Citric Acid → (2S,3S)-2-tert-butoxycarbonylamino-3-(2-nitro-phenylamino)-butyric acid

HRID 1486031Notes

Reaction equation

HRID 1486031 reaction equation
C[O:2][C:3](=[O:25])[C@@H:4]([NH:17][C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[C@@H:5]([NH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[N+:14]([O-:16])=[O:15])[CH3:6].[OH-].[Li+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O.O1CCOCC1.O>[C:21]([O:20][C:18]([NH:17][C@@H:4]([C@@H:5]([NH:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][C:9]=1[N+:14]([O-:16])=[O:15])[CH3:6])[C:3]([OH:25])=[O:2])=[O:19])([CH3:22])([CH3:23])[CH3:24]

Participants

6

Reactant 3

HCID 311Citric AcidHCID 3939Lithium HydroxideHCID 90079370(2S,3S)-2-tert-butoxycarbonylamino-3-(2-nitro-phenylamino)-butyric acid methyl ester

Product 1

HCID 90079360(2S,3S)-2-tert-butoxycarbonylamino-3-(2-nitro-phenylamino)-butyric acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 218864351,4-Dioxane--water (1/1)Solvent

Procedure

To a solution of (2S,3S)-2-tert-butoxycarbonylamino-3-(2-nitro-phenylamino)-butyric acid methyl ester (5.71 g, 16.2 mmol) in dioxane water (1:1, 100 ml) was added an aqueous solution of 2.5 M lithium hydroxide (31 ml) and the reaction was stirred at ambient temperature for 2 h. The reaction was made acidic with 10% aqueous citric acid, diluted with water (60 ml) and extracted with ethyl acetate (2×100 mL). The organic layers were combined, washed with water (1×50 mL), brine, dried over sodium sulfate, filtered and concentrated in vacuo to give (2S,3S)-2-tert-butoxycarbonylamino-3-(2-nitro-phenylamino)-butyric acid which was carried to the subsequent step without purification (5.48 g, 99%).

Workup

  1. extractionextracted with ethyl acetate (2×100 mL)
  2. washwashed with water (1×50 mL), brine
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-951b67ba631b4b81a5e1c85e103319ff
Source dataset
uspto-grants-2016_08
Patent number
US09422331B2

Reaction notes

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