Potassium Hydroxide → 6,7,8,9-Tetrahydro-5-oxo-5H-benzocycloheptene-6-acetic acid

HRID 1918407Notes

Reaction equation

HRID 1918407 reaction equation
[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[CH2:6][CH2:5][CH2:4][CH:3]1[CH2:13][C:14]([O:16]CC)=[O:15].[OH-].[K+]>C(O)C>[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[CH2:6][CH2:5][CH2:4][CH:3]1[CH2:13][C:14]([OH:16])=[O:15]

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 592956445H-Benzocycloheptene-6-acetic acid, 6,7,8,9-tetrahydro-5-oxo-, ethyl ester

Product 1

HCID 3445076,7,8,9-Tetrahydro-5-oxo-5H-benzocycloheptene-6-acetic acid

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

The compound of formula (Db), ethyl 2-(5-oxo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-6-yl)acetate, (6.6 g, 26.8 mmol) was dissolved in ethanol (EtOH) (30 mL), then 10% potassium hydroxide (KOH) aqueous solution (37.5 mL, 67 mmol) was added and the resulting mixture was refluxed for 2 h. After cooling to ambient temperature, the EtOH was removed by evaporation. The residue was extracted with EtOAc twice (15 mL×2). The aqueous layer was then transferred into a flask and cooled with an ice-water bath, con. HCI was added dropwise to adjust pH to about 2.0. EtOAc (60 mL) was then added, the layers were separated, and the aqueous layer was extracted with EtOAc. The combined extracts were washed with brine. After being dried (MgSO4), filtered, and concentrated, the compound of formula (Dc), 2-(5-oxo-6,7,8,9-tetrahydro-5H-benzo[7]annulen-6-yl)acetic acid, was obtained as an orange oil (5.7 g, 97%); 1H NMR (300 MHz, CDCl3) δ: 7.71-7.68 (m, 1H), 7.41-7.20 (m, 3H), 3.37-3.31 (m, 1H), 3.12-2.91 (m, 3H), 2.57-2.49 (m, 1H), 2.15-1.90 (m, 2H), 1.75-1.62 (m, 2H); LC-MS: purity: 100%; MS (m/e) : 219 (MH+).

Workup

  1. temperaturethe resulting mixture was refluxed for 2 h
  2. customthe EtOH was removed by evaporation
  3. extractionThe residue was extracted with EtOAc twice (15 mL×2)
  4. customThe aqueous layer was then transferred into a flask
  5. temperaturecooled with an ice-water bath
  6. additionHCI was added dropwise
  7. additionEtOAc (60 mL) was then added
  8. customthe layers were separated
  9. extractionthe aqueous layer was extracted with EtOAc
  10. washThe combined extracts were washed with brine
  11. dry with materialAfter being dried (MgSO4)
  12. filtrationfiltered
  13. concentrationconcentrated

Sources & evidence

ORD record
ord-df77b902e4984da297859f41e3104774
Source dataset
uspto-grants-2013_12
Patent number
US08618331B2

Reaction notes

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