in diethylene glycol dimethyl ether T=130 - 140°C; 3 h;

in N,N-dimethyl acetamide T=140 - 142°C; 24 h;

1: 81 percent / triethylamine / dimethylformamide / 0 °C 2: tin(II) chloride hydrate, concentrated hydrochloric acid / bis-(2-methoxy-ethyl) ether / 1.5 h / Ambient temperature 3: 38 percent / bis-(2-methoxy-ethyl) ether / 3 h / 130 - 140 °C View Scheme

1: tin(II) chloride hydrate, concentrated hydrochloric acid / bis-(2-methoxy-ethyl) ether / 1.5 h / Ambient temperature 2: 38 percent / bis-(2-methoxy-ethyl) ether / 3 h / 130 - 140 °C View Scheme

1: 82 percent / dimethylformamide / 2 h / 140 - 150 °C 2: 81 percent / triethylamine / dimethylformamide / 0 °C 3: tin(II) chloride hydrate, concentrated hydrochloric acid / bis-(2-methoxy-ethyl) ether / 1.5 h / Ambient temperature 4: 38 percent / bis-(2-methoxy-ethyl) ether / 3 h / 130 - 140 °C View Scheme

1: 72 percent / KHCO3 / N,N-dimethyl-acetamide / 0 °C 2: 67 percent / N,N-dimethyl-acetamide / 24 h / 140 - 142 °C View Scheme