Sodium Bicarbonate → (2S)-5-(tert-butoxy)-2-{[(tert-butoxy)carbonyl]amino}-5-oxopentanoic acid

HRID 1532933Notes

Reaction equation

HRID 1532933 reaction equation
[NH2:1][C@H:2]([C:12]([OH:14])=[O:13])[CH2:3][CH2:4][C:5](=[O:11])[O:6][C:7]([CH3:10])([CH3:9])[CH3:8].[C:15]([O-:18])(O)=[O:16].[Na+]>O.O1CCOCC1>[NH:1]([C:15]([O:18][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:16])[C@H:2]([C:12]([OH:14])=[O:13])[CH2:3][CH2:4][C:5](=[O:11])[O:6][C:7]([CH3:10])([CH3:8])[CH3:9]

Participants

5

Reactant 2

HCID 516892Sodium BicarbonateHCID 7010573(2S)-2-amino-5-(tert-butoxy)-5-oxopentanoic acid

Product 1

HCID 6993432(2S)-5-(tert-butoxy)-2-{[(tert-butoxy)carbonyl]amino}-5-oxopentanoic acid

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 312751,4-DioxaneSolvent

Procedure

H-Glu(OtBu)-OH (Rf(BuOH/AcOH/H2O 4:1:1 v/v/v): 0.52, [α]D=+9.3° C.=1.05 H2O, mp: 181° C. (dec.); lit24: [α]D=+9.8° C.=2 H2O, mp: 182° C.) (2.0 g, 9.85 mmol), NaHCO3 (1.86 g, 22.2 mmol, 2.25 eq.) were dissolved in H2O (40 mL) and Boc2O25 (2.36 g, 10.8 mmol, 1.10 eq.) dissolved in dioxane (20 mL) was added. The reaction mixture became turbid and gas evolution started. After 3 hrs of stirring at room temperature, the reaction mixture was partially evaporated in vacuo. The aqueous solution was acidified with 10% citric acid and the precipitating oil was taken up into EtOAc (three extractions 20 mL). The EtOAc layer was subsequently washed with H2O (five times 30 mL), saturated NaCl (three times 30 mL) and dried on Na2SO4. The residue obtained after evaporation in vacuo was an oil which crystallized slowly. Yield: 2.91 g (98%), Rf(BuOH/AcOH/H2O 4:1:1 v/v/v): 0.87, Rf(CH2Cl2/MeOH 9:1 v/v): 0.17, [α]D=−10.3° C.=0.93 MeOH, mp: 98-99° C. (lit26: [α]D=−10.9° C.=1 MeOH, mp:101-102° C.), 1H NMR (CDCl3): δ=1.44 (s, 18H, Boc/OtBu (2×9H)); 1.99/2.18 (dm, 2H, β-CH2); 2.38 (m, 2H, γ-CH2); 4.34 (m, 1H, α-CH); 5.23 (d, 1H, NH).

Workup

  1. additionwas added
  2. customthe reaction mixture was partially evaporated in vacuo
  3. washThe EtOAc layer was subsequently washed with H2O (five times 30 mL), saturated NaCl (three times 30 mL)
  4. customdried on Na2SO4
  5. customThe residue obtained
  6. customafter evaporation in vacuo
  7. customcrystallized slowly

Sources & evidence

ORD record
ord-036ab89d60e7495ba9afb496dc2aa7ae
Source dataset
uspto-grants-2001_03
Patent number
US06207399B1

Reaction notes

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