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 K 2 CO 3 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.
