Propanoic acid, 2-bromo-2-methyl-, ethyl ester → 2-(N-Boc-aminooxy)isobutyric acid ethyl ester

HRID 79000

Reaction equation

HRID 79000 reaction equation
[C:1]([NH:8][OH:9])([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2].[OH-].[K+].[CH2:12]([O:14][C:15](=[O:20])[C:16](Br)([CH3:18])[CH3:17])[CH3:13]>C(O)C>[CH2:12]([O:14][C:15](=[O:20])[C:16]([O:9][NH:8][C:1]([O:3][C:4]([CH3:7])([CH3:6])[CH3:5])=[O:2])([CH3:18])[CH3:17])[CH3:13]

Participants

5

Reactant 3

HCID 11745Propanoic acid, 2-bromo-2-methyl-, ethyl esterHCID 14797Potassium HydroxideHCID 97534tert-butyl N-hydroxycarbamate

Product 1

HCID 108243852-(N-Boc-aminooxy)isobutyric acid ethyl esterYield 99%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of N-Boc-hydroxylamine (5.2 g, 39.05 mmol) in ethanol (100 mL) was added potassium hydroxide (2.63 g, 46.86 mmol), the mixture stirred at room temperature until a solution was formed. 2-Bromoisobutyric acid ethyl ester (6.87 mL, 46.9 mmol) was added and the reaction mixture heated at reflux for 18 hours. The reaction mixture was cooled to room temperature then filtered, and the filtrate was concentrated in vacuo. The resultant oily residue was partitioned between water (75 mL) and diethyl ether and the aqueous fraction was extracted with diethyl ether (2×100 mL). The combined organic extracts were dried (Na2SO4), filtered and concentrated in vacuo to give the title compound as a clear oil (9.5 g, 99%). LCMS (method C): RT=2.55 min, [M+H]+=248. 1H NMR (CDCl3, 400 MHz) 4.20 (q, 2H), 1.50 (s, 6H), 1.49 (s, 9H), 1.30 (t, 3H).

Workup

  1. customwas formed
  2. temperaturethe reaction mixture heated
  3. temperatureat reflux for 18 hours
  4. temperatureThe reaction mixture was cooled to room temperature
  5. filtrationthen filtered
  6. concentrationthe filtrate was concentrated in vacuo
  7. customThe resultant oily residue was partitioned between water (75 mL) and diethyl ether
  8. extractionthe aqueous fraction was extracted with diethyl ether (2×100 mL)
  9. dry with materialThe combined organic extracts were dried (Na2SO4)
  10. filtrationfiltered
  11. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-ec5c5cb3f62f46ea91771219c60f6fd9
Source dataset
uspto-grants-2014_09
Patent number
US08841462B2

Linked notes

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