Boron tribromide → 3-[4-(5-Hydroxy-2-methyl-phenoxy)-2-methyl-phenyl]-propionic acid ethyl ester

HRID 1822344Notes

Reaction equation

HRID 1822344 reaction equation
[CH2:1]([O:3][C:4](=[O:24])[CH2:5][CH2:6][C:7]1[CH:12]=[CH:11][C:10]([O:13][C:14]2[CH:19]=[C:18]([O:20]C)[CH:17]=[CH:16][C:15]=2[CH3:22])=[CH:9][C:8]=1[CH3:23])[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[CH2:1]([O:3][C:4](=[O:24])[CH2:5][CH2:6][C:7]1[CH:12]=[CH:11][C:10]([O:13][C:14]2[CH:19]=[C:18]([OH:20])[CH:17]=[CH:16][C:15]=2[CH3:22])=[CH:9][C:8]=1[CH3:23])[CH3:2]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 578941493-[4-(5-Methoxy-2-methyl-phenoxy)-2-methyl-phenyl]-propionic acid ethyl ester

Product 1

HCID 578941473-[4-(5-Hydroxy-2-methyl-phenoxy)-2-methyl-phenyl]-propionic acid ethyl esterYield 50%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

The compound of 3-[4-(5-Methoxy-2-methyl-phenoxy)-2-methyl-phenyl]-propionic acid ethyl ester (1.02 g, 3.10 mmol) is dissolved in DCM (15 mL) under nitrogen at −78° C., and BBr3 (1M, CH2Cl2) (4.64 mL, 4.64 mmol) is added. The mixture is stirred at that temperature for 10 minutes and the bath is removed. The mixture is stirred at rt for 2 h, and water is added. The mixture is neutralized to pH=7 with NaOH (10%). The mixture is extracted with DCM. The organic layer is dried with Na2SO4 and filtered, and then the solvent is evaporated in vacuo. Purification by flash chromatography by eluting with hexane:ethyl acetate 5:1 to afford the title compound (0.48 g, 50%). Rf=0.13 (hexane:ethyl acetate 5:1). 1H NMR (300 MHz, CDCl3): δ1.26 (t, 3H, J=7.3 Hz), 2.16 (s, 3H), 2.26 (s, 3H), 2.57 (t, 2H, J=7.3 Hz), 2.89 (t, 2H, J=7.5 Hz), 4.15 (q, 2H, J=7.3 Hz), 6.44 (d, 1H, J=2.4 Hz), 6.58 (dd, 1H, J=2.4, 8.1 Hz), 6.68 (dd, 1H, J=2.4, 8.3 Hz), 6.75 (d, 1H, J=2.2 Hz), 6.92 (s, 1H), 7.04 (t, 2H, J=8.1 Hz).

Workup

  1. customthe bath is removed
  2. stirringThe mixture is stirred at rt for 2 h
  3. additionwater is added
  4. extractionThe mixture is extracted with DCM
  5. dry with materialThe organic layer is dried with Na2SO4
  6. filtrationfiltered
  7. customthe solvent is evaporated in vacuo
  8. customPurification by flash chromatography
  9. washby eluting with hexane:ethyl acetate 5:1

Sources & evidence

ORD record
ord-9f817ed0467e4f548bd8971a13029a30
Source dataset
uspto-grants-2009_10
Patent number
US07608639B2

Reaction notes

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