tetraphosphorus decasulfide; xylene

trimethylsilylazide; tin(IV) chloride in dichloromethane 22 h; Ambient temperature;

1: 40 percent / Et3N / tetrahydrofuran / 1 h 2: Ac2O, Et3N / 0.25 h 3: xylene / 20 h / Heating 4: 94 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / dioxane / 18 h / Heating 5: 75 percent / 10percent NaOH, aq. EtOH / 1 h / Heating 6: 240 °C View Scheme