Boron tribromide → HCID 19101398, compound

HRID 1975261Notes

Reaction equation

HRID 1975261 reaction equation
B(Br)(Br)Br.[Br:5][C:6]1[CH:7]=[C:8]([CH2:27][C:28]([O:30][CH3:31])=[O:29])[CH:9]=[C:10]([Br:26])[C:11]=1[S:12]([C:15]1[CH:20]=[CH:19][C:18]([O:21]C)=[C:17]([CH:23]([CH3:25])[CH3:24])[CH:16]=1)(=[O:14])=[O:13]>ClCCl>[Br:26][C:10]1[CH:9]=[C:8]([CH2:27][C:28]([O:30][CH3:31])=[O:29])[CH:7]=[C:6]([Br:5])[C:11]=1[S:12]([C:15]1[CH:20]=[CH:19][C:18]([OH:21])=[C:17]([CH:23]([CH3:24])[CH3:25])[CH:16]=1)(=[O:14])=[O:13]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 19101407HCID 19101407, compound

Product 1

HCID 19101398HCID 19101398, compoundYield 85.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A 1M solution of boron tribromide (17 mL, 0.017 mol) in dichloromethane was added to an ice-cooled solution of methyl 3,5-dibromo-4-(3-isopropyl-4-methoxyphenylsulfonyl)phenylacetate (3.5 g, 0.0067 mol), from Example 1, in dichloromethane. The mixture was warmed to room temperature and allowed to react for 3 hrs. Excess boron tribromide was quenched by the addition of methanol to the ice-cooled reaction mixture and the reaction mixture was concentrated on a rotary evaporator. The residue was dissolved in ethyl acetate, washed with water and brine, and dried (Na2SO4). The residue obtained after removal of the solvent was purified by flash chromatography (silica gel, 45:45:10 hexane:CH2Cl2 : acetone) to obtain methyl 3,5-dibromo-4-(4-hydroxy-3-isopropylphenylsulfonyl)phenylacetate (2.9 g, 0.0057 mol, 85% yield). MP: 159°-160° C. (hexane/ethyl acetate).

Workup

  1. customto react for 3 hrs
  2. customExcess boron tribromide was quenched by the addition of methanol to the ice-
  3. temperaturecooled
  4. customreaction mixture
  5. concentrationthe reaction mixture was concentrated on a rotary evaporator
  6. dissolutionThe residue was dissolved in ethyl acetate
  7. washwashed with water and brine
  8. dry with materialdried (Na2SO4)
  9. customThe residue obtained
  10. customafter removal of the solvent
  11. customwas purified by flash chromatography (silica gel, 45:45:10 hexane:CH2Cl2 : acetone)

Sources & evidence

ORD record
ord-cd2ba012e33341658927d1e75047b0be
Source dataset
uspto-grants-1994_02
Patent number
US05284971

Reaction notes

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