Ammonium formate → Ethyl 4-ethyloxazole-5-carboxylate

HRID 639657Notes

Reaction equation

HRID 639657 reaction equation
[CH2:1]([O:3][C:4](=[O:11])[CH:5](Cl)[C:6](=O)[CH2:7][CH3:8])[CH3:2].[CH:12]([O-:14])=O.[NH4+:15]>C(O)=O>[CH2:1]([O:3][C:4]([C:5]1[O:14][CH:12]=[N:15][C:6]=1[CH2:7][CH3:8])=[O:11])[CH3:2]

Participants

4

Reactant 2

HCID 2723923Ammonium formateHCID 12923424Ethyl 2-chloro-3-oxopentanoate

Product 1

HCID 19018567Ethyl 4-ethyloxazole-5-carboxylateYield 29.5%

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

Procedure

2-Chloro-3-oxo-pentanoic acid ethyl ester (13.5 g) was dissolved in 75 ml of 95% formic acid. Ammonium formate (27.6 g) was added and the reaction heated at reflux under nitrogen for 6 hours. After cooling to room temperature the reaction mixture was evaporated and the residue extracted with ether (3×50 ml). Combined ether extracts were washed with water and brine, dried (MgSO4), filtered and evaporated to give a crude oil (9 g). The oil was purified by chromatography on silica gel, eluting with CH2Cl2/MeOH 99:1, providing the title compound (3.77 g) as a pale brown oil.

Workup

  1. temperaturethe reaction heated
  2. temperatureat reflux under nitrogen for 6 hours
  3. customwas evaporated
  4. extractionthe residue extracted with ether (3×50 ml)
  5. washCombined ether extracts were washed with water and brine
  6. dry with materialdried (MgSO4)
  7. filtrationfiltered
  8. customevaporated
  9. customto give a crude oil (9 g)
  10. customThe oil was purified by chromatography on silica gel
  11. washeluting with CH2Cl2/MeOH 99:1

Sources & evidence

ORD record
ord-969e100c556f41658ddb4f7cff307a9e
Source dataset
uspto-grants-2010_04
Patent number
US07691877B2

Reaction notes

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