1: pyridine / 5 h / Ambient temperature 2: 80percent aq. AcOH / 20 h / Ambient temperature 3: 68 percent / 3-nitro-1-(2,4,6-triisopropylbenzenesulfonyl)-1,2,4-triazole / pyridine / 18 h / 37 °C / var. reag.: DCC 4: 83 percent / Et3N, MeOH, H2O / 16 h / 4 °C View Scheme

1: pyridine / 5 h / Ambient temperature 2: 80percent aq. AcOH / 20 h / Ambient temperature 3: 68 percent / 3-nitro-1-(2,4,6-triisopropylbenzenesulfonyl)-1,2,4-triazole / pyridine / 18 h / 37 °C / var. reag.: DCC 4: 83 percent / Et3N, MeOH, H2O / 16 h / 4 °C View Scheme