1-Indanone, 6-bromo- → 6-Bromo-1-methylene-indan

HRID 2091599Notes

Reaction equation

HRID 2091599 reaction equation
[Li][CH2:2]CCC.[Br:6][C:7]1[CH:15]=[C:14]2[C:10]([CH2:11][CH2:12][C:13]2=O)=[CH:9][CH:8]=1>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1>[Br:6][C:7]1[CH:15]=[C:14]2[C:10]([CH2:11][CH2:12][C:13]2=[CH2:2])=[CH:9][CH:8]=1

Participants

5

Reactant 2

HCID 1397781-Indanone, 6-bromo-HCID 178418339Butyllithium

Product 1

HCID 574838316-Bromo-1-methylene-indanYield 62%

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

A 2.5 M solution of n-BuLi in hexanes (23.6 mL, 59 mmol) was added dropwise to a 0° C. slurry of methyltriphenylphosphonium bromide (16.8 g, 47.0 mmol) in THF (200 mL). After 1 h, a solution of 6-bromo-2,3-dihydro-1H-inden-1-one (10.0 g, 47.0 mmol) in THF (50 mL) was added to the resulting solution and the reaction cold bath was removed. Upon completion, the reaction was quenched with water (40 mL). The layers were separated and the aqueous layer was extracted with EtOAc (2×40 mL). The combined organics were washed with brine (50 mL), dried over Na2SO4, filtered and concentrated to afford 6-bromo-1-methylene-2,3-dihydro-1H-indene (6.06 g, 62% yield) as a clear oil after purification by flash chromatography over silica gel (hexane eluent). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 7.61 (d, J=1.5 Hz, 1H), 7.32 (dd, J=8.0, 1.8 Hz, 1H), 7.13 (d, J=8.0 Hz, 1H), 5.45 (t, J=2.5 Hz, 1H), 5.08 (t, J=2.1 Hz, 1H), 2.88-2.98 (m, 2H), 2.78-2.86 (m, 2H); MS (EI) m/z=210.1 [M+1]+.

Workup

  1. customthe reaction cold bath was removed
  2. customUpon completion, the reaction was quenched with water (40 mL)
  3. customThe layers were separated
  4. extractionthe aqueous layer was extracted with EtOAc (2×40 mL)
  5. washThe combined organics were washed with brine (50 mL)
  6. dry with materialdried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-72293ec1529845e38d0a8856a4c51e6e
Source dataset
uspto-grants-2013_05
Patent number
US08440652B2

Reaction notes

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