Chlorotrimethylsilane → HCID 10592115, compound

HRID 1602308Notes

Reaction equation

HRID 1602308 reaction equation
[C:1]([C:4]1[CH:14]=[C:13]([C:15]([CH3:18])([CH3:17])[CH3:16])[C:7]2[O:8][CH2:9][C:10]([CH3:12])([CH3:11])[C:6]=2[CH:5]=1)(=[O:3])[CH3:2].C([N-]C(C)C)(C)C.[Li+].Cl[Si](C)(C)C.[Br:32]N1C(=O)CCC1=O>C1COCC1>[Br:32][CH2:2][C:1]([C:4]1[CH:14]=[C:13]([C:15]([CH3:18])([CH3:17])[CH3:16])[C:7]2[O:8][CH2:9][C:10]([CH3:11])([CH3:12])[C:6]=2[CH:5]=1)=[O:3]

Participants

6

Reactant 4

HCID 6397ChlorotrimethylsilaneHCID 67184N-bromobutanimideHCID 2724682Lithium diisopropylamideHCID 10514594HCID 10514594, compound

Product 1

HCID 10592115HCID 10592115, compoundYield 88%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-78 °C

Procedure

A solution of 5-acetyl-7-tert-butyl-2,3-dihydro-3,3-dimethylbenzo[b]furan (2.46 g, 10.0 mmol) in 25 mL of anhydrous THF is added dropwise to lithium diisopropylamide (6.0 mL, 12.0 mmol, 2.0M solution in heptane-THF-ethyl benzene) at -78° C. The resulting solution in stirred at -78° C. for 15 min, and chlorotrimethylsilane (1.5 mL, 12.0 mmol) is introduced. The reaction mixture is stirred at -78° C. for 15 min, warmed to room temperature, stirred for 1.5 h, quenched with water, and extracted with ether. The extract is dried over anhydrous sodium sulfate and concentrated in vacuo; the residue is dissolved in 25 mL of anhydrous THF and reacted at 0° C. with N-bromosuccinimide (1.78 g, 10.0 mmol). The resulting yellowish solution is kept at 0° C. for 0.5 h, warmed to room temperature, stirred for 0.5 h, quenched with water, and extracted with ether. The extract is dried over anhydrous magnesium sulfate and concentrated in vacuo. Purification of the residue by flash column chromatography on silica gel (5%→20% ether-hexane) affords about 2.85 g (88%) of 5-bromoacetyl-7-tert-butyl-2,3-dihydro-3,3-dimethyl-benzo[b]furan as a yellowish solid: mp 54-56° C.

Workup

  1. stirringThe reaction mixture is stirred at -78° C. for 15 min
  2. temperaturewarmed to room temperature
  3. stirringstirred for 1.5 h
  4. customquenched with water
  5. extractionextracted with ether
  6. dry with materialThe extract is dried over anhydrous sodium sulfate
  7. concentrationconcentrated in vacuo
  8. dissolutionthe residue is dissolved in 25 mL of anhydrous THF
  9. waitThe resulting yellowish solution is kept at 0° C. for 0.5 h
  10. temperaturewarmed to room temperature
  11. stirringstirred for 0.5 h
  12. customquenched with water
  13. extractionextracted with ether
  14. dry with materialThe extract is dried over anhydrous magnesium sulfate
  15. concentrationconcentrated in vacuo
  16. customPurification of the residue by flash column chromatography on silica gel (5%→20% ether-hexane)

Sources & evidence

ORD record
ord-44ec394306754ec4b0f5efa82acc34dd
Source dataset
uspto-grants-1999_11
Patent number
US05981547

Reaction notes

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