反应详情

A suspension of 2-bromo-5-fluorobenzonitrile (10.0 g, 50 mmol), potassium fluoride (9.59 g, 165 mmol) and 2,6-difluorophenylboronic acid (9.87 g, 62.5 mmol) in tetrahydrofuran (120 ml) and water (15 ml) was degassed with nitrogen for 30 min. Tris(dibenzylidineacetone)-dipalladium(0) (916 mg, 1.0 mmol) and tri-tert-butylphosphine (10% w/w solution in hexane, 0.5 ml) were added and the mixture stirred at ambient temperature for 18 h. The black solution was washed with 1N sodium hydroxide solution (2×100 ml), and the aqueous phase was re-extracted with diethyl ether (100 ml). The combined organic layer was washed with brine (50 ml), filtered through a glass microfibre filter paper then evaporated to give an orange solid. The solid was suspended in 2-propanol (120 ml) and heated to 70° C. to aid dissolution. The solution was left to cool to ambient temperature then water (120 ml) added dropwise over 1 h. The solid was filtered and washed with 2-propanol/water (1:1, 30 ml) then dried under vacuum to give 4,2′,6′-trifluorobiphenyl-2-carbonitrile (9.92 g, 85%) as a grey solid: δH (360 MHz, CDCl3) 7.06 (2H, t, J 8), 7.38-7.52 (4H, m).

1. customwas degassed with nitrogen for 30 min
2. washThe black solution was washed with 1N sodium hydroxide solution (2×100 ml)
3. extractionthe aqueous phase was re-extracted with diethyl ether (100 ml)
4. washThe combined organic layer was washed with brine (50 ml)
5. filtrationfiltered through a glass microfibre
6. filtrationfilter paper
7. customthen evaporated
8. customto give an orange solid
9. temperatureheated to 70° C.
10. dissolutiondissolution
11. waitThe solution was left
12. temperatureto cool to ambient temperature
13. filtrationThe solid was filtered
14. washwashed with 2-propanol/water (1:1, 30 ml)
15. customthen dried under vacuum