in ethanol T=15 - 35°C; polarographic reduction at the dropping mercury electrode at the different concentrations and pH; Mechanism;

1: sodium hydroxide / 8 h / Reflux 2: dicyclohexyl-carbodiimide / dichloromethane / 5 h / 0 °C View Scheme

in anhydrous butyl ether 18 h; Heating;

sunlight in pentane 240 h;

1.1: 93 percent / Et2NH / methanol / 16 h / Heating 2.1: KOH / methanol; tetrahydrofuran / 1 h / 20 °C 2.2: H2SO4 / tetrahydrofuran / 1 h / 20 °C 3.1: 0.31 g / AcOH; NH4OAc / 1 h / 100 °C View Scheme