反应详情

In acetic acid-water (1:1) (5 ml) was dissolved ethyl 2-formyl-3-pyridinecarboxylate (1.3 g) followed by addition of t-butylhydrazine hydrochloride (1.8 g), and the mixture was refluxed with stirring for 1 hour. This reaction mixture was cooled to room temperature, adjusted to pH 5.0 with saturated aqueous NaHCO3 solution, and extracted with dichloromethane. The organic layer was washed with saturated aqueous NaCl solution, dried over anhydrous magnesium sulfate, and concentrated. The residue was dissolved in acetic acid (2 ml) and refluxed for 1 hour. This reaction mixture was cooled, adjusted to pH 5.0 with saturated aqueous NaHCO3 solution, and extracted with dichloromethane. The organic layer was washed with saturated aqueous NaCl solution, dried over anhydrous magnesium sulfate, and concentrated. The residue was purified by silica gel chromatography (n-hexane: ethyl acetate =1:1). White powder, 1.2 g. 1H-NMR (CDCl3) δ: 1.73(9H,s), 7.64(1H,dd,J=8.2&4.4Hz), 8.38(1H,s), 8.69(1H,d,J=8.2Hz), 9.03(1H,d,J=4.4Hz).

1. temperaturethe mixture was refluxed
2. extractionextracted with dichloromethane
3. washThe organic layer was washed with saturated aqueous NaCl solution
4. dry with materialdried over anhydrous magnesium sulfate
5. concentrationconcentrated
6. dissolutionThe residue was dissolved in acetic acid (2 ml)
7. temperaturerefluxed for 1 hour
8. temperatureThis reaction mixture was cooled
9. extractionextracted with dichloromethane
10. washThe organic layer was washed with saturated aqueous NaCl solution
11. dry with materialdried over anhydrous magnesium sulfate
12. concentrationconcentrated
13. customThe residue was purified by silica gel chromatography (n-hexane: ethyl acetate =1:1)