1.1: thionyl chloride; N,N-dimethyl-formamide / tetrahydrofuran / 6 h / |Reflux 2.1: triethylamine / tetrahydrofuran / 2 h / 0 - 5 °C 2.2: 10 - 20 °C 3.1: sodium tetrahydroborate; boron trifluoride diethyl etherate / tetrahydrofuran / 0 - 20 °C / |Inert atmosphere 3.2: 0 °C / |Reflux 4.1: 5 palladium on charcoal; hydrogen / ethanol / 48 h / 20 °C 5.1: 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; benzotriazol-1-ol / N,N-dimethyl-formamide / 24 h / 20 °C 5.2: 3 h / |Reflux 6.1: 5 palladium on charcoal; hydrogen / ethanol / 48 h / 20 °C View Scheme

1: thionyl chloride / 5 h / 60 °C / |Inert atmosphere 2: AlCl3, aluminium chloride / dichloromethane / 5 h / 60 °C / |Inert atmosphere 3: SnCl2·2H2O; water / ethanol / 12 h / 80 °C / |Inert atmosphere View Scheme

1: PCl5 / 1.) RT, 10 min, 2.) RT to 45 deg C, 45 min 2: AlCl3 / 2 h / 50 °C View Scheme

pyridine in benzene