1: With hydrogenchloride; sodium nitrite in water T=0°C; 1 h; 2: With hydrogenchloride; tin(ll) chloride in water T=-10°C; 1.5 h;

1: With potassium phosphate; N,N'-bis(2,5-dimethylpyrrol-1-yl)oxalamide; N-hexadecyl-N,N,N-trimethylammonium bromide; copper(I) bromide in water T=80°C; 0.166667 h; Sealed tubeInert atmosphere; 2: With hydrazine hydrate in water T=80°C; 2 h; Sealed tubeInert atmosphere; 3: With hydrogenchloride in dichloromethane; water

1: 1.) H2O, 2.) conc. aq. HCl / 1.) EtOH, 60 deg C, 1 h, 2.) EtOH, reflux, 14 h 2: 94 percent / hydrazine hydrate, water / ethanol / 15 h / Ambient temperature View Scheme