1: 49 percent / AlCl3 / CH2Cl2 / 0.5 h / -6 °C 2: sulfur, p-toluenesulfonic acid / 5 h / Heating 3: 78 percent / HOAc, H2SO4, H2O / 4 h / Heating 4: conc. H2SO4 / toluene / 3 h / Heating 5: AlCl3 / CS2 / 2 h / Heating 6: aq. NaOH / methanol / 2 h / Heating View Scheme