1: dichloromethane; acetonitrile / 72 h / 40 °C / Inert atmosphere 2: hydrogenchloride; water / ethanol / 24 h / Inert atmosphere; Reflux 3: caesium carbonate / N,N-dimethyl-formamide / 30 h / 30 °C / Inert atmosphere 4: lithium aluminium tetrahydride / tetrahydrofuran / 72 h / Inert atmosphere; Reflux View Scheme