摘要 |
<p>A process is described for preparing fesoterodine and/or fesoterodine fumarate comprising the esterification of (R)-feso deacyl with isobutyric acid or a precursor thereof, such as for example an isobutyryl halide or the isobutyric acid anhydride, to give fesoterodine, in a mixture of water at alkaline pH and/or at least one organic solvent. Such process allows obtaining products with high yields and purities, and in particular a product having a content of (R)-2-[3-(diisopropylamino)-1-phenylpropyl]-4-isobutyroyloxymethyl-phenyl isobutyrate less than 1% by mole and a content of (R)-2-[3-(diisopropylamino)-1-phenylpropyl]-4-(hydroxymethyl)phenol less than 0.05% by mole.</p> |