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

HRID 58662Notes

Reaction equation

HRID 58662 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-24248dc4354d4e08bdce9172e0798284
Source dataset
uspto-grants-2016_09
Patent number
US09434722B2

Reaction notes

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