反应详情

0.72 g of 2-cyano-5-(4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)pyridine, 3.3 g of caesium carbonate and 92 mg of 1,1′-bis(diphenyl-phosphino)ferrocenepalladium(II) dichloride as a complex with dichloromethane (1/1) [PdCl2(dppf).CH2Cl2] are successively added, under argon, to a solution of 0.8 g of 4-trifluoromethanesulphonyloxycarbazole, obtained in stage 1 of Example 1, in a mixture of 37 ml of dioxane and 12 ml of water. The reaction mixture is refluxed for 4 hours, cooled to ambient temperature, filtered through celite and concentrated under reduced pressure. The residue is subsequently purified by silica gel chromatography, elution being carried out with a mixture of cyclohexane and ethyl acetate (85/15 by volume), so as to give 0.24 g of 5-(9H-carbazol-4-yl)pyridine-2-carbonitrile in the form of a yellow solid, the characteristics of which are the following:

1. temperatureThe reaction mixture is refluxed for 4 hours
2. filtrationfiltered through celite and
3. concentrationconcentrated under reduced pressure
4. customThe residue is subsequently purified by silica gel chromatography, elution
5. additionbeing carried out with a mixture of cyclohexane and ethyl acetate (85/15 by volume)