formic acid; potassium iodide T=105°C;

boron trifluoride diethyl etherate; benzene

1: 79 percent / AlCl3 / nitrobenzene / 3.5 h / 5 - 29 °C 2: 61 percent / H2NNH2*H2O; NaOH / triethylene glycol; H2O / Heating 3: 89 percent / polyphosphoric acid / 0.5 h / 80 °C 4: 76 percent / BBr3 / CH2Cl2 / -78 - 20 °C View Scheme

1: 61 percent / H2NNH2*H2O; NaOH / triethylene glycol; H2O / Heating 2: 89 percent / polyphosphoric acid / 0.5 h / 80 °C 3: 76 percent / BBr3 / CH2Cl2 / -78 - 20 °C View Scheme

sodium hydroxide

1: concd. HCl / ethanol / 1 h / Heating 2: 92 percent / (i-Pr)2NH, TMEDA, MeLi / diethyl ether / Ambient temperature 3: 86 percent / 50percent NaH/oil / dimethylformamide / Ambient temperature 4: 98 percent / tert-BuLi / pentane; diethyl ether / 2 h / Ambient temperature 5: 10percent HCl / methanol / 0.17 h / Heating 6: K2CO3 / acetone / 0.75 h / Heating View Scheme

1: concd. HCl / ethanol / 1 h / Heating 2: 92 percent / (i-Pr)2NH, TMEDA, MeLi / diethyl ether / Ambient temperature 3: 86 percent / 50percent NaH/oil / dimethylformamide / Ambient temperature View Scheme

1: concd. HCl / ethanol / 1 h / Heating 2: 92 percent / (i-Pr)2NH, TMEDA, MeLi / diethyl ether / Ambient temperature 3: 86 percent / 50percent NaH/oil / dimethylformamide / Ambient temperature 4: 98 percent / tert-BuLi / pentane; diethyl ether / 2 h / Ambient temperature 5: 10percent HCl / methanol / 0.17 h / Heating View Scheme