1.1: potassium carbonate / tetrahydrofuran; methanol / 1 h / Inert atmosphere 2.1: potassium carbonate / N,N-dimethyl-formamide / 1 h / 40 °C / Inert atmosphere 2.2: 40 °C / Inert atmosphere 3.1: sodium hydride / tetrahydrofuran / 2 h / 60 °C / Inert atmosphere 3.2: 30 °C / Inert atmosphere 4.1: sodium methylate / tetrahydrofuran; methanol / 0.5 h / -45 °C / Inert atmosphere View Scheme

4-(N,N-dimethlyamino)pyridine; triethylamine in dichloromethane T=25°C; 12 h;

4-(N,N-dimethlyamino)pyridine; triethylamine in dichloromethane T=20°C; 5 h; Inert atmosphere;