Synthetic Approaches to the Multifunctional Drug Ebselen and Analogs: Past and Present

Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is a widely known magical heterocyclic compound with anti-inflammatory, anti-oxidant and cytopro- tective activity. It acts as a mimic of glutathione peroxidase; used for the treatment of Alzheimer's disease and HCV disorder as well as effective against Clostridium difficile infections. Since its first synthesis in 1924, relatively a few synthetic ap- proaches have been reported for such a versatile drug. It may be due to the presence of Se-N linkage, which is quite a challenging step for synthetic chemists. The cycli- zations via primary amines, free radical synthesis and transition metal catalyzed syn- thesis are the widely employed routes for the synthesis of ebselen and its derivatives. This review aims to provide readers an insight into the past and present synthetic approaches towards ebselen and its derivatives.