potassium dihydrogenphosphate; Fremy’s salt in methanol; water 1 h;

1: 81 percent / H2SO4, dilute HNO3 / CH2Cl2 / 0.5 h / -5 - 0 °C 2: 65 percent / hydrazine hydrate / Pd/C / ethanol / 0.25 h / Heating 3: 1.) H2O/H2SO4; 2.) 5percent H2SO4 / 1.) 0 deg C; 2.) r. t. 4: 56 percent / potassium dihydrogen phosphate/potassium nitrosodisulphonate / methanol; H2O / 1 h View Scheme

1: 65 percent / hydrazine hydrate / Pd/C / ethanol / 0.25 h / Heating 2: 1.) H2O/H2SO4; 2.) 5percent H2SO4 / 1.) 0 deg C; 2.) r. t. 3: 56 percent / potassium dihydrogen phosphate/potassium nitrosodisulphonate / methanol; H2O / 1 h View Scheme

in acetic acid Diels-Alder reaction; Heating;