Patent ID: 8455692
Filing Date: 2013-06-04
Classification: C07C

Abstract:
1. A process for resolution of racemic 1-(3-hydroxyphenyl)-2-methylamino ethanol to obtain (R)-1-(3-hydroxyphenyl)-2-methylamino ethanol, (R-phenylephrine) comprising the steps of: (a) treating racemic 1-(3-hydroxyphenyl)-2-methylamino ethanol or its salt with (R)-2-(6-methoxy-2-naphthyl) propionic acid, (R-naproxen) or its salt, in a suitable medium as a solution or suspension to precipitate a first salt of (R)-1-(3-hydroxyphenyl)-2-methylamino ethanol with R-naproxen; (b) filtering the precipitated first salt, optionally washing and drying the first salt and recovering the first salt; (c) treating the recovered first salt with an adequate amount of an acid to liberate free R-naproxen and converting the R-phenylephrine to a second salt of the acid added; (d) treating a solution of the second salt of R-phenylephrine as obtained in step (c) with a base to liberate free R-phenylephrine base, optionally washing and drying the precipitated solid; and (e) converting the free R-phenylephrine base to a pharmaceutically acceptable salt.