反应详情

To a solution of 1-(2-Chloropyridin-3-yl)ethanone (III) (0.311 g, 2 mmol) in n-butanol (10 mL) was added hydrazine hydrate (1.45 mL, 30 mmol). The reaction was refluxed overnight. The solution was cooled and the solvent was evaporated under vacuum. The residue was dissolved in DCM and washed successively by water and brine. The organic layers were dried over MgSO4, filtered and concentrated under reduced pressure to give 3-methyl-1H-pyrazolo[3,4-b]pyridine (IV) as a white solid (192 mg, 1.44 mmol, 72% yield). 1H NMR (CDCl3) δ ppm 2.64 (s, 3H), 7.14 (dd, J=8.01, 4.62 Hz, 1H), 8.14 (dd, J=7.54, 1.88 HZ, 1H), 8.59 (dd, J=4.52, 1.32 HZ, 1H), 11.68 (brs, 1H).

1. temperatureThe reaction was refluxed overnight
2. temperatureThe solution was cooled
3. customthe solvent was evaporated under vacuum
4. dissolutionThe residue was dissolved in DCM
5. washwashed successively by water and brine
6. dry with materialThe organic layers were dried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure