0.54 g of (5-methoxypyridin-3-yl)boronic acid, 3.3 g of caesium carbonate and 93 mg of 1,1′-bis(diphenylphosphino)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 3 and a half hours, 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 (75/25 by volume), so as to give 0.7 g of 4-(5-methoxypyridin-3-yl)-9H-carbazole in the form of a colourless oil, the characteristics of which are the following:
