1: acetic acid / 0.25 h / Heating 2: 60percent nitric acid, conc. sulfuric acid / 1.) 0 deg C, 10 min, 2.) RT, 30 min View Scheme

sulfuric acid; nitric acid 1.) 0 deg C, 10 min, 2.) RT, 30 min;

sulfuric acid

nitric acid

sulfuric acid T=120°C;

1: potassium carbonate / N,N-dimethyl-formamide / 12 h / 90 °C / Industry scale 2: sodium hydroxide; water / methanol / 4 h / 50 °C / Industry scale 3: hydrogen; sodium hydroxide / Raney nickel / methanol / 12 h / 100 °C / Industry scale View Scheme

1.1: potassium carbonate / N,N-dimethyl-formamide / 12 h / 20 - 90 °C / |Large scale 1.2: 4 h / 50 °C / |Large scale 2.1: sodium hydroxide; hydrogen / methanol / 12 h / 100 °C / |Inert atmosphere 3.1: methanol / 6 h / |Reflux 3.2: 4 h / 60 - 90 °C 4.1: methanol; water / 0.5 h / 60 °C 4.2: 1.5 h / 60 °C View Scheme

1: With potassium carbonate in N,N-dimethyl-formamide T=20 - 90°C; 12 h; Large scale; 2: With sodium hydroxide in methanol; water; N,N-dimethyl-formamide T=50°C; 4 h; Large scale;

1: potassium carbonate / N,N-dimethyl-formamide / 12 h / 90 °C / Industry scale 2: sodium hydroxide; water / methanol / 4 h / 50 °C / Industry scale View Scheme