Diethyl Ether → 2-(5-Bromo-3,3,6-trimethyl-2,3-dihydro-benzofuran-7-yl)-propan-2-ol

HRID 2290148Notes

Reaction equation

HRID 2290148 reaction equation
[Br:1][C:2]1[C:3]([CH3:16])=[C:4]([C:13](=[O:15])[CH3:14])[C:5]2[O:9][CH2:8][C:7]([CH3:11])([CH3:10])[C:6]=2[CH:12]=1.[CH3:17][Mg]Br.C(OCC)C>>[Br:1][C:2]1[C:3]([CH3:16])=[C:4]([C:13]([OH:15])([CH3:17])[CH3:14])[C:5]2[O:9][CH2:8][C:7]([CH3:11])([CH3:10])[C:6]=2[CH:12]=1

Participants

4

Reactant 3

HCID 3283Diethyl EtherHCID 186991761-(5-Bromo-3,3,6-trimethyl-2,3-dihydro-benzofuran-7-yl)-ethanone2×HCID 178418573HCID 178418573, compound

Product 1

HCID 186991752-(5-Bromo-3,3,6-trimethyl-2,3-dihydro-benzofuran-7-yl)-propan-2-olYield 71.5%

Procedure

A stirred, cooled (ice bath) solution of 1-(5-bromo-3,3,6-trimethyl-2,3-dihydro-benzofuran-7-yl)-ethanone (Compound 48, 2.0 g, 7.09 mmol), was treated drop wise with a 3M solution of methylmagnesium bromide in diethylether (2.84 mL, 8.51 mmol) and the resulting reaction mixture was stirred at ambient temperature for 2 hours. The reaction mixture was cooled (ice bath), quenched with saturated ammonium chloride solution and extracted with ether. The organic extract was washed with brine and dried over anhydrous sodium sulfate, filtered and evaporated to a residue which on flash column chromatography using 7% ethyl acetate in hexanes as the eluent afforded the title compound (I.51 g, 71.5%) as a white solid. 1H NMR (300 MHz, CDCl3): δ 7.21 (s, 1H), 4.35 (s, 1H), 4.22 (s, 2H), 2.53 (s, 3H), 1.67 (s, 6H), 1.31 (s, 6H).

Workup

  1. customthe resulting reaction mixture
  2. temperatureThe reaction mixture was cooled (ice bath)
  3. customquenched with saturated ammonium chloride solution
  4. extractionextracted with ether
  5. extractionThe organic extract
  6. washwas washed with brine
  7. dry with materialdried over anhydrous sodium sulfate
  8. filtrationfiltered
  9. customevaporated to a residue which on flash column chromatography

Sources & evidence

ORD record
ord-55520423be3e4aef9f2f16b30728f7b3
Source dataset
uspto-grants-2000_07
Patent number
US06093838

Reaction notes

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