Ethyl bromoacetate → tert-butyl(2S,3S)-2-[(2-ethoxy-2-oxoethyl)amino]-3-methylpentanoate

HRID 243609Notes

Reaction equation

HRID 243609 reaction equation
Cl.[C:2]([O:6][C:7](=[O:14])[C@H:8]([C@H:10]([CH2:12][CH3:13])[CH3:11])[NH2:9])([CH3:5])([CH3:4])[CH3:3].C(N(CC)CC)C.Br[CH2:23][C:24]([O:26][CH2:27][CH3:28])=[O:25]>CN(C)C=O>[CH2:27]([O:26][C:24](=[O:25])[CH2:23][NH:9][C@@H:8]([C@@H:10]([CH3:11])[CH2:12][CH3:13])[C:7]([O:6][C:2]([CH3:4])([CH3:5])[CH3:3])=[O:14])[CH3:28]

Participants

5

Reactant 3

HCID 7748Ethyl bromoacetateHCID 8471Triethylamine2×HCID 11687228tert-Butyl isoleucinate--hydrogen chloride (1/1)

Product 1

HCID 54030946tert-butyl(2S,3S)-2-[(2-ethoxy-2-oxoethyl)amino]-3-methylpentanoateYield 93.3%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of (L)-iso-leucine tert-butyl ester hydrochloride (5 g, 22.34 mmol) in N,N-dimethylformamide (30 mL) was added triethylamine (3.1 mL, 22.34 mmol), and the mixture was stirred for 1 h. The reaction was filtered to remove solid salts, and the filtrate was treated with triethylamine (9.3 mL, 67.0 mmol) and ethyl bromoacetate (9.9 mL, 67.0 mmol), and the reaction was stirred for 3 h at 25° C. The reaction was partitioned between ethyl acetate and water, and the organic was washed with brine and dried over MgSO4, filtered and evaporated to give 5.7 g (93%) of the product which was used without further purification.

Workup

  1. filtrationThe reaction was filtered
  2. customto remove solid salts
  3. stirringthe reaction was stirred for 3 h at 25° C
  4. customThe reaction was partitioned between ethyl acetate and water
  5. washthe organic was washed with brine
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. customevaporated

Sources & evidence

ORD record
ord-00f2cc18424549f6a45967ce3545bf0d
Source dataset
uspto-grants-2014_02
Patent number
US08653141B2

Reaction notes

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