Isopropyl chloroformate → HCID 53997155, compound

HRID 1279092Notes

Reaction equation

HRID 1279092 reaction equation
[NH2:1][C@@H:2]([C:6]([S:9][CH:10]([CH3:12])[CH3:11])([CH3:8])[CH3:7])[C:3]([OH:5])=[O:4].O1CCOCC1.[OH-].[Na+].Cl[C:22]([O:24][CH:25]([CH3:27])[CH3:26])=[O:23]>O>[CH:25]([O:24][C:22]([NH:1][C@@H:2]([C:6]([S:9][CH:10]([CH3:12])[CH3:11])([CH3:7])[CH3:8])[C:3]([OH:5])=[O:4])=[O:23])([CH3:27])[CH3:26]

Participants

6

Reactant 4

HCID 7917Isopropyl chloroformateHCID 14798Sodium Hydroxide3×HCID 312751,4-DioxaneHCID 22958551HCID 22958551, compound

Product 1

HCID 53997155HCID 53997155, compoundYield 64%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

2-(R)-Amino-3-isopropylsulfanyl-3-methyl-butyric acid (17 mmol; crude material obtained from D-penicillamine and isopropyl iodide) was dissolved in 40 mL of water and 40 mL of dioxane and pH 9.5 was adjusted by adding aqueous NaOH. Isopropyl chloroformate (22 mL; 1 M solution in toluene) was slowly added at 5° C. while maintaining pH 9.5 by addition of the appropriate amount of aqueous NaOH. Stirring was continued for 6 h at room temperature. Aqueous NaOH was added (pH 11) and the dioxane removed in vacuo followed by extraction of the remaining aqueous solution with ethyl acetate. KHSO4 was added and the acidified aqueous solution extracted with ethyl acetate several times, Evaporation of the solvent in vacuo gave a yellow oil, which was purified by HPLC (RP-18; pH 2.3; H2O/CH3OH 3/7) to give 3.0 g (64%) of the title compound as a colorless oil. (−)-APCI-MS: 276 ([M−H]−).

Workup

  1. temperaturewhile maintaining pH 9.5
  2. customthe dioxane removed in vacuo
  3. extractionfollowed by extraction of the remaining aqueous solution with ethyl acetate
  4. additionKHSO4 was added
  5. extractionthe acidified aqueous solution extracted with ethyl acetate several times, Evaporation of the solvent in vacuo
  6. customgave a yellow oil, which
  7. customwas purified by HPLC (RP-18; pH 2.3; H2O/CH3OH 3/7)

Sources & evidence

ORD record
ord-f305e649e1694f9ab55d9aee249793fd
Source dataset
uspto-grants-2002_09
Patent number
US06444672B1

Reaction notes

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