dimethyl sulfoxide

1: 30 percent / HNO3; AcOH / 16 h / 20 °C 2: 60 percent / aq. CrO3; H2SO4 / acetone / 0.17 h / -10 °C 3: 95 percent / 13 h / 35 - 40 °C 4: 49 percent / 22 h / 20 °C 5: 37 percent / NaH / dimethylsulfoxide / 20 °C View Scheme

1: 1.) oxalyl chloride, Me2SO, 2.) triethylamine / 1.) CH2Cl2, -78 deg C, 5 min, 2.) CH2Cl2, 15 min 2: 77 percent / hydroxylamine hydrochloride, sodium acetate / ethanol; H2O / 24 h / Heating 3: 60 percent / sodium hydride / tetrahydrofuran / 14 h / Heating 4: 98 percent / KH / tetrahydrofuran / 15 h / Ambient temperature View Scheme