1: N,N-di-iso-propylbenzamide With sec.-butyllithium in tetrahydrofuran; cyclohexane T=-78°C; Metallation; 1 h; 2: ethyl iodide in tetrahydrofuran; cyclohexane T=-78 - 20°C; Alkylation; Further stages.;

1.1: 100 percent / diethyl ether / 0 - 20 °C 2.1: sec-butyllithium / tetrahydrofuran; cyclohexane / 1 h / -78 °C 2.2: tetrahydrofuran; cyclohexane / 0.5 h / -78 °C View Scheme

1.1: 100 percent / diethyl ether / 0 - 20 °C 2.1: sec-butyllithium / tetrahydrofuran; cyclohexane / 1 h / -78 °C 2.2: tetrahydrofuran; cyclohexane / 0.5 h / -78 °C View Scheme