trifluoroacetic acid in dichloromethane T=20°C;

sulfuric acid

1.1: nitric acid; acetic acid; sulfuric acid / 1 h / 0 - 20 °C 2.1: palladium 10 on activated carbon; hydrogen / ethanol; methanol; acetic acid / 36 h / 20 °C 3.1: sodium nitrite; sulfuric acid / water / 0.5 h / 0 °C 3.2: 2 h / 100 °C 4.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / N,N-dimethyl-formamide / 50 °C 5.1: hydrazine hydrate / tert-butyl alcohol / 110 °C / |Inert atmosphere 6.1: trifluoroacetic acid / dichloromethane / 20 °C View Scheme

1.1: 1 h / 0 - 20 °C 2.1: nitric acid; acetic acid; sulfuric acid / 1 h / 0 - 20 °C 3.1: palladium 10 on activated carbon; hydrogen / ethanol; methanol; acetic acid / 36 h / 20 °C 4.1: sodium nitrite; sulfuric acid / water / 0.5 h / 0 °C 4.2: 2 h / 100 °C 5.1: 4-(N,N-dimethlyamino)pyridine; triethylamine / N,N-dimethyl-formamide / 50 °C 6.1: hydrazine hydrate / tert-butyl alcohol / 110 °C / |Inert atmosphere 7.1: trifluoroacetic acid / dichloromethane / 20 °C View Scheme