1: 81 percent / CCl4; PPh3 / acetonitrile / 4 h / 45 °C 2: 90 percent / methanesulfonic acid / CHCl3 / 1 h / 20 °C View Scheme

4-(N,N-dimethlyamino)pyridine; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride in dichloromethane T=20°C; 16 h;

1: aq. NH4OH; MH4Cl / 56 h / 20 °C 2: 6.08 g / N-(3-dimehylaminopropyl)-N'-ethylcarbodiimide hydrochloride; 4-(N,N-dimethylamino)pyridine / CH2Cl2 / 16 h / 20 °C View Scheme