Graphite oxide: a metal free highly efficient carbocatalyst for the synthesis of 1,5-benzodiazepines under room temperature and solvent free heating conditions

Abstract

Graphite Oxide (GO), an attractive metal free carbocatalyst, was employed as a green and highly efficient catalytic system for the synthesis of 1,5-benzodiazepines. The reaction was studied at room temperature as well as at 80 °C under solvent free heating conditions. In both cases, GO showed high catalytic activity which is attested by the desired products being produced in good to excellent yields. The present catalytic process eliminates the inconvenience of metal waste disposal, metal contamination in the product and metal toxicity, which are all of significance to the pharmaceutical industry. Furthermore, the present methodology addresses several issues of sustainability and environmental problems such as catalyst reusability (nine consecutive runs), solvent free reaction conditions (SFRC) and high substrate variation. The excellent gram scale applicability also points towards its possible implementation in industrial use.