1.1: sodium tetrahydroborate; cobalt(II) chloride / methanol / 24 h / 0 - 20 °C / |Inert atmosphere 1.2: 3 h / |Inert atmosphere 2.1: Lawesson's reagent / tetrahydrofuran / 17 h / 20 °C / |Inert atmosphere 3.1: hydrogen / water; tetrahydrofuran / 2 h / 20 °C / |Inert atmosphere 4.1: sodium hydroxide / water / 16 h / 20 °C / pH 8 - 10 5.1: trifluoroacetic acid / dichloromethane / 17 h / 20 °C 6.1: hydrogen; palladium 10 on activated carbon / methanol / 1 h / 20 °C View Scheme

1.1: sodium tetrahydroborate; cobalt(II) chloride / methanol / 24 h / 0 - 20 °C / |Inert atmosphere 1.2: 3 h / |Inert atmosphere 2.1: Lawesson's reagent / tetrahydrofuran / 17 h / 20 °C / |Inert atmosphere 3.1: hydrogen / water; tetrahydrofuran / 2 h / 20 °C / |Inert atmosphere 4.1: sodium hydroxide / water / 16 h / 20 °C / pH 8 - 10 5.1: trifluoroacetic acid / dichloromethane / 17 h / 20 °C View Scheme