Ethyl oxoacetate → Ethyl 1,3-oxazole-5-carboxylate

HRID 1918651Notes

Reaction equation

HRID 1918651 reaction equation
[N:1]12CCCN=[C:7]1CCCC[CH2:2]2.[C:12]([O:16][CH2:17][CH3:18])(=[O:15])[CH:13]=[O:14].S(C[N+]#[C-])(C1C=CC(C)=CC=1)(=O)=O>ClCCl>[O:14]1[C:13]([C:12]([O:16][CH2:17][CH3:18])=[O:15])=[CH:7][N:1]=[CH:2]1

Participants

5

Reactant 3

HCID 70211Ethyl oxoacetateHCID 811841,8-Diazabicyclo(5.4.0)undec-7-eneHCID 161915Tosylmethyl isocyanide

Product 1

HCID 10964603Ethyl 1,3-oxazole-5-carboxylateYield 54%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

1,8-Diazabicyclo[5.4.0]undec-7-ene (0.574 mL; 3.84 mmol) was added simultaneously with ethyl glyoxalate (50% in toluene, 0.659 mL; 3.33 mmol) to a mixture of tosylmethyl isocyanide (0.500 g; 2.560 mmol) in dichloromethane (10 mL) at 0° C. The resulting mixture was stirred at room temperature for 3 hours, diluted in dichloromethane and washed with sodium hydrogen sulphate, sodium carbonate, dried over magnesium sulphate and concentrated under reduced pressure. The crude mixture was purified by flash chromatography on silica (eluent 5 to 60% ethyl acetate in heptane) to yield 0.194 g (54%) of ethyl oxazole-5-carboxylate as a colorless oil.

Workup

  1. washwashed with sodium hydrogen sulphate, sodium carbonate
  2. dry with materialdried over magnesium sulphate
  3. concentrationconcentrated under reduced pressure
  4. customThe crude mixture was purified by flash chromatography on silica (eluent 5 to 60% ethyl acetate in heptane)

Sources & evidence

ORD record
ord-d4c555c1b9c14ae9a0aed3e07b6a2d7b
Source dataset
uspto-grants-2013_12
Patent number
US08618138B2

Reaction notes

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