1: 54 percent / NaH / tetrahydrofuran 2: 54 percent / K2CO3 / aq. ethanol / 3 h / 25 °C 3: AcOH / tetrahydrofuran; H2O 4: 95 percent / conc. NH4OH / 0.5 h / 25 °C View Scheme

1: POCl3 / acetonitrile / 0.25 h / 0 °C 2: acetonitrile / 3 h / 0 °C 3: 1.62 g / acetic acid; methanol / 5 h / Ambient temperature 4: 97 percent / ethanol / 1.5 h / Ambient temperature View Scheme