1: 42 percent / N-bromosuccinimide, H2SO4 / tetrahydrofuran / 10 h / -78 °C 2: 85 percent / dioxane / 10 h / 105 °C View Scheme

N-bromosuccinmide; sulfuric acid in tetrahydrofuran T=-78°C; 1 h;

N-bromosuccinmide; sulfuric acid in tetrahydrofuran T=-78°C; 10 h;

1: 42 percent / N-bromosuccinimide, H2SO4 / tetrahydrofuran / 10 h / -78 °C 2: 85 percent / dioxane / 10 h / 105 °C 3: 68 percent / NaH / tetrahydrofuran; dimethylformamide / 3 h / 25 °C 4: 91 percent / Bu3SnH, AIBN / benzene / 3 h / 80 °C 5: 1.) ozone, 2.) NaBH4 / 1.) EtOH, -78 deg C, 3 min, 2.) EtOH, H2O, -78 to 24 deg C, 4 h 6: 89 percent / Et3N / CH2Cl2 / 0.42 h / 0 °C 7: 75 percent / H2 / 10percent Pd/C / tetrahydrofuran / 7 h / 24 °C / 760 Torr 8: 100 percent / HCl / ethyl acetate / 0.17 h / 24 °C 9: 71 percent / 1-<3-(dimethylamino)propyl>-3-ethylcarbodiimide, K2CO3 / dimethylformamide / 20 h / 24 °C View Scheme

1: 96 percent / EDC; DMAP / CH2Cl2 / 0.5 h / 20 °C 2: 74 percent / KOH; tetrabutylammonium bromide / CH2Cl2 / 3 h / 20 °C View Scheme

1: conc. hydrochloric acid / ethanol / 48 h / Heating 2: 40 percent / ethylmagnesium bromide / tetrahydrofuran / 14 h 3: hydrogen / 10percent palladiun on charcoal 4: 73 percent / trifluoroacetic acid / Heating View Scheme

in methanol T=0 - 20°C; 3 h;

1: 40 percent / N,N-dimethylaniline, N,N-diisopropylethylamine / 72 h / Heating 2: 32 percent / N,N-dimethylaniline, POCl3 / 1,2-dichloro-ethane / 0.5 h / Heating 3: 98 percent / BBr3 / CH2Cl2; 1,2-dichloro-ethane / 2 h / Heating 4: 72 percent / tetrahydrofuran; methanol / 88 h / 60 °C 5: 70 percent / N,N-diisopropylethylamine / 1,2-dichloro-ethane / 1.5 h / 60 °C View Scheme

4-(N,N-dimethlyamino)pyridine; N'-(3-dimethylaminopropyl)-N-ethylcarbodiimide in dichloromethane T=20°C; 0.5 h;