Sulfonic Acid Functionalized Nano-γ-Al2O3: A New, Efficient, and Reusable Catalyst for Synthesis of 3-Substituted-2H-1,4-Benzothiazines

<table>A plausible mechanism for the synthesis of 3-substituted-2H-1,4-benzothiazines.</table>

The Scientific World Journal

Scheme 3: Sulfonic Acid Functionalized Nano-γ-Al2O3: A New, Efficient, and Reusable Catalyst for Synthesis of 3-Substituted-2H-1,4-Benzothiazines