Hydrochloric Acid → 2-(1-Benzothiophen-5-yl)ethan-1-ol

HRID 2232354Notes

Reaction equation

HRID 2232354 reaction equation
[Mg].CI.Br[C:5]1[CH:13]=[CH:12][C:8]2[S:9][CH:10]=[CH:11][C:7]=2[CH:6]=1.[CH2:14]1[O:16][CH2:15]1.Cl>C1COCC1>[OH:16][CH2:15][CH2:14][C:5]1[CH:13]=[CH:12][C:8]2[S:9][CH:10]=[CH:11][C:7]=2[CH:6]=1

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 6328Methyl iodideHCID 6354Ethylene OxideHCID 27765785-Bromo-1-benzothiopheneHCID 5462224Magnesium

Product 1

HCID 119833712-(1-Benzothiophen-5-yl)ethan-1-olYield 48%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

To a flame dried flask under N2 was added magnesium turnings (6 g, 0.25 mol) and THF (100 ml). The mixture was heated at reflux and a solution of methyl iodide (7.2 ml, d=2.28, 0.116 mol), and 5-bromobenzo[b]thiophene (24.4 g, 0.114 mol) in THF (50 ml) were added dropwise. The mixture was heated at reflux for 5 hours, then cooled to 0°-4° C. and a solution of ethylene oxide (15 g, 0.33 mol) in THF (20 ml) was added dropwise. After the addition, the reaction mixture was allowed to stir at room temperature overnight. The suspension was then cooled and a solution of 3N HCl (75 ml) was added dropwise. The aqueous layer was extracted with ethyl acetate (3×) and the organic layer was backwashed with saturated Na2CO3, dried, filtered and concentrated to dryness. The residue was chromatographed on silica gel and the product was eluted with 30% ethyl acetate/hexane to yield 9.3 g (48%) of product, m.p. 56°-57° C.

Workup

  1. customTo a flame dried flask under N2
  2. temperatureThe mixture was heated
  3. temperatureat reflux
  4. temperatureThe mixture was heated
  5. temperatureat reflux for 5 hours
  6. temperaturecooled to 0°-4° C.
  7. additionAfter the addition
  8. temperatureThe suspension was then cooled
  9. extractionThe aqueous layer was extracted with ethyl acetate (3×)
  10. customdried
  11. filtrationfiltered
  12. concentrationconcentrated to dryness
  13. customThe residue was chromatographed on silica gel
  14. washthe product was eluted with 30% ethyl acetate/hexane

Sources & evidence

ORD record
ord-a196c1710b144385afc0267e2f96b27d
Source dataset
uspto-grants-1988_11
Patent number
US04788192

Reaction notes

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