Patent 7368607 was granted and assigned to Orion Corporation on May, 2008 by the United States Patent and Trademark Office.
The invention relates to a method for isolating toremifene from a mixture of toremifene and its corresponding E isomer. The method comprises contacting the isomer mixture with a first solvent comprising methanol, allowing toremifene to crystallize in said first solvent, allowing the crystallized product of the previous step to crystallize from a second solvent comprising acetone, methyl ethyl ketone or ethyl acetate, and optionally converting toremifene crystallized from the previous step to a pharmaceutically acceptable salt thereof.