Pyridinium chloride → (2E)-3-[4-(9a-butyl-7-hydroxy-3-oxo-2,3,9,9a-tetrahydro-1H-fluoren-4-yl)phenyl]-2-propenoic acid

HRID 7844

Reaction equation

HRID 7844 reaction equation
[CH2:1]([C:5]12[CH2:17][CH2:16][C:15](=[O:18])[C:14]([C:19]3[CH:24]=[CH:23][C:22](/[CH:25]=[CH:26]/[C:27]([O:29]C)=[O:28])=[CH:21][CH:20]=3)=[C:13]1[C:12]1[C:7](=[CH:8][C:9]([O:31]C)=[CH:10][CH:11]=1)[CH2:6]2)[CH2:2][CH2:3][CH3:4].Cl.N1C=CC=CC=1>>[CH2:1]([C:5]12[CH2:17][CH2:16][C:15](=[O:18])[C:14]([C:19]3[CH:20]=[CH:21][C:22](/[CH:25]=[CH:26]/[C:27]([OH:29])=[O:28])=[CH:23][CH:24]=3)=[C:13]1[C:12]1[C:7](=[CH:8][C:9]([OH:31])=[CH:10][CH:11]=1)[CH2:6]2)[CH2:2][CH2:3][CH3:4]

Participants

3

Reactant 2

HCID 10176127Pyridinium chloride2×HCID 67400795methyl (2E)-3-[4-(9a-butyl-7-methoxy-3-oxo-2,3,9,9a-tetrahydro-1H-fluoren-4-yl)phenyl]-2-propenoate

Product 1

HCID 10294530(2E)-3-[4-(9a-butyl-7-hydroxy-3-oxo-2,3,9,9a-tetrahydro-1H-fluoren-4-yl)phenyl]-2-propenoic acid

Conditions

Temperature
190 °C

Procedure

A mixture of methyl (2E)-3-[4-(9a-butyl-7-methoxy-3-oxo-2,3,9,9a-tetrahydro-1H-fluoren-4-yl)phenyl]-2-propenoate (60 mg, 92% weight pure, 0.128 mmol) and pyridine hydrochloride (741 mg, 6.41 mmol) was placed under a nitrogen atmosphere, heated in an oil bath at 190° C., and stirred. The reaction flask was periodically dipped deeper into the heating bath in order to melt the pyridine hydrochloride that condensed on the sides of the flask. After 2 hours at 190° C., the reaction mixture was cooled to room temperature and partitioned between EtOAc (10 mL) and water (10 mL). The aqueous phase was extracted with more EtOAc (2×5 mL). The combined EtOAc extracts were washed with brine, dried over MgSO4, filtered, and evaporated under vacuum to a yellow solid (55 mg). The crude product was suspended in EtOAc (10 mL) and extracted with 5% NaHCO3 (5 mL). The NaHCO3 solution was acidified with 2N HCl (2.5 mL) and extracted with EtOAc (2×5 mL). The latter EtOAc extracts were combined, washed with brine, dried over MgSO4, filtered, and evaporated under vacuum to a yellow solid (39.4 mg). This material was triturated with diethyl ether and dried under vacuum to afford (2E)-3-[4-(9a-butyl-7-hydroxy-3-oxo-2,3,9,9a-tetrahydro-1H-fluoren-4-yl)phenyl]-2-propenoic acid as a pale yellow solid.

Workup

  1. customthat condensed on the sides of the flask
  2. temperaturethe reaction mixture was cooled to room temperature
  3. custompartitioned between EtOAc (10 mL) and water (10 mL)
  4. extractionThe aqueous phase was extracted with more EtOAc (2×5 mL)
  5. washThe combined EtOAc extracts were washed with brine
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. customevaporated under vacuum to a yellow solid (55 mg)
  9. extractionextracted with 5% NaHCO3 (5 mL)
  10. extractionextracted with EtOAc (2×5 mL)
  11. washwashed with brine
  12. dry with materialdried over MgSO4
  13. filtrationfiltered
  14. customevaporated under vacuum to a yellow solid (39.4 mg)
  15. customThis material was triturated with diethyl ether
  16. customdried under vacuum

Sources & evidence

ORD record
ord-80bc9e40f544428a8eacc0993ff83f3d
Source dataset
uspto-grants-2006_08
Patent number
US07087599B2

Linked notes

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