反应详情

A solution of 4-bromobenzeneboronic acid (6.0 g) in absolute ethanol (15 ml) was added slowly to a stirred mixture of a solution of 3-bromopyridine (4.7 g) in toluene (30 ml), a saturated aqueous solution of sodium carbonate (10 ml) and tetrakistriphenylphosphine palladium [0] (1.0 g) under an atmosphere of argon. The mixture was then heated to reflux and stirred at reflux under an atmosphere of argon for 6 hours. The mixture was cooled and water (50 ml) added. The resulting mixture was extracted with ethyl acetate (3×30 ml). The ethyl acetate extracts were combined, and then extracted with 2M aqueous hydrochloric acid (3×20 ml). The acidic extracts were combined, cooled by the addition of ice and basified by the addition of sodium hydroxide solution (1.35 g.cm-3) to give a pH of 9. The mixture was then extracted with ethyl acetate (3×30 ml). These ethyl acetate extracts were combined, dried (MgSO4) and evaporated to afford 4-(pyrid-3-yl)bromobenzene as a colourless oil (1.2 g); NMR (CDCl3): 7.3-7.5 (3H, m), 7.6(2H, d), 7.85(1H, d of t), 8.6(1H, d of d) and 8.8(1H, d).

1. temperatureThe mixture was then heated
2. temperatureto reflux
3. temperatureat reflux under an atmosphere of argon for 6 hours
4. temperatureThe mixture was cooled
5. extractionThe resulting mixture was extracted with ethyl acetate (3×30 ml)
6. extractionextracted with 2M aqueous hydrochloric acid (3×20 ml)
7. temperaturecooled by the addition of ice
8. additionbasified by the addition of sodium hydroxide solution (1.35 g.cm-3)
9. customto give a pH of 9
10. extractionThe mixture was then extracted with ethyl acetate (3×30 ml)
11. dry with materialdried (MgSO4)
12. customevaporated