1: POCl3 / 0.5 h / 100 - 110 °C 2: 99.4 percent / 2N NaOH / ethanol / 0.25 h / 90 deg C bath 3: SOCl2 / 1 h / Heating 4: NaBH4, 2N HCl / 1,2-dimethoxy-ethane / ice cooling 30 min, reflux 30 min View Scheme