1: 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride / dichloromethane / 24 h / 20 °C 2: 4-pyrrolidin-1-ylpyridine / dichloromethane / 10 h / 0 - 5 °C 3: hydrogenchloride / water; tetrahydrofuran; methanol / 0 - 5 °C View Scheme