triethylamine in diethyl ether 1 h; Ambient temperature;

1: 74 percent / SO3-pyridine, triethylamine / dimethylsulfoxide; CH2Cl2 / 1 h / 0 °C 2: dimethylsulfoxide / 1.5 h / Ambient temperature 3: KOH, hydrazine monohydrate / ethane-1,2-diol / 3 h / Heating 4: 72 percent / triethylamine / diethyl ether / 1 h / Ambient temperature View Scheme

1: KOH, hydrazine monohydrate / ethane-1,2-diol / 3 h / Heating 2: 72 percent / triethylamine / diethyl ether / 1 h / Ambient temperature View Scheme

1: dimethylsulfoxide / 1.5 h / Ambient temperature 2: KOH, hydrazine monohydrate / ethane-1,2-diol / 3 h / Heating 3: 72 percent / triethylamine / diethyl ether / 1 h / Ambient temperature View Scheme

1: 91 percent / 4 N aq. NaOH / a) 0 deg C, 30 min, b) RT, 30 min 2: 74 percent / SO3-pyridine, triethylamine / dimethylsulfoxide; CH2Cl2 / 1 h / 0 °C 3: dimethylsulfoxide / 1.5 h / Ambient temperature 4: KOH, hydrazine monohydrate / ethane-1,2-diol / 3 h / Heating 5: 72 percent / triethylamine / diethyl ether / 1 h / Ambient temperature View Scheme