反应详情

n-Butyl lithium (1 mL, 1.6 M in hexane, 1.6 mmol) was added dropwise to a solution of 2-(4-bromo-phenyl)-1,1,1,3,3,3-hexamethyl-disilazane (0.7 g, 2.20 mmol) in dry diethyl ether (10 mL) and stirred at room temperature for 15 min then cooled in an ice bath. A solution of 4′,6′-dimethyl-2,3,5,6-tetrahydro-[1,2′]bipyridinyl-4-one (0.3 g, 1.47 mmol) in dry tetrahydrofuran (15 mL) was added and the resulting mixture heated at 50° C. for 2.5 h. The reaction mixture was brought to room temperature and stirred overnight, then cooled to 0° C. and quenched into ammonium chloride solution. The organics were extracted with ethyl acetate, washed with water, brine, dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to yield the crude compound, to which was added 2N HCl and the resulting mixture was stirred overnight at room temperature. The pH of the solution was adjusted to pH 10 with dilute sodium hydroxide and the organics extracted with chloroform. The extract was dried over anhydrous sodium sulfate, filtered and evaporated to dryness to give a red viscous oil which was purified by washing with pentane (5×10 mL) to afford 4-(4-amino-phenyl)-4′,6′-dimethyl-3,4,5,6-tetrahydro-2H-[1,2′]-bipyridinyl-4-ol (0.25 g, 57.3%).

1. temperaturethen cooled in an ice bath
2. temperaturethe resulting mixture heated at 50° C. for 2.5 h
3. customwas brought to room temperature
4. stirringstirred overnight
5. temperaturecooled to 0° C.
6. customquenched into ammonium chloride solution
7. extractionThe organics were extracted with ethyl acetate
8. washwashed with water, brine
9. dry with materialdried over anhydrous sodium sulfate
10. filtrationfiltered
11. customevaporated in vacuo
12. customto yield the crude compound
13. stirringthe resulting mixture was stirred overnight at room temperature
14. extractionthe organics extracted with chloroform
15. dry with materialThe extract was dried over anhydrous sodium sulfate
16. filtrationfiltered
17. customevaporated to dryness
18. customto give a red viscous oil which
19. customwas purified
20. washby washing with pentane (5×10 mL)