4-(N,N-dimethlyamino)pyridine; dicyclohexyl-carbodiimide in tetrahydrofuran T=4 - 20°C; 24 h;

1: sodium hydroxide / 1 h / 0 °C 2: thionyl chloride; N,N-dimethyl-formamide / 4 h / |Reflux 3: organic base / dichloromethane / 12 h / 20 °C 4: 1-methylguanidine hydrochloride; triethylamine / dichloromethane; methanol / 20 °C / |Inert atmosphere View Scheme

1: thionyl chloride; N,N-dimethyl-formamide / 4 h / |Reflux 2: organic base / dichloromethane / 12 h / 20 °C 3: 1-methylguanidine hydrochloride; triethylamine / dichloromethane; methanol / 20 °C / |Inert atmosphere View Scheme

1: organic base / dichloromethane / 12 h / 20 °C 2: 1-methylguanidine hydrochloride; triethylamine / dichloromethane; methanol / 20 °C / |Inert atmosphere View Scheme