boron tribromide in dichloromethane 48 h; Ambient temperature;

1: 69 percent / molecular sieves / dimethylformamide / Heating 2: 92 percent / cuprous chloride / dimethylformamide / 5 h / Heating 3: 67.8 percent / 98percent hydrazine / ethanol / 0.25 h / Heating 4: BBr3 / CH2Cl2 / 48 h / Ambient temperature View Scheme

1: 67.8 percent / 98percent hydrazine / ethanol / 0.25 h / Heating 2: BBr3 / CH2Cl2 / 48 h / Ambient temperature View Scheme

1: 92 percent / cuprous chloride / dimethylformamide / 5 h / Heating 2: 67.8 percent / 98percent hydrazine / ethanol / 0.25 h / Heating 3: BBr3 / CH2Cl2 / 48 h / Ambient temperature View Scheme