反应详情

温度

-10 °C

The product of Example 27 (1 g, 3.93 mnmol) was dissolved in Et2O (35 mL) and TMEDA (1.7 mL, 1.18 mmol) and cooled to −78° C. n-Butyllithium (4.75 mL, 11.87 mmol) was added dropwise and the reaction was allowed to stir for 15 minutes at −78 C. before warming to −10° C. for 2.5 hours. The solution was cooled back to −78° C. and methyl chloroforrnate (0.6 mL, 7.8 mmol) dissolved in Et2O (4.5 mL) was added dropwise. The reaction was held at −78° C. for 10 minutes and then warmed to −10° C. and allowed to stir for 1.5 hours before quenching with NH4Cl (sat). The reaction mixture was extracted 3× with EtOAc. The organics were combined, washed with brine, dried over MgSO4, concentrated in vacuo. The residue was purified by column chromatography using hexane/ethyl acetate as eluant (gradient 9/1 to 4/1) to provide 0.423 g (34%) of tert-butyl N-(4-carbomethoxy-2,6-dimethoxy-3-pyridyl)carbamate as a white solid. Electrospray Mass Spec: 312.8 (M+H)+

1. additionwas added dropwise
2. temperatureThe solution was cooled back to −78° C.
3. additionwas added dropwise
4. waitThe reaction was held at −78° C. for 10 minutes
5. temperaturewarmed to −10° C.
6. stirringto stir for 1.5 hours
7. custombefore quenching with NH4Cl (sat)
8. extractionThe reaction mixture was extracted 3× with EtOAc
9. washwashed with brine
10. dry with materialdried over MgSO4
11. concentrationconcentrated in vacuo
12. customThe residue was purified by column chromatography