反应详情

温度

-78 °C

The product of Example 27 (1 g, 3.93 mmol) 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 chloroformate (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. temperaturebefore warming to -10° C. for 2.5 hours
3. temperatureThe solution was cooled back to -78° C.
4. additionwas added dropwise
5. waitThe reaction was held at -78° C. for 10 minutes
6. temperaturewarmed to -10° C.
7. stirringto stir for 1.5 hours
8. custombefore quenching with NH4Cl(sat)
9. extractionThe reaction mixture was extracted 3× with EtOAc
10. washwashed with brine
11. dry with materialdried over MgSO4
12. concentrationconcentrated in vacuo
13. customThe residue was purified by column chromatography