sulfuryl dichloride; 2,2'-azo-bisisobutyronitrile T=100°C; 9 h;

1: 92 percent / 85percent hydrazine hydrate / Raney-Ni / ethanol / 1 h / 90 °C 2: 1) NaNO2, HCl, NaBF4 / 1) water, 25 deg C, 1h, 2) Δ 3: SO2Cl2 / azobisisobutyronitrile / 9 h / 100 °C View Scheme

1: 1) NaNO2, HCl, NaBF4 / 1) water, 25 deg C, 1h, 2) Δ 2: SO2Cl2 / azobisisobutyronitrile / 9 h / 100 °C View Scheme