1: triethylamine / ethanol / 36 h / 125 °C / 3677.86 Torr / Autoclave; Inert atmosphere 2: isopentyl nitrite / acetonitrile / 50 - 70 °C 3: N-ethyl-N,N-diisopropylamine / dichloromethane / 25 - 35 °C 4: lithium borohydride / tetrahydrofuran / 0 - 30 °C 5: hydrogenchloride; water / methanol / 25 - 30 °C View Scheme