Nitrogen → 1-(Benzofuran-5-yl)-2-bromopropan-1-one

HRID 1671316Notes

Reaction equation

HRID 1671316 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([C:10](=[O:13])[CH2:11][CH3:12])=[CH:9][C:4]=2[CH:3]=[CH:2]1.N#N.C(=O)=O.CC(C)=O.C[Si]([N-][Si](C)(C)C)(C)C.[Li+].C1C(=O)N([Br:40])C(=O)C1>C1COCC1>[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([C:10](=[O:13])[CH:11]([Br:40])[CH3:12])=[CH:9][C:4]=2[CH:3]=[CH:2]1

Participants

7

Reactant 5

HCID 947NitrogenHCID 67184N-bromobutanimideHCID 2733832Lithium HexamethyldisilazideHCID 18522661Acetone cardiceHCID 673362701-(Benzofuran-5-yl)propan-1-one

Product 1

HCID 866389381-(Benzofuran-5-yl)-2-bromopropan-1-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

To an oven dried roundbottom flask is added 1-(benzofuran-5-yl)propan-1-one (160 mg, 0.919 mmol) and dissolved in dry THF (5 ml). The flask is then cycled through a vacuum/N2 protocol and then cooled under N2 to −78° C. using dry ice/acetone. At this temperature, lithium bis(trimethylsilyl)amide (1M in hexanes) (1.378 ml, 1.378 mmol) is added and stirring continues for ˜30 mins. After this time, NBS (180 mg, 1.010 mmol) in THF (5 ml) is then added dropwise keeping the temp below −60° C. The mixture is left to warm to RT and stirring continued for ˜5 hr. After this time, LCMS looked to show ˜50% conversion to product. The raection is quenched by addition of NH4Cl and allowed to warm to RT. The contents are transferred to a separating funnel and extracted into EtOAc. The organic portion is washed with NaHCO3, water, brine, dried (MgSO4) and evaporated to give a clear oil. Purification by chromatography on silica gel (20 g) eluting with 100% iso-hexane followed by 5% EtOAc/iHex affords the title product as a clear oil. MS: m/z 253 [M+H]+.

Workup

  1. customTo an oven dried roundbottom flask
  2. customthe temp below −60° C
  3. waitThe mixture is left
  4. temperatureto warm to RT
  5. stirringstirring
  6. waitcontinued for ˜5 hr
  7. customThe raection is quenched by addition of NH4Cl
  8. temperatureto warm to RT
  9. customThe contents are transferred to a separating funnel
  10. extractionextracted into EtOAc
  11. washThe organic portion is washed with NaHCO3, water, brine
  12. dry with materialdried (MgSO4)
  13. customevaporated
  14. customto give a clear oil
  15. customPurification by chromatography on silica gel (20 g)
  16. washeluting with 100% iso-hexane

Sources & evidence

ORD record
ord-be6db1cfb12a423aa0f31009dff26aa6
Source dataset
uspto-grants-2011_08
Patent number
US07994203B2

Reaction notes

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