1.1: triethylamine / N,N-dimethyl-formamide / 60 °C 2.1: trifluoroacetic anhydride; dimethyl sulfoxide / dichloromethane / 1 h / -78 °C 2.2: 0.5 h 3.1: trifluoroacetic acid; pyridine / toluene / 0.5 h / 0 °C 3.2: 20 h / 15 °C 4.1: ammonia / isopropyl alcohol; water / 20 h / 100 °C / 31029.7 Torr 5.1: hydrogenchloride / methanol / 2 h / 65 °C View Scheme

Multi-step reaction with 3 steps 1.1: triethylamine / N,N-dimethyl-formamide / 60 °C2.1: trifluoroacetic anhydride; dimethyl sulfoxide / dichloromethane / 1 h / -78 °C2.2: 0.5 h3.1: trifluoroacetic acid; pyridine / toluene / 0.5 h / 0 °C3.2: 20 h / 15 °C  

Multi-step reaction with 4 steps 1.1: triethylamine / N,N-dimethyl-formamide / 60 °C2.1: trifluoroacetic anhydride; dimethyl sulfoxide / dichloromethane / 1 h / -78 °C2.2: 0.5 h3.1: trifluoroacetic acid; pyridine / toluene / 0.5 h / 0 °C3.2: 20 h / 15 °C4.1: ammonia / isopropyl alcohol; water / 20 h / 100 °C / 31029.7 Torr