| abstract |
Process for the preparation of aromatic derivatives of titanocene useful as catalysts for the polymerization and hydrogenation of polymers, characterized by the use of a Grignard reactant. This process enables to prepare easily compounds having the general formula (I) wherein L, which can be identical or different from each other, are cyclopentadiene or pentamethylcyclopentadiene; preferably at least one L is cyclopentadiene; R?1, R2, R3¿, which are identical or different from each other, are selected in the group comprising hydrogen, alkyl group with 1 to 4 carbon atom(s), OR4 wherein R4 is an alkyl group with 1 to 4 carbon atom(s); at least one of R?1, R2 or R3¿ is hydrogen. The preparation is carryied out by reacting titanocene dichloride with the corresponding Grignard derivative. This method improves substantially the security, reproducibility, yield and cost in comparison with the method using lithium compounds. |