反应详情

A mixture of 5-formylbenzofurazan (0.60 g, 4.1 mmol), methyl acetoacetate (0.52 g, 4.5 mmol), piperidine (0.019 g, 0.23 mmol), and acetic acid (0.014 g, 0.23 mmol) in benzene (30 mL) was heated at reflux temperature (equipped with a Dean-Stark trap) for 8 h. Benzene was evaporated in vacuo, the residue was dissolved in ethyl acetate (80 mL) and washed with brine (50 mL), saturated potassium bisulfate solution (50 mL), and saturated sodium bicarbonate solution. The ethyl acetate solution was dried over magnesium sulfate, the solvent removed under reduced pressure and the residue was purified by column chromatography (EtOAc/hexane, 1/9 to 3/20). The desired product was obtained as oil (0.98 g, 98%) and was used in the next step without any further characterization.

1. temperaturewas heated
2. temperatureat reflux temperature (
3. customequipped with a Dean-Stark trap) for 8 h
4. customBenzene was evaporated in vacuo
5. dissolutionthe residue was dissolved in ethyl acetate (80 mL)
6. washwashed with brine (50 mL), saturated potassium bisulfate solution (50 mL), and saturated sodium bicarbonate solution
7. dry with materialThe ethyl acetate solution was dried over magnesium sulfate
8. customthe solvent removed under reduced pressure
9. customthe residue was purified by column chromatography (EtOAc/hexane, 1/9 to 3/20)