Sulfuric Acid → L-Phenylalanine, methyl ester

HRID 52750

Reaction equation

HRID 52750 reaction equation
S(=O)(=O)(O)O.[NH2:6][C@H:7]([C:15]([OH:17])=[O:16])[CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.N[C@@H:19](C(O)=O)CC1C=CC=CC=1>CO>[CH3:19][O:16][C:15](=[O:17])[C@H:7]([CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)[NH2:6]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 6140L-Phenylalanine2×HCID 71567D-Phenylalanine2×

Product 1

HCID 736234L-Phenylalanine, methyl esterYield 12.6%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

5.8 ml of 95% sulfuric acid was added to 33 ml of methanol and heat-refluxed. Subsequently, methanol was removed under reduced pressure and water was added to provide 15 ml of CH3SO4H solution. 2.7 g L-Phe and 0.3 g (D-Phe/L-Phe=11.1%) D-Phe were added thereto and dissolved by heat, following which was then cooled with ice. The separated crystals were isolated by suction filtration and washed with a small amount of cold water. Yield, 3.73 g. The results of HPLC analysis using an optically active column revealed that the crystals contained 1.66 g L-Phe and 0.049 g (D-Phe/L-Phe=2.9%) D-Phe. In addition, 41 mg of L-phenylalanine methyl ester was also produced as a result of esterification of L-Phe with the methanol remaining in the CH3SO4H solution.

Workup

  1. temperatureheat-refluxed
  2. customSubsequently, methanol was removed under reduced pressure and water
  3. additionwas added
  4. customto provide 15 ml of CH3SO4H solution
  5. dissolutiondissolved
  6. temperatureby heat
  7. temperaturewas then cooled with ice
  8. customThe separated crystals were isolated by suction filtration
  9. washwashed with a small amount of cold water
  10. customYield
  11. customThe results of HPLC analysis

Sources & evidence

ORD record
ord-c867ddd3934a4c33b216e8b9d4aa106b
Source dataset
uspto-grants-1997_04
Patent number
US05616766

Linked notes

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