hydrazine hydrate in ethanol 1.) 3 h, reflux; 2.) 12 h, 0 deg C;

1: 1.) bromine; 2.) 25 percent NH4OH / 1.) glacial acetic acid, 2 h, 60-70 deg C 2: 82 percent / POCl3 / 0 °C 3: 85 percent / 98 percent hydrazine hydrate / ethanol / 1.) 3 h, reflux; 2.) 12 h, 0 deg C View Scheme

1: 95 percent / 98 percent hydrazine hydrate / ethanol / 2 h / Heating 2: 1.) bromine; 2.) 25 percent NH4OH / 1.) glacial acetic acid, 2 h, 60-70 deg C 3: 82 percent / POCl3 / 0 °C 4: 85 percent / 98 percent hydrazine hydrate / ethanol / 1.) 3 h, reflux; 2.) 12 h, 0 deg C View Scheme

1: 82 percent / POCl3 / 0 °C 2: 85 percent / 98 percent hydrazine hydrate / ethanol / 1.) 3 h, reflux; 2.) 12 h, 0 deg C View Scheme

1: 71 percent / H2O / Ambient temperature 2: 95 percent / 98 percent hydrazine hydrate / ethanol / 2 h / Heating 3: 1.) bromine; 2.) 25 percent NH4OH / 1.) glacial acetic acid, 2 h, 60-70 deg C 4: 82 percent / POCl3 / 0 °C 5: 85 percent / 98 percent hydrazine hydrate / ethanol / 1.) 3 h, reflux; 2.) 12 h, 0 deg C View Scheme