1: N,N-Diethyl-2-chlorobenzamide With N,N,N',N,-tetramethylethylenediamine; sec.-butyllithium in tetrahydrofuran; cyclohexane T=-78°C; 0.5 h; 2: dimethyl-disulfide in tetrahydrofuran; cyclohexane T=-78 - 20°C;