1: 42 percent / thioxanthen-9-one / methanol / 1 h / Irradiation 2: 15 h / 55 °C 3: 0.45 g / N,N-diisopropylethylamine; trifluoromethanesulfonic anhydride / CH2Cl2 / 1.17 h / 0 °C View Scheme

1: 45 percent / thioxanthen-9-one / benzene / 0.67 h / Irradiation; ice-water cooling 2: 88 percent / acetic acid / H2O 3: 15 h / 55 °C 4: 0.45 g / N,N-diisopropylethylamine; trifluoromethanesulfonic anhydride / CH2Cl2 / 1.17 h / 0 °C View Scheme

Irradiation;