Reaction SMILES: [NH:1]([C:13]([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14])[C@H:2]([C:10](O)=[O:11])[CH2:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.C1C2C3C(=O)[N:32](O)C(=O)C3C1C=C2.CCN=C=NCCCN(C)C.Cl.N>CC#N.CN(C=O)C>[NH:1]([C:13]([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14])[C@H:2]([C:10]([NH2:32])=[O:11])[CH2:3][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1
Reactant: O=C(N[C@@H](Cc1ccccc1)C(=O)O)OCc1ccccc1
Reactant: O=C1C2C3C=CC(C3)C2C(=O)N1O
Agent: CCN=C=NCCCN(C)C
Agent: Cl
Agent: N
Solvent: CC#N
Solvent: CN(C)C=O
Product: NC(=O)[C@H](Cc1ccccc1)NC(=O)OCc1ccccc1
Temperature: 25 °C
Reaction time: 4 h
Yield: 24.8 %

Procedure:
In 30 mL of MeCN, 5.99 g of Z-Phe was dissolved and 3.94 g of HONB and 4.59 g of WSCD HCl were added to the solution at 0° C., followed by stirring at room temperature for 4 hours. While keeping at 0° C., 3.4 mL of 25% NH3 aq. solution and 10 mL of DMF were added to the mixture, followed by stirring for 4 hours. After the solvent was distilled off, the residue was dissolved in AcOEt and the solution washed with 1N HCl aq. solution, satd. NaHCO3 aq. solution and then satd. NaCl aq. solution. After drying over Na2SO4, the solvent was concentrated and diethyl ether was added to give 1.48 g (yield 99%) of Z-Phe-NH2 as the precipitate. After 1.94 g of [Bis(trifluoroacetoxy)iodo]benzene was dissolved in 20 mL of MeCN and 5 mL of H2O, 890 mg of Z-Phe-NH2 prepared above and 972 μL of pyridine were added to the precipitate at 0° C., followed by stirring at room temperature for 15 hours. After the solvent was concentrated, the concentrate was subjected to liquid-liquid separation with diethyl ether-1N HCl aq. solution and the 1N HCl aq. solution layer was concentrated and then dried. Its half volume was dissolved in 5 mL of DMF, and 486 μL of mono-tert-butyl malonate and 540 mg of HOBt were added to the solution. Then, 2.08 g of PyBOP and 1394 μL of DIEA were added at 0° C. to the mixture, followed by stirring at room temperature for 15 hours. After the solvent was distilled off, the residue was dissolved in AcOEt and the solution washed with 1N HCl aq. solution, satd. NaHCO3 aq. solution and then satd. NaCl aq. solution. After drying over Na2SO4, the solvent was concentrated and the concentrate was purified by flush column chromatography. Diethyl ether-petroleum ether was added to give 304 mg (yield 33%) of Z-PheΨ(NHCO)Gly-OBut as the precipitate. After 154 mg of the product was dissolved in 20 mL of MeOH, 10% Pd—C was added to the solution, followed by catalytic hydrogenation for 2 hours in a hydrogen flow. After removal of the catalyst by filtration, the solvent was concentrated and dried. The residue was dissolved in 10 mL of MeCN 10 mL and 152 mg of Fmoc-OSu and 78 μL of DIEA were added to the solution, followed by stirring for 15 hours. After the solvent was distilled off, the residue was dissolved in AcOEt and the solution washed with 1N HCl aq. solution, satd. NaHCO3 aq. solution and then satd. NaCl aq. solution. After drying over Na2SO4, the solvent was concentrated and diethyl ether-petroleum ether was added to give 127 mg (yield 68%) of Fmoc-PheΨ(NHCO)Gly-OBut as the precipitate. Fmoc-Leu was introduced into 63 mg of Fmoc-Arg(Boc2,Me)Phe-Rink Amide MBHA resin prepared in EXAMPLE 10. After Fmoc deprotection, Fmoc-PheΨ(NHCO)Gly-OH (prepared by treating 25 mg of Fmoc-PheΨ(NHCO)Gly-OBut with TFA for 3 minutes), 300 μL of 0.5M HOAt, 78 mg of PyAOP and 52 μL of DIEA were added to the resin, followed by shaking for 6 hours. After the resin washed, 2 mL of DMF, 9 μL of DIEA and 12 μL of Ac2O were added to the resin, followed by shaking for 30 minutes. After the resin washed, the peptide chain was extended on ABI 433A to give Boc-D-Tyr(But)Asn(Trt)Trp(Boc)Asn(Trt)Ser(But)PheΨ(NHCO)GlyLeuArg(Boc2,Me)Phe-Rink Amide MBHA resin. To 34 mg of the product, 200 μL of TFA/PhSMe/m-cresol/TIS/EDT (85/5/5/2.5/2.5) was added, followed by stirring for 2 hours. Ether was added to the reaction solution, the resulting precipitate was centrifuged and the supernatant was removed. This procedure was repeated for washing. The residue was extracted with an aqueous acetic acid solution and the extract was filtered to remove the resin. Then, linear density gradient elution (30 minutes) was performed with eluants A/B: 76/24-66/34 using: 0.1% TFA in water and eluant B: 0.1% TFA-containing acetonitrile on preparative HPLC using YMC D-ODS-5-ST S-5 120A column (20×150 mm). The fractions containing the product were collected and lyophilized to give 0.7 mg of white powders.