1,5-Diacetylindoline → 1-(1-acetyl-2,3-dihydro-1H-indol-5-yl)-2-bromoethanone

HRID 1910047Notes

Reaction equation

HRID 1910047 reaction equation
[C:1]([N:4]1[C:12]2[C:7](=[CH:8][C:9]([C:13](=[O:15])[CH3:14])=[CH:10][CH:11]=2)[CH2:6][CH2:5]1)(=[O:3])[CH3:2].[Br-:16].[Br-].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>C1COCC1.[Br-].[Br-].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>[C:1]([N:4]1[C:12]2[C:7](=[CH:8][C:9]([C:13](=[O:15])[CH2:14][Br:16])=[CH:10][CH:11]=2)[CH2:6][CH2:5]1)(=[O:3])[CH3:2]

Participants

5

Reactant 2

HCID 32808501,5-DiacetylindolineHCID 21124087Pyridiniumtribromide

Product 1

HCID 197113291-(1-acetyl-2,3-dihydro-1H-indol-5-yl)-2-bromoethanoneYield 92.9%

Reagents, catalysts & solvents 2

HCID 21124087PyridiniumtribromideCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

To a suspension of 1,5-diacetylindoline (10.0 g, 49.2 mmol) in 90 mL of THF at rt was added pyridinium tribromide (16.52 g, 51.7 mmol, 1 equiv) as solids portionwise over a period of 10 min. When there was still about 1.5 g of pyridinium tribromide left, the mixture solidified. Added another 30 mL of THF to make the mixture stirrable again. The remaining 1.5 g tribromide was added in one portion. The mixture was stirred at rt (no exotherm as checked by a thermometer). After 1.5 h, LCMS showed conversion complete. The suspension was filtered. The cake was washed with THF (2×30 mL), and then water (2×50 mL). The wet cake was sucked under house vacuum at rt for 2 days to give 1-(1-acetyl-2,3-dihydro-1H-indol-5-yl)-2-bromoethanone (12.89 g) as light grey solids. LC-MS (ES) m/z=281.9, 283.9.

Workup

  1. waitleft
  2. filtrationThe suspension was filtered
  3. washThe cake was washed with THF (2×30 mL)
  4. waitThe wet cake was sucked under house vacuum at rt for 2 days

Sources & evidence

ORD record
ord-210e48e64b6b4bd4aafb2fb21acb8785
Source dataset
uspto-grants-2013_12
Patent number
US08598156B2

Reaction notes

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