1: 1 N aq. NaOH / tetrahydrofuran / 48 h / 20 °C 2: 72 percent / NaH / toluene; dimethylformamide / 16 h / 110 °C 3: SOCl2 / ethanol / Heating 4: 65 percent / AlMe3 / toluene / 3 h / Heating View Scheme