反应详情

温度

-75 °C

To a solution of butyllithium (1.6M in hexanes, 9.7 ml, 16 mmol) in 25 ml of anhydrous ether at −78° C. was added 3-bromopyridine (1.5 ml, 16 mmol) over 5 min. The resulting mixture was stirred at −75° C. for 1 h. A suspension of 2-chloropyrimidine (1.8 g, 16 mmol) in 15 ml of ether was then added in portions over 8 min. The resulting suspension was stirred for 30 min at −30° C. and allowed to warm to 0° C. for 1 h. The reaction was quenched with water (0.5 ml, 1.5 eq.) in THF (5 ml) and then 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (3.8 g, 17 mmol) in THF (12 ml) was added. The resulting suspension was stirred at RT for 15 min, then cooled to 0° C. Hexane (13 mL) was added followed by 0° C. solution of NaOH (12 ml, 3N). The suspension was stirred at 0° C. for 5 min, 50 ml of water was added and the layers were separated. The organic layer was dried (Na2SO4) and concentrated in vacuo. The crude product was dissolved in DCM and chromatographed through a Redi-Sep® pre-packed silica gel column (120 g), eluting with a gradient of 20% to 65% EtOAc in hexane, to provide 2-chloro-4-(pyridin-3-yl)pyrimidine as off-white solid. Found M+H+=192, 194

1. additionwas then added in portions over 8 min
2. stirringThe resulting suspension was stirred for 30 min at −30° C.
3. temperatureto warm to 0° C. for 1 h
4. stirringThe resulting suspension was stirred at RT for 15 min
5. temperaturecooled to 0° C
6. customfollowed by 0° C.
7. stirringThe suspension was stirred at 0° C. for 5 min
8. customthe layers were separated
9. dry with materialThe organic layer was dried (Na2SO4)
10. concentrationconcentrated in vacuo
11. dissolutionThe crude product was dissolved in DCM
12. customchromatographed through a Redi-Sep® pre-packed silica gel column (120 g)
13. washeluting with a gradient of 20% to 65% EtOAc in hexane