Fexofenadine → Fexofenadine Hydrochloride

Participants

Reaction Steps

To pure Fexofenadine (50 g), toluene (500 ml) is added and the mixture is refluxed azeotropically for about 3 hours. The reaction mass is then cooled to room temperature followed by slow addition of isopropanol hydrogen chloride, to pH 2. The reaction mass is then stirred for about 15 and a half hours. The separated solid is filtered, washed with toluene (50 ml) and dried (Yield 43.3 g). Part of this solid (42 g) is suspended in ethyl acetate (420 ml) and refluxed for about 1 hour (this operation was performed for removal of residual organic solvents). The suspension is then cooled to room temperature and stirred for 20 minutes. The reaction mass is filtered and washed with ethyl acetate (42 ml). The desired Form X of Fexofenadine hydrochloride is dried at 90-96° C. to constant weight.

Provenance & Evidence