1: 91 percent / pyridine, 4-(dimethylamino)pyridine / 1.5 h / Ambient temperature 2: 67 percent / triethylamine / CH2Cl2 / 24 h / Heating 3: 99 percent / NH3 (g), CH3OH / 16 h / Ambient temperature 4: 60 percent / 1 M NBu4F / tetrahydrofuran / 18 h / Heating 5: 45 percent / SnCl4 / CH2Cl2 / 2 h View Scheme

1: 45 percent / 1,5-diazabicyclo<4.3.0>non-5-ene (DBN) / dimethylformamide / 30 h / Heating 2: 74 percent / aq. M NaOH / dioxane / 6 h / Ambient temperature View Scheme

With  hydrogenchloride 15 h;  Heating;   

With  DBN in  N,N-dimethyl-formamide 30 h;  Heating;   

Multi-step reaction with 2 steps 1: 91 percent / pyridine, 4-(dimethylamino)pyridine / 1.5 h / Ambient temperature2: 67 percent / triethylamine / CH2Cl2 / 24 h / Heating  

Multi-step reaction with 3 steps 1: 91 percent / pyridine, 4-(dimethylamino)pyridine / 1.5 h / Ambient temperature2: 67 percent / triethylamine / CH2Cl2 / 24 h / Heating3: 99 percent / NH3 (g), CH3OH / 16 h / Ambient temperature  

Multi-step reaction with 4 steps 1: 91 percent / pyridine, 4-(dimethylamino)pyridine / 1.5 h / Ambient temperature2: 67 percent / triethylamine / CH2Cl2 / 24 h / Heating3: 99 percent / NH3 (g), CH3OH / 16 h / Ambient temperature4: 60 percent / 1 M NBu4F / tetrahydrofuran / 18 h / Heating