1: dimethylformamide / 40 °C 2: TFA / CH2Cl2 / 1 h / Ambient temperature; stoppered flask 3: 1-ethyl-3-<3-(dimethylamino)propyl>carbodiimide hydrochloride / dimethylformamide / 40 °C 4: TFA / CH2Cl2 5: EDC / dimethylformamide / 40 °C 6: H2 / 5percent Pd/C / dimethylformamide / 2 h / 3102.9 Torr / Ambient temperature 7: 88 percent / DCC / dimethylformamide / 1.) 70 min, 0 deg C, 2.) 40 deg C, overnight 8: 1.) NaHCO3, 2.) HCl / H2O; dioxane / 1.) 15 min, ice-cooled, 2.) room temperature, overnight View Scheme

1: dimethylformamide / 40 °C 2: TFA / CH2Cl2 / 1 h / Ambient temperature; stoppered flask 3: 1-ethyl-3-<3-(dimethylamino)propyl>carbodiimide hydrochloride / dimethylformamide / 40 °C 4: TFA / CH2Cl2 5: EDC / dimethylformamide / 40 °C 6: H2 / 5percent Pd/C / dimethylformamide / 2 h / 3102.9 Torr / Ambient temperature View Scheme