Sulfuric Acid → ethyl 10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene-2-carboxylate

HRID 885419Notes

Reaction equation

HRID 885419 reaction equation
[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][C:11]([C:13]([OH:15])=[O:14])=[CH:12][C:7]=2[CH2:6][CH2:5][C:4]2[CH:16]=[CH:17][CH:18]=[CH:19][C:3]1=2.C(OCC)(OCC)O[CH2:22][CH3:23].S(=O)(=O)(O)O>C(O)C.C(OCC)(=O)C>[O:1]=[C:2]1[C:8]2[CH:9]=[CH:10][C:11]([C:13]([O:15][CH2:22][CH3:23])=[O:14])=[CH:12][C:7]=2[CH2:6][CH2:5][C:4]2[CH:16]=[CH:17][CH:18]=[CH:19][C:3]1=2

Participants

6

Reactant 3

HCID 1118Sulfuric AcidHCID 31214Ethyl orthoformateHCID 125258755-Oxo-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-2-carboxylic acid

Product 1

HCID 67211051ethyl 10,11-dihydro-5-oxo-5H-dibenzo[a,d]cycloheptene-2-carboxylateYield 94%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8857Ethyl AcetateSolvent

Procedure

[step 1] 5-Oxo-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-2-carboxylic acid (JP-B-2526005, 19.9 g, 79 mmol) and triethyl orthoformate (17.0 mL, 102 mmol) were dissolved in ethanol (130 mL), followed by adding concentrated sulfuric acid (1.68 mL, 32 mmol) and the mixture was stirred under reflux for 12 hr. The mixture was diluted with ethyl acetate, and the organic layer was washed with saturated aqueous sodium hydrogen carbonate solution, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=90/10) to give ethyl 5-oxo-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-2-carboxylate (20.8 g, 94%).

Workup

  1. temperatureunder reflux for 12 hr
  2. washthe organic layer was washed with saturated aqueous sodium hydrogen carbonate solution
  3. dry with materialdried over anhydrous magnesium sulfate
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate=90/10)

Sources & evidence

ORD record
ord-f0290d29aef146bb918f6953f59f159c
Source dataset
uspto-grants-2012_08
Patent number
US08242151B2

Reaction notes

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