3-Cyclohexyl-L-alanine → (S)-a-Hydroxy-cyclohexanepropanoic acid

HRID 2387757Notes

Reaction equation

HRID 2387757 reaction equation
[CH2:1]1[CH2:6][CH2:5][CH:4]([CH2:7][C@H:8](N)[C:9]([OH:11])=[O:10])[CH2:3][CH2:2]1.N([O-])=[O:14].[Na+]>OS(O)(=O)=O>[OH:14][C@@H:8]([CH2:7][CH:4]1[CH2:5][CH2:6][CH2:1][CH2:2][CH2:3]1)[C:9]([OH:11])=[O:10]

Participants

4

Reactant 2

HCID 7124213-Cyclohexyl-L-alanineHCID 23668193Sodium Nitrite

Product 1

HCID 12756210(S)-a-Hydroxy-cyclohexanepropanoic acidYield 52.1%

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

To a stirring suspension of L-cyclohexylalanine (4.00 g, 23.4 mmol) in 0.5M H2SO4 (120 mL) at 0° C. is slowly added dropwise an aqueous solution of NaNO2 (12.1 g in 40 mL H2O). Addition is complete after approximately 1 hour, at which point the solution is allowed to warm to room temperature. After 16 hours, the reaction mixture is extracted with ether (3×100 mL), and the combined organic extracts are washed with 1M NaHSO4 (1×200 mL) and brine (1×100 mL) and then dried over anhydrous Na2SO4. The solvent is removed in vacuo, and the crude product is recrystallized from Et2O/pentane (10 mL/100 mL) to afford 2.1 g (52% yield) of (S)-2-hydroxy-3-cyclohexylpropionic acid as fine white needles.

Workup

  1. additionAddition
  2. waitAfter 16 hours
  3. extractionthe reaction mixture is extracted with ether (3×100 mL)
  4. washthe combined organic extracts are washed with 1M NaHSO4 (1×200 mL) and brine (1×100 mL)
  5. dry with materialdried over anhydrous Na2SO4
  6. customThe solvent is removed in vacuo
  7. customthe crude product is recrystallized from Et2O/pentane (10 mL/100 mL)

Sources & evidence

ORD record
ord-84b6eafd807a4615874b537da10c9c4a
Source dataset
uspto-grants-2012_09
Patent number
US08268996B2

Reaction notes

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