1: 99.5 percent / NaOH, tetrabutylammonium hydrogen sulfate / CH2Cl2 / 2 h / 0 °C 2: 31.2 percent / triethylamine, palladium(II) acetate / acetonitrile / 0.67 h / 99 - 100 °C 3: 91.5 percent / NaOH, tetrabutylammonium hydrogen sulfate / CH2Cl2 / 2 h / 0 °C 4: hydrogen / PtO2 / 6 h / Ambient temperature 5: potassium hydroxide / aq. acetic acid / 4 h / 0 °C View Scheme