N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium in tetrahydrofuran; cyclohexane T=20°C; cyclocondensation; 1 h;

1: 30 g / HCl / ethyl acetate 2: 45 percent / sec-BuLi; tetramethylenediamine / cyclohexane; tetrahydrofuran / 1 h / 20 °C View Scheme

1: thionyl chloride / 1 h / Heating 2: 30 g / HCl / ethyl acetate 3: 45 percent / sec-BuLi; tetramethylenediamine / cyclohexane; tetrahydrofuran / 1 h / 20 °C View Scheme

Yield given. Multistep reaction;