1: 68 percent / Li, EtNH2 / Ambient temperature; further reagent 2: 53 percent / n-butyl-lithium / tetrahydrofuran; hexane / 1 h / -20 °C 3: 38 percent / K, 18-crown-6, t-BuNH2 / tetrahydrofuran / Ambient temperature View Scheme

1: 68 percent / Li, EtNH2 / Ambient temperature; further reagent 2: 53 percent / n-butyl-lithium / tetrahydrofuran; hexane / 1 h / -20 °C 3: 19 percent / K, 18-crown-6, t-BuNH2 / tetrahydrofuran / Ambient temperature View Scheme