5-Bromo-3-indoleacetic acid → 5-Bromo-1H-indole-3-ethanol

HRID 1033500Notes

Reaction equation

HRID 1033500 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[C:5]2[CH2:11][C:12](O)=[O:13].[H-].[Al+3].[Li+].[H-].[H-].[H-]>C1COCC1>[Br:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][CH:6]=[C:5]2[CH2:11][CH2:12][OH:13]

Participants

4

Reactant 2

HCID 967345-Bromo-3-indoleacetic acidHCID 21226445Aluminium lithium hydride

Product 1

HCID 1229565-Bromo-1H-indole-3-ethanolYield 64.6%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a stirred solution of 5-bromoindole-3-acetic acid (1.9 g., 7.48 mmol., 1 eq.) in dry THF (17 mL.) at 0° C. was added lithium aluminum hydride (570 mg. 14.96 mmol., 2 eq.) portionwise over 30 minutes. The reaction mixture coagulated. THF (20 mL.) was added and the cooling bath was removed. The mixture was stirred vigorously. Let stir overnight. The reaction mixture was carefully quenched with 1N aqueous HC1 and then acidified with 2N aqueous HC1. The mixture was filtered through Celite™ and the Celite™ was washed with THF. The filtrate was concentrated in vacuo, dissolved in EtOAc, and washed with water. The organic layer was dried over anhydrous MgSO4, filtered and concentrated in vacuo. TLC analysis of the residue showed unreacted starting material. The residue was dissolved in Et2O and extracted with 0.25N aqueous NaOH. The organic layer was dried over anhydrous MgSO4, filtered and concentrated in vacuo giving 1.16 g 5-bromo-3-hydroxyethylindole.

Workup

  1. customthe cooling bath was removed
  2. stirringLet stir overnight
  3. customThe reaction mixture was carefully quenched with 1N aqueous HC1
  4. filtrationThe mixture was filtered through Celite™
  5. washthe Celite™ was washed with THF
  6. concentrationThe filtrate was concentrated in vacuo
  7. dissolutiondissolved in EtOAc
  8. washwashed with water
  9. dry with materialThe organic layer was dried over anhydrous MgSO4
  10. filtrationfiltered
  11. concentrationconcentrated in vacuo
  12. dissolutionThe residue was dissolved in Et2O
  13. extractionextracted with 0.25N aqueous NaOH
  14. dry with materialThe organic layer was dried over anhydrous MgSO4
  15. filtrationfiltered
  16. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-dacba1175c074eb89c14bbc3c4ddcb33
Source dataset
uspto-grants-1994_05
Patent number
US05310901

Reaction notes

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