“…All chemical reagents and solvents were purchased from commercial suppliers and used without further purification. + ;found: 276.11, [1,4] oxazine (9) White solid; yield: 46%; 1 H NMR (500 MHz, DMSO-d 6 ) δ 7.37 (d, J = 8.0 Hz, Ar-H, 1H), 7.33 (dd, J = 8.0, 2.5 Hz, Ar-H, 1H), 7.30 (d,J = 2.5 Hz,1H),CH 2 ,2H),CH General procedure B for the synthesis of intermediates (13)(14)(15)(16)(17)(18) Compounds 4 and 5 (1.00 mmol) and TEA (5.00 mmol) were dissolved in DCM (3.0 mL). The corresponding sulfonyl chloride (1.50-2.00 mmol) was added to the solution with an atmosphere of 0 °C and nitrogen.…”