Citric Acid → (2S)-2-(((tert-butoxy)carbonyl)amino)-3-methoxypropanoic acid

HRID 2269630Notes

Reaction equation

HRID 2269630 reaction equation
[NH:1]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[C@H:2]([C:5]([OH:7])=[O:6])[CH2:3][OH:4].[H-].[Na+].CI.[C:19](O)(=O)CC(CC(O)=O)(C(O)=O)O>CN(C=O)C>[CH3:12][C:11]([O:10][C:8]([NH:1][C@H:2]([C:5]([OH:7])=[O:6])[CH2:3][O:4][CH3:19])=[O:9])([CH3:14])[CH3:13]

Participants

6

Reactant 4

HCID 311Citric AcidHCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 98766N-[tert-butoxycarbonyl]-L-serine

Product 1

HCID 7016354(2S)-2-(((tert-butoxy)carbonyl)amino)-3-methoxypropanoic acid

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

In a DMF solution containing 2.00 g of Boc-Ser-OH, 0.86 g of sodium hydride (60% oily suspension) was added under ice cooling and the resultant mixture was stirred for 30 min. To the resultant solution, 0.72 ml of methyl iodide was added and the resultant solution was stirred for 3 hr. The reaction mixture was neutralized with citric acid and evaporated under reduced pressure. The obtained residue was redissolved in ethyl acetate, and the solution was washed with 5% aqueous citric acid solution and saturated aqueous sodium chloride solution, successively, and dried over anhydrous sodium sulfate. The dried solution was evaporated under reduced pressure. The residue was subjected to a silica gel column chromatography (chloroform:methanol=10:1) and crystallized as its DCHA salt from n-hexane to give 0.79 g of the title compound.

Workup

  1. additionwas added under ice cooling
  2. customevaporated under reduced pressure
  3. dissolutionThe obtained residue was redissolved in ethyl acetate
  4. washthe solution was washed with 5% aqueous citric acid solution and saturated aqueous sodium chloride solution
  5. dry with materialsuccessively, and dried over anhydrous sodium sulfate
  6. customThe dried solution was evaporated under reduced pressure
  7. customcrystallized as its DCHA salt from n-hexane

Sources & evidence

ORD record
ord-c7e583b5117847ff8d0d6168ff54b183
Source dataset
uspto-grants-2001_12
Patent number
US06329502B1

Reaction notes

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