1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C 4: 81 percent / 1 N NaOH / 10 h / Heating View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating View Scheme

1: AcOH 2: POCl3, NEt3 / Heating 3: liq. NH3 / 150 - 160 °C 4: PBr3 / tetrahydrofuran View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C 4: PBr3 / tetrahydrofuran / 8 h 5: N,N-dimethyl-acetamide / 72 h / Ambient temperature 6: 72 percent / 1 N NaOH / ethanol / 48 h / Ambient temperature View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C 4: PBr3 / tetrahydrofuran / 8 h 5: 1.) NaOC2H5 / 1.) ethanol, room temperature, 1 h, 2.) dimethylacetamide, room temperature, 10 h 6: 62 percent / 1 N NaOH / ethanol / 48 h / Ambient temperature View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C 4: 81 percent / 1 N NaOH / 10 h / Heating 5: PBr3 / tetrahydrofuran / 12 h 6: N,N-dimethyl-acetamide / 6 h / Heating 7: 58 percent / 1 N NaOH / ethanol / 48 h / Ambient temperature View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C 4: 81 percent / 1 N NaOH / 10 h / Heating 5: PBr3 / tetrahydrofuran / 12 h 6: 1.) NaBH4 / 1.) ethanol, 2.) dimethylacetamide, room temperature, 6 h 7: 72 percent / 1 N NaOH / ethanol / 48 h / Ambient temperature View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C 4: PBr3 / tetrahydrofuran / 8 h 5: N,N-dimethyl-acetamide / 6 h / Heating 6: 68 percent / 1 N NaOH / ethanol / 48 h / Ambient temperature View Scheme

1: 85 percent / acetic acid / 0.5 h / Heating 2: 62 percent / POCl3, (C2H5)3N / 8 h / Heating 3: 84 percent / liquid NH3 / 18 h / 160 - 170 °C 4: PBr3 / tetrahydrofuran / 8 h 5: 1.) NaBH4 / 1.) ethanol, 2.) dimethylacetamide, room temperature, 6 h 6: 68 percent / 1 N NaOH / ethanol / 48 h / Ambient temperature View Scheme