反应详情

To a solution of 2.73 g (14.12 mmol) 2,4-diethyl-pyridine-3-carboxylic acid ethylester in chloroform (109 ml) was added 6.97 g, (70% pure, 28.29 mmol) mCPBA at 0° C. The reaction mixture was stirred at RT for 6 h and was then diluted with chloroform and washed with a sat. NaHCO3 sol and brine. The organic layer was dried over Na2SO4 and concentrated in vacuo. The residue was dissolved in POCl3 (70 ml) and the reaction mixture was heated at 110° C. for 6.5 h. Then excess POCl3 was evaporated and cold water was added to the residue. The mixture was basified with a sat. NaHCO3 sol to pH˜10 and was extracted EtOAc. The organic layer was washed with water and brine, dried over Na2SO4 and concentrated in vacuo. Purification of this residue by CC (hexane/EtOAc 9:1) provided 1.6 g (7.02 mmol, 20%) 6-chloro-2,4-diethyl-pyridine-3-carboxylic acid ethylester.

1. washwashed with a sat. NaHCO3 sol and brine
2. dry with materialThe organic layer was dried over Na2SO4
3. concentrationconcentrated in vacuo
4. dissolutionThe residue was dissolved in POCl3 (70 ml)
5. temperaturethe reaction mixture was heated at 110° C. for 6.5 h
6. customThen excess POCl3 was evaporated
7. additioncold water was added to the residue
8. extractionwas extracted EtOAc
9. washThe organic layer was washed with water and brine
10. dry with materialdried over Na2SO4
11. concentrationconcentrated in vacuo
12. customPurification of this residue by CC (hexane/EtOAc 9:1)