1: With hydrogenchloride; sodium nitrite in water 1.5 h; 2: With tin(ll) chloride in water T=5°C; 3 h;

1: With hydrogenchloride; sodium nitrite in water T=0°C; 1.5 h; 2: With hydrogenchloride; tin(ll) chloride in water T=5°C; 3 h; 3: With sodium hydroxide in water T=0°C; Product distribution / selectivity;

1: With sulfuric acid 24 h; Heating / reflux; 2: With triethylamine in water T=4°C; pH=7 - 8; 18 h; Product distribution / selectivity;