5-Bromoisatin → 5-Bromo-3-hydroxy-3-methyl-2-oxindole

HRID 6988

Reaction equation

HRID 6988 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6](=[O:11])[C:5]2=[O:12].[CH3:13][Mg]Br.[Cl-].[NH4+]>C1COCC1>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][C:6](=[O:11])[C:5]2([OH:12])[CH3:13]

Participants

5

Reactant 3

HCID 68895-BromoisatinHCID 25517Ammonium ChlorideHCID 178418573HCID 178418573, compound

Product 1

HCID 120859355-Bromo-3-hydroxy-3-methyl-2-oxindoleYield 29%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 5-bromoisatin (5.0 g, 22 mmol) in dry THF (50 cm3) under N2 was cooled to 0° C. and treated drop-wise with methyl magnesium bromide (3M in diethylether, 14.7 cm3, 44 mmol) and the mixture was allowed to warm up-to room temperature. The reaction was poured into sat. ammonium chloride solution, then extracted into EtOAc (×3). The combined organic layers were then washed with water, brine, dried (MgSO4) and evaporated. The residue was then purified by column chromatography (SiO2, EtOAc: hexane, gradient elution) to afford 5-bromo-3-hydroxy-3-methyl-1,3-dihydro-indol-2-one (1.53 g, 6.32 mmol, 29%): 1H NMR (DMSO-d6) δ 1.38 (s, 3H), 5.99 (s, 1H), 6.77 (d, 1H, J=1.7 Hz), 7.38 (s, 1H, br); MS ((−) ESI) m/z 240/242 (M)−.

Workup

  1. extractionextracted into EtOAc (×3)
  2. washThe combined organic layers were then washed with water, brine
  3. dry with materialdried (MgSO4)
  4. customevaporated
  5. customThe residue was then purified by column chromatography (SiO2, EtOAc: hexane, gradient elution)

Sources & evidence

ORD record
ord-685d956059c54290a7022e11e3dec19f
Source dataset
uspto-grants-2006_08
Patent number
US07084168B2

Linked notes

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