Synthesis process of carbetocin

The invention provides a synthesis process of carbetocin. The synthesis process comprises the following steps: performing a coupling reaction on Fmoc-Gly-OH with Rink Amide-AM Resin obtained in the first step to obtain Fmoc-Gly-Rink Amide-AM Resin; performing deprotection (20% piperidine) with DBLK to obtain H-Gly-Rink Amide-AM RFesin, and orderly completing the coupling of the H-Gly-Rink Amide-AM Resin with Fmoc-Leu-OH, Fmoc-Pro-OH, Fmoc-Cys(Trt)-OH, Fmoc-Asn(Trt)-OH, Fmoc-Gln(Trt)-OH, Fmoc-Ile-OH, Fmoc-Tyr(Me)-OH and tetrachlorobutyric acid until carbetocin linear peptide resin is synthesized; mixing a cracking agent with the carbetocin linear peptide resin obtained in the fourth step to have a cracking reaction, thereby removing the Rink Amide-AM Resin and side chain protecting groups; cyclizing the carbetocin linear crude peptide into a carbetocin crude product, and separating and purifying the carbetocin crude product to obtain the carbetocin. The synthesis process has the advantages that the polymerization side reaction is prevented, the process route is greatly simplified, the production cost is reduced and the synthesis efficiency is improved; in addition, the purity of the finished product is high; in short, the synthesis process is convenient for large-scale production, and meanwhile, advantageous for environmental protection, and has remarkable economic and social benefits.