1: 89 percent / tin tetrachloride / 1,2-dichloro-ethane / 0.08 h / 20 °C 2: 86 percent / triethylamine / dioxane / 1 h / 20 °C 3: 80 percent / sulfuric acid / acetic acid / 18 h / 20 °C 4: 1)1,1,1,3,3,3-hexamethyldisilazane 2)trimethylsilyl trifluormethanesulfonate / 1) pyridine, 2) 1,2-dichloroethane, 1.5 h, reflux 5: 79 percent / 5 M aqueous ammonia / methanol View Scheme

With  triethylamine in  1,4-dioxane  

With  tin(IV) chloride in  1,2-dichloro-ethane T=20°C; 0.0833333 h;   

Multi-step reaction with 4 steps 1: 89 percent / tin tetrachloride / 1,2-dichloro-ethane / 0.08 h / 20 °C2: 78 percent / triphenylphosphine/carbon tetrabromide / dimethylformamide / 16 h / 20 °C3: 100 percent / 4 h / Heating4: sulfuric acid / acetic acid / 18 h / 20 °C  

Multi-step reaction with 5 steps 1: 89 percent / tin tetrachloride / 1,2-dichloro-ethane / 0.08 h / 20 °C2: 78 percent / triphenylphosphine/carbon tetrabromide / dimethylformamide / 16 h / 20 °C3: 100 percent / 4 h / Heating4: sulfuric acid / acetic acid / 18 h / 20 °C5: 30 percent / trimethylsilyl trifluoromethanesulfonate / 1,2-dichloro-ethane / 16 h / 20 °C  

Multi-step reaction with 4 steps 1: 89 percent / tin tetrachloride / 1,2-dichloro-ethane / 0.08 h / 20 °C2: 78 percent / triphenylphosphine/carbon tetrabromide / dimethylformamide / 16 h / 20 °C3: 100 percent / 4 h / Heating4: sulfuric acid / acetic acid / 18 h / 20 °C