Reflux;

triethylamine in diethyl ether; dichloromethane 15 deg C and 6 h, room t.;

1: 64.6 percent / Br2 / CCl4 / 2.25 h / Heating; Irradiation 2: 99 percent / cc. H2SO4 / 7 h / Ambient temperature 3: 98percent N2H4*H2O / ethanol / 6 h / Ambient temperature 4: 90 percent / Et3N / CH2Cl2; diethyl ether / 15 deg C and 6 h, room t. View Scheme

1: 98percent N2H4*H2O / ethanol / 6 h / Ambient temperature 2: 90 percent / Et3N / CH2Cl2; diethyl ether / 15 deg C and 6 h, room t. View Scheme

1: hydrogenchloride; sodium nitrite / water 2: trifluoroacetic anhydride 3: Reflux View Scheme

1: trifluoroacetic anhydride 2: Reflux View Scheme