1: 42 percent / various solvent(s) / 20 h / 250 - 255 °C 2: 65 percent / POCl3 / bis-(2-methoxy-ethyl) ether / 0.75 h / 100 - 102 °C View Scheme

1.1: acetic acid / 20 °C 1.2: 1.5 h 2.1: sodium hydride / dimethyl sulfoxide; mineral oil / 2 h / 20 °C / Cooling with ice 2.2: pH 3 - 4 3.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: nitric acid / dichloromethane / 2 h / 25 °C 1.2: Raney-Ni / 20 °C / 760.05 Torr 2.1: acetic acid / 20 °C 2.2: 1.5 h 3.1: sodium hydride / dimethyl sulfoxide; mineral oil / 2 h / 20 °C / Cooling with ice 3.2: pH 3 - 4 4.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: ammonium chloride; iron / ethanol / 1 h / 75 °C 2.1: trifluoroacetic acid / ethyl acetate 3.1: ethanol; sodium / 1 h / 70 °C 3.2: pH 3 4.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: trifluoroacetic acid / ethyl acetate 2.1: ethanol; sodium / 1 h / 70 °C 2.2: pH 3 3.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: ethanol; sodium / 1.5 h / 75 °C 1.2: 50 °C / pH 6 - 7 2.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: sodium ethanolate / ethanol / 10 h / 20 - 60 °C / Inert atmosphere 1.2: 40 - 50 °C / pH 3 2.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: sodium hydride / dimethyl sulfoxide; mineral oil / 2 h / 20 °C / Cooling with ice 1.2: pH 3 - 4 2.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: ethanol; sodium / 1 h / 70 °C 1.2: pH 3 2.1: trichlorophosphate / diethylene glycol dimethyl ether / 4 - 4.5 h / 85 °C View Scheme

1.1: potassium carbonate / N,N-dimethyl-formamide / 7 h / 60 °C / |Large scale 2.1: nitric acid / nitromethane / 8 h / 20 - 35 °C / |Large scale 3.1: hydrogen / methanol / 12 h / 20 °C / 760.05 Torr / |Large scale 4.1: acetic acid / 5 h / 20 °C / |Large scale 5.1: sodium t-butanolate / tert-butyl alcohol / 3 h / |Reflux; |Large scale 5.2: 1 h / 40 - 50 °C / pH Ca. 4 / |Large scale 6.1: trichlorophosphate; 4-(N,N-dimethlyamino)pyridine / ethyl acetate / 3 h / |Reflux; |Large scale View Scheme