Preparation method of [Pyr1]-apelin-13

The invention relates to a preparation method of [Pyr1]-apelin-13. The method comprises the following steps: step (1), placing phenylalanine resin in a reaction flask for swelling treatment; step (2),adding a mixed solution containing raw material amino acid Fmoc-Pro-OH with a protecting group, a coupling agent and DMF into the reaction flask for a coupling reaction, and then performing deprotection to remove the protecting group Fmoc; step (3), respectively performing the step (2) by successively using Fmoc-Met-OH, Fmoc-Pro-OH, Fmoc-Gly-OH, Fmoc-Lys(Boc)-OH, Fmoc-His(Trt)-OH, Fmoc-Ser(tBu)-OH, Fmoc-Leu-OH, Fmoc-Arg(Pbf)-OH, Fmoc-Pro-OH, Fmoc-Arg(Pbf)-OH and Boc-Pyr-OH, and not removing Boc after coupling of Boc-Pyr-OH is completed to obtain [Pyr1]-apelin-13 protecting peptide resin witha side chain protecting group; step (4) cracking to obtain [Pyr1]-apelin-13 crude peptide; and step (5) purifying to obtain [Pyr1]-apelin-13. The preparation method is safe and environmentally friendly, and is high in yield an