1: 73 percent / HCl(g) / tetrahydrofuran; toluene / 20 h / Ambient temperature 2: 64 percent / 18 h / 40 °C 3: 70 percent / hydroxylamine / methanol; tetrahydrofuran / 7 h / Heating 4: 88 percent / pyridine / tetrahydrofuran / 1.5 h / Ambient temperature 5: 81 percent / acetic acid / 2 h / Heating 6: 25 percent / NaHCO3 / H2O; methanol / 2 h / Heating View Scheme

1: acetic acid / 2 h / Ambient temperature 2: 95 percent / acetic acid / 1.5 h / Heating 3: 58 percent / KOH / ethanol / 10 h / Heating 4: 79 percent / anhydrous hydrogen chloride / ethanol / 1.5 h / Heating View Scheme

1: acetic acid / 2 h / Ambient temperature 2: 95 percent / acetic acid / 1.5 h / Heating 3: 12 percent / KOH / ethanol / 10 h / Heating View Scheme

1: 93 percent / hydroxylamine 2: 74 percent / NEt3 / tetrahydrofuran / 1. 5 h/RT 2. 30 min reflux 3: 65 percent / xylene / 2 h / Heating; using Dean-Stark Water separator 4: 75 percent / K2CO3 / ethanol; H2O / 5 h / Heating View Scheme

1: acetic acid / 2 h / Ambient temperature 2: 95 percent / acetic acid / 1.5 h / Heating View Scheme

1: acetic acid / 2 h / Ambient temperature 2: 95 percent / acetic acid / 1.5 h / Heating 3: 58 percent / KOH / ethanol / 10 h / Heating View Scheme