1: With trichlorophosphate Vilsmeier-Haack formylation; 2 h; Heating; 2: With water T=20°C; 18 h;

1.1: 94 percent / conc. H2SO4 / 18 h / Heating 2.1: 33 percent / zinc amalgam; conc. HCl / methanol / 3 h / Heating 3.1: phosphorus oxychloride / 2 h / Heating 3.2: 35 percent / H2O / 18 h / 20 °C View Scheme

1.1: aluminum chloride / nitrobenzene / 23 h / 0 - 20 °C 2.1: 11.4 g / 3 M NaOH 3.1: 94 percent / conc. H2SO4 / 18 h / Heating 4.1: 33 percent / zinc amalgam; conc. HCl / methanol / 3 h / Heating 5.1: phosphorus oxychloride / 2 h / Heating 5.2: 35 percent / H2O / 18 h / 20 °C View Scheme

1.1: aluminum chloride / nitrobenzene / 23 h / 0 - 20 °C 2.1: 11.4 g / 3 M NaOH 3.1: 94 percent / conc. H2SO4 / 18 h / Heating 4.1: 33 percent / zinc amalgam; conc. HCl / methanol / 3 h / Heating 5.1: phosphorus oxychloride / 2 h / Heating 5.2: 35 percent / H2O / 18 h / 20 °C View Scheme

1.1: 33 percent / zinc amalgam; conc. HCl / methanol / 3 h / Heating 2.1: phosphorus oxychloride / 2 h / Heating 2.2: 35 percent / H2O / 18 h / 20 °C View Scheme