JPH10316686A - Production of trityltetrakis (pentafluorophenyl)borate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for safely and inexpensively producing trityltetrakis(pentafluorophenyl)borate. SOLUTION: This trityltetrakis(pentafluorophenyl)borate expressed by the formula; [C6 F5 )4 B]<-> C<+> (C6 H5 )3 is produced by reacting 1 equiv. of a boron compound of the formula: BX3 (X is a halogen atom such as fluorine, chlorine, bromine or iodine, preferably fuorine) or a boron compound formed a complex with an ether-based compound in a mixed solvent of an ether-based solvent and a hydrocarbon solvent with >=3.7 molar equiv. of a pentafluorophenylmagnesium derivative of the formula: (C6 F5 )2-n MgXn (n) is an integer of 0 or 1; X is a halogen atom such as fluorine, chlorine, bromine or iodine, preferably bromine}, and reacting with trityl chloride.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel process for producing trityltetrakis (pentafluorophenyl) borate. The boron derivative obtained in the present invention is a very important substance as a cocatalyst for the cationic complex polymerization reaction.

[0002]

2. Description of the Related Art In recent years, a cation complex has been generated using a tetrakis (pentafluorophenyl) borate derivative and a cyclopentadienyl transition metal complex, a so-called metallocene derivative, and academic literature or patents on polymerization reaction research using this as a catalyst have been made. Has increased significantly. For example, APPLIED
ORGANOMETALLIC CHEMISTRY, VOL8, 393-396 (1994). However, conventionally, for the production of tetrakis (pentafluorophenyl) borate derivative, a process using 1 to 4 molar equivalents of pentafluorophenyllithium derived from pentafluorobenzene bromide as a pentafluorophenyl group source per mole of boron compound is conventionally used. It was manufactured in.

[0003]

In addition, pentafluorophenyllithium is easily decomposed as the temperature increases, and explosively decomposes at -20 ° C or higher.
Generate at a low temperature of about -70 ° C and use at the same temperature.
Therefore, since low-temperature equipment is required, it is not a method superior in safety and cost. On the other hand, J. Am. Chem. Soc113,
8570-8571 (1991) separately isolated lithium tetrakis (pentafluorophenyl) borate prepared using the above-mentioned pentafluorophenyllithium by a method similar to that for producing trityltetrakis (pentafluorophenyl) borate. A method of reacting with trityl chloride has been proposed, but the yield is not always good.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present inventor has proposed trityltetrakis (pentafluorophenyl).
The present invention has been achieved by variously examining methods using a pentafluorophenylmagnesium derivative as a pentafluorophenyl group source when borate is produced and eliminating the need for using a very low temperature.

That is, the present invention relates to a compound of the formula (1) BX ₃ (1) (wherein X represents a halogen atom, preferably fluorine, chlorine, bromine or iodine) in a mixed solvent of a hydrocarbon solvent and an ether solvent. The compound represented by the general formula (2) (C ₆ F ₅ ) _2-n MgX _n (2) is equivalent to 1 equivalent of the boron compound represented by the following formula: , N represents an integer of 0 or 1, X represents a halogen atom, and fluorine, chlorine, bromine or iodine, preferably bromine) is reacted. , it is reacted with trityl chloride, formula _{(4) [(C 6 F} 5) 4 B] - C + (C 6 H 5) 3 (4) production of tetrakis (pentafluorophenyl) borate represented by That the method and general formula _{(5) (C 6 F 5} ) 3 B (5) tris represented by (pentafluorophenyl) borane or tris (pentafluorophenyl) complex 1 one-to-one with borane and ether solvents With respect to the equivalent, the general formula (2) (C ₆ F ₅ ) _2-n MgX _n (2) (wherein, n represents an integer of 0 or 1, X represents a halogen atom, fluorine, chlorine, bromine or A pentafluorophenyl magnesium derivative represented by iodine (preferably bromine) is reacted in an amount of 0.8 molar equivalent or more, and then reacted with trityl chloride to give a compound of the general formula (4) [(C ₆ F ₅ ) ₄ B] ⁻ C ⁺ The present invention relates to a method for producing trityltetrakis (pentafluorophenyl) borate represented by (C ₆ H ₅ ) ₃ (4).

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. In a chain ether-based solvent or a mixed solvent of a chain ether-based solvent and a hydrocarbon-based solvent, a boron compound represented by the general formula (1) BX ₃ (1) (wherein X represents a halogen atom) or to the ether complex, 3.7 molar equivalent or more of the general formula _{(2) (C 6 F 5} ) 2-n MgX n is preferably in the range of -20 to 150 ° C. the pentafluorophenyl magnesium derivatives represented by (2) 0 Mix at ~ 35 ° C, 50
After preferably from to 200 DEG ° C. and reacted for 1 hour at 70 to 120 ° C., by the addition of trityl chloride to the reaction mixture, represented by the general formula _{(4) [(C 6 F} 5) 4 B] - C ⁺ (C ₆ H ₅ ) ₃ (4) Produce trityltetrakis (pentafluorophenyl) borate.

[0007] X is fluorine, chlorine, bromine or iodine, preferably chlorine or fluorine.

Formula (1) specifically includes boron trichloride, boron tribromide and boron trifluoride. Examples of the complex of the formula (1) and an ether include an ether complex of boron trifluoride.

Examples of the magnesium compound represented by the formula (2) include pentafluoromagnesium bromide, bis (pentafluorophenyl) magnesium and the like.

As the chain ether solvent, diethyl ether, dipropyl ether, diisopropyl ether,
Saturated hydrocarbon ethers such as methyl t-butyl ether, dibutyl ether, diisobutyl ether, dipentyl ether and diisopentyl ether can be mentioned. As the hydrocarbon solvent, a hydrocarbon solvent having a boiling point of 50 ° C. or more is particularly preferable. There are no restrictions, for example, hexane, heptane, aliphatic hydrocarbons such as octane and toluene,
Examples thereof include aromatic hydrocarbon solvents such as xylene.

When the boron compound represented by the general formula (1) is used in the reaction, the theoretical amount of the pentafluorophenylmagnesium derivative is 4 molar equivalents. Since the yield of the (pentafluorophenyl) borate derivative is remarkably reduced, it is preferable to use 3.7 molar equivalents or more.

Also, tris (pentafluorophenyl) borane represented by the general formula (5) (C ₆ F ₅ ) ₃ B (5) or a one-to-one complex of tris (pentafluorophenyl) borane and an ether solvent. Is used as a boron compound,
This is reacted with a pentafluorophenylmagnesium derivative represented by the general formula (2) (C ₆ F ₅ ) _2-n MgX _n (2) to obtain a compound of the general formula (3) [(C ₆ F ₅ ) ₄ B] _{2 When} a reaction for producing a tetrakis (pentafluorophenyl) borate derivative represented by _-n MgX _n (3) is performed, the theoretical amount is 1 equivalent, but the general formula (5) (C ₆ F ₅ ) ₃ B ( 5) A tris (pentafluorophenyl) borane represented by the following formula or a one-to-one complex of tris (pentafluorophenyl) borane and an ether solvent with respect to a boron compound is represented by the general formula (2) (C ₆ F ₅ ) _2- for _n MgX n ₍₂₎ when the amount of the pentafluorophenyl magnesium derivative is less than 0.7 molar equivalents of tetrakis decrease in the yield of (pentafluorophenyl) borate derivatives represented by a marked, 0.8 Le or more equivalents of use is desirable.

The pentafluorophenyl magnesium derivative and the boron compound may be mixed at a temperature lower than -40 ° C., depending on the type of the pentafluorophenyl magnesium derivative. Since the decomposition of the pentafluorophenyl magnesium derivative occurs, a temperature lower than this is desirable. If the reaction temperature is lower than 50 ° C., the progress of the reaction is extremely slow. If the reaction temperature is higher than 200 ° C., the generated tetrakis (pentafluorophenyl) borate derivative is decomposed.
It is desirable to carry out the reaction at ~ 200 ° C.

[0014]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited by the following examples unless it exceeds the gist of the invention.

(Example 1) 200 ml 3 sufficiently purged with nitrogen
3.09g (127.2mmo) of metallic magnesium
l), 50 ml of diethyl ether are mixed at room temperature, then 1.8 g (16.7 mmol) of ethyl bromide are added at 20-35 ° C., followed by 31.43 g (127.8 mmol) of pentafluorobenzene bromide
Was added at 20 to 35 ° C. to prepare a pentafluorophenylmagnesium derivative. 4.15 g (29.2 mmol) of boron trifluoride diethyl ether complex and 50 ml of toluene were added to the solution.
Mix at 6060 ° C. After heating the reaction mixture to 100-110 ° C. and stirring for 2 hours, the solvent was distilled off under reduced pressure at the same temperature. 30 ml of dichloromethane was added into the reaction vessel. Thereafter, a mixed solution of 8.42 g (30.2 mmol) of trityl chloride and 200 ml of hexane was added, and the mixture was added at 20 to 30 ° C.
For a minute. The precipitated trityltetrakis (pentafluorophenyl) borate and a by-product salt were collected by filtration and redissolved in 500 ml of dichloromethane. The insolubles were filtered through a glass filter using Celite as a filter aid. The filtrate
The organic layer was washed in the order of 100 ml of 0.5N HCl (twice) and 100 ml of water, and the obtained organic layer was concentrated under reduced pressure at 40 ° C., and the residue was dissolved by adding 20 ml of dichloromethane, and then hexane was added. Crystals were precipitated by slow addition at room temperature. The obtained crystals were collected by filtration with a glass filter, sufficiently washed with hexane, and then dried at 50 ° C. under reduced pressure for 15 hours. 21.28g (78.8%)

(Example 2) 200 ml 3 sufficiently purged with nitrogen
3.09g (127.2mmo) of metallic magnesium
l), 50 ml of diethyl ether are mixed at room temperature, then 1.8 g (16.7 mmol) of ethyl bromide are added at 20-35 ° C., followed by 31.38 g (127.6 mmol) of pentafluorobenzene bromide
Was added at 20 to 35 ° C. to prepare a pentafluorophenylmagnesium derivative. 4.23 g (29.8 mmol) of boron trifluoride diethyl ether complex and 50 ml of toluene were added to the solution.
Mix at 6060 ° C. After heating the reaction mixture to 100-110 ° C. and stirring for 2 hours, the solvent was distilled off under reduced pressure at the same temperature. 30 ml of dichloromethane was added into the reaction vessel. Thereafter, a dichloromethane mixed solution of the tetrakis (pentafluorophenyl) borate derivative was added to a mixed solution of 8.30 g (29.8 mmol) of trityl chloride and 250 ml of hexane, and the mixture was stirred at 20 to 30 ° C. for 30 minutes. A suspension of the precipitated trityltetrakis (pentafluorophenyl) borate and a by-product salt was mixed with 100 ml of 1N HCl (2 mL).
Times) and water (100 ml) in that order. The obtained organic layer was dried over anhydrous magnesium sulfate, and hexane was gradually added to the solution at room temperature to precipitate crystals. The obtained crystals were collected by filtration with a glass filter, washed well with hexane, and
Dried under reduced pressure at 15 ° C. for 15 hours. 25.17g (91.5
%)

(Comparative Example 1) 172.0 g (7.1 mol) of metallic magnesium and 6000 ml of diethyl ether were mixed at room temperature in a 20-L four-necked flask sufficiently purged with nitrogen, and 43.6 g (0.4 mol) of ethyl bromide was added to the flask. At 22 ° C, 1742.36 g (7.1 mol) of pentafluorobenzene bromide was added at 20 to 35 ° C to prepare a pentafluorophenylmagnesium derivative. Boron trifluoride diethyl ether complex
322.4 g (2.8 mol) and 3.7 kg of toluene were mixed at 18 to 32 ° C. After heating the reaction mixture to 100 to 110 ° C. and stirring for 1.5 hours, the precipitated by-product magnesium salt was removed by filtration to prepare a toluene solution of tris (pentafluorophenyl) borane. In a 10 L four-necked flask, a mixed solution of 582.52 g (2.4 mol) of pentafluorobenzene bromide and 2.8 L of diethyl ether is cooled to -70 ° C or lower. 25.8 below -50 ° C
544.94 g of a wt% n-butyllithium / hexane solution (2.2 mol
l) was added. Immediately thereafter, a toluene solution of tris (pentafluorophenyl) borane was added in a temperature range of -70 to -50 ° C. Immediately after the introduction, the mixture was naturally allowed to warm under stirring overnight. The solvent was distilled off under reduced pressure at an internal temperature of 60 ° C., and 5 L of hexane was gradually added at room temperature to precipitate lithium tetrakis (pentafluorophenyl) borate. The crystals were collected by filtration and dried under a N ₂ atmosphere. 1577g.

A part of the obtained lithium tetrakis (pentafluorophenyl) borate is dissolved in dichloromethane, and quantified by ¹⁹ F-NMR using pentafluorotoluene as an internal standard substance. The borate content was determined. Trityl chloride 80.45g (0.29mol), hexane 2.7L
237.6 g of lithium tetrakis (pentafluorophenyl) borate (content 0.29mo) at room temperature
l), 250 ml of a mixed solution of dichloromethane was gradually added and stirred for 1 hour. The precipitated trityltetrakis (pentafluorophenyl) borate and by-product salts were collected by filtration. The obtained crystals were dissolved in dichloromethane, and insolubles were removed by filtration.
The filtrate was evaporated at 40 ° C. under reduced pressure and redissolved in 150 ml of dichloromethane. Subsequently, hexane was gradually added to precipitate trityltetrakis (pentafluorophenyl) borate. Filter through a glass filter and filter the obtained crystals
At 15 ° C. under reduced pressure for 15 hours to obtain 230 g of trityltetrakis (pentafluorophenyl) borate (yield 86
%).

[0019]

According to the present invention, a boron derivative is a tetrakis (pentafluorophenyl) borate derivative, which is a very important substance as a cocatalyst for a cationic complex polymerization reaction.
In particular, a method for producing trityltetrakis (pentafluorophenyl) borate in high yield in two steps including cation exchange from a pentafluorophenylmagnesium derivative without using pentafluorophenyllithium, which requires a reaction at a low temperature of -70 ° C. Can be provided. Further, in the present invention, trityl chloride is allowed to act directly on a tetrakis (pentafluorophenyl) borate derivative, which is a very important substance as an intermediate of a co-catalyst for a cationic complex polymerization reaction, to produce trityltetrakis (pentafluorophenyl).
The effect of the invention is to provide a method for producing borate in two steps including cation exchange from pentafluorophenylmagnesium derivative without using pentafluorophenyllithium which requires a reaction at a low temperature of -70 ° C. in a high yield. It is enormous.

Claims (2)

[Claims] In a mixed solvent of an ether solvent and a hydrocarbon solvent, a compound represented by the following general formula (1): BX ₃ (1) (wherein X represents a halogen atom and is fluorine, chlorine, bromine or iodine, preferably fluorine) With respect to 1 equivalent of the boron compound represented by the formula (2) (C ₆ F ₅ ) _2-n MgX _n (2) Represents an integer of 0 or 1, X represents a halogen atom, and fluorine, chlorine, bromine or iodine, and preferably bromine), is reacted with 3.7 mol equivalent or more of pentafluorophenylmagnesium derivative. It is reacted with trityl, formula _{(4) [(C 6 F} 5) 4 B] - C + (C 6 H 5) 3 (4) tetrakis represented by (pentafluorophenyl) a method for producing a borate. 2. A one-to-one ratio of tris (pentafluorophenyl) borane or tris (pentafluorophenyl) borane represented by the general formula (5) (C ₆ F ₅ ) ₃ B (5) to an ether solvent. With respect to 1 equivalent of the complex, the general formula (2) (C ₆ F ₅ ) _2-n MgX _n (2) (wherein, n represents an integer of 0 or 1, X represents a halogen atom, fluorine, chlorine, A pentafluorophenylmagnesium derivative represented by bromine or iodine, which is preferably bromine) is reacted in an amount of 0.8 molar equivalent or more, and trityl chloride is allowed to act thereon, whereby the general formula (4) [(C ₆ F ₅ ) ₄ B] ⁻ A method for producing trityltetrakis (pentafluorophenyl) borate represented by C ⁺ (C ₆ H ₅ ) ₃ (4).