The invention relates to a preparation method of
apixaban, which comprises the following steps: carrying out
aldol condensation on ethyl methoxyacetate serving as a
raw material and
ethyl pyruvate to obtain an intermediate II, carrying out
alkylation reaction on the intermediate II and 1, 2-
dichloroethane to obtain an intermediate III, carrying out
pyrazole synthesis reaction on the intermediate III and 4-methoxyphenylhydrazine to obtain an intermediate IV, carrying out
alkylation reaction on the intermediate IV and 4-
nitroaniline to obtain an intermediate V, and carrying out recrystallization on the intermediate V to obtain the
apixaban. The preparation method comprises the following steps: carrying out ester group
hydrolysis to prepare an intermediate VI, carrying out molecular lactamization in the presence of a condensing agent to prepare an intermediate VII, carrying out
nitro reduction to prepare an intermediate VIII, carrying out amidation on the intermediate VIII and 5-bromovaleryl
chloride under the action of an acid-binding agent, further carrying out an intramolecular
alkylation reaction under the action of a strong alkali to prepare an intermediate IX, adding tert-butyl hydroperoxide and
ammonia water, and carrying out a reaction under the action of a strong alkali to prepare the intermediate IX. Under the
catalysis of
iodine, carrying out oxidation amidation to prepare
apixaban; the method has the advantages of cheap and easily available raw materials, easy realization of industrialization, high product purity, no dangerous process, simple equipment, novel
route and short synthesis
route.