Potassium Carbonate → 7-(2-Octynyloxy)coumarin

HRID 1587050Notes

Reaction equation

HRID 1587050 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([CH:6]=[CH:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1.Br[CH2:14][C:15]#[C:16][CH2:17][CH2:18][CH2:19][CH2:20][CH3:21].C(=O)([O-])[O-].[K+].[K+]>CC(C)=O.C(OCC)(=O)C>[CH2:14]([O:1][C:2]1[CH:11]=[C:10]2[C:5]([CH:6]=[CH:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1)[C:15]#[C:16][CH2:17][CH2:18][CH2:19][CH2:20][CH3:21]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 27570871-Bromo-2-octyneHCID 5281426Umbelliferone

Product 1

HCID 197604967-(2-Octynyloxy)coumarin

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 7-hydroxycoumarin (0.324 g, 1.99 mmol) and 1-bromo-2-octyne (0.378 g, 1.99 mmol) in 200 ml of acetone was heated under reflux in the presence of anhydrous potassium carbonate (3 grams) for 24 hours. After the reflux period, the reaction mixture was cooled, filtered and the collected solid was washed with fresh acetone. The acetone washings and the filtrate were combined and the solvent evaporated under reduced pressure to yield a pale yellow viscous liquid. The crude product was dissolved in a minimum amount of ethyl acetate and petroleum ether added until the solution became cloudy. The cloudy solution was concentrated under reduced pressure and a white precipitate formed. This precipitate was collected by vacuum filtration and recrystallized from aqueous methanol to yield the title compound as shiny, colorless plates, m.p. 74°-75° C., 0.245 g, 50%. 1H-NMR: 0.8-2.2 (m, 11H, (CH2)4CH3), 4.7 (t, 2H, OCH2C C), 6.2 (d, 1H, C3 --H J=9.3 Hz), 6.8 (dd, 1H, C6 --H), 6.9 (d, 1H, C8 --H, J=2.1 Hz), 7.4 (dd, 1H, C5 --H, J=8.1 Hz), 7.6 (d, 1H, C4 --H, J=9.3 Hz).

Workup

  1. temperatureAfter the reflux period, the reaction mixture was cooled
  2. filtrationfiltered
  3. washthe collected solid was washed with fresh acetone
  4. customthe solvent evaporated under reduced pressure
  5. customto yield a pale yellow viscous liquid
  6. additionadded until the solution
  7. concentrationThe cloudy solution was concentrated under reduced pressure
  8. customa white precipitate formed
  9. filtrationThis precipitate was collected by vacuum filtration
  10. customrecrystallized from aqueous methanol

Sources & evidence

ORD record
ord-739dc0af988c4ff5a38b6e8451d90a51
Source dataset
uspto-grants-1993_06
Patent number
US05216176

Reaction notes

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