Toluene → (2S)-2-bromo-3-phenylpropanoic acid

HRID 1189

Reaction equation

HRID 1189 reaction equation
N[C@H:2]([C:10]([OH:12])=[O:11])[CH2:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.[Br-:13].[K+].N([O-])=O.[Na+].C1(C)C=CC=CC=1>S(=O)(=O)(O)O.C(O)(=O)C>[Br:13][C@@H:2]([CH2:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)[C:10]([OH:12])=[O:11]

Participants

7

Reactant 4

HCID 1140TolueneHCID 6140L-PhenylalanineHCID 253877Potassium BromideHCID 23668193Sodium Nitrite

Product 1

HCID 9816009(2S)-2-bromo-3-phenylpropanoic acid

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 1118Sulfuric AcidSolvent

Procedure

A solution of L-phenylalanine (30.0 g., 0.175 mole) and potassium bromide (73.5 g., 0.618 mole) in 2.5N sulfuric acid (365 ml.) was cooled down to 0° (ice-salt bath) and treated portionwise with sodium nitrite (19.3 g., 0.28 mole) over a period of 1.0 hour. Stirring was continued for 1.0 hour at 0° and at room temperature for 1.0 hour after which the reaction mixture was extracted with ether (3×250 ml.). The combined organic extracts were washed with water (100 ml.) and brine (50 ml.), dried (anhydrous magnesium sulfate), filtered, evaporated to dryness and dried in vacuo to give 34.46 g., of product; Rf =0.45 (toluene:acetic acid, 95:5).

Workup

  1. extractionafter which the reaction mixture was extracted with ether (3×250 ml.)
  2. washThe combined organic extracts were washed with water (100 ml.) and brine (50 ml.)
  3. dry with materialdried (anhydrous magnesium sulfate)
  4. filtrationfiltered
  5. customevaporated to dryness
  6. customdried in vacuo
  7. customto give 34.46 g

Sources & evidence

ORD record
ord-89c19946194d4a158a9cbb1375586293
Source dataset
uspto-grants-1998_03
Patent number
US05723457

Linked notes

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