反应详情

温度

110 °C

Diphenylphosphoryl azide (DPPA) (129 mmol) was added to a mixture of 2-chloro-3-fluoro-pyridine-4-carboxylic acid (85.7 mmol), Et3N (257 mmol) in 1:1 tert-BuOH/toluene (200 mL). The mixture was heated at 110° C. for 4 h. Mixture was diluted with H2O and extracted with DCM. The organic layer was dried (Na2SO4) and concentrated. The residue was purified by flash column chromatography (SiO2, 100:0 to 80:20 DCM/EtOAc) to yield the desired product tert-butyl N-(2-chloro-3-fluoro-4-pyridyl)carbamate.

1. extractionextracted with DCM
2. dry with materialThe organic layer was dried (Na2SO4)
3. concentrationconcentrated
4. customThe residue was purified by flash column chromatography (SiO2, 100:0 to 80:20 DCM/EtOAc)