Acetic Acid → 2-(S)-(Phenylmethylthiomethyl)butanoic Acid

HRID 341998Notes

Reaction equation

HRID 341998 reaction equation
CC(O)=O.[C:5]1([CH2:11][S:12][CH2:13][C@@H:14]([CH2:25][CH3:26])[C:15]([O:17]CC2C=CC=CC=2)=[O:16])[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1>Br.O>[C:5]1([CH2:11][S:12][CH2:13][C@@H:14]([CH2:25][CH3:26])[C:15]([OH:17])=[O:16])[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1

Participants

5

Reactant 2

HCID 176Acetic Acid2×HCID 9995793Benzyl 2-(S)-(Phenylmethylthiomethyl)butanoate

Product 1

HCID 102630532-(S)-(Phenylmethylthiomethyl)butanoic AcidYield 76.2%

Reagents, catalysts & solvents 2

HCID 260Hydrogen BromideSolventHCID 962WaterSolvent

Conditions

Temperature
70 °C

Procedure

Glacial HOAc (120 ml) was added to a suspension of the product of step 8 (32.4 g, approx. 103 mmol) in 210 ml of 30-32% anhydrous HBr in glacial HOAc (approx. 1.03 mol) to complete the dissolution. The resulting solution was stirred at 70° C. for 6 h and at 50° overnight. The reaction mixture was then cooled to r.t., diluted with H2O (750 mL) and extracted with CH2Cl2 (7×). The combined organic extracts were concentrated in vacuo. The residue was diluted with toluene (500 mL) and concentrated in vacuo 5 times to remove HOAc. The residue was dissolved in 1M aq KOH (750 mL), washed with CH2Cl2 (4×), acidified to pH 1 with concentrated HCl and extracted with CH2Cl2 (6×). The combined organic extracts were dried over Na2SO4 and concentrated in vacuo to afford 17.6 g of the title compound as a pale yellow liquid which was used as such for the next step.

Workup

  1. dissolutionthe dissolution
  2. temperatureThe reaction mixture was then cooled to r.t.
  3. extractionextracted with CH2Cl2 (7×)
  4. concentrationThe combined organic extracts were concentrated in vacuo
  5. additionThe residue was diluted with toluene (500 mL)
  6. concentrationconcentrated in vacuo 5 times
  7. customto remove HOAc
  8. dissolutionThe residue was dissolved in 1M aq KOH (750 mL)
  9. washwashed with CH2Cl2 (4×)
  10. extractionextracted with CH2Cl2 (6×)
  11. dry with materialThe combined organic extracts were dried over Na2SO4
  12. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-7183d03f1d9b4c0c8144da726f268837
Source dataset
uspto-grants-1999_01
Patent number
US05856322

Reaction notes

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