Iodine → 4-(tert-Butyldimethylsilanyloxy)-1-(7-methoxybenzofuran-2-yl)-butan-1-ol

HRID 1282028Notes

Reaction equation

HRID 1282028 reaction equation
[Mg].Br[CH2:3][CH2:4][CH2:5][O:6][Si:7]([C:10]([CH3:13])([CH3:12])[CH3:11])([CH3:9])[CH3:8].II.[CH3:16][O:17][C:18]1[C:26]2[O:25][C:24]([CH:27]=[O:28])=[CH:23][C:22]=2[CH:21]=[CH:20][CH:19]=1>O1CCCC1>[Si:7]([O:6][CH2:5][CH2:4][CH2:3][CH:27]([C:24]1[O:25][C:26]2[C:18]([O:17][CH3:16])=[CH:19][CH:20]=[CH:21][C:22]=2[CH:23]=1)[OH:28])([C:10]([CH3:13])([CH3:12])[CH3:11])([CH3:9])[CH3:8]

Participants

6

Reactant 4

HCID 807IodineHCID 607486(3-Bromopropoxy)(tert-butyl)dimethylsilaneHCID 34573107-Methoxy-1-benzofuran-2-carbaldehydeHCID 5462224Magnesium

Product 1

HCID 184236524-(tert-Butyldimethylsilanyloxy)-1-(7-methoxybenzofuran-2-yl)-butan-1-olYield 81.8%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Conditions

Temperature
80 °C

Procedure

A suspension of dried magnesium turnings (0.42 g) in anhydrous tetrahydrofuran (20 ml) was treated with 2 ml of (3-Bromopropoxy)-tert-butyldimethylsilane (4.4 g) in anhydrous tetrahydrofuran (10 ml) at room temperature under a dry nitrogen atmosphere. Initiation was achieved by the addition of catalytic iodine and warming to 80° C. The remaining solution (8 ml) was then added carefully. The reaction was cooled to −5° C. and a solution of 7-methoxybenzofuran-2-carbaldehyde (3 g) in anhydrous tetrahydrofuran (20 ml) was added carefully. After stirring at ambient temperature overnight the solvent was removed in vacuo. The residue was partitioned between ethyl acetate (100 ml) and saturated aqueous ammonium chloride solution (100 ml). The organic extract was dried over magnesium sulphate, filtered and preadsorbed onto silica. Purification by column chromatography on silica eluting with 10% ethyl acetate in hexane afforded the title compound as a yellow oil (4.88 g).

Workup

  1. temperatureThe reaction was cooled to −5° C.
  2. customwas removed in vacuo
  3. customThe residue was partitioned between ethyl acetate (100 ml) and saturated aqueous ammonium chloride solution (100 ml)
  4. extractionThe organic extract
  5. dry with materialwas dried over magnesium sulphate
  6. filtrationfiltered
  7. customPurification by column chromatography on silica eluting with 10% ethyl acetate in hexane

Sources & evidence

ORD record
ord-603df14aee2d4c34afcce143b8cc1090
Source dataset
uspto-grants-2002_09
Patent number
US06455561B1

Reaction notes

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