1: With boron trichloride in dichloromethane; toluene T=-78 - 20°C; 12 h; Inert atmosphere; 2: With water; sodium hydroxide in dichloromethane; toluene T=20°C; 0.5 h;

1: 1.0 g / KOH / aq. ethanol / Ambient temperature 2: 450 mg / 85percent H3PO4 / ethanol / 50 h / Heating 3: 350 mg / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / dioxane / 10 h / Heating 4: 120 mg / H2 / Pd-C / ethyl acetate 5: AlCl3 / nitrobenzene / Ambient temperature View Scheme

1: 1.0 g / KOH / aq. ethanol / Ambient temperature 2: 450 mg / 85percent H3PO4 / ethanol / 50 h / Heating 3: 350 mg / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / dioxane / 10 h / Heating 4: 120 mg / H2 / Pd-C / ethyl acetate 5: AlCl3 / nitrobenzene / Ambient temperature View Scheme

1: 450 mg / 85percent H3PO4 / ethanol / 50 h / Heating 2: 350 mg / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / dioxane / 10 h / Heating 3: 120 mg / H2 / Pd-C / ethyl acetate 4: AlCl3 / nitrobenzene / Ambient temperature View Scheme

1: 350 mg / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / dioxane / 10 h / Heating 2: 120 mg / H2 / Pd-C / ethyl acetate 3: AlCl3 / nitrobenzene / Ambient temperature View Scheme

aluminium trichloride in nitrobenzene Ambient temperature;

1.1: potassium tert-butylate / tetrahydrofuran / 1 h / Reflux; Inert atmosphere 2.1: toluene-4-sulfonic acid / benzene / 7 h / Reflux; Inert atmosphere 3.1: boron trichloride / dichloromethane; toluene / 12 h / -78 - 20 °C / Inert atmosphere 3.2: 0.5 h / 20 °C View Scheme

1.1: toluene-4-sulfonic acid / benzene / 7 h / Reflux; Inert atmosphere 2.1: boron trichloride / dichloromethane; toluene / 12 h / -78 - 20 °C / Inert atmosphere 2.2: 0.5 h / 20 °C View Scheme

1.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / dichloromethane / 1 h / 20 °C / Cooling with ice; Inert atmosphere 2.1: potassium tert-butylate / tetrahydrofuran / 1 h / Reflux; Inert atmosphere 3.1: toluene-4-sulfonic acid / benzene / 7 h / Reflux; Inert atmosphere 4.1: boron trichloride / dichloromethane; toluene / 12 h / -78 - 20 °C / Inert atmosphere 4.2: 0.5 h / 20 °C View Scheme