Boron tribromide → 7-hydroxy-3-(4-hydroxyphenyl)-2H-chromen-2-one

HRID 2045735Notes

Reaction equation

HRID 2045735 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([CH:6]=[C:7]([C:13]3[CH:18]=[CH:17][C:16]([O:19]C)=[CH:15][CH:14]=3)[C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1.B(Br)(Br)Br>ClCCl>[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([CH:6]=[C:7]([C:13]3[CH:18]=[CH:17][C:16]([OH:19])=[CH:15][CH:14]=3)[C:8](=[O:12])[O:9]2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 53931747-Hydroxy-3-(4'-methoxyphenyl)coumarin

Product 1

HCID 102440187-hydroxy-3-(4-hydroxyphenyl)-2H-chromen-2-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

4.00 g (14.9 mmol) of 7-hydroxy-3-(4-methoxyphenyl)chromen-2-one are initially introduced in 190 ml of dichloromethane, and a solution of 2.5 ml (26.3 mmol) of boron tribromide in 10 ml of dichloromethane is added with ice-cooling. The cooling is removed, and the batch is stirred overnight at room temp. The solution is added to ice-water, acidified using 2 N hydrochloric acid and extracted three times with ethyl acetate. The combined org. phases are washed with water and dried over sodium sulfate. The solvent is removed in vacuo, and the residue is recrystallised from toluene/ethyl acetate (2:1), giving 7-hydroxy-3-(4-hydroxyphenyl)chromen-2-one as yellow crystals.

Workup

  1. temperaturecooling
  2. customThe cooling is removed
  3. additionThe solution is added to ice-water
  4. extractionextracted three times with ethyl acetate
  5. washphases are washed with water
  6. dry with materialdried over sodium sulfate
  7. customThe solvent is removed in vacuo
  8. customthe residue is recrystallised from toluene/ethyl acetate (2:1)

Sources & evidence

ORD record
ord-44f91c4a567545cf900c075a8adf01d9
Source dataset
uspto-grants-2013_11
Patent number
US08592007B2

Reaction notes

Loading…