1: dipyridinium dichromate / N,N-dimethyl-formamide / 12 h / 20 °C 2: AlCl3, aluminium chloride / dichloromethane / 12 h / 20 °C View Scheme

dipyridinium dichromate in N,N-dimethyl-formamide T=20°C; 12 h;

1: dipyridinium dichromate / N,N-dimethyl-formamide / 12 h / 20 °C 2: AlCl3, aluminium chloride / dichloromethane / 12 h / 20 °C 3: pyridine / dichloromethane / 3 h / 45 °C / Cooling with ice 4: sodium hydride / dimethyl sulfoxide / 12 h / 100 °C 5: potassium carbonate / N,N-dimethyl-formamide / 12 h / 50 - 60 °C View Scheme