Sodium Chloride → (2S,3S)-2-Hydroxy-3-methylpentanoic acid

HRID 617691Notes

Reaction equation

HRID 617691 reaction equation
C([O:3][C:4](=[O:11])[C:5](=[O:10])[C@@H:6]([CH3:9])[CH2:7][CH3:8])C.N([O-])=O.[Na+].C([O-])(O)=O.[Na+].[Na+].[Cl-]>OS(O)(=O)=O.O>[OH:10][C@@H:5]([C@@H:6]([CH3:9])[CH2:7][CH3:8])[C:4]([OH:11])=[O:3]

Participants

7

Reactant 4

HCID 5234Sodium ChlorideHCID 516892Sodium BicarbonateHCID 18391773226414-39-7HCID 23668193Sodium Nitrite

Product 1

HCID 854025(2S,3S)-2-Hydroxy-3-methylpentanoic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1118Sulfuric AcidSolvent

Procedure

To a solution of L-isoleucine(+) [1] (11.73 g, 89.4 mmol, [α]D20 =+40° (5% in 6M HCl)) in 300 ml of 1N aq. H2SO4 at 2° was slowly added (ca. 12 h) a solution of NaNO2 (19.5 g, 0.28 mol) in 300 ml of demineralised water. After stirring overnight at room temperature, 7.7 g of powdered NaHCO3 were added to bring the pH above 2. The solution was saturated with NaCl and extracted 6 times with ethyl acetate, maintaining the pH between 2 and 3 (1N aq. H2SO4, pH meter). After drying (Na2SO4), the organic layer was concentrated and the crude product (10.73 g, 91%) was recrystallised from hexane/ethyl acetate 9/1 at -30° to give pure (+)-(2S, 3S)-2-hydroxy-3-methylpentanoic acid [2].

Workup

  1. extractionextracted 6 times with ethyl acetate
  2. temperaturemaintaining the pH between 2 and 3 (1N aq. H2SO4, pH meter)
  3. dry with materialAfter drying (Na2SO4)
  4. concentrationthe organic layer was concentrated
  5. customthe crude product (10.73 g, 91%) was recrystallised from hexane/ethyl acetate 9/1 at -30°

Sources & evidence

ORD record
ord-b36ec97d4fc74e5688392d727545ec10
Source dataset
uspto-grants-1999_09
Patent number
US05952292

Reaction notes

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