反应详情

温度

65 °C

A mixture of 5-bromo-3-fluoropicolinonitrile (1.0 g, 5 mmol), Pd(dppf)Cl2 (82 mg, 0.1 mmol) and cesium carbonate (3.26, 10 mmol) in THF (20 mL) was degassed with N2. After addition of a solution of triethylborane (1.0 M THF, 10 mL), the mixture was heated at 65° C. for 5 h. The mixture was cooled down to room temperature, and then further cooled down in an ice bath. Into the mixture was added a solution of NaOH (1.2 g) in 20 mL of H2O, followed by H2O2 (30% aqueous 7 mL). The mixture was stirred at 0° C. for 30 min and extracted with ether (4×). The organic layer was washed with brine and dried (MgSO4), and concentrated. The product 5-ethyl-3-fluoropicolinamide (370 mg) was obtained from silica gel chromatography (elution with 0-40% EtOAc/Hex).

1. customwas degassed with N2
2. additionAfter addition of a solution of triethylborane (1.0 M THF, 10 mL)
3. temperatureThe mixture was cooled down to room temperature
4. temperaturefurther cooled down in an ice bath
5. additionInto the mixture was added a solution of NaOH (1.2 g) in 20 mL of H2O
6. extractionextracted with ether (4×)
7. washThe organic layer was washed with brine
8. dry with materialdried (MgSO4)
9. concentrationconcentrated