The invention relates to the field of
medicine synthesis, in particular to a synthesis method of
tropisetron. Compared with the traditional method, the synthesis method of
tropisetron provided by the invention has the advantages that the synthesis
route is more efficient, rapid, environment-friendly and mild, and the selectivity is higher. On the basis of the effect of the Pd monatomic catalyst, the Pd monatomic catalyst has good selectivity on indole serving as an N-H substrate,
tropisetron with a
substituent group being N-H can be synthesized, and the problem that in the prior art, an N-CH3 substituted tropisetron analogue can only be synthesized by taking 1-methylindole serving as an N-CH3 substrate as a
raw material is solved. The yield of the synthesized tropisetron is close to 98%, the purity of the product can reach the medication standard of
Chinese pharmacopoeia through a simple purification process, and large-scale industrial production is facilitated. The coordination structure of the Pd monatomic catalyst is optimized, the positive valence state of Pd is kept, a C-H bond at the 3-position of indole can be directly activated, I2 and K2CO3 do not need to be additionally added, and no waste residues are generated after the reaction.