Microwave assisted rapid synthesis of phenoxazines and benzopyridoxazines

Abstract

A facile protocol for the synthesis of phenoxazines and benzopyridoxazines by Smiles rearrangement have been demonstrated in short reaction time under microwave irradiation. The control experiments suggest that a reaction proceeds through Smiles rearrangement followed S_NAr ring closure by in situ cascade process. In our present work, both the electron donating and electron withdrawing groups were tolerant and provided a corresponding phenoxazine/benzopyridoxazine in good to moderate yields.

GRAPHICAL ABSTRACT

Keywords:

• Benzopyridoxazines
• microwave irradiation
• phenoxazines
• smiles rearrangement
• SNAr cyclization

Acknowledgments

The authors are thankful to Dr. Subhendu Kumar Mohanty, Dr. Sathya Shanker and Karthik T. Pai for their support and encouragement throughout this work. Kavitha is grateful to Syngene International Ltd, Bangalore, India for analytical support and the permission for higher education (Ph.D.).

Additional information

Funding

Kavitha is grateful to Syngene International Ltd, Bangalore, India for financial support.