Efficient and Convenient Synthesis of 1,4-Benzoxazines, 1,4-Benzothiazines, Spiro-1,4-benzoxazines, and Spiro-1,4-benzothiazines

Abstract

An efficient, convenient synthesis of 1,4-benzoxazines, 1,4-benzothiazines, spiro-1,4-benzoxazines, and spiro-1,4-benzothiazines derivatives was accomplished in good yields via the novel intramolecular cyclization mediated by mild base K₂CO₃ in ethanol solvent. A variety of substrates can participate in the process with good yields, making this methodology have broad applicability. All the structures of synthesized compound have been confirmed by spectral analysis.

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GRAPHICAL ABSTRACT

Keywords:

• 1,4-Benzothiazines
• 1,4-benzoxazines
• 4-bromomethylcoumarin
• intramolecular
• spiro-1,4-benzothiazines
• spiro-1,4-benzoxazines
• Schiff base

ACKNOWLEDGMENTS

We acknowledge the University Grants Commission, New Delhi, and Department of Science and Technology, New Delhi, for financial support.