Sulfur Dioxide → Benzoic acid, 2-[2-(4-bromophenyl)ethyl]-

HRID 2396502Notes

Reaction equation

HRID 2396502 reaction equation
S(=O)=O.C(O)(C(F)(F)F)=O.[Br:11]Br.[CH2:13]([C:21]1[CH:29]=[CH:28][CH:27]=[CH:26][C:22]=1[C:23]([OH:25])=[O:24])[CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>C1(C)C=CC=CC=1.CCCCCC.CCOCC>[Br:11][C:18]1[CH:17]=[CH:16][C:15]([CH2:14][CH2:13][C:21]2[CH:29]=[CH:28][CH:27]=[CH:26][C:22]=2[C:23]([OH:25])=[O:24])=[CH:20][CH:19]=1

Participants

7

Reactant 4

HCID 1119Sulfur DioxideHCID 6422Trifluoroacetic acidHCID 24408BromineHCID 78603o-Phenethylbenzoic acid

Product 1

HCID 11449587Benzoic acid, 2-[2-(4-bromophenyl)ethyl]-

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 21889329Toluene hexaneSolvent

Conditions

Temperature
-28 °C

Procedure

Sulfur dioxide (625 mL) was condensed into a large flask with a dry ice condenser to this flask was added TFA (10 mL) and bromine (2 equiv). When the solution temperature reached -50°, o-phenethylbenzoic acid was added. The reaction was stirred at -28° C. for 17 hours. The SO2 and excess bromine were evaporated off at room temperature over a 2 hour period leaving slightly yellow solid. A 30 g sample was dissolved in hot toluene-hexane (100 mL of 2:3) with a few mL of Et2O. The solution was cooled slowly to 10° C., and the product was isolated by filtration.

Workup

  1. customcondensed into a large flask with a dry ice condenser to this flask
  2. customreached -50°
  3. customThe SO2 and excess bromine were evaporated off at room temperature over a 2 hour period
  4. customleaving slightly yellow solid
  5. temperatureThe solution was cooled slowly to 10° C.
  6. customthe product was isolated by filtration

Sources & evidence

ORD record
ord-45af11bb44aa426487030b663068ee55
Source dataset
uspto-grants-1996_02
Patent number
US05492917

Reaction notes

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