1: 94 percent / NaH, DMPU / dimethylformamide / 2 h / 100 °C 2: 74 percent / aq. NaOH / methanol / Heating 3: 88 percent / tetrahydrofuran / 0.75 h / Ambient temperature 4: 1.) PPh3, Pd(OAc)2, aq. Na2CO3 / 1.) DME, room temperature, 1 h, 2.) DME, reflux 5: 1.) NaH / 1.) 30 min, room temperature, 2.) room temperature, 1.5 h 6: 91 percent / POCl3 / acetonitrile / 0.5 h / Heating View Scheme

1: 94 percent / NaH, DMPU / dimethylformamide / 2 h / 100 °C 2: 74 percent / aq. NaOH / methanol / Heating 3: 88 percent / tetrahydrofuran / 0.75 h / Ambient temperature 4: 1.) PPh3, Pd(OAc)2, aq. Na2CO3 / 1.) DME, room temperature, 1 h, 2.) DME, reflux 5: 99 percent / POCl3 / acetonitrile / 0.5 h / Heating View Scheme