1: triethylamine; 4-(N,N-dimethlyamino)pyridine / dichloromethane / 16 h / 20 °C / |Cooling with ice 2: tetrahydrofuran; diethyl ether / 2 h / -78 - 20 °C / |Inert atmosphere 3: trifluoroacetic acid / dichloromethane / 3 h / 20 °C 4: palladium 10 on activated carbon; hydrogen / methanol / 16 h / 20 °C / 760.05 Torr 5: sodium hydroxide / acetonitrile; water / 1 h / 20 °C View Scheme

1.1: 73 percent / DMAP / acetonitrile 2.1: H2 / Pd/C / ethyl acetate 2.2: 83 percent / DMAP; TEA / acetonitrile View Scheme

1: 9.0 g / Et3N; 4-(dimethylamino)pyridine / CH2Cl2 / 384 h / 20 °C 2: 93 percent / H2 / Pd-C / methanol / 6 h View Scheme

1: 37.5 g / 4-dimethylaminopyridine / acetonitrile / 3 h / 25 °C 2: 88 percent / LiEt3BH / tetrahydrofuran / 2 h / -78 °C 3: 98 percent / p-toluenesulfonic acid / 5 h / 25 °C View Scheme

4-(N,N-dimethlyamino)pyridine in dichloromethane T=0 - 20°C;

4-(N,N-dimethlyamino)pyridine in dichloromethane T=20°C; 4 h;

1: 37.5 g / 4-dimethylaminopyridine / acetonitrile / 3 h / 25 °C 2: 88 percent / LiEt3BH / tetrahydrofuran / 2 h / -78 °C 3: 98 percent / p-toluenesulfonic acid / 5 h / 25 °C 4: 93 percent / BF3*Et2O / diethyl ether / -78 - 25 °C View Scheme