1: tetrahydrofuran / Ambient temperature 2: H2 / Pd/C / ethyl acetate / 2206.5 Torr 3: 95 percent / KOH, EtOH / 13 h / Heating 4: 58 percent / N-chlorosuccinimide View Scheme

(i) AlCl3, CS2, (ii) H2SO4; Multistep reaction;