Iodine-mediated synthesis of 3-acylbenzothiadiazine 1,1-dioxides

• Long-Yi Xi,
• Ruo-Yi Zhang,
• Lei Shi,
• Shan-Yong Chen and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2016, 12, 1072–1078, doi:10.3762/bjoc.12.101

• described. A range of electronically diverse acetophenones reacted well with several 2-aminobenzenesulfonamides, affording 3-acylbenzothiadiazine 1,1-dioxides in good yields. Keywords: 3-acylbenzothiadiazine 1,1-dioxides; cyclization; metal-free; oxidation; Introduction Benzothiadiazine 1,1-dioxide

• of luotonin F and derivatives from aromatic ketones and 2-aminobenzamides via iodination/Kornblum oxidation/annulation [25]. We envisioned that 2-aminobenzenesulfonamides would undergo a similar reaction to afford 3-acylbenzothiadiazine 1,1-dioxides. Herein, we report the first synthesis of 3

• biologically active benzothiadiazine 1,1-dioxides. Experimental Typical procedure for the synthesis of 3-acylbenzothiadiazine 1,1-dioxides: A mixture of acetophenone (0.040 mL, 0.33 mmol), I2 (0.057 g, 0.225 mmol) and 2-aminobenzenesulfonamide (0.051 g, 0.3 mmol) in DMSO (2 mL) was stirred at 110 °C under air