PROCESS FOR THE PRODUCTION OF `2- (4-FLUORO-BENZYL) -PHENYL ! -ACETIC ACID

摘要

The present invention relates to a novel process for the production of [2-(4-fluoro-benzyl)-phenyl]-acetic acid, a compound obtainable from phthalic anhydride. The process comprises the subsequent steps a) through e): a) reacting phthalic anhydride with fluorobenzene or a derivative thereof in appropriate reaction conditions; b) over reducing the product obtained in step a) at the ketone moiety; c) reducing the product obtained in step b) with sodium dihydro-bis (2- 15 methoxyethoxy) aluminate (Red-Al) to the corresponding alcohol ; d) chlorinat ing the alcohol obtained in step c) ; e) inserting CO into the product obtained in step d) through an appropriate Pd-containing catalytic system. In an alternative embodiment, the step e) is replaced by the steps f1) and f2) : f1) reacting the product obtained in step d) with sodium cyanide ; f2) hydro lysing the product obtained in step f1). The present invention provides a process for the production of [2-(4-fluoro-benzyl)- phenyl]-acetic acid which is suitable for industrial scale reactors (e.g. which is cleaner and more efficient). Also, [2-(4-fluoro-benzyl)-phenyl]-acetic acid is obtained as a crystalline material with a purity > 95%.