反应详情

To a cooled mixture of 6-fluoro picolinic acid (1.19 g, 8.43 mmol), N,O-dimethylhydroxylamine (860 mg, 8.82 mmol) and Et3N (3.27 mL, 23.52 mmol) in CH2Cl2 (10 mL) was added 1-propane phosphonic acid cyclic anhydride (4.49 mL, 7.05 mmol; 50 wt % solution in EtOAc) dropwise and stirred at room temperature for 3 h. The reaction mixture was filtered, washed with CH2Cl2 (2×10 mL), evaporated to dryness, and subjected to column chromatography (SiO2, 40% EtOAc-hexanes) to obtain 6-fluoro-pyridine-2-carboxylic acid methoxy-methyl-amide (1.19 g) in 73% yield. ESMS m/z (relative intensity): 185 (M+H)+ (100).

1. filtrationThe reaction mixture was filtered
2. washwashed with CH2Cl2 (2×10 mL)
3. customevaporated to dryness