potassium tert-butylate T=20°C; 2 h;

1: 53 percent / conc. H2SO4 / methanol / 0.33 h / Irradiation 2: 1.12 g / NaOCH3 / CH2Cl2 / 96 h / Ambient temperature 3: acetonitrile; aq. HCl / 16 h / Ambient temperature 4: 1.) powdered iron, 6 N HCl/MeOH, 2.) sodium nitrite, conc. HCl / 1.) 50 deg C, 16 h, 2.) room temp., 30 min View Scheme