1.1: imidazole; I2; triphenylphosphane / diethyl ether; acetonitrile / 3 h / 20 °C 2.1: 2.9 g / acetonitrile / 4 h / Heating 3.1: KN(SiMe3)2 / tetrahydrofuran / -78 - 20 °C 4.1: tetrahydrofuran / 0.5 h / -78 - 0 °C 4.2: 32 percent / tetrahydrofuran / 0.5 h / -78 - 20 °C View Scheme