反应详情

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.

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)