1: 1.) nitrosylsulfuric acid, 2.) sodium azide; / 1.) acetic anhydride, acetic acid, 20-35 deg C, 30 min, 2.) 25 deg C, 15 min; 2: 80 percent / Cu powder / various solvent(s) / 0.83 h / 180 °C 3: 15 percent / H2O / 1 h / 100 °C View Scheme

1: 1.) nitrosylsulfuric acid, 2.) sodium azide; / 1.) acetic anhydride, acetic acid, 20-35 deg C, 30 min, 2.) 25 deg C, 15 min; 2: 80 percent / Cu powder / various solvent(s) / 0.83 h / 180 °C View Scheme