Europaisches Patentamt J European Patent Office © Publication number: 0 608 563 A2 Office europeen des brevets EUROPEAN PATENT APPLICATION © Application number: 93120975.3 int. ci 5 C07F 5/02 @ Date of filing: 27.12.93 ® Priority: 28.12.92 JP 361478/92 © Applicant: TOSOH AKZO CORPORATION 28.12.92 JP 361479/92 No. 11-37, Akasaka 8-chome, Minato-ku @ Date of publication of application: Tokyo(JP) 03.08.94 Bulletin 94/31 @ Inventor: Ikeda, Yoshihiko © Designated Contracting States: No. 4-6, Mandokoro DE FR GB IT NL Shinnanyo-shi, Yamaguchi-ken(JP) Inventor: Yamane, Takeo No. 773-1, Shimogo, Ogori-machi Yoshiki-gun, Yamaguchi-ken(JP) Inventor: Kaji, Eiichi No. 1-1-31, Miyanomae Shinnanyo-shi, Yamaguchi-ken(JP) Inventor: Ishimaru, Kenji No. 1-1-31, Miyanomae Shinnanyo-shi, Yamaguchi-ken(JP) © Representative: TER MEER - MULLER - STEINMEISTER & PARTNER Mauerkircherstrasse 45 D-81679 Munchen (DE) © Method of producing tetrakis(pentafluorophenyl)borate derivatives using pentafluorophenyl alkali metal salt prepared from pentafluorobenzene. © The invention relates to a production method, ganometallic compound represented by the formula wherein, with 1 equivalent of pentafluorobenzene re- [II] are reacted at -120 °C to 80 °C in an ether type presented by a formula [I], 0.5 to 1 .5 equivalents of solvent, a hydrocarbon type solvent or a mixed sol- formula of the ether solvent with the CM organometallic compound represented by a vent type hydrocarbon < [II] are reacted at -120 °C to 80 °C in an ether type type solvent to generate pentafluorophenyl alkali solvent, a hydrocarbon type solvent or a mixed sol- metal salt represented by the formula [III], and then, 00 vent of the ether solvent with the with 1 of CO type hydrocarbon equivalent tris(pentafluorophenyl)borane re- m type solvent to generate pentafluorophenyl alkali presented by a formula [VIII], not less than 0.8 metal salt represented by a formula [III], and then, equivalents of pentafluorophenyl metal compound oo o with 1 equivalent of boron compound represented by represented by the formula [III] are reacted to pro- CO a formula [IV], not less than 3.7 equivalents of pen- duce tetrakis(pentafluorophenyl)borate derivatives re- tafluorophenyl metal compound represented by the presented by the formula [VII]. formula [III] are reacted to produce tetrakis- (pentafluorophenyl)borate derivatives represented by a formula [VII], or a production method, wherein, with 1 equivalent of pentafluorobenzene represented by the formula [I], 0.5 to 1.5 equivalents or or- Rank Xerox (UK) Business Services (3. 10/3.09/3.3.4) 1 EP 0 608 563 A2 2 The present invention relates to a novel pro- that of pentafluorobenzene as a starting substance duction of tetrakis(pentafluorophenyl)borate deriva- for the production of tetrakis(pentafluorophenyl)- tives using pentafluorobenzene. borate derivatives and eliminating the brominating The boron derivatives obtainable according to process of pentafluorobenzene, leading to the in- the invention is a very useful substance as an 5 vention. intermediate of a cocatalyst for the cationic com- The gist of the invention lies in a production plex polymerization. method, wherein, with 1 equivalent of pen- In recent years, scientific literatures or patents tafluorobenzene represented by a formula [I], 0.5 to on the studies, in which a cationic complex is 1 .5 equivalents of organometallic compound repre- generated using tetrakis(pentafluorophenyl)borate io sented by a general formula [II] are reacted at -120 derivatives and cyclopentadienyl transition metal ° C to 80 ° C in an ether type solvent, a hydrocar- complex, so-called metallocene derivatives, and bon type solvent or a mixed solvent of the ether this is used as a catalyst for the polymerization type solvent with the hydrocarbon type solvent to reaction, have increased remarkably. For example, generate pentafluorophenyl alkali metal salt repre- Macromol. Chem. Rapid Commun., 2, p.p. 663-667 75 sented by a formula [III], and then, with 1 equiv- (1991) etc. are available. However, for the produc- alent of boron compound represented by a formula tion of tetrakis(pentafluorophenyl)borate derivatives, [IV], not less than 3.7 equivalents of pen- relatively expensive bromopentafluorobenzene has tafluorophenyl metal compound represented by the been used conventionally as a starting substance formula [III] are reacted to produce tetrakis- for the source of pentafluorophenyl group. 20 (pentafluorophenyl)borate derivatives represented The method was that bromopentafluoroben- by a formula [VII], or a production method, wherein, zene was submitted to the bromine-metal ex- with 1 equivalent of pentafluorobenzene represent- change reaction using organometallic compounds ed by the formula [I], 0.5 to 1.5 equivalents of such as butyllithium to generate pentafluorophenyl- organometallic compound represented by the gen- lithium, which was then reacted with boron trichlo- 25 eral formula [II] are reacted at -120 °C to 80 °C in ride, boron trifluoride, or the like as a starting raw an ether type solvent, hydrocarbon type solvent or material for the source of boron to synthesize di- a mixed solvent of the ether type solvent with the rectly, or that bromopentafluorobenzene was reac- hydrocarbon type solvent to generate pen- ted with magnesium to generate a Grignard tafluorophenyl alkali metal salt represented by the reagent such as pentafluorophenylmagnesium bro- 30 formula [III], and then, with 1 equivalent of tris- mide, which was then reacted with boron trichlo- (pentafluorophenyl)borane represented by a formu- ride, boron trifluoride, or the like similarly as a la [VIII], not less than 0.8 equivalents of pen- starting raw material for the source of boron to tafluorophenyl metal compound represented by the synthesize tris(pentafluorophenyl)borane, and this formula [III] are reacted to produce tetrakis- was further reacted with pentafluorophenyllithium to 35 (pentafluorophenyl)borate derivatives represented produce tetrakis(pentafluorophenyl)borate deriva- by the formula [VII]. tives (J. Organometallic Chem., 2, 245-250 (1964)). In following, the invention will be illustrated Bromopentafluorobenzene is obtained by concretely. brominating pentafluorobensene. If it is possible to The ether type solvents referred to so in the directly produce tetrakis(pentafluorophenyl)borate 40 specification indicate diethyl ether, dipropyl ether, derivatives from pentafluorobenzene, then the pro- diisopropyl ether, dibutyl ether, diisoamyl ether, duction processes can be reduced by one process, 1 ,2-dimethoxyethane, 1 ,2-diethoxyethane, di-2- leading to easy availability and also decreased methoxyethyl ether, tetrahydrofuran, price of a starting raw material. Moreover, litera- tetrahydropyran, 1,4-dioxane, etc. tures, in which pentafluorophenyllithium or pen- 45 Next, the hydrocarbon type solvents referred to tafluorophenylmagnesium bromide is generated us- so in the invention indicate saturated hydrocarbons ing pentafluorobenzene as a starting raw material such as pentane, isopentane, hexane, cyclohexane, and this is used for reaction, have already been heptane, octane, nonane, decane, undecane, presented (J. Chem. Soc, 166 (1959), Synthesis of dodecane, tridecane, tetradecane, pentadecane, Fluoroorganic Compounds, p141, J. Org. Chem., 50 hexadecane, n-paraffin and petroleum ether, ar- 29, 2385 (1964) and ibid, 3^, 4229 (1966)), but omatic hydrocarbons such as benzene, toluene, o- application to the production of tetrakis- xylene, m-xylene, p-xylene, 1 ,2,3-trimethylbenzene, (pentafluorophenyl)borate derivatives is not made. 1 .2.4- trimethylbenzene, 1 ,2,5-trimethylbenzene, In view of the said situation, the inventors in- 1 .3.5- trimethylbenzene, ethylbenzene, propylben- vestigated extensively on a synthetic method with- 55 zene and butylbenzene, and mixtures thereof. out using relatively expensive bromopen- Next, the functional groups having no influence tafluorobenzene as a starting raw material by on the reaction in the formula [II] referred to so in changing the use of bromopentafluorobenzene to the specification indicate methyl group, ethyl 2 3 EP 0 608 563 A2 4 group, propyl group, isopropyl group, propenyl then a lot of unreacted pentafluorobenzene comes group, 2-isopropenyl group, allyl group, butyl to remain, and, if excess amount of organometallic group, sec-butyl group, tert-butyl group, isobutyl compound is used, then there is a fear of the group, pentyl group, sec-pentyl group, tert-pentyl halogen-metal exchange reaction with also fluorine group, neo-pentyl group, isopentyl group, sec- 5 of pentafluorophenyl metal salt produced and re- isopentyl group, hexyl group, sec-hexyl group, presented by the formula [III]. Hence, it is prefer- isohexyl group, sec-isohexyl group, cyclohexyl able to use 0.8 to 1.20 equivalents of the or- group, phenyl group, benzyl group, o-tolyl group, ganometallic compound represented by the formula m-tolyl group, p-tolyl group, methoxymethyl group, [II]. If the reaction temperature is too lower than -80 methylthiomethyl group, 2-dimethylaminoethyl io °C, the reaction proceeds extremely slowly, while group, o-anisyl group, m-anisyl group, p-anisyl if it is too higher than 0 ° C, side reactions proceed group, trimethylsilylmethyl group, etc., and exam- extremely rapidly, thus coming to very low yield in ples of organometallic compounds represented by both cases. Hence, it is desirable to conduct the the formula [II] include methyllithium, ethyllithium, reaction in a range of -80 to 0 °C. The reaction propyllithium,