Lawesson's reagent

1: 50 percent / dioxane / 0.17 h 2: 73 percent / Lawesson's reagent 3: 42 percent / dimethylformamide / cathodic reduction, Hg cathode View Scheme

1: 50 percent / dioxane / 0.17 h 2: 73 percent / Lawesson's reagent 3: 42 percent / dimethylformamide / cathodic reduction, Hg cathode View Scheme

trifluoromethylsulfonic anhydride; copper(I) bromide 1.) Et2O, THF, -50 deg C, 1 h, 2.) Et2O, THF, -50 deg C, 0.5 h then -50 to 0 deg C, 5 h, 3.) Et2O, THF, 0 deg C, 0.5 h then reflux 12 h; Yield given. Multistep reaction;

oxygen; copper(l) chloride in dimethyl sulfoxide T=80°C; 1.5 h;