N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium in tetrahydrofuran T=-65°C;

N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium 1.) THF, -100 deg C, 2.) THF, from -70 deg C to -60 deg C, 1 h; Yield given. Multistep reaction. Yields of byproduct given;