palladium 10 on activated carbon; hydrogen in methanol T=35°C; 3 h; Inert atmosphere;

sodium dithionite; sodium hydroxide in water 4 h; Reflux;

1: sodium hydroxide; sodium dithionite / water / 4 h / |Reflux 2: sulfuric acid / 15 h / 20 °C 3: 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / |Reflux; |Inert atmosphere 4: zinc / methanol; acetic acid / 1.08 h / 20 °C 5: potassium carbonate / N,N-dimethyl-formamide / 2.5 h / 35 °C View Scheme

1: sodium hydroxide; sodium dithionite / water / 4 h / |Reflux 2: sulfuric acid / 15 h / 20 °C 3: 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / |Reflux; |Inert atmosphere 4: zinc / methanol; acetic acid / 1.08 h / 20 °C 5: potassium carbonate / N,N-dimethyl-formamide / 2.5 h / 35 °C 6: sodium hydroxide / methanol; water / 0.75 h / |Reflux View Scheme