Graphene oxide (GO): An efficient carbocatalyst for the benign synthesis of functionalized 1,4-benzothiazines

Graphene oxide (GO) has been found to be highly efficient and recyclable carbocatalyst for the benign construction of heterocyclic molecule 1,4-benzothiazine from 2-aminothiophenol and 1,3-dicarbonyl compound. A vast range of highly functionalized 1,4-benzothiazine derivatives has been synthesized constituting a general and sustainable protocol. It is proposed that the large surface area of GO nanosheet along with the presence of acidic and oxidative groups present on the edges, basal plane and intercalated layers catalyze the oxidative cyclization effectively.