boron tribromide in dichloromethane T=20°C; 10 h;

sulfuric acid T=170 - 180°C;

potassium acetate; acetic anhydride in hydrochloric acid-methanol; water; chlorobenzene

hydrogenchloride in methanol T=80°C; 5 h;

1: potassium acetate; isoamyl nitrite / CHCl3 / 18 h / 80 °C 2: 7.99 g / HCl / methanol / 5 h / 80 °C View Scheme

1: Raney nickel / Hydrogenation 2: aqueous H2SO4 / 170 - 180 °C View Scheme

in methanol

1: 76 percent / 2 h / 175 °C 2: 94 percent / H2O, HCl / 2 h / 50 - 60 °C View Scheme

potassium carbonate in N,N-dimethyl-formamide T=0 - 20°C;

1.1: 1H-imidazole / N,N-dimethyl-formamide / 3.5 h / 0 - 18 °C 2.1: N-iodo-succinimide / dichloromethane / 3.5 h / 10 - 20 °C 3.1: methanesulfonic acid / dichloromethane; tetrahydrofuran / 3.5 h / 10 - 20 °C 3.2: 10 °C 4.1: tributyl-amine / bis-triphenylphosphine-palladium(II) chloride / N,N-dimethyl-formamide / 18.67 h / 95 - 100 °C / Inert atmosphere 4.2: 3.67 h / 40 - 95 °C / Inert atmosphere 5.1: caesium carbonate / acetonitrile / 60 °C / Inert atmosphere 6.1: acetyl chloride; methanol / 4 h / 20 °C / Inert atmosphere; Cooling with ice 6.2: 0.5 h / 20 °C View Scheme