Multi-step reaction with 4 steps 1: 70 percent / thionyl chloride / benzene; CH2Cl2 / 1.) reflux, 2.) room temperature, 2.5 h2: 2.) EtOH / 1.) pentane, -78 deg C, 0.5 h; room temperature, 0.5 h, 2.) pentane, room temperature, 6 h3: 4.5 N HCl / 14 h / Heating4: diethyl ether / 2 h