1: 71 percent / dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt) / dimethylformamide / -10 °C 2: TFA, anisole / 0.75 h / 0 - 20 °C 3: 1.) HCl/dioxane, isoamyl nitrite / 1.) DMF, -10 deg C, 10 min, 2.) DMF, overnight 4: H2, AcOH / Pd / methanol / 12 h View Scheme