反应详情

A mixture of 7-bromo-1-(2-pyridyl)-3,6,6-trimethyl-4-oxo-4,5,6,7-tetrahydro-indazole (0.3 g, 0.9 mmol), prepared as described in example 4, hydroxylamine hydrochloride (0.37 g, 4.5 mmol), and sodium acetate (0.44 g, 5.4 mmol) in 1,4-dioxane (50 ml) was heated under reflux for about 4 hours. Additional hydroxylamine hydrochloride (0.123 g, 1.6 eq) and sodium acetate (0.146 g, 2 eq) were added and heating was continued for further 4 hours. The reaction mixture was poured onto ice/water and extracted with dichloromethane. The combined organic layers were washed with brine, dried over sodium sulfate and evaporated. The residue was chromatographed on silica gel (cyclohexane:ethyl acetate=90:10) to give the title compound as a colourless solid (0.14 g, 45%): m.p. 195-196° C.

1. customprepared
2. temperaturewas heated
3. temperatureunder reflux for about 4 hours
4. temperatureheating
5. additionThe reaction mixture was poured onto ice/water
6. extractionextracted with dichloromethane
7. washThe combined organic layers were washed with brine
8. dry with materialdried over sodium sulfate
9. customevaporated
10. customThe residue was chromatographed on silica gel (cyclohexane:ethyl acetate=90:10)