manganese(IV) oxide in benzene 24 h; Heating;

1: aq. NaNO2; HCl; CuCl2 / 60 °C 2: MnO2 / CH2Cl2 / 25 °C View Scheme

1: 62 percent / (NH4)2S / methanol / 5 h / Heating 2: 1.) HNO2, 2.) CuCl2, CuCl, 12percent aq. HCl / 1.) 0 deg C, 2.) 60 deg C, 1 h 3: MnO2 / benzene / 24 h / Heating View Scheme

(i) CrO3, Ac2O, AcOH, H2SO4, (ii) aq. HCl; Multistep reaction;