Benzyl Bromide → 7-Benzyloxychromanone

HRID 1600021Notes

Reaction equation

HRID 1600021 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH2:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1.[CH2:13](Br)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1.C(=O)([O-])[O-].[K+].[K+]>CC(C)=O>[CH2:13]([O:1][C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH2:7][C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 2981307-Hydroxychromanone

Product 1

HCID 144156387-BenzyloxychromanoneYield 81.4%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

A mixture of 7-hydroxychromanone (10.0 g, 61 mmol), benzyl bromide (7.6 mL,64 mmol), and potassium carbonate (16.5 g, 120 mmol) in acetone (250 mL) was gently refluxed 24 h. The mixture was cooled and filtered through celite. The filtrate 20 was concentrated and the residue was taken up in ethyl acetate. The organic solution was washed with water and brine, driedover calcium sulfate, and concentrated to a tan solid. Recrystallization from ethanol gave 12.63 g (81%) of 7-benzyloxychromanone as tan crystal which had mp 99°-102° C.; NMR δ7.85 (d, J=9 Hz, 1H), 7.44-7.32 (m,5H), 6.66 (dd, J=2.4, 9Hz, 1H), 6.49 (d, J=2.4 Hz, 1H), 5.09 (s,2H), 4.52 (t, J=6.5 Hz, 2H), 2.76 (t, J=6.5 Hz, 2H).

Workup

  1. temperatureThe mixture was cooled
  2. filtrationfiltered through celite
  3. concentrationThe filtrate 20 was concentrated
  4. washThe organic solution was washed with water and brine, driedover calcium sulfate
  5. concentrationconcentrated to a tan solid
  6. customRecrystallization from ethanol

Sources & evidence

ORD record
ord-7cc06498d887470f86c9943aab5eb2ee
Source dataset
uspto-grants-1998_04
Patent number
US05744483

Reaction notes

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