1: 80 percent / K, 18-crown-6, t-BuNH2 / tetrahydrofuran / Ambient temperature 2: 70 percent / sodium hydride, iodomethane / tetrahydrofuran / 16 h / 23 °C 3: 74 percent / K, 18-crown-6 / tetrahydrofuran; 1,2-dimethoxy-ethane / Ambient temperature View Scheme

18-crown-6 ether; tert-butylamine in tetrahydrofuran Ambient temperature;

18-crown-6 ether; tert-butylamine in tetrahydrofuran Ambient temperature;