n-butyllithium in tetrahydrofuran 1.) - 40 deg C, 30 min; 2.) 15 min;

1: 85.4 percent / 1.) sodium hydride / dioxane / 1.) 90 deg C, 10 min; reflux, 30 min; 2.) 90-95 deg C, 20 min; reflux, 1 h 2: 83.8 percent / hydrazine hydrate / ethanol / 5 h / Heating 3: N-bromosuccinimide / dioxane / 1 h / Ambient temperature 4: sodium hydroxyde / dioxane; H2O / 1.) 50 deg C, 45 min; 2.) 90 deg C, 2 h 5: 74 percent / 1.) butyllithium / tetrahydrofuran / 1.) - 40 deg C, 30 min; 2.) 15 min View Scheme

1: 90 percent / SnCl4 2: 85.4 percent / 1.) sodium hydride / dioxane / 1.) 90 deg C, 10 min; reflux, 30 min; 2.) 90-95 deg C, 20 min; reflux, 1 h 3: 83.8 percent / hydrazine hydrate / ethanol / 5 h / Heating 4: N-bromosuccinimide / dioxane / 1 h / Ambient temperature 5: sodium hydroxyde / dioxane; H2O / 1.) 50 deg C, 45 min; 2.) 90 deg C, 2 h 6: 74 percent / 1.) butyllithium / tetrahydrofuran / 1.) - 40 deg C, 30 min; 2.) 15 min View Scheme

1: SOCl2 / 1 h / 60 °C 2: diethyl ether / Ambient temperature 3: 2 N H2SO4 / dioxane / 2 h / 45 °C View Scheme