Phthalic Anhydride → 5-(2-Carboxybenzoyloxy)-4-methoxy-2,6,6-trimethyl-2-cyclohepten-1-one

HRID 2258501Notes

Reaction equation

HRID 2258501 reaction equation
[OH:1][CH:2]1[C:8]([CH3:10])([CH3:9])[CH2:7][C:6](=[O:11])[C:5]([CH3:12])=[CH:4][CH:3]1[O:13][CH3:14].[C:15]1(=[O:25])[O:20][C:18](=[O:19])[C:17]2=[CH:21][CH:22]=[CH:23][CH:24]=[C:16]12.CC1C=CN=C(N)C=1C.C(=O)([O-])[O-].[K+].[K+]>N1C=CC=CC=1>[C:18]([C:17]1[CH:21]=[CH:22][CH:23]=[CH:24][C:16]=1[C:15]([O:1][CH:2]1[C:8]([CH3:9])([CH3:10])[CH2:7][C:6](=[O:11])[C:5]([CH3:12])=[CH:4][CH:3]1[O:13][CH3:14])=[O:25])([OH:20])=[O:19]

Participants

6

Reactant 4

HCID 6811Phthalic AnhydrideHCID 11430Potassium CarbonateHCID 110078842-Amino-3,4-dimethylpyridineHCID 229223715-Hydroxy-4-methoxy-2,6,6-trimethyl-2-cyclohepten-1-one

Product 1

HCID 229224315-(2-Carboxybenzoyloxy)-4-methoxy-2,6,6-trimethyl-2-cyclohepten-1-oneYield 53%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Conditions

Temperature
90 °C

Procedure

To a solution of 5-hydroxy-4-methoxy-2,6,6-trimethyl-2-cyclohepten-1-one (AU154) obtained in Example 4 (1.98 g, 10 mM) in pyridine (10 ml), phthalic anhydride (1.78 g, 12 mM) and dimethyl aminopyridine (0.05 g) were added and warmed to 90° C. for three hours, left to cool, poured onto ice-water, alkalified with potassium carbonate and extracted with ethyl acetate. The aqueous layer was acidified with hydrochloric acid and extracted with ethyl acetate, washed with brine, dried over magnesium sulfate, filtered, and concentrated. The residue was crystallized from a mixed solvent of ethyl acetate and hexane to obtain 1.80 g (53%) of 5-(2-carboxybenzoyloxy)-4-methoxy-2,6,6-trimethyl-2-cyclohepten-1-one (AU218) as colorless plates. Melting point: 158.0° to 158.5° C.

Workup

  1. additionwere added
  2. waitleft
  3. temperatureto cool
  4. additionpoured onto ice-water
  5. extractionextracted with ethyl acetate
  6. extractionextracted with ethyl acetate
  7. washwashed with brine
  8. dry with materialdried over magnesium sulfate
  9. filtrationfiltered
  10. concentrationconcentrated
  11. customThe residue was crystallized from a mixed solvent of ethyl acetate and hexane

Sources & evidence

ORD record
ord-c3b72c3ef46546498f37c54a616ac24d
Source dataset
uspto-grants-1997_08
Patent number
US05661166

Reaction notes

Loading…