1: With sulfuric acid in water T=90°C; 5 h; Inert atmosphere; 2: With sodium nitrite in water T=0 - 20°C; Inert atmosphere; 3: With sulfuric acid in water T=90°C; 1 h; Inert atmosphere;

1.1: sulfuric acid / water / 5 h / 90 °C / |Inert atmosphere 1.2: 0 - 20 °C / |Inert atmosphere 1.3: 1 h / 90 °C / |Inert atmosphere 2.1: potassium carbonate / N,N-dimethyl-formamide / 0.33 h / 20 °C / |Inert atmosphere 2.2: 2 h / 0 - 20 °C / |Inert atmosphere View Scheme

SnCl2·2H2O in ethyl acetate T=50°C; Inert atmosphere;

ammonium chloride in aqueous 2-propanol

1: thionyl chloride / 6 h / Reflux 2: triethylamine / 1 h 3: SnCl2·2H2O / ethyl acetate / 1 h / Reflux View Scheme

1: pyridine; potassium permanganate / water / 12 h / Reflux 2: thionyl chloride / 6 h / Reflux 3: triethylamine / 1 h 4: SnCl2·2H2O / ethyl acetate / 1 h / Reflux View Scheme

1: triethylamine / 1 h 2: SnCl2·2H2O / ethyl acetate / 1 h / Reflux View Scheme