Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUSRE38325 E1
Publication typeGrant
Application numberUS 10/050,869
Publication dateNov 18, 2003
Filing dateJan 18, 2002
Priority dateJul 14, 1999
Also published asUS6096928
Publication number050869, 10050869, US RE38325 E1, US RE38325E1, US-E1-RE38325, USRE38325 E1, USRE38325E1
InventorsTerry E. Krafft
Original AssigneeBoulder Scientific Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method for the production of tetrakis (pentafluorophenyl) borates
US RE38325 E1
Abstract
A process for preparing tetrakis (pentafluorophenyl) borate is described that involves reaction of a pentafluorophenyl magnesium halide with an alkali metal tetrafluoroborate.
Images(2)
Previous page
Next page
Claims(7)
I claim:
1. A method for the production of tetrakis (pentafluorophenyl) borate which comprises reacting a pentafluorophenyl compound having the formula C6F5MgX in which X is a halide with an alkali metal salt of tetrafluoroborate in a non-interfering solvent.
2. The claim 1 method in which the pentafluorophenyl compound is C6F5MgBr and said alkali metal salt is NaBF4.
3. The claim 1 or claim 2 method in which said solvent has the formula ROR′ in which R and R′ are the same or different aliphatic hydrocarbon groups having 2 to 10 carbon atoms.
4. The claim 1 or claim 2 method in which said solvent is ethyl ether.
5. A method which comprises reacting a compound having the formula C6F5MgX in which X is a halide with a compound having the formula QBF4 in which Q is sodium, lithium or potassium,
said reaction being conducted at a temperature of 0 C. to 100 C. in a solvent being the formula ROR′ in which R and R′ are the same or different aliphatic hydrocarbon groups having 2 to 10 carbon atoms to produce a reaction mixture containing a tetrakis (pentafluorophenyl) borate and
recovering said tetrakis (pentafluorophenyl) borate from said reaction mixture.
6. The claim 5 method in which C6H5MgBr is reacted with NaBF4 in ethyl ether.
7. The claim 5 method in which the compound having the formula C6H5MgX and compound QBF4 are reacted in an amount which is more than 15% of the stoichiometric amount.
Description

This application is a continuation-in-part of Ser. No. 09/077,999 filed Jun. 15, 1998, now abandoned, which is the 35 U.S.C. 371 counterpart of application PCT/U.S.96/16390 filed Oct. 15, 1996.

FIELD OF THE INVENTION

This invention relates to the synthesis of tetrakis (pentafluorophenyl) borates by reaction of a tetrafluoroborate salt with a pentafluorophenyl compound.

BACKGROUND OF THE INVENTION

It is known to produce tetrakis (pentafluorophenyl) borates by reaction of boron trihalide with pentafluorophenyl lithium or pentafluorophenyl magnesium halide and by reaction of tris (pentafluorophenyl) boron with pentafluorophenyl lithium. See generally, published European patent application No. 0 604 961 A2 and U.S. Pat. No. 5,473,036. Such borates are important intermediates in the synthesis of catalysts used in combination with metallocene polymerization catalysts.

SUMMARY OF THE INVENTION

The invention provides a method for the production of tetrakis (pentafluorophenyl) borates by reacting a tetrafluoroborate salt with pentafluorophenyl magnesium halide in a non-interfering solvent.

DETAILED DESCRIPTION OF THE INVENTION

Pentafluorophenyl magnesium halides (Grignards) are known. See, e.g., Respess, et al., J. Organometal. Chem. (1969) 18:263-274 and Respess, et al., J. Organometal. Chem. (1969) 19:191-195. Pentafluorophenyl magnesium halides useful in the invention have the formula C6F6MgX in which X is a halogen, e.g., iodine, chlorine or bromine, preferably bromine.

Tetrafluoroborate salts useful in the invention have the formula QBF4 in which Q is sodium, lithium or potassium, preferably sodium.

The reaction between the Grignard and the tetrafluoroborate salt may be conducted in any non-interfering solvent. Typical solvents have the formula ROR′ in which the R and R′ are the same or different aliphatic hydrocarbon groups having 2-10 carbon atoms. Ethyl ether is preferred. The reaction is appropriately conducted at a temperature of 0 C. to 100 C., preferably at 30 C. to 35 C.

The tetrafluoroborate salt is added to the Grignard solution in stoichiometric amounts or in such greater or lesser amount as may be deemed appropriate. In the preferred practice of the invention the tetrafluoroborate salt is added in an amount more than 15% of stoichiometric. Preferably the reaction mixture is refluxed to expedite the reaction.

EXEMPLIFICATION OF THE INVENTION EXAMPLE I

A reaction vessel is changed with 0.25 mol of C6H5MgBr and 0.056 mol of NaBF4 in an ethyl ether solvent. The reaction mixture is refluxed overnight under nitrogen. The reaction mixture was processed to recover 24.4 g of brown solids. Apparent yield 62.1%.

19F NMR peaks established the presence of tetrakis (pentafluorophenyl) borate in an amount corresponding to approximately 50% of the total product of the reaction.

EXAMPLE II

Example I was repeated using NaBF4 ground by pestle and mortar and a 36 hour reflux time. Yield: 62.2% of a product having a tetrakis (pentafluorophenyl) borate purity of about 60% as indicated by 19F NMR.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US5488169 *Dec 21, 1993Jan 30, 1996Tosoh Akzo CorporationBorating, metallization, complexing
US5600005 *Jun 6, 1995Feb 4, 1997Idemitsu Kosan Co., Ltd.Using a mixture of hydrocarbon and ether solvent for the reaction of a halopolyfluorobenzene and a metal alkylate; reacting the product with a boron trihalide; purity; coordination catalyst components
Classifications
U.S. Classification568/6
International ClassificationC07F5/02
Cooperative ClassificationC07F5/027
European ClassificationC07F5/02D