1: 93 percent / NaOMe / benzene; tetrahydrofuran; methanol / 8 h / Heating 2: 69 percent / KOH / ethanol / 24 h / Heating 3: 54 percent / PCl5 / chlorobenzene / 3 h / 20 °C 4: 89 percent / Zn; AcOH / 3 h 5: 55 percent / 48 h / 120 °C / in sealed tube View Scheme

1: potassium carbonate / ethanol / 20 °C 2: dicyclohexyl-carbodiimide; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 0 - 20 °C 3: acetic anhydride / 12 h / 140 °C / |Inert atmosphere View Scheme