Process for preparing citalopram
AssigneeEsteve Quimica, S.A.
InventorsLaura Coppi, Yolanda Gasanz Guillen, Julio Campon Pardo
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Abstract
Process for preparing purified citalopram or one of its salts that comprises the purification of citalopram by selective extractions of citalopram or of its impurities with organic solvents and water under specific conditions of pH and temperature. The crude citalopram can be prepared by a process that comprises reacting 1-[3-(dimethylamine)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-bromoisobenzofuran with copper cyanide.
Claims12
A process for preparing pure citalopram that comprises purifying citalopram by selective extractions of citalopram or its impurities, said method comprising the following steps:
- a) extraction of citalopram dissolved in an organic solvent immiscible in water, with water at a pH of between 3.0 and 6.0, at a temperature of between 10° C. and 60° C., and separation of the aqueous phase that contains citalopram;
- b) washing the aqueous phase that contains citalopram proceeding from step a) with an organic solvent immiscible in water, at a pH of between 4.0 and 7.0, at a temperature of between 20° C. and 60° C., and separation of the purified aqueous phase that contains citalopram;
- and
- c) extraction of citalopram contained in the aqueous phase proceeding from step b) with a solvent immiscible in water at a pH in the interval from 5.0 to 7.5, at a temperature between 20° C. and 60° C.
A process for preparing pure citalopram that comprises reacting 1-[3-(dimethylamine)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-bromoisobenzofuran with copper cyanide in the absence of solvent to obtain crude citalopram and purifying the crude citalo by selective extractions of citalopram or of its impurities comprising purifying the crude citalopram by the following steps:
- a) extraction of citalopram dissolved in an organic solvent immiscible in water, with water at a pH of between 3.0 and 6.0, at a temperature of G ), 0 S between 10° C. and 60° C., and separation of the aqueous phase that contains citalopram;
- b) washing the aqueous phase that contains citalopram proceeding from step a) with an organic solvent immiscible in water, at a pH of between 4.0 and 7.0, at a temperature of between 20° C. and 60° C., and separation of the purified aqueous phase that contains citalopram;
- and
- c) extraction of citalopram contained in the aqueous phase proceeding from step b) with a solvent immiscible in water at a pH in the interval from 5.0 to 7.5, at a temperature between 20° C. and 60° C.
Dependencies are inferred from the claim text.