Patent 7598387 was granted and assigned to Cipla on October, 2009 by the United States Patent and Trademark Office.
A process of preparing rosiglitazone, or a pharmaceutically acceptable salt thereof, which process employs an intermediate metabisulphite complex of 4-[2-(N-methyl-N-(2-pyridyl)amino)ethoxy]benzaldehyde, which metabisulphite complex is represented by following formula (III):