反应详情

To a solution of 5-methyl-4H-1,2,4-triazol-3-amine (16.35 g) and ethyl 3-oxocyclobutanecarboxylate (12.41 g) in acetic acid (150 mL) was added sodium triacetoxyborohydride (36.56 g), and the mixture was stirred at room temperature for 5 days. The solvent was evaporated under reduced pressure, the residue was diluted with saturated aqueous sodium hydrogen carbonate solution, and the mixture was extracted with ethyl acetate-isopropyl alcohol (3:1). The extract was washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel chromatography [eluent: methanol/ethyl acetate=0/100→10/90 (volume ratio)], and crystallized from diethyl ether to give the title compound as a colorless solid (15.93 g, 62%).

1. customThe solvent was evaporated under reduced pressure
2. additionthe residue was diluted with saturated aqueous sodium hydrogen carbonate solution
3. extractionthe mixture was extracted with ethyl acetate-isopropyl alcohol (3:1)
4. washThe extract was washed with saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customThe solvent was evaporated under reduced pressure
7. customthe residue was purified by silica gel chromatography [eluent: methanol/ethyl acetate=0/100→10/90 (volume ratio)]
8. customcrystallized from diethyl ether