SU727652A1

SU727652A1 - Method of para-carborane isolation

Info

Publication number: SU727652A1
Application number: SU782660715A
Authority: SU
Inventors: Владимир Цвиевич Кампель; Владимир Иосифович Брегадзе; Николай Николаевич Годовиков
Original assignee: Ордена Ленина Институт Элементоорганических Соединений Ан Ссср
Priority date: 1978-09-07
Filing date: 1978-09-07
Publication date: 1980-04-15

Description

Изобретение относится к новому способу выделения п-карборана из его смеси с м-карбораном. п-Карборан является важным промежуточным продук- ₍том для синтеза термостойких полимеров и материалов карборанового ряда [1].The invention relates to a new method for the isolation of p-carborane from its mixture with m-carborane. p-Carboran is an important intermediate product ₍ for the synthesis of heat-resistant polymers and materials of the carboran series [1].

п-Карборан получают изомеризацией м-карборана при температуре 700°С. ’p-Carboran is obtained by isomerization of m-carborane at a temperature of 700 ° C. ’

Образующаяся смесь содержит примерно 25% п-карборана и 75% м-карборана[2]. Несмотря на несомненную ценность п-карборана, это соединение труднодоступно по причине отсутствия удоб- 1 ных методов выделения. В патенте США [3] лишь перечисляются методы, используя которые можно количественно разделить смесь м~ и п-карборанов, это: препаративная газовая хромато- 2 графия, колоночная хроматография, зонная плавка и т.д. В работе [4] кратко упоминается о возможности разделения смеси м- и п-карборанов, используя метод контролируемого хлори- 2 рования смеси, при этом м-карборан образует хлорпроизводное, а п-карборан остается без изменения; последний рекомендуется выделять, или используя метод колоночной хроматогра- 3 фии, или путем расщепления хлорированного м-карборана пиперидином.The resulting mixture contains approximately 25% p-carborane and 75% m-carborane [2]. Despite the undoubted value of p-carborane, this compound is difficult to access due to the lack of convenient isolation methods. The US patent [3] only lists methods using which you can quantitatively separate a mixture of m ~ and p-carboranes, these are: preparative gas chromatography 2, column chromatography, zone melting, etc. [4] briefly mentions the possibility of separating a mixture of m- and p-carboranes using the method of controlled chlorination of the mixture, while m-carboran forms a chlorine derivative, and p-carboran remains unchanged; the latter is recommended to be isolated either using column chromatography 3 or by digesting chlorinated m-carborane with piperidine.

Наиболее близким по технической сущности и достигаемому результату является способ выделения п-карборана из смеси с м-карбораном, заключающийся в хроматографировании смейи на активной окиси алюминия [5]. Этот метод трудоемок, длителен, требует применения большого количества легкокипящих органических растворителей, а также вследствие большой летучести п-карборана с растворителем, упаривание растворителя приводит к большим потерям п-карборана. Выход п-карборана не превышает 50% при чистоте 99%.The closest in technical essence and the achieved result is a method for the isolation of p-carborane from a mixture with m-carborane, which consists in chromatography of a mixture on active alumina [5]. This method is laborious, time-consuming, requires the use of a large number of boiling organic solvents, and also due to the high volatility of p-carborane with a solvent, evaporation of the solvent leads to large losses of p-carborane. The yield of p-carborane does not exceed 50% at a purity of 99%.

Цель изобретения упрощение процесса и увеличение степени извлечения.The purpose of the invention is to simplify the process and increase the degree of extraction.

Поставленная цель достигается описываемым способом выделения п-карборана, заключающемся в том, что смесь м- и п-карборанов в углеводородном растворителе обрабатывают раствором трифторацетата ртути в трифторуксусной кислоте при температуре 20-35^вС. Выход 91%, Предложенный способ выделения п-карборана из его смеси с м-карбораном основан на различной ре,ч=г ЗД.-5Э-~Т#4гК.5^£й«.х.The goal is achieved the described method separation of p-carborane, consists in the fact that a mixture of m- and p-carboranes in a hydrocarbon solvent is treated with a solution of mercury trifluoroacetate in trifluoroacetic acid at ^a temperature of 20-35 C. Yield: 91%, proposed a method of separating para-carborane from its mixture with m-carborane is based on various pe, h = r ZD.-5E- ~ T # 4rK.5 ^ £ yx.

акционной способности м- и п-карборанов в реакции меркурирования [6]. Сущность способа заключается в том, что раствор смеси м- и п-карборанов, полученной изомеризацией м-карборана, в углеводородном растворителе обрабатывают раствором трифторцетата ртути в трифторуксусной кислоте. При . этом м-карборан реагирует с трифторацетатом ртути, и образовавшийся продукт переходит в трифторуксусную кислоту, а в углеводородном растворе остается практически чистый п~карборан. Дальнейшее выделение заключается в упаривании растворителя и вакуумной возгонке п-карборана.the action ability of m- and p-carboranes in the reaction of mercury [6]. The essence of the method lies in the fact that a solution of a mixture of m- and p-carboranes obtained by isomerization of m-carborane in a hydrocarbon solvent is treated with a solution of mercury trifluoroacetate in trifluoroacetic acid. At. In this case, m-carborane reacts with mercury trifluoroacetate, and the resulting product passes into trifluoroacetic acid, and almost pure p ~ carborane remains in the hydrocarbon solution. Further isolation consists in evaporation of the solvent and vacuum sublimation of p-carborane.

Предложенный способ позволяет вы-, делить п-карборан из смеси, с м-карбораном с выходом 91% и высокой степенью чистоты (99%). Способ прост в аппаратурном оформлении и не требует применения большого количества легкокипящих органических растворителей,The proposed method allows you to-, share p-carborane from the mixture, with m-carborane with a yield of 91% and a high degree of purity (99%). The method is simple in hardware design and does not require the use of a large number of boiling organic solvents,

Пример 1. 25 г смеси, содержащей 25% п-карборана и 75% м-карборана, растворяют в 200 мл пентана, к раствору добавляют раствор 110 г трифторацетата ртути в 200 мл трифторуксусной кислоты. Реакционную смесь интенсивно перемешивают при 20-35°С. Ход реакции контролируют методом ГЖХ углеводородного слоя. После окончания реакции (7-10 ч) углеводородный слой отделяют, и целевой продукт выделяют известными методами.Example 1. 25 g of a mixture containing 25% p-carborane and 75% m-carborane was dissolved in 200 ml of pentane, a solution of 110 g of mercury trifluoroacetate in 200 ml of trifluoroacetic acid was added to the solution. The reaction mixture is stirred vigorously at 20-35 ° C. The progress of the reaction is controlled by GLC of the hydrocarbon layer. After the reaction (7-10 hours), the hydrocarbon layer is separated, and the target product is isolated by known methods.

Выход п-карборана 5,7 г (91%), степень чистоты (ГЖХ) более 99%. Пример 2. Опыт проводят по примеру 1, но в качестве углеводородного растворителя используют гексан.The yield of p-carborane 5.7 g (91%), the degree of purity (GLC) of more than 99%. Example 2. The experiment is carried out as in example 1, but hexane is used as a hydrocarbon solvent.

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Claims

This invention relates to a novel process for isolating p-carboran from its mixture with m-carborane. p-Carboran is an important intermediate for the synthesis of heat-resistant polymers and carborane-type materials. 1. Carborane is obtained by isomerization of m-carboran at 700 C. The resulting mixture contains about 25% p-carboran and 75% m-carborane 2 Despite the undoubted value of p-carboran, this compound is difficult to access due to the lack of convenient methods of isolation. In US 3, only methods are listed that can quantitatively separate a mixture of m- and p-carboranes: preparative gas chromatography, column chromatography, zone melting, etc. Reference 4 briefly mentions the possibility of separating the mixture of m- and p-carboranes using the method of controlled chlorination of the mixture, whereby the m-carborane forms the chlorine derivative, and the p-carborane remains unchanged; the latter is recommended to be isolated either by using the column chromatography method or by cleaving the chlorinated m-carboran with piperidine. The closest in technical essence and the achieved result is a method of separating p-carboran from a mixture with m-carborane, consisting in chromatography of a slate on active alumina 5. This method is laborious, time consuming, requires the use of a large number of light boiling organic solvents, as well as high volatility of p-carboran with a solvent; evaporation of the solvent leads to a large loss of p-carboran. The output of p-carboran does not exceed 50% with a purity of 99%. The purpose of the invention. The simplification of the process and an increase in the degree of extraction. This goal is achieved by the described method of isolating p-carborane, which consists in the fact that a mixture of m- and p-carboranes in a hydrocarbon solvent is treated with a solution of mercury trifluoroacetate in trifluoroacetic acid at a temperature of 20-35 ° C. Yield 91%. The proposed method for the isolation of p-carboran from its mixture with m-carborane is based on the different reactivity of the m- and p-boron in the mercury reaction 6. The essence of the method is that the solution of the mixture of m- and p-carboranes, resulting in isomerization of m -carborane in a hydrocarbon solvent is treated with a solution of mercury trifluoroacetate in trifluoroacetic acid. At. This m-carborane reacts with mercury trifluoroacetate, and the resulting product is converted to trifluoroacetic acid, and in the hydrocarbon solution there is left almost pure carborane and a further release is evaporation of the solvent and vacuum sublimation of p-carborane. The proposed method allows p-carborane to be isolated from the mixture with m-carborane with a yield of 91% and a high degree of purity (99%). The method is simple in hardware design and does not require the use of a large amount of easily boiling organic solvents. Example 1.25 g of a mixture containing 25% p-carboran and 75% m-carboran is dissolved in 200 ml of pentane, and a solution of 110 g of mercury trifluoroacetate in 200 ml of trifluoroacetic acid is added to pacTBot y. The reaction mixture is vigorously stirred at 20–35 s. The course of the reaction is monitored by the GLC method of the hydrocarbon layer. After completion of the reaction (7-10 hours), the hydrocarbon layer is separated, and the target product is isolated by means of p-carborane yield 5.7 g (91%), purity (GLC) is more than 99%. Example 2. The experiment was carried out according to Example 1, but hexane was used as the hydrocarbon solvent. Claims of the method of isolation of p-carboran, characterized in that, in order to increase the degree of extraction and simplify the process, the mixture of para-carboranes in a hydrocarbon solvent is treated with a solution of trifluoroacetate 4 mercury in trifluoroacetic acid at a temperature of 20-35 ° C. Sources of information taken into account during the examination 1. Grimes R., Karborany, Mir. M. 1974, p., 191.

2. S. Papetti et al. Vapor phase isomerization of the carborane, PpeC. Eng. Chem, Prod. Res. Develop. 5, 334 (1066) ..

3. The patent of the USA 3509216, cl, 260-606.5. Publ. 1970.

4.Stanko VI, Golt Nin Yu.V., On the halogenation of a p-baren, JOH, 39 611 1969.

5.SieckhausD.F. et al .TJnorg.Cheml, 2452 (1969) (proto.type). 6.4Bregad2e et al., In, Wereurated arboranes, J. Organc. Netal Chem. 136, 81, 1977.