1: 96 percent / K2CO3 / acetone / 1 h / Heating 2: 96 percent / HF, pyridine / tetrahydrofuran / 0.5 h / 0 °C 3: 95 percent / 1,3-dicyclohexylcarbodiimide (DCC), 4-(dimethylamino)pyridine (DMAP), camphorsulfonic acid (CSA) / CH2Cl2 / 4 h / 25 °C 4: 89 percent / HF, pyridine / tetrahydrofuran / 0 °C 5: 93 percent / H2 / 10percent Pd(OH)2/C / ethyl acetate / 2 h / Ambient temperature 6: 45 percent / triphenylphosphine, 2,2'-dipyridyl disulfide / toluene / 1.) 25 deg C, 3 h, 2.) reflux, 12 h View Scheme

hydrogen; palladium on activated charcoal Hydrogenolysis;

1H-imidazole in N,N-dimethyl-formamide T=25°C; 0.25 h;

1: With water; sodium hydroxide in ethanol 3 h; Reflux; 2: With hydrogenchloride in ethanol; water T=20°C; pH=2;

sodium hydroxide in tetrahydrofuran; methanol; water

sodium hydroxide; potassium carbonate in N-methyl-acetamide; water

1.1: 20 percent; aq. nBu4NOH / 2 h / 65 °C 1.2: 89 percent / dimethylformamide / 24 h 2.1: 92 percent / imidazole / dimethylformamide 3.1: 95 percent / H2 / 5 percent Pd/C View Scheme

sodium hydroxide in methanol; water; N,N-dimethyl-formamide 13 h; Yield given;

1: 92 percent / imidazole / dimethylformamide 2: 95 percent / H2 / 5 percent Pd/C View Scheme

1: 89 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene 2: 100 percent / NaOH / tetrahydrofuran; methanol; H2O View Scheme