DOWEX 50W x 4-100 resin in methanol T=20°C; 2 h; Inert atmosphere;

1.1: sodium hydride; sodium iodide / tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide / 0.08 h / |Inert atmosphere 1.2: 48 h / 20 °C / |Inert atmosphere 2.1: DOWEX 50W x 4-100 resin / methanol / 2 h / 20 °C / |Inert atmosphere View Scheme