1: hydrogenchloride / water; acetic acid / 72 h / |Reflux 2: tetrafluoroboric acid / water / 48 h / 60 °C / |Sealed tube 3: N-ethyl-N,N-diisopropylamine; bromo-tris(1-pyrrolidinyl)phosphonium hexafluorophosphate / dichloromethane; N,N-dimethyl-formamide / 20 °C 4: trifluoroacetic acid / dichloromethane / 3.5 h / 35 °C View Scheme

Multi-step reaction with 2 steps 1: 86 percent / potassium carbonate / H2O; tetrahydrofuran / 1 h2: 93 percent / cc. HCl / tetrahydrofuran; H2O / Ambient temperature  

Multi-step reaction with 2 steps 1: 86 percent / potassium carbonate / H2O; tetrahydrofuran / 1 h2: 93 percent / cc. HCl / tetrahydrofuran; H2O / Ambient temperature