RU2034823C1 - Process for preparing 2,2,-bis-(3,5-dibromo-4- hydrobyphenyl) propane - Google Patents

Abstract

FIELD: production of halogen- containing bis-phenols. SUBSTANCE: the process comprises reacting 2,2-bis-(4-hydroxyphenyl) propane with bromine in the presence of water, a 30% aqueous solution of hydrogen peroxide with a solvent such as methylene chloride. 2 moles of bromine per 1 mole of 2,2-bis(4- hydroxyphenyl) propane are added to the aqueous mixture. EFFECT: improved preparation process.

Description

H являющегося ключевым исходным продуктом в производстве подавляющего числа антипиренов соединений, используемых для получения негорючих материалов.The invention relates to polyhalogenated aromatic compounds, to an improved method for producing 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane of the formula (1)
H

H, which is a key source product in the production of the overwhelming number of flame retardants, of compounds used to produce non-combustible materials.

OH + 4Br₂___ ÷ H

H + 4HBr
После перемешивания в течение 150 мин к смеси добавляют воду до соотношения воды и метанола 1:1, кипятят 25 мин и отфильтровывают выпавший осадок. После стандартной обработки и сушки в вакууме получают 96% продукта с температурой плавления 183^оС. Недостатками данного способа являются: использование половинного количества дорогостоящего брома, так как вторая половина превращается в бромистоводородную кислоту, применение высокотоксичного растворителя метанола, необходимость утилизации образующейся бромистоводородной кислоты, необходимость утилизации образующегося после выделения целевого продукта раствора метанола.A known method for producing 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane, which consists in adding a methanol solution of bromine to a stirred mixture of one mole of 2,2-bis- (4-hydroxyphenyl) propane and 20 mol of methanol without reaction cooling:
HO

OH + 4Br ₂ ___ ÷ H

H + 4HBr
After stirring for 150 minutes, water is added to the mixture to a ratio of water: methanol 1: 1, boiled for 25 minutes and the precipitate formed is filtered off. After standard workup and drying in vacuo gave 96% of product with melting point 183 ^C. The disadvantages of this method are: the use of half amount of expensive bromine, as the other half is converted into hydrobromic acid, the use of highly toxic methanol solvent, the need of recycling the resulting hydrobromic acid need disposal of the methanol solution formed after isolation of the target product.

A known method of producing 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane, which consists in the simultaneous addition at a temperature of 8-10 ^about C 42% hydrobromic acid and 30% hydrogen peroxide to solution 2, 2-bis- (4-hydroxyphenyl) propane in alcohol. After standard workup and drying gave 83% of product with melting point 178 ^C. The disadvantages of this method are: the use of expensive hydrobromic acid, low product yield.

Also known is a method for producing 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane, which consists in adding bromine to a stirred mixture of 2,2-bis- (4-hydroxyphenyl) propane, water and methylene chloride at boiling point last one. After the total amount of bromine was added, the mixture was stirred at the boil for 1 h, cooled, the precipitate formed of 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane was filtered off and dried in air. The solvents are separated on a separatory funnel, methylene chloride is washed with a weak alkaline solution and used in the following experiments. The yield after 18 experiments is 95.5% of 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane with a T _m. 178-179 ^about With and the bromine content of 59.1% The disadvantages of this method are: the use of half the amount of expensive bromine, since the second half is converted into hydrobromic acid, the need for disposal of the resulting hydrobromic acid.

The closest technical solution is a method for producing 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane, which consists in adding to the stirred mixture 2,2-bis- (4-hydroxyphenyl) propane, water and methanol at a temperature 20-30 ^about With bromine and then at the same temperature 35% hydrogen peroxide. After addition of all the peroxide temperature was raised to 55 ^{° C,} the mixture was stirred for 3 hours, poured into water, cooled, the precipitate of the reaction product is separated, washed with water and dried to give 96% 2,2-bis- (3,5-dibromo-4- hydroxyphenyl) propane of unspecified purity. The disadvantages of the prototype are as follows: the use of a highly toxic methanol solvent, an increased reaction time due to the sequential addition of two reagents, the need to dispose of a large amount of the resulting methanol aqueous solution.

 The aim of the invention is to search for the conditions for the bromination of 2,2-bis- (4-hydroxyphenyl) propane without the formation of by-products requiring recycling, with repeated use of the solvent, in which the added bromine is used completely to form the target product.

[___ ÷ После выделения продукта хлористый метилен, пройдя незначительную очистку, используется в следующем цикле реакции.This goal is achieved by the fact that bromine is added to the reaction mixture, consisting of 2,2-bis- (4-hydroxyphenyl) propane, water, methylene chloride and 30% hydrogen peroxide in an amount of 2 mol of bromine per mole of 2.2 bis- (4-hydroxyphenyl) propane. In this case, the following reaction occurs:

[___ ÷ After isolation of the product, methylene chloride, after a minor purification, is used in the next reaction cycle.

The proposed method has the following advantages:
full use of the bromine introduced into the reaction;
reuse of solvent;
reduction of environmental pressure on the environment;
cheaper product reaction.

PRI me R 1. To a mixture of 91.3 g (0.4 mol) of 2,2-bis- (4-hydroxyphenyl) propane, 100 ml of methylene chloride, 150 ml of water and 85.8 ml (91.2 g, 0.84 mol) of 30% hydrogen peroxide, 41.3 ml (128 g, 0.8 mol) of bromine are added with stirring. After the reaction mixture was refluxed with stirring for 1 hour. The mixture was then cooled to 10 ^C. The precipitate was 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane was filtered off, washed with cold water until neutral reaction of universal indicator and dried on air. 200.14 g (0.37 mol) of the product 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane are obtained. Yield 92%. Solvents were separated on a separatory funnel; methylene chloride was washed with 5 ml of 10% sodium hydroxide solution and used in the following syntheses. The yield after 6 experiments is 96% of 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane.

The resulting product has the following characteristics. T _pl. 182-183 ^about S.

 Calculated, C 33.13; H 2.22; Br 58.77.

 Found C 33.42; H 2.48; Br 58.34.

PMR spectrum (δ, ppm): 1.56 s. (CH ₃ ) 5.83 s. (OH) 7.84 s. (CH).

 Thus, a method has been developed for the production of 2,2-bis- (3,5-dibromo-4-hydroxyphenyl) propane, which can significantly reduce the consumption of one of the reagents and shorten the reaction time.

Claims (1)

 METHOD FOR PRODUCING 2,2-BIS- (3,5-DIBROM-4-HYDROXYPHENYL) PROPANE by reacting 2,2-bis- (4-hydroxyphenyl) propane with bromine in the presence of water, a 30% aqueous solution of hydrogen peroxide and a chlorine-substituted solvent while stirring and heating the mixture, followed by separation and purification of the resulting precipitate of the final product, characterized in that methylene chloride is used as chlorine-substituted methane and 2 moles of bromine per 1 are added to the aqueous mixture of 2,2-bis (4-hydroxyphenylpropane and hydrogen peroxide) mol 2,2-bis- (4-hydroxyphenyl) Pan.