bromine in dichloromethane T=-55°C; 1.5 h; in the dark;

bromine in chloroform -78 deg C to r.t.;

1: 1.) Mg, iodine / 1.) diethyl ether, reflux, 1 h, 2.) room temperature, 1 h, reflux, 1 h 2: bromine / CH2Cl2 / 1.5 h / -55 °C / in the dark View Scheme

diethyl ether; bromine

1: aluminum chloride / CH2Cl2 / 1.25 h 2: 18.5 g / sodium hypobromite / dioxane 3: thionyl chloride / benzene / 2 h / Heating 4: aqueous ammonia 5: thionyl chloride / benzene / 6 h / Heating 6: acetic acid, zinc powder / ethanol / 1.25 h / Heating View Scheme