1: 41.1 percent / H2O/KOH / bis-(2-hydroxy-ethyl) ether / 24 h / Heating 2: 64.1 percent / polyphosphoric acid / 1 h / 100 °C View Scheme

1: 41.1 percent / H2O/KOH / bis-(2-hydroxy-ethyl) ether / 24 h / Heating 2: 64.1 percent / polyphosphoric acid / 1 h / 100 °C 3: 67 percent / Ag2O / methanol; CHCl3 / 6 h / 60 °C View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: 54.2 percent / POCl₃ / toluene / 2.5 h / 120 &deg;C<br />2: 70.9 percent / dimethylformamide / 5 h / 180 &deg;C<br /> <br /> &nbsp;