反应详情

温度

0 °C

To a suspension of 7-hydroxy-2-oxo-2H-chromene-3-carbothioic acid amide (221 mg, 1.0 mmol) in anhydrous N,N-dimethylformamide (5 mL) stirred at 0° C., sodium hydride (60% in oil, 44 mg, 1.1 mmol) was added portionwise. During addition a clear solution was formed with moderate effervescence. After 10 min, a solution of 2-bromo-3-oxo butyric acid tert-butyl ester (474 mg, 2.0 mmol) in anhydrous N,N-dimethylformamide (2 mL) was added dropwise and the mixture was stirred at room temperature for 16 h. The reaction was poured into water (20 mL) and extracted with chloroform (3×10 mL). The combined organic extracts were washed with water (3×5 mL), dried over MgSO4 and concentrated. The residue was triturated with diethyl ether, the solid product was collected and washed with diethyl ether. The title compound (224 mg, 0.623 mmol, 62.3%) was obtained as a yellow solid.

1. additionDuring addition a clear solution
2. customwas formed with moderate effervescence
3. stirringthe mixture was stirred at room temperature for 16 h
4. extractionextracted with chloroform (3×10 mL)
5. washThe combined organic extracts were washed with water (3×5 mL)
6. dry with materialdried over MgSO4
7. concentrationconcentrated
8. customThe residue was triturated with diethyl ether
9. customthe solid product was collected
10. washwashed with diethyl ether