Abstract: There is described a process for the preparation of citalopram and of its pharmaceutically acceptable salts, which comprises treating a 1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5 isobenzofurancarbaldoxime, O-substituted preferably with a diphenylmethyl or triphenylmethyl group, with formic-acetic anhydride. Furthermore, the total synthesis of citalopram, as free base or in form of its pharmaceutically acceptable salt, starting from 5-formylphthalide is described.
Abstract: There is described a process for the preparation of 5-formylphthalide by hydrogenation of a halide of 5-carboxyphthalide, dissolved in a dipolar aprotic solvent, in the presence of a catalyst. Furthermore, the use of 5-formylphthalide in the preparation of citalopram is described.
Abstract: There is described a process for the preparation of 5-carboxy phthalide, which comprises adding terephthalic acid to fuming sulfuric acid containing at least 20% of SO3, then adding formaldehyde to the mixture, heating the mixture at a temperature of 120-145° C. and isolating 5-carboxyphthalide from the reaction mixture.
Type:
Grant
Filed:
August 23, 2002
Date of Patent:
March 9, 2004
Assignee:
Infosint SA
Inventors:
Leone Dall'Asta, Umberto Casazza, Giovanni Cotticelli