Boron tribromide → 3-(4-Hydroxyphenyl)-7-(3-hydroxypropyl)chromen-2-one

HRID 2045734Notes

Reaction equation

HRID 2045734 reaction equation
[OH:1][CH2:2][CH2:3][CH2:4][C:5]1[CH:14]=[C:13]2[C:8]([CH:9]=[C:10]([C:16]3[CH:21]=[CH:20][C:19]([O:22]C)=[CH:18][CH:17]=3)[C:11](=[O:15])[O:12]2)=[CH:7][CH:6]=1.B(Br)(Br)Br>ClCCl>[OH:22][C:19]1[CH:18]=[CH:17][C:16]([C:10]2[C:11](=[O:15])[O:12][C:13]3[C:8]([CH:9]=2)=[CH:7][CH:6]=[C:5]([CH2:4][CH2:3][CH2:2][OH:1])[CH:14]=3)=[CH:21][CH:20]=1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 584024107-(3-Hydroxypropyl)-3-(4-methoxyphenyl)chromen-2-one

Product 1

HCID 584023923-(4-Hydroxyphenyl)-7-(3-hydroxypropyl)chromen-2-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

1.00 g (3.22 mmol) of 7-(3-hydroxypropyl)-3-(4-methoxyphenyl)chromen-2-one (see Ex. 3.1) is initially introduced in 30 ml of dichloromethane, and a solution of 0.4 ml (4.2 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 chromatographed on silica gel with toluene/ethyl acetate (1:1). After first runnings, 3-(4-hydroxyphenyl)-7-(3-hydroxypropyl)chromen-2-one is obtained as colourless solid in a second fraction (Rf=0.3).

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 chromatographed on silica gel with toluene/ethyl acetate (1:1)

Sources & evidence

ORD record
ord-d9c19003a2a74f7dbe912b64081d710b
Source dataset
uspto-grants-2013_11
Patent number
US08592007B2

Reaction notes

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