3,4-dihydro-2H-pyran → 5-bromo-1-(oxan-2-yl)-1H-indazole
Reaction equation
[O:1]1[CH:6]=[CH:5][CH2:4][CH2:3][CH2:2]1.C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1.[Br:24][C:25]1[CH:26]=[C:27]2[C:31](=[CH:32][CH:33]=1)[NH:30][N:29]=[CH:28]2.C(=O)([O-])O.[Na+]>C(Cl)Cl>[Br:24][C:25]1[CH:26]=[C:27]2[C:31](=[CH:32][CH:33]=1)[N:30]([CH:6]1[CH2:5][CH2:4][CH2:3][CH2:2][O:1]1)[N:29]=[CH:28]2Participants
Procedure
3,4-dihydro-2H-pyran (0.84 ml, 9.21 mmol) and pyridinium p-toluenesulfonate (202 mg, 0.804 mmol) were added to a solution of 5-bromo-1H-indazole (790 mg, 4.01 mmol) in methylene chloride (15 ml) at room temperature, and the resulting mixture was refluxed for 6 hours. Then, the reaction solution was poured into a saturated aqueous sodium hydrogencarbonate solution and extracted with chloroform. The organic layer was washed with a saturated aqueous sodium chloride solution and then dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the resulting residue was purified by a silica gel column chromatography (eluent: hexane/ethyl acetate=93/7) to obtain 5-bromo-1-tetrahydro-2H-pyran-2-yl-1H-indazole (1.06 g, 94%).
Workup
- temperaturethe resulting mixture was refluxed for 6 hours
- extractionextracted with chloroform
- washThe organic layer was washed with a saturated aqueous sodium chloride solution
- dry with materialdried over anhydrous magnesium sulfate
- distillationThe solvent was distilled off under reduced pressure
- customthe resulting residue was purified by a silica gel column chromatography (eluent: hexane/ethyl acetate=93/7)
Sources & evidence
- ORD record
- ord-04f3a2f624b84b9f9e6b3292cf02264c
- Source dataset
- uspto-grants-2007_04
- Patent number
- US07199147B2
Reaction notes
Loading…