Hydrochloric Acid → (E)-5-tert-Butoxycarbonylamino-3,5-dimethylhex-2-enoic acid ethylester

HRID 1601946Notes

Reaction equation

HRID 1601946 reaction equation
[C:1]([O:5][C:6](=[O:15])[NH:7][C:8]([CH3:14])([CH3:13])[CH2:9][C:10](=O)[CH3:11])([CH3:4])([CH3:3])[CH3:2].[C:16]([O:19][CH2:20][CH3:21])(=[O:18])[CH3:17].Cl>O1CCCC1>[CH2:20]([O:19][C:16](=[O:18])/[CH:17]=[C:10](\[CH3:11])/[CH2:9][C:8]([NH:7][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:15])([CH3:13])[CH3:14])[CH3:21]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 8857Ethyl AcetateHCID 15933114Tert-butyl (2-methyl-4-oxopentan-2-yl)carbamate

Product 1

HCID 10684548(E)-5-tert-Butoxycarbonylamino-3,5-dimethylhex-2-enoic acid ethylester

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

(1,1-dimethyl-3-oxobutyl)carbamic acid tert-butylester (2.5 g; 11.6 mmol) was dissolved in tetrahydrofuran (15 mL) and added dropwise to the reaction mixture which was heated to reflux for 12 h. Ethyl acetate (100 mL) and hydrochloric acid (1 N; 100 mL) were added and the phases were separated. The aqueous phase was extracted with ethyl acetate (3×50 mL). The combined organic phases were washed with an aqueous solution of sodium hydrogen carbonate (saturated; 100 mL), dried (magnesium sulfate) and evaporated in vacuo. The residue was chromatographed on silica (3×40 cm) using ethyl acetate/heptane (1:2) as eluent to afford 2.0 g of (E)-5-tert-Butoxycarbonylamino-3,5-dimethylhex-2-enoic acid ethyl ester.

Workup

  1. additionadded dropwise to the reaction mixture which
  2. temperaturewas heated
  3. temperatureto reflux for 12 h
  4. customthe phases were separated
  5. extractionThe aqueous phase was extracted with ethyl acetate (3×50 mL)
  6. washThe combined organic phases were washed with an aqueous solution of sodium hydrogen carbonate (saturated; 100 mL)
  7. dry with materialdried (magnesium sulfate)
  8. customevaporated in vacuo
  9. customThe residue was chromatographed on silica (3×40 cm)

Sources & evidence

ORD record
ord-e9003fee7c314e28ad0b0c31627a570b
Source dataset
uspto-grants-1999_11
Patent number
US05977178

Reaction notes

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