O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; N-ethyl-N,N-diisopropylamine in dichloromethane T=0 - 20°C;

O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate; N-ethyl-N,N-diisopropylamine in dichloromethane T=20°C;

N-ethyl-N,N-diisopropylamine; HATU in dichloromethane T=0 - 20°C; 16 h;

N-ethyl-N,N-diisopropylamine; HATU in dichloromethane T=0.2 - 23°C; 17.5 h; Inert atmosphere;

N-ethyl-N,N-diisopropylamine; N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate in dichloromethane T=20°C; 16 h; Inert atmosphere;

1.1: n-butyllithium; tri-isopropoxy-borane / hexane; tetrahydrofuran / 0.75 h / -78 - -65 °C 1.2: 1.17 h / -60 - 20 °C 1.3: 0 °C / pH 6 2.1: diazomethyl-trimethyl-silane / hexane; acetonitrile / 14 h / 0 - 20 °C 3.1: potassium tert-butylate / dimethyl sulfoxide / 10 - 20 °C 4.1: N-ethyl-N,N-diisopropylamine; HATU / 16 h 5.1: hydrogenchloride / water; methanol / 2 h / Reflux 6.1: N-ethyl-N,N-diisopropylamine; HATU / dichloromethane / 16 h / 0 - 20 °C View Scheme

1: diazomethyl-trimethyl-silane / hexane; acetonitrile / 14 h / 0 - 20 °C 2: potassium tert-butylate / dimethyl sulfoxide / 10 - 20 °C 3: N-ethyl-N,N-diisopropylamine; HATU / 16 h 4: hydrogenchloride / water; methanol / 2 h / Reflux 5: N-ethyl-N,N-diisopropylamine; HATU / dichloromethane / 16 h / 0 - 20 °C View Scheme

1: potassium tert-butylate / dimethyl sulfoxide / 10 - 20 °C 2: N-ethyl-N,N-diisopropylamine; HATU / 16 h 3: hydrogenchloride / water; methanol / 2 h / Reflux 4: N-ethyl-N,N-diisopropylamine; HATU / dichloromethane / 16 h / 0 - 20 °C View Scheme

1.1: diphenyl phosphoryl azide; triethylamine / benzene / 2 h / |Inert atmosphere 2.1: bis-maleimidodiphenyl-methane acid / 3.5 h / 90 °C / |Inert atmosphere 3.1: N-bromosuccinmide / acetonitrile / 3.5 h / |Reflux; |Inert atmosphere 4.1: trichlorophosphate / 5 h / |Reflux; |Inert atmosphere 5.1: n-butyllithium / hexane; tetrahydrofuran / 0.75 h / 65 °C / |Inert atmosphere 5.2: 0.75 h / 65 °C / |Inert atmosphere 5.3: 0.5 h / -60 - -40 °C 6.1: diazomethyl-trimethyl-silane / hexane; acetonitrile / 14 h / 0 - 20 °C / |Inert atmosphere 7.1: potassium tert-butylate / dimethyl sulfoxide / 3.5 h / 10 - 20 °C / |Sonication; |Inert atmosphere 8.1: N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate; N-ethyl-N,N-diisopropylamine / dichloromethane / 16 h / |Inert atmosphere 9.1: N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate; N-ethyl-N,N-diisopropylamine / dichloromethane / 16 h / 20 °C / |Inert atmosphere View Scheme

1.1: N-bromosuccinmide / acetonitrile / 3.5 h / |Reflux; |Inert atmosphere 2.1: trichlorophosphate / 5 h / |Reflux; |Inert atmosphere 3.1: n-butyllithium / hexane; tetrahydrofuran / 0.75 h / 65 °C / |Inert atmosphere 3.2: 0.75 h / 65 °C / |Inert atmosphere 3.3: 0.5 h / -60 - -40 °C 4.1: diazomethyl-trimethyl-silane / hexane; acetonitrile / 14 h / 0 - 20 °C / |Inert atmosphere 5.1: potassium tert-butylate / dimethyl sulfoxide / 3.5 h / 10 - 20 °C / |Sonication; |Inert atmosphere 6.1: N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate; N-ethyl-N,N-diisopropylamine / dichloromethane / 16 h / |Inert atmosphere 7.1: N-[(dimethylamino)-3-oxo-1H-1,2,3-triazolo[4,5-b]pyridin-1-yl-methylene]-N-methylmethanaminium hexafluorophosphate; N-ethyl-N,N-diisopropylamine / dichloromethane / 16 h / 20 °C / |Inert atmosphere View Scheme