hydrogen fluoride in benzene 1.) RT, 0.5 h, 2.) 50 deg C, 10 min;

1: 37 percent / 40percent aq. HF / benzene / 1.) RT, 0.5 h, 2.) 50 deg C, 10 min 2: 1.) Mg / 2.) ether, 2.) ether, reflux, 4 h 3: 85 percent / BBr3 / CH2Cl2 / 1 h / Ambient temperature 4: KOH / ethanol / 20 h / Heating View Scheme