinated hydrocarbon with a mass” ratio of triallyliocyanurate and carbon tetrachloride 1: (5 - 7 ) 1 1006433 2