Improved synthesis of paroxetine hydrochloride propan-2-ol solvate throughone of metabolites in humans, and characterization of the solvate crystals

Paroxetine, a potent and selective inhibitor of 5-hydroxytryptamine (seroto nin) uptake, was prepared through a piperidine derivative, which was report ed to be one of the paroxetine metabolites in humans. Thus, the piperidine derivative was converted to its N-tert-butoxycarbonyl (N-Boc) derivative, which was then converted to N-Boc paroxetine. Paroxetin e hydrochloride propan-2-ol (isopropyl alcohol (IPA)) solvate crystals were directly obtained from the N-Boc paroxetine by adding hydrogen chloride to the N-Boc paroxetine IPA solution. The amount of IPA content in the crysta ls was reduced by drying with a continuous change of powder X-ray diffracti on patterns. Other characterizations of the solvate crystals were also cond ucted.