in ethyl acetate T=0 - 20°C; 18 h;

1: 4-methylmorpholine / CH2Cl2 / Ambient temperature 2: DMAP, Et3N / tetrahydrofuran / 2 h / Heating 3: 0.50 M aq. LiOH / dioxane / 0.5 h / Ambient temperature 4: 1-hydroxybenzotriazole hydrate, N-ethyl-N'-<(dimethylamino)propyl>carbodiimide / tetrahydrofuran / 16 h / Ambient temperature View Scheme

1: 16 percent / tetrahydrofuran / 4 h / Ambient temperature 2: 1-hydroxybenzotriazole hydrate, N-ethyl-N'-<(dimethylamino)propyl>carbodiimide / tetrahydrofuran / 16 h / Ambient temperature View Scheme

1: DMAP, Et3N / tetrahydrofuran / 2 h / Heating 2: 0.50 M aq. LiOH / dioxane / 0.5 h / Ambient temperature 3: 1-hydroxybenzotriazole hydrate, N-ethyl-N'-<(dimethylamino)propyl>carbodiimide / tetrahydrofuran / 16 h / Ambient temperature View Scheme

1: DMAP, Et3N / tetrahydrofuran / 2 h / Heating 2: 0.50 M aq. LiOH / dioxane / 0.5 h / Ambient temperature 3: 1-hydroxybenzotriazole hydrate, N-ethyl-N'-<(dimethylamino)propyl>carbodiimide / tetrahydrofuran / 16 h / Ambient temperature View Scheme

1: 0.50 M aq. LiOH / dioxane / 0.5 h / Ambient temperature 2: 1-hydroxybenzotriazole hydrate, N-ethyl-N'-<(dimethylamino)propyl>carbodiimide / tetrahydrofuran / 16 h / Ambient temperature View Scheme

N-ethyl-N'-(3-diethylaminopropyl)-carbodiimide; 1-hydroxybenzotriazol-hydrate in tetrahydrofuran 16 h; Ambient temperature; Yield given;