1: With hydrogenchloride; trifluoroacetic acid; sodium nitrite in water T=0°C; 0.5 h; 2: With sulfuric acid; acetic acid; copper(l) chloride; copper dichloride in water T=0 - 20°C; 15 h;
1.1: hydrogenchloride; hydroxylamine hydrochloride; sodium sulfate / water / 0.67 h / |Reflux 2.1: sulfuric acid / water / 1 h / 80 °C 2.2: 70 °C / pH Ca. 4 View Scheme