反应详情

Under a nitrogen atmosphere, trifluoroacetic acid (5.5 ml) was added to a solution of 4-propoxy-1-tetrahydro-2H-pyran-2-yl-5-(tetrahydro-2H-pyran-2-yloxy)-1H-indazole (852.6 mg) in dichloromethane (16.5 ml) at room temperature. After 2.5 hours, the reaction solution was poured onto ice, adjusted to pH 7 with an aqueous sodium hydroxide solution, and then extracted with ethyl acetate. The extract solution was concentrated under reduced pressure and the resulting residue was purified by a silica gel column chromatography (eluent: hexane/ethyl acetate). The residue purified was concentrated under reduced pressure and the resulting residue was washed with diethyl ether/hexane by repulping to obtain 4-propoxy-1H-indazol-5-ol (338.2 g, 80%, two steps).

1. additionthe reaction solution was poured onto ice
2. extractionextracted with ethyl acetate
3. concentrationThe extract solution was concentrated under reduced pressure
4. customthe resulting residue was purified by a silica gel column chromatography (eluent: hexane/ethyl acetate)
5. customThe residue purified
6. concentrationwas concentrated under reduced pressure
7. washthe resulting residue was washed with diethyl ether/hexane