1: 1,4-dihydro-4-oxo-quinoline-3-carboxylic acid ester With O-(1H-benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate; triethylamine in N,N-dimethyl-formamide T=20°C; 0.166667 h; 2: 5-amino-2,4-di-tert-butyl-phenol in N,N-dimethyl-formamide T=20°C;

1: With pyridine; 1-propanephosphonic acid cyclic anhydride in 2-methyl tetrahydrofuran T=47.5°C; 8 h; 2: With methanol; sodium methylate in 2-methyl tetrahydrofuran Temperature;

1: With methanol; sodium methylate in 2-methyl tetrahydrofuran 2: With hydrogenchloride in 2-methyl tetrahydrofuran; water Product distribution / selectivity;

pyridine; hydrogenchloride; sodium methylate in methanol; water; acetonitrile

1.1: triethylamine / diethyl ether / 0 - 20 °C 2.1: nitric acid; sulfuric acid / 1 h / 0 - 20 °C 3.1: hydrogen / 5 palladium on charcoal / methanol / 20 - 30 °C / 1500.15 Torr / Inert atmosphere 4.1: pyridine; 1-propanephosphonic acid cyclic anhydride / 2-methyl tetrahydrofuran / 8 h / 47.5 °C 5.1: sodium methylate / 2-methyl tetrahydrofuran; methanol / 1 h / 25 °C 5.3: 78 °C View Scheme

1.1: nitric acid; sulfuric acid / 1 h / 0 - 20 °C 2.1: hydrogen / 5 palladium on charcoal / methanol / 20 - 30 °C / 1500.15 Torr / Inert atmosphere 3.1: pyridine; 1-propanephosphonic acid cyclic anhydride / 2-methyl tetrahydrofuran / 8 h / 47.5 °C 4.1: sodium methylate / 2-methyl tetrahydrofuran; methanol / 1 h / 25 °C 4.3: 78 °C View Scheme

1.1: hydrogen / 5 palladium on charcoal / methanol / 20 - 30 °C / 1500.15 Torr / Inert atmosphere 2.1: pyridine; 1-propanephosphonic acid cyclic anhydride / 2-methyl tetrahydrofuran / 8 h / 47.5 °C 3.1: sodium methylate / 2-methyl tetrahydrofuran; methanol / 1 h / 25 °C 3.3: 78 °C View Scheme

1.1: ethanol / 3 h / 30 - 110 °C / Inert atmosphere 2.1: diphenylether; ethanol / 3.5 h / 228 - 232 °C / Inert atmosphere 3.1: sodium hydroxide; water / ethanol / 16 h / Reflux 3.2: 20 - 25 °C / pH 2 - 3 4.1: pyridine; 1-propanephosphonic acid cyclic anhydride / 2-methyl tetrahydrofuran / 8 h / 47.5 °C 5.1: sodium methylate / 2-methyl tetrahydrofuran; methanol / 1 h / 25 °C 5.3: 78 °C View Scheme

1.1: sodium hydroxide; water / ethanol / 16 h / Reflux 1.2: 20 - 25 °C / pH 2 - 3 2.1: pyridine; 1-propanephosphonic acid cyclic anhydride / 2-methyl tetrahydrofuran / 8 h / 47.5 °C 3.1: sodium methylate / 2-methyl tetrahydrofuran; methanol / 1 h / 25 °C 3.3: 78 °C View Scheme

1.1: diphenylether; ethanol / 3.5 h / 228 - 232 °C / Inert atmosphere 2.1: sodium hydroxide; water / ethanol / 16 h / Reflux 2.2: 20 - 25 °C / pH 2 - 3 3.1: pyridine; 1-propanephosphonic acid cyclic anhydride / 2-methyl tetrahydrofuran / 8 h / 47.5 °C 4.1: sodium methylate / 2-methyl tetrahydrofuran; methanol / 1 h / 25 °C 4.3: 78 °C View Scheme