Boron trifluoride etherate → 3-(1-(4-Bromophenyl)-2-methylpropyl)-4-hydroxycoumarin

HRID 2293666Notes

Reaction equation

HRID 2293666 reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[O:5][C:4](=[O:12])[CH:3]=1.[Br:13][C:14]1[CH:19]=[CH:18][C:17]([CH:20](O)[CH:21]([CH3:23])[CH3:22])=[CH:16][CH:15]=1.B(F)(F)F.CCOCC>O1CCOCC1>[Br:13][C:14]1[CH:19]=[CH:18][C:17]([CH:20]([C:3]2[C:4](=[O:12])[O:5][C:6]3[C:11]([C:2]=2[OH:1])=[CH:10][CH:9]=[CH:8][CH:7]=3)[CH:21]([CH3:23])[CH3:22])=[CH:16][CH:15]=1

Participants

5

Reactant 3

HCID 8000Boron trifluoride etherateHCID 217141961-(4-Bromophenyl)-2-methylpropan-1-olHCID 546829304-Hydroxycoumarin

Product 1

HCID 546764233-(1-(4-Bromophenyl)-2-methylpropyl)-4-hydroxycoumarinYield 3.8%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

To a flame-dried flask containing a near-solution of 324 mg of 4-hydroxycoumarin and 573 mg of 1-(4-bromophenyl)-2-methylpropan-1-ol of Preparation 14 in 10 mL of dioxane under an argon atmosphere is added 1.2 mL of boron trifluoride etherate. The resulting yellow solution is left to stir at room temperature overnight. The volatiles are removed and the residue is partioned between diethyl ether and 1N sodium hydroxide. The basic aqueous phase is washed with diethyl ether and acidified to pH=1 with 6N hydrochloric acid. The resulting precipitant is repeatedly extracted with dichloromethane (methanol-chloroform co-solvents). The combined dichloromethane extracts are washed once with dilute sodium bicarbonate to remove most of the unreacted 4-hydroxycoumarin, then brine, dried (magnesium sulfate), and finally concentrated under reduced pressure. The residue is adsorbed onto silica and flash column chromatographed with 50% to 60% ethyl acetate in hexanes to yield 28 mg of the title product as a tan solid.

Workup

  1. additionTo a flame-dried flask containing
  2. waitThe resulting yellow solution is left
  3. customThe volatiles are removed
  4. washThe basic aqueous phase is washed with diethyl ether
  5. extractionThe resulting precipitant is repeatedly extracted with dichloromethane (methanol-chloroform co-solvents)
  6. washThe combined dichloromethane extracts are washed once with dilute sodium bicarbonate
  7. customto remove most of the unreacted 4-hydroxycoumarin
  8. dry with materialbrine, dried (magnesium sulfate)
  9. concentrationfinally concentrated under reduced pressure
  10. customchromatographed with 50% to 60% ethyl acetate in hexanes

Sources & evidence

ORD record
ord-a10e17d137cf4c908846e5b8b762ed86
Source dataset
uspto-grants-1997_11
Patent number
US05686486

Reaction notes

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