1: hydrazine / methanol; chloroform; water / 12 h / 20 °C 2: acetic acid / water / 0.5 h / 20 °C 3: oxygen; copper(II) bis(trifluoromethanesulfonate) / toluene / 1.5 h / 80 °C View Scheme

1: With methanol; hydrazine in chloroform T=20°C; 22 h; 2: With hydrogenchloride in 1,4-dioxane; ethanol; ethyl acetate Heating / reflux;

aluminium trichloride in benzene 1 h; Ambient temperature;

aluminium trichloride 1 h; Ambient temperature;