1: lithium hydroxide hydrate / tetrahydrofuran; water / 12 h / 60 °C 2: diphenyl phosphoryl azide; triethylamine / benzene / 1.5 h / 50 °C / Inert atmosphere 3: 1,2-dichloro-benzene / 0.25 h / 180 °C / Inert atmosphere View Scheme

1.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.5 h / 20 °C / Inert atmosphere; Cooling with ice 1.2: 12 h / 20 °C / Inert atmosphere; Cooling with ice 2.1: lithium hydroxide hydrate / tetrahydrofuran; water / 12 h / 60 °C 2.2: 20 °C 3.1: diphenyl phosphoryl azide; triethylamine / toluene / 0.17 h / 100 °C / Inert atmosphere; Microwave irradiation 4.1: pyridine / dichloromethane / 0.5 h / 20 °C / Inert atmosphere; Cooling with ice 5.1: triethylsilane; 1,3-bis-(diphenylphosphino)propane; palladium diacetate / N,N-dimethyl-formamide / 1 h / 60 °C / Inert atmosphere 6.1: methanol; trifluorormethanesulfonic acid; trimethyl orthoformate / nitromethane / 1 h / 100 °C / Inert atmosphere; Cooling with ice View Scheme

With  trifluoroacetic acid in  dichloromethane T=20°C; 12 h;  Inert atmosphere;