Acetic Anhydride → 1-Acetyl-1H-indol-3-yl acetate

HRID 582653Notes

Reaction equation

HRID 582653 reaction equation
[C:1]1([N:7]([C:12]([OH:14])=O)[CH2:8][C:9]([OH:11])=O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[CH3:15][C:16]([O-:18])=O.[Na+].[CH3:20]C(OC(C)=O)=O>CN(C=O)C>[C:12]([N:7]1[C:1]2[C:2](=[CH:3][CH:4]=[CH:5][CH:6]=2)[C:9]([O:11][C:16](=[O:18])[CH3:15])=[CH:8]1)(=[O:14])[CH3:20]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 517045Sodium AcetateHCID 53420527HCID 53420527, compound

Product 1

HCID 5836021-Acetyl-1H-indol-3-yl acetateYield 74%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a mixture of phenylglycine-o-carboxylic acid obtained in Example 30 (2.30 g, 11.8 mmol) and NaOAc (3.75 g, 47.1 mmol) in DMF (29 mL) was slowly added Ac2O (11.7 mL, 118 mmol) and the mixture was refluxed for 2 hours. After cooling, the mixture was concentrated to 10 mL, partitioned between H2O (60 mL) and CHCl3 (120 mL), and the aqueous layer was extracted with CHCl3 (3×). The combined organics were washed with Na2CO3 (1 M), H2O, brine and dried (MgSO4). Purification of the crude oil by LPLC, eluting with hexane-EtOAc (2:1), afforded 1.89 g (74%) of the title compound as a light yellow powder, Rf 0.34 (hexane-EtOAc 2:1), mp 79.6-80.5° C.; 1H NMR (CDCl3) δ 8.47 (d, J=8.0, 1H), 7.72 (s, 1H), 7.55 (d, J=8.0, 1H), 7.40 (t, J=8.0, 1H), 7.31 (t, J=8.0, 1H), 2.62 (s, 3H), 2.40 (s, 3H), 13C NMR (CDCl3) δ 168.7, 167.8, 134.6, 132.8, 126.2, 123.7, 123.6, 117.4, 116.7, 113.3, 23.9, 21.0; MS (EI, m/z) 217 (M+)

Workup

  1. temperaturethe mixture was refluxed for 2 hours
  2. temperatureAfter cooling
  3. concentrationthe mixture was concentrated to 10 mL
  4. custompartitioned between H2O (60 mL) and CHCl3 (120 mL)
  5. extractionthe aqueous layer was extracted with CHCl3 (3×)
  6. washThe combined organics were washed with Na2CO3 (1 M), H2O, brine
  7. dry with materialdried (MgSO4)
  8. customPurification of the crude oil by LPLC
  9. washeluting with hexane-EtOAc (2:1)

Sources & evidence

ORD record
ord-8efd5bb1a71f40d1af1279bb09205739
Source dataset
uspto-grants-1999_07
Patent number
US05925647

Reaction notes

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