bis(trichloromethyl) carbonate; triethylamine in dichloromethane 1.) -10 deg C, 5 min, 2.) r.t., 4 h;

1: 94 percent / Ac2O / 3.5 h / 60 °C 2: 87 percent / diethyl ether; CH2Cl2 / 24 h 3: 69.5 percent / Et3N, triphosgen / CH2Cl2 / 1.) -10 deg C, 5 min, 2.) r.t., 4 h View Scheme

1: 87 percent / diethyl ether; CH2Cl2 / 24 h 2: 69.5 percent / Et3N, triphosgen / CH2Cl2 / 1.) -10 deg C, 5 min, 2.) r.t., 4 h View Scheme