反应详情

A 3 L round bottom flask was charged with 8-chlorotetrazolo[1,5-a]pyrazine (350 g, 2.3 mol), tert-butyl piperazine-1-carboxylate (420 g, 2.3 mol), triethylamine (460 g, 4.5 mol), and EtOH (2 L). The mixture was heated at reflux for 1 h. Work-up: the reaction mixture was concentrated in vacuo. The residue was mixed with saturated aqueous NaHCO3 (1 L) and then extracted with CH2Cl2 (1 L×3). The combined organic layers were dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was further purified by flash column chromatography on silica gel with 8% EtOAc in CH2Cl2 (containing 2% Et3N), to afford 630 g (91%) of the product as a white solid. MS m/z: 306 (M+H+).

1. temperatureThe mixture was heated
2. temperatureat reflux for 1 h
3. concentrationthe reaction mixture was concentrated in vacuo
4. additionThe residue was mixed with saturated aqueous NaHCO3 (1 L)
5. extractionextracted with CH2Cl2 (1 L×3)
6. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
7. concentrationconcentrated in vacuo
8. customThe residue was further purified by flash column chromatography on silica gel with 8% EtOAc in CH2Cl2 (containing 2% Et3N)