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

HRID 1490286Notes

Reaction equation

HRID 1490286 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

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 (3x). The combined organics were washed with Na2CO3 (1M), 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 (3x)
  6. washThe combined organics were washed with Na2CO3 (1M), 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-6bc93645b7eb40c0ba70d0fd3beb58a3
Source dataset
uspto-grants-1997_10
Patent number
US05681958

Reaction notes

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