Potassium Carbonate → Ethyl 7-(3-benzyloxypropoxy)-chromane-2-carboxylate

HRID 51071Notes

Reaction equation

HRID 51071 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH2:7][CH:8]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[O:9]2)=[CH:4][CH:3]=1.Br[CH2:18][CH2:19][CH2:20][O:21][CH2:22][C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1.C(=O)([O-])[O-].[K+].[K+]>[I-].C([N+](CCCC)(CCCC)CCCC)CCC.CC(C)=O>[CH2:22]([O:21][CH2:20][CH2:19][CH2:18][O:1][C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH2:7][CH:8]([C:12]([O:14][CH2:15][CH3:16])=[O:13])[O:9]2)=[CH:4][CH:3]=1)[C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][CH:24]=1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 2776064Benzyl 3-Bromopropyl EtherHCID 11085381Ethyl 7-hydroxychromane-2-carboxylate

Product 1

HCID 22737349Ethyl 7-(3-benzyloxypropoxy)-chromane-2-carboxylateYield 66%

Reagents, catalysts & solvents 2

HCID 67553Tetrabutylammonium IodideCatalystHCID 180AcetoneSolvent

Procedure

To a 200 ml acetone solution of ethyl 7-hydroxychromane-2-carboxylate (9.18 g, 41.3 mmol) was added benzyl 3-bromopropyl ether (14.2 g, 62.0 mmol), powdered potassium carbonate (11.4 g, 82.5 mmol), and tetrabutylammonium iodide (1.53 g, 4 mmol). The resulting suspension was heated to reflux overnight. Acetone was removed under reduced pressure, diluted with AcOEt and sat. NH4Claq. The organic layer was separated, and the aqueous layer was extracted twice with AcOEt. The combined organic layers were dried over anhydrous Na2SO4, filtered, concentrated, and chromatographed on silica gel eluting with 10% AcOEt/hexanes to give the title compound 10.1 g (66%).

Workup

  1. temperatureThe resulting suspension was heated
  2. temperatureto reflux overnight
  3. customAcetone was removed under reduced pressure
  4. additiondiluted with AcOEt and sat. NH4Claq
  5. customThe organic layer was separated
  6. extractionthe aqueous layer was extracted twice with AcOEt
  7. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customchromatographed on silica gel eluting with 10% AcOEt/hexanes

Sources & evidence

ORD record
ord-4795e508b2ae4b97aa5be6d3ec7ae4b9
Source dataset
uspto-grants-2004_03
Patent number
US06713508B2

Reaction notes

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