Structural Examination of 6-Methylsulphonylphenanthro- [9,10-C]-furan-1(3H)-one—A Rofecoxib Degradation Product

Abstract

In the attempt to discover a new polymorph of rofecoxib (Vioxx®), an unexpected product resulted. The product was characterised by chemical composition, thermal behaviour and structure and found to be 6-methylsulphonylphenanthro-[9,10-C] furan-1(3H)-one, a photo-cyclization degradation product of rofecoxib. This is a significant finding because it indicates that without appropriate control of the recrystallisation procedures, the structural integrity of rofecoxib may be seriously compromised.

Keywords

• rofecoxib
• structural characterisation
• NSAID
• crystallography