nitric acid; acetic anhydride in acetic acid T=-78°C; 3 h;

1.1: potassium tert-butylate / tetrahydrofuran / 1 h / 20 °C / Inert atmosphere 1.2: 12 h / 20 °C 2.1: hydrogen / palladium 10 on activated carbon / ethanol / 12 h 3.1: methanesulfonic acid; phosphorous pentoxide / 12 h / Inert atmosphere 4.1: nitric acid; acetic anhydride / acetic acid / 3 h / -78 °C View Scheme

1: hydrogen / palladium 10 on activated carbon / ethanol / 12 h 2: methanesulfonic acid; phosphorous pentoxide / 12 h / Inert atmosphere 3: nitric acid; acetic anhydride / acetic acid / 3 h / -78 °C View Scheme

1.1: potassium tert-butylate / tetrahydrofuran / 0.25 h / 20 °C 1.2: 8 h / 0 - 20 °C 2.1: palladium 10 on activated carbon; hydrogen / methanol / 24 h 3.1: phosphorous pentoxide; methanesulfonic acid / 12 h / |Inert atmosphere 4.1: acetic acid; acetic anhydride; nitric acid / -10 °C View Scheme

1: palladium 10 on activated carbon; hydrogen / methanol / 24 h 2: phosphorous pentoxide; methanesulfonic acid / 12 h / |Inert atmosphere 3: acetic acid; acetic anhydride; nitric acid / -10 °C View Scheme

1: methanesulfonic acid; phosphorous pentoxide / 12 h / Inert atmosphere 2: nitric acid; acetic anhydride / acetic acid / 3 h / -78 °C View Scheme

1: phosphorous pentoxide; methanesulfonic acid / 12 h / |Inert atmosphere 2: acetic acid; acetic anhydride; nitric acid / -10 °C View Scheme