JP2868201B2 - Method for producing tris (pentafluorophenyl) borane using pentafluorophenylmagnesium derivative prepared from pentafluorobenzene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to tris (pentafluorophenyl) using pentafluorobenzene as a raw material.
It relates to a novel method for producing borane. Tris (pentafluorophenyl) borane obtained in the present invention is a compound useful as a co-catalyst for cationic complex polymerization and also a compound useful as a co-catalyst for cationic complex polymerization of N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate. It is a very useful substance as an intermediate.

[0002]

2. Description of the Related Art In recent years,
Academic literature or patents for performing polymerization reactions using these compounds and organometallic complexes have been remarkably increasing. For example, J. Am. Chem. Soc., 113 , 3626 (1991) or Macr.
mol. Chem. Rapid Commun., 2 , pp 663-667 (1991)
etc. However, in the production of tris (pentafluorophenyl) borane, relatively expensive pentafluorobromobenzene has been used as a starting material of a pentafluorophenyl group source.

In this method, pentafluorobenzene bromide is subjected to a bromine-metal exchange reaction at a low temperature of -70 ° C. using an organometallic compound such as butyllithium to generate pentafluorophenyllithium (J. Org. Chem., 29, 2385 (196
4), J. Org. Chem., 31, 4229 (1966) and Synthesis of
Fluoroorganic Compounds, p.190, Springer-Verlag (1
985)) Reaction with boron trichloride or boron trifluoride as a starting material of the boron source, or reaction of pentafluorobenzene bromide with magnesium to generate a Grignard reagent such as pentafluorophenyl magnesium bromide ( J. Chem. Soc., 166 (1959), Z. Naturfo
rschg., 20b, 5 (1965) and Synthesis of Fluoroorganic
Compounds, p.141, Springer-Verlag (1985), etc.), as well as producing tris (pentafluorophenyl) borane by reacting with boron trichloride or boron trifluoride as a starting material of a boron source. J.Or
ganometallic Chem., 2 , 245-250 (1964)).

[0004] Brominated pentafluorobenzene can be obtained by brominating pentafluorobenzene. However, if tris (pentafluorophenyl) borane can be directly produced from pentafluorobenzene, the number of production steps can be reduced by one, so that it is also available. This makes it easier and lowers the price of starting materials.

On the other hand, although literatures for generating and reacting pentafluorophenylmagnesium bromide using pentafluorobenzene as a starting material have already been published (J. Chem.
Soc., 166 (1959), Synthesis of Fluoroorganic Com
pounds, p.141, J. Org.Chem., 29, 2385 (1964) and i.
bid, 31 , 4229 (1966)), production of tris (pentafluorophenyl) borane is not known.

[0006]

Means for Solving the Problems In view of the above-mentioned circumstances, the present inventors have changed from using pentafluorobenzene bromide as a starting material to the production of tris (pentafluorophenyl) borane to pentafluorobenzene. By eliminating the step of brominating pentafluorobenzene and eliminating the need for a very low temperature of -70 ° C. for generating pentafluorophenyllithium from pentafluorobenzene bromide, the cost of manufacturing equipment can be reduced. Various studies have been made in order to reduce the use of a relatively expensive reactant such as an organolithium compound, and have reached the present invention.

That is, the gist of the present invention is that a pentafluorophenylmagnesium derivative (C ₆ F ₅ ) _2-n MgX _n having the following general formula ( _{where n} represents a real number of 0 or 1; Represents halogen from pentafluorobenzene at a temperature of 0 to 250 ° C. and using this as a pentafluorophenyl group source, characterized in that tris (pentafluorophenyl) borane or tris (pentafluorophenyl) is used. The present invention relates to a method for producing a complex in which borane is coordinated with an ether solvent.

[0008]

The present invention will be described below in detail. The ether solvent referred to in the present invention includes diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisoamyl ether, 1,2-dimethoxyethane, 1,2
-Diethoxyethane, di-2-methoxyethyl ether, tetrahydrofuran, tetrahydropyran, 1,4
-Represents dioxane and the like.

Next, the hydrocarbon solvent referred to in the present invention is pentane, isopentane, hexane, cyclohexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, n-paraffin or petroleum ether. Such as benzene, toluene, o-xylene, m-
Xylene, p-xylene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,2,5-
Aromatic hydrocarbons such as trimethylbenzene, 1,3,5-trimethylbenzene, ethylbenzene, propylbenzene and butylbenzene, and mixtures thereof are shown.

Next, in the formula [II] of the present invention, the functional groups which do not affect the reaction include methyl group, ethyl group,
Propyl, isopropyl, propenyl, 2-isopropenyl, allyl, butyl, sec-butyl,
tert-butyl group, isobutyl group, pentyl group, sec-pentyl group, tert-pentyl group, neo-pentyl group, sec
-Isopentyl, hexyl, sec-hexyl, isohexyl, sec-isohexyl, cyclohexyl, phenyl, benzyl, o-tolyl, m-tolyl, p-tolyl, methoxymethyl, methylthiomethyl Group, 2-dimethylaminoethyl group, o-anis group,
m-anis group, p-anis group, trimethylsilylmethyl group and the like.

Next, some examples of the organomagnesium compound represented by the formula [II] in the present invention include methylmagnesium iodide, methylmagnesium bromide, methylmagnesium chloride, dimethylmagnesium, ethylmagnesium bromide, ethylmagnesium chloride. , Ethyl magnesium iodide, diethyl magnesium, propyl magnesium bromide, propyl magnesium chloride, butyl magnesium bromide, butyl magnesium chloride, sec-butyl magnesium bromide, sec-butyl magnesium chloride, tert- bromide
Butylmagnesium, tert-butylmagnesium chloride,
Isobutylmagnesium bromide, isobutylmagnesium chloride, hexylmagnesium bromide, hexylmagnesium chloride, cyclohexylmagnesium bromide, cyclohexylmagnesium chloride, ethylbutylmagnesium, dibutylmagnesium and the like.

R in the substituent represented by the formula [V] in the present invention is, for example, methyl, ethyl, propyl, isopropyl, propenyl, isopropenyl, allyl, butyl, sec-butyl group, tert-butyl group, isobutyl group, pentyl group, sec-pentyl group,
Hexyl group, cyclohexyl group, octyl group, decyl group, phenyl group, benzyl group, methoxymethyl group, methylthiomethyl group, 2-methoxyethyl group, acetyl group,
Examples include a benzoyl group and a trimethylsilyl group.

Next, R in the substituent represented by the formula [VI] referred to in the present invention is, for example, methyl, ethyl, propyl, isopropyl, propenyl, 2-isopropenyl, allyl, Butyl, sec-butyl, tert-butyl, isobutyl, pentyl, sec-pentyl, hexyl, cyclohexyl, octyl, decyl, phenyl, benzyl, methoxymethyl, methylthiomethyl, 2-dimethoxyethyl group, o-anis group, m-anis group, p-anis group, acetyl group, benzoyl group, trimethylsilyl group, tetramethylene group, pentamethylene group, N-methyl-3-azapentamethylene group, 3 -Oxapentamethylene group or 3-thiapentamethylene group.

As described above, examples of the boron compound represented by the formula [IV] in the present invention include boron trifluoride, boron trichloride, boron tribromide, boron triiodide, trimethyl boric acid, triethyl boric acid, Tripropyl boric acid, triisopropyl boric acid, tributyl boric acid, trimethylene borate, tris (dimethylamino) boron, tris (diethylamino) boron, tripyrrolidino boron, tripiperidino boron or trimorpholino boron. Further, complexes such as boron trifluoride diethyl ether complex, boron trifluoride dibutyl ether complex, boron trifluoride dimethyl sulfide complex, boron trichloride diethyl ether complex and boron trichloride dibutyl ether complex also fall into this category.

The specific method of manufacturing will be described below in order. The method for generating the pentafluorophenylmagnesium derivative represented by the formula [III] is based on 0.5 to 1.5 equivalents of the organomagnesium compound represented by the formula [II] based on 1 equivalent of the pentafluorobenzene represented by the formula [I]. To -40 to 25
Mix at 0 ° C and then react at 25-250 ° C. In this reaction, when the amount of the organomagnesium compound represented by the formula [II] is too much larger than that of the pentafluorobenzene represented by the formula [I], the unreacted organomagnesium compound represented by the formula [II] may be produced in a large amount. If the amount of impurities remains and generates too much, and if the amount is too small, pentafluorobenzene is wasted, so it is desirable to use 0.8 to 1.2 equivalents of the organomagnesium compound represented by the formula [II].
If the temperature is lower than 25 ° C, the progress of the reaction becomes extremely slow.
If the temperature is too high, the side reaction proceeds extremely rapidly, and the yield becomes extremely low in any case. Therefore, it is desirable to carry out the reaction in the range of 25 ° C to 200 ° C.

The reaction mixture is reacted at the same temperature for 0.5 to 70 hours to prepare a pentafluorophenylmagnesium derivative represented by the formula [III]. Examples of the pentafluorophenylmagnesium derivative represented by the formula [III] produced here include C ₆ F ₅ MgCl and C ₆ F ₅
MgBr, C ₆ F ₅ MgI, (C ₆ F ₅ ) ₂ Mg, C ₆
It is something like F ₅ mget or C ₆ F ₅ MgBu.

Next, 2.1 to 3.9 equivalents of the pentafluorophenylmagnesium derivative of the formula [III] prepared by the above-mentioned method is added at 0 ° C. to 250 ° C. for 1 equivalent of the boron compound of the formula [IV]. Mix within ° C. In this reaction, if a large amount of the initial pentafluoromagnesium derivative remains, the reaction rate will decrease significantly if the reaction temperature is lower than 25 ° C, and the reaction will take a long time, and if it is higher than 200 ° C, the pentafluoromagnesium derivative will decompose. It is desirable to carry out the reaction at a temperature in the range of 25 ° C to 200 ° C because there is a risk of this.

Further, if the equivalent number of the pentafluoromagnesium derivative used is too low, the yield is remarkably reduced if it is lower than 2.1 equivalents. If it is too high, the yield is reduced due to the production of tetrakis (pentafluorophenyl) borate. Considering the nature, it is desirable to use 2.5 to 3.5 equivalents.

The reaction mixture is reacted at 0 to 250 ° C. for 0.5 to 50 hours to form tris (pentafluorophenyl) borane of the formula [VII] or tris (pentafluorophenyl) borane with an ether solvent. Coordinated complexes can be produced. At that time, it is desirable to further raise the reaction temperature to a range of
The reaction can be completed by continuing the reaction for 50 to 50 hours.

The reason for this is that, in this case, fluorobis (pentafluorophenyl) borane and tetrakis (pentafluorophenyl) borate derivative or a complex in which an ether solvent thereof is coordinated are formed as by-products. This is because the reaction rate is extremely slow below 60 ° C. to form a (pentafluorophenyl) borane complex, and the decomposition of the product occurs above 200 ° C.

The ether solvent coordinated to tris (pentafluorophenyl) borane can be removed by a direct removal method or an indirect removal method. The direct removal method referred to here is a complex in which an ether solvent is coordinated with tris (pentafluorophenyl) borane.
This is a method of sublimating by evaporation at 30 to 200 ° C. or lower, preferably 1 Torr or lower.

Next, there are two methods of the indirect removal method here. (1) a method in which one or more equivalents of an alkyl aluminum is allowed to act on the coordinated solvent, and the solvent coordinated to tris (pentafluorophenyl) borane is coordinated to the alkyl aluminum to remove the solvent;
(2) A method of mixing a hydrocarbon solvent having a higher boiling point than the coordinated solvent and distilling off the hydrocarbon solvent to remove the coordinated solvent azeotropically.

When the solvent coordinated by the method (2) is removed, the mixture is heated to 60 to 200 ° C. using a hydrocarbon-based solvent to remove difluoropentafluorophenylborane which is partially left in the reaction system. Alternatively, complexes in which fluorobis (pentafluorophenyl) borane and magnesium halide tetrakis (pentafluorophenyl) borate or their ether-based solvents are coordinated cause disproportionation, and the yield of the product is improved. Therefore, the hydrocarbon solvent used for azeotropic removal preferably has a boiling point of 60 to 200 ° C.
When the saturated hydrocarbon is formed by removing the coordinating solvents due to the low solubility of the formed tris (pentafluorophenyl) borane represented by the formula [VIII], and then purifying by crystallization,
Above all, hexane, heptane, octane, nonane, decane, undecane, dodecane or tridecane or a mixture thereof is preferably used. On the contrary, the aromatic hydrocarbon is formed by tris (pentafluorophenyl) borane or tris (pentafluoro). Phenyl)
Since the solubility of the complex in which the solvent is coordinated with borane is relatively high, benzene, toluene, o-
It is desirable to use xylene, m-xylene, p-xylene, ethylbenzene, propylbenzene and the like.

[0024]

According to the present invention, the starting material is changed from expensive pentafluorobenzene bromide to pentafluorobenzene to shorten the production process by one step, and tris (a very important compound as a cocatalyst for cationic complex polymerization) is obtained. It is possible to provide an inexpensive method for producing a complex in which an ether solvent is coordinated with pentafluorophenyl) borane or tris (pentafluorophenyl) borane, and the ability as a cocatalyst is obtained by removing the coordinated ether solvent. The industrial value is enormous in that it can be completely extracted.

[0025]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention.

The yield of the reaction is determined by measuring the amount of tris (pentafluorophenyl) borane produced by using pentafluorotoluene as an internal standard substance or the complex obtained by coordinating tris (pentafluorophenyl) borane with an ether solvent to ¹⁹ F.
Quantitatively by -NMR or further reacted with 1.1 equivalents of pentafluorophenyllithium and then counter-cation exchanged with N, N-dimethylanilinium chloride to give N, N-dimethylanilinium tetrakis (pentanefluorophenyl) borate This is a value determined by ¹⁹ F-NMR after derivation and using pentafluorotoluene as an internal standard substance.

Example 1 Pentafluorobenzene (1
0.66 g, 63.5 mmol) and anhydrous tetrahydrofuran (20 m
25.5 wt% of ethyl magnesium bromide / diethyl ether solution (31.81 g, 60.9 mm
ol) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 35 ° C., and the mixture was stirred at the same temperature for 50 hours. Further, a solution of boron trifluoride-diethyl ether complex (2.70 g, 19.0 mmol) and toluene (50 ml) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C. The mixture is heated and stirred for about 5 hours while maintaining the temperature of the reaction solution at 70 ° C. The reaction liquid was sampled, and the yield of tris (pentafluorophenyl) borane obtained by ¹⁹ F-NMR was measured using pentafluorotoluene as an internal standard substance. As a result, a tetrahydrofuran complex of tris (pentafluorophenyl) borane was obtained at a yield of 91%. I got it.

To a solution of tris (pentafluorophenyl) borane in tetrahydrofuran was added toluene (100 m
l) was added, and the mixture was heated to 110 ° C to remove the tetrahydrofuran to precipitate a magnesium salt, followed by filtration. The mixture was mixed with a separately prepared diethyl ether solution of pentafluorophenyllithium at -70 ° C. Thereafter, the temperature of the reaction mixture was gradually raised to 25 ° C., and then the solvent was distilled off under reduced pressure to remove N chloride,
Upon mixing with an aqueous solution of N-dimethylanilinium, crystals of N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate precipitate immediately. The obtained crystals were filtered, dissolved in diethyl ether, added with hexane, recrystallized, and dried to obtain N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate at a yield of 61%. ^The purity was measured by ¹⁹ F-NMR using pentafluorotoluene as an internal standard substance and found to be 98 wt% or more.

Example 2 Pentafluorobenzene (1
0.50 g, 62.5 mmol) and anhydrous 1,2-dimethoxyethane (40 ml) were added under an inert atmosphere to a 18.1 wt% ethylmagnesium bromide / 1,2-dimethoxyethane solution (45.1 wt%).
8 g, 61.4 mmol) using a dropping funnel to raise the temperature of the reaction solution.
The solution was added dropwise while maintaining the temperature at 25 to 35 ° C, and the mixture was stirred at the same temperature for 65 hours.
Furthermore, boron trifluoride diethyl ether complex (2.70 g, 1
A solution of 9.0 mmol) and ethylbenzene (50 ml) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C., and the mixture was heated with stirring for about 3 hours while the temperature of the reaction solution was maintained at 85 ° C. The reaction liquid was sampled, and the yield of tris (pentafluorophenyl) borane obtained by ¹⁹ F-NMR was measured using pentafluorotoluene as an internal standard substance. As a result, 1,2-dimethoxyethane complex of tris (pentafluorophenyl) borane was obtained. Obtained in 94% yield.

Example 3 Pentafluorobenzene (1
1.01 g, 65.5 mmol) and anhydrous diethyl ether (20 ml)
25.5 wt% ethyl magnesium bromide / diethyl ether solution (32.29 g, 61.8 mmol)
Was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 35 ° C, and the mixture was stirred under heating and reflux for 72 hours. Further, a solution of boron trifluoride-diethyl ether complex (2.74 g, 19.3 mmol) and octane (50 ml) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C. Diethyl ether was distilled off, and the temperature of the reaction solution was reduced to 150
While maintaining the temperature at ° C, the by-product magnesium bromide is crystallized and stirred with heating for about 5 hours until it becomes a suspension. Magnesium bromide was removed from the obtained suspension by filtration, and the obtained octane solution of tris (pentafluorophenyl) borane was cooled to 0 ° C., and the precipitated white crystals were dried to dry tris (pentafluorophenyl). Phenyl)
Borane was obtained in 65% yield.

Example 4 Pentafluorobenzene (1
0.50 g, 62.5 mmol) and anhydrous tetrahydrofuran (40 m
l) under an inert atmosphere under a 18.1 wt% butylmagnesium chloride / tetrahydrofuran solution (45.18 g, 61.4 g).
mmol) was added dropwise using a dropping funnel while maintaining the reaction solution temperature at 25 to 35 ° C, and the mixture was stirred at the same temperature for 5 hours. Further, a solution of boron trifluoride-diethyl ether complex (2.70 g, 19.0 mmol) and octane (50 ml) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C. The tetrahydrofuran is distilled off, and the temperature of the reaction solution is reduced to 1
Heat and stir for about 11 hours while maintaining at 10 ° C. The yield of the obtained solution was measured by ¹⁹ F-NMR using pentafluorotoluene as an internal standard substance. As a result, a tetrahydrofuran complex of tris (pentafluorophenyl) borane was obtained.
Obtained in 93% yield.

Example 5 Pentafluorobenzene (1
1.01 g, 65.5 mmol) and anhydrous 1,2-dimethoxyethane (20 ml) in an inert atmosphere under a 25.5 wt% butylethylmagnesium / heptane solution (32.29 g, 61.8 mmol).
l) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 35 ° C, and the mixture was stirred at the same temperature for 72 hours. Further, a solution of boron trifluoride-diethyl ether complex (2.74 g. 19.3 mmol) and octane (50 ml) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C., and immediately after completion of the addition, heating was performed. The mixture is heated and stirred for 3 hours while maintaining the temperature of the reaction solution at 85 ° C. The reaction liquid was sampled, and the yield of tris (pentafluorophenyl) borane obtained by ¹⁹ F-NMR was measured using pentafluorotoluene as an internal standard substance. As a result, 1,2-dimethoxyethane complex of tris (pentafluorophenyl) borane was obtained. Obtained in 94% yield.

To a solution of the obtained tris (pentafluorophenyl) borane in 1,2-dimethoxyethane was added toluene.
(100 ml), heated to 110 ° C. to distill off 1,2-dimethoxyethane to precipitate a magnesium salt, filtered, and mixed with a separately prepared diethyl ether solution of pentafluorophenyllithium at −70 ° C. . Thereafter, the temperature of the reaction mixture was gradually raised to 25 ° C., and the solvent was distilled off under reduced pressure. The mixture was mixed with an aqueous solution of N, N-dimethylanilinium chloride and immediately mixed with N, N-dimethylanilinium tetrakis (pentafluorophenyl). Borate crystals precipitate. The obtained crystals are filtered, dissolved in diethyl ether, added with hexane, recrystallized, and dried to obtain N, N
-Dimethylanilinium tetrakis (pentafluorophenyl) borate was obtained with a yield of 58%. ^The purity was measured by ¹⁹ F-NMR using pentafluorotoluene as an internal standard substance and found to be 98 wt% or more.

Example 6 Pentafluorobenzene (1
1.01 g, 65.5 mmol) and anhydrous diethyl ether (20 ml)
25.5 wt% ethyl magnesium bromide / diethyl ether solution (32.29 g, 61.8 mmol)
Was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 35 ° C, followed by stirring at 60 ° C for 72 hours. 1.0mol / after further cooling
L in boron trichloride / hexane solution (19.3 ml, 19.3 mmol)
And a solution of toluene (50 ml) were added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C. The mixture is heated and stirred for about 8 hours until the magnesium chloride is crystallized to form a suspension. Magnesium chloride was removed from the resulting suspension by filtration, and octane (30 ml) was added to the obtained toluene solution of tris (pentafluorophenyl) borane. The toluene was distilled off at 70 ° C. and 200 Torr, followed by cooling. Crystallization yielded tris (pentafluorophenyl) borane in a 53% yield.

Example 7 Pentafluorobenzene (1
1.01 g, 65.5 mmol) and a solution of anhydrous 1,2-dimethoxyethane (20 ml) were dripped with a 25.5 wt% cyclohexylmagnesium bromide / 1,2-dimethoxyethane solution (45.41 g, 61.8 mmol) under an inert atmosphere. The reaction solution was added dropwise using a funnel while maintaining the temperature of the reaction solution at 25 to 35 ° C, and the mixture was stirred at 60 ° C for 72 hours. After cooling, a 1.0 mol / L solution of boron trichloride / hexane (19.3 ml, 19.3 mmol) and decane (50 ml) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C. Immediately after completion, heat the reaction solution to 85 ° C.
While stirring for 3 hours. The reaction solution was collected and ¹⁹ F-NMR using pentafluorotoluene as an internal standard substance
When the yield of tris (pentafluorophenyl) borane obtained in step was measured, tris (pentafluorophenyl) borane was obtained.
Borane 1,2-dimethoxyethane complex was obtained in 94% yield.

Example 8 Pentafluorobenzene (1
1.01 g, 65.5 mmol) and a solution of anhydrous 1,2-dimethoxyethane (20 ml) were dripped with a 25.5 wt% cyclohexylmagnesium bromide / 1,2-dimethoxyethane solution (45.41 g, 61.8 mmol) under an inert atmosphere. The reaction solution was added dropwise using a funnel while maintaining the temperature of the reaction solution at 25 to 35 ° C, and the mixture was stirred at 60 ° C for 72 hours. After further cooling, trimethyl boric acid (2.01 g, 19.3 mm
ol) was added dropwise using a dropping funnel while maintaining the temperature of the reaction solution at 25 to 40 ° C., and immediately after completion of the addition, the mixture was heated and stirred for 3 hours while maintaining the temperature of the reaction solution at 85 ° C. The reaction solution was collected ¹⁹ F pentafluorotoluene as an internal standard
-Tris (pentafluorophenyl) obtained by NMR
When the borane yield was measured, 91% of 1,2-dimethoxyethane complex of tris (pentafluorophenyl) borane was obtained.
In a yield of

Example 9 Pentafluorobenzene (1
1.01 g, 65.5 mmol) and anhydrous diethyl ether (20 ml)
In an inert atmosphere, a 25.5 wt% cyclohexylmagnesium bromide / diethyl ether solution (45.41 g, 6
1.8 mmol) using a dropping funnel to raise the temperature of the reaction solution to 25-35.
The mixture was added dropwise while maintaining the temperature at 60 ° C, and the mixture was stirred at 60 ° C for 72 hours. After further cooling, a 1.0 mmol / L boron trichloride / hexane solution (19.3
ml, 19.3 mmol) using a dropping funnel to raise the temperature of the reaction solution to 25.
Dropwise while maintaining the temperature at 4040 ° C., and toluene (100 m
l) is added, and the mixture is heated and stirred for about 5 hours while maintaining the temperature of the reaction solution at 110 ° C. until crystallized by-produced magnesium fluorobromide becomes a suspension. Magnesium chloride was removed from the resulting suspension by filtration, and the obtained toluene solution of tris (pentafluorophenyl) borane was concentrated to dryness and sublimated under vacuum to obtain tris (pentafluorophenyl) borane. Was obtained in 71% yield. ¹⁹ F with pentafluorotoluene as internal standard
-Tris (pentafluorophenyl) obtained by NMR
When the borane purity was measured, it was 95 wt% or more.

────────────────────────────────────────────────── ─── The continuation of the front page (72) Inventor Kenji Ishimaru 1-1-1, Miyanoe, Shinnanyo-shi, Yamaguchi Prefecture Isshin-ryo (56) References JP-A-6-247976 (JP, A) Patent 2790605 (JP, B2) (58) Fields investigated (Int.Cl. ⁶ , DB name) C07F 5/02 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. A pentafluorobenzene represented by the following formula [I] C ₆ HF ₅ [I] in an ether solvent or a mixed non-aqueous solvent of an ether solvent and a hydrocarbon solvent in the range of -40 to 250: In the temperature range of 0.5 ° C., 0.5 to 1.5 equivalents of the general formula [II] R _2-n MgX _n [II] (wherein n represents a real number of 0 or 1, X represents halogen, and R represents 1 carbon atom). ~ 10 hydrocarbon groups, and the hydrocarbon groups may contain a functional group which does not affect the reaction.)
By reacting as described above, the following general formula [III] (C ₆ F ₅ ) _2-n MgX _n [III] (where n represents a real number of 0 or 1 and X represents halogen). A pentafluorophenylmagnesium derivative represented by the formula [IV] BX ₃ [IV] wherein X is a halogen or the following general formula [V] OR [V] 1-10 hydrocarbon groups, which may contain a functional group that does not affect the reaction.) Or the following general formula [VI] NRR ′ [ VI] (wherein, R and R ′ each represent a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may contain a functional group that does not affect the reaction. Each of which may be bonded to each other to form a ring). It may form. ]
From 2.1 equivalents to 1 equivalent of the boron compound represented by
3.9 equivalents of a pentafluorophenylmagnesium derivative represented by the formula [III] are reacted in a temperature range of 0 ° C. to 250 ° C. to be represented by the following general formula [VII] (C ₆ F ₅ ) ₃ B [VII] A method for producing a complex in which tris (pentafluorophenyl) borane or tris (pentafluorophenyl) borane is coordinated with an ether solvent.