The invention discloses a preparation method of
teriflunomide and an intermediate thereof in the technical field of
medicine preparation. The preparation method comprises the following steps: step 1, mixing and stirring
cyanoacetic acid, p-trifluoromethylaniline and an
ethyl acetate solvent; 2, putting the mixture into
microwave reaction equipment, and carrying out
condensation reaction by utilizing the
microwave reaction equipment to generate a key intermediate; step 3, after the
condensation reaction is finished, carrying out condensation post-treatment, and
drying the key intermediate by using
microwave reaction equipment to obtain a purified intermediate; and 4, mixing the purified intermediate with
acetyl chloride and
sodium methoxide in a proper
solvent to generate
teriflunomide. According to the invention, the biocatalyst is adopted to replace the traditional
metal catalyst, the
reaction conditions are optimized, the post-treatment steps are simplified, the operation difficulty and cost are reduced, and the environmental
pollution is reduced while the yield is improved.