Patent ID: 6239300
Filing Date: 2001-05-29
Classification: C07F,Y10S

Abstract:
A process for producing a bridged cyclopentadienyl-fluorenyl metallocene comprising:(a) passing a dicyclopentadiene compound in liquid form into and through an evaporator under conditions conducive to the vaporization and cracking of the dicyclopentadiene compound, thereby producing a cyclopentadiene compound as a vapor;(b) condensing the vaporous cyclopentadiene compound to a liquid;(c) reacting, in a water-soluble alcohol and in the presence of an organic base, the liquid cyclopentadiene compound with a carbonyl compound selected from an aldehyde or a ketone to thereby produce a first mixture containing a fulvene compound;(d) adding an acid and a first hydrocarbon to the first mixture, the acid being reactive with the organic base to produce a water-soluble salt and the fulvene compound being soluble in the first hydrocarbon to thereby result in a second mixture;(e) passing second mixture to a water-containing extraction column to establish therein a bottom liquid phase, containing the water-soluble salt and alcohol as dissolved in the water, and a top liquid phase containing the fulvene compound as dissolved in the first hydrocarbon;(f) withdrawing top liquid phase from the extraction column and separating the first hydrocarbon from the fulvene compound;(g) reacting a fluorene compound with an alkali metal alkyl in a noncyclic ether, and then adding thereto the fulvene compound and additional alkali metal alkyl to produce a cyclopentadienyl-fluorenyl alkali metal salt in a resulting third mixture;(h) providing a second hydrocarbon in the third mixture and separating the noncyclic ether therefrom to form a fourth mixture having the alkali metal salt as solids in a second hydrocarbon-based liquid comprising the second hydrocarbon with any unreacted fluorene, alkali metal alkyl, and fulvene compound dissolved therein, and then separating the second hydrocarbon-based liquid from the alkali metal salt solids;(i) mixing the alkali metal salt solids with fresh second hydrocarbon and a zirconium, titanium, or hafnium tetrahalide compound so that the tetrahalide compound reacts with the alkali metal salt to produce a raw product comprising the bridged cyclopentadienyl-fluorenyl metallocene and an alkali metal halide as solids in the second hydrocarbon as a fifth mixture, and then separating the second hydrocarbon from the raw product;(j) mixing the raw product with a halogenated organic solvent in which the metallocene is soluble and the alkali metal halide is insoluble, thereby producing a sixth mixture comprising a metallocene solution and the alkali metal halide solids; and(k) subjecting the sixth mixture to centrifuging so as to separate the alkali metal halide solids from the metallocene solution and then recovering the metallocene as solids from the metallocene solution.