0.036 g of O-(1H-benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate is added to a solution of 0.035 g of 3-[5,6-dimethoxy-3-(1H-pyrrolo[2,3-b]pyridin-2-yl)indol-1-yl]propionic acid in 3 ml of dimethylformamide, under an inert argon atmosphere at a temperature in the region of 20° C. The reaction medium is agitated at this temperature for 1 hour. 0.01 ml of morpholine and then 0.017 ml of diisopropylethylamine are added. After agitation at the same temperature for 3 hours, 10 ml of water and 10 ml of ethyl acetate are added. After separation by settling out, the organic phase is dried over sodium sulfate, filtered, and then concentrated under reduced pressure. The residue obtained is purified by flash-pack chromatography (silica, 98/02 by volume dichloromethane/methanol as eluents). The fractions containing the product are concentrated under reduced pressure. 0.025 g of 3-[5,6-dimethoxy-3-(1H-pyrrolo[2,3-b]pyridin-2-yl)indol-1-yl]-1-morpholin-4-ylpropan-1-one is thus obtained, the characteristics of which are as follows:
