2: 73 percent / 5 h / 220 °C 3: 87 percent / hydrazine hydrate / ethanol; bis-(2-hydroxy-ethyl) ether / 72 h / Heating View Scheme

2: 73 percent / 5 h / 220 °C 3: 87 percent / hydrazine hydrate / ethanol; bis-(2-hydroxy-ethyl) ether / 72 h / Heating 4: 69 percent / Et3N, S2Cl2 / petroleum ether / 4 h View Scheme

2: 73 percent / 5 h / 220 °C 3: 87 percent / hydrazine hydrate / ethanol; bis-(2-hydroxy-ethyl) ether / 72 h / Heating 4: 69 percent / Et3N, S2Cl2 / petroleum ether / 4 h 5: 83 percent / petroleum ether / 3 h / 0 °C 6: 79 percent / 0.5 h / 140 °C 7: 1.) (n-Bu)3P 2.) MeI / 1.) 140 deg C 2.) petroleum ether (60-70 deg C) 8: 57 percent / tetracyanoethylene, ozone / ethyl acetate / 0.5 h / -78 °C View Scheme