Patent ID: 7375181
Filing Date: 2008-05-20
Classification: A61P,C07K

Abstract:
1. A method of purifying a compound of formula I: wherein: R R R R or a pharmaceutically acceptable salt or stereoisomer, thereof; the method comprising the steps of: (a) contacting a polystyrene divinyl benzene resin with a first acidified aqueous solution comprising the compound; (b) eluting the contacted resin with a second acidified aqueous solution comprising a polar organic solvent selected from methanol, ethanol, isopropyl alcohol, acetonitrile, acetone, n-propyl alcohol, n-butyl alcohol, isobutyl alcohol, methyl ethyl ketone, and tetrahydrofuran to form an eluate containing the compound; and (c) isolating the compound from the eluate.