Sulfuric Acid → Benzenepropanoic acid, beta-(benzoylamino)-alpha-hydroxy-, methyl ester, (alphaR,betaS)-

HRID 1584650Notes

Reaction equation

HRID 1584650 reaction equation
[NH2:1][C@@H:2]([C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)[CH:3]([OH:7])[C:4]([OH:6])=[O:5].OS(O)(=O)=O.[OH-].[Na+].[C:21]([O-])(O)=O.[Na+].[C:26](Cl)(=[O:33])[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1>CO>[CH3:21][O:5][C:4](=[O:6])[C@H:3]([OH:7])[C@@H:2]([NH:1][C:26](=[O:33])[C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

7

Reactant 5

HCID 1118Sulfuric AcidHCID 7412Benzoyl chlorideHCID 14798Sodium HydroxideHCID 516892Sodium BicarbonateHCID 57197199HCID 57197199, compound

Product 1

HCID 182104Benzenepropanoic acid, beta-(benzoylamino)-alpha-hydroxy-, methyl ester, (alphaR,betaS)-

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a suspension of 15.0 g (55.5 mmol, thus only 67%) (2RS,3S)-2-Amino-3-hydroxy-2-phenylpropionic acid (from Example 3) in 250 ml methanol one carefully adds dropwise at room temperature 5 ml of concentrated H2SO4 and heated for 6 hours under reflux. 50 ml H2 0 are added and the pH adjusted to 6.8 with 50% NaOH at +5° C. Subsequently the methanol is removed by vacuum distillation, the mixture cooled to +5° C. and reacted with 10 g (120 mmol) NaHCO3 and 8.4 ml (72 mmol) benzoylchloride are added dropwise over 20 minutes. After further stirring for 2 hours the precipitated raw product is vacuum filtered, recrystallized out of 150 ml of methanol and dried to a colorless product at 50° C. in a vacuum drying vessel.

Workup

  1. temperatureheated for 6 hours
  2. temperatureunder reflux
  3. addition50 ml H2 0 are added
  4. customSubsequently the methanol is removed by vacuum distillation
  5. temperaturethe mixture cooled to +5° C.
  6. additionare added dropwise over 20 minutes
  7. customprecipitated raw product
  8. filtrationfiltered
  9. customrecrystallized out of 150 ml of methanol
  10. customdried to a colorless product at 50° C. in a vacuum
  11. customdrying vessel

Sources & evidence

ORD record
ord-4c1332ba006442ce94e60c6c7cb16e49
Source dataset
uspto-grants-1999_08
Patent number
US05932758

Reaction notes

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