The invention relates to a method for preparing
sunitinib. The method comprises the steps of dissolving 5-fluoro-1,3-
indoline-2-
ketone and N-(2-diethylin ethyl)-2,4-dimethyl-5-
formyl group-1H-
pyrrole-3-
formamide into methylbenzene, then carrying out
backflow reaction for 2.5-3.5 hours with
piperidine as a catalyst, cooling to
room temperature, carrying out suction filtering, and washing and
drying filter cakes obtained by suction
filtration through
petroleum ether, so as to obtain the
sunitinib, wherein the N-(2-diethylin ethyl)-2,4-dimethyl-5-
formyl group-1H-
pyrrole-3-
formamide is prepared through hot melting and
decarboxylation of 3,5-dimethyl-1H-
pyrrole-4-carbethoxy-2-
carboxylic acid, Vilsmeier-Haack
formylation,
hydrolysis reaction and amidation. According to the method, an intermediate of the
sunitinib is prepared and synthesized through a
solvent-free method, so that the overall yield of the sunitinib is greatly increased; in addition, the technology for
elementary reaction is optimized; furthermore, the raw materials are easy to obtain, and by optimizing all reaction steps in the synthetic process, the
elementary reaction yield of each step is increased, the total yield of the sunitinib is increased, and thus the synthetic cost of the sunitinib is lowered.