Complete protected Arg-Gly-Asp (RGD) tripeptide, Boc-Arg(Tos)-Gly- Asp(OcHex)-OBzl (TM), was synthesized via two synthetic routes and with different coupling reagents. After activated by coupling reagents such as DCC, EDCI, GDI and EEDQ in short time, Boc-Arg(Tos)-OH was coupled with TsOH o Gly-OBzl to produce N-terminal dipeptide Hoc-Arg(Tos)-Gly- OBzl (1) in suitable reactive condition in 43% ~ 97% yield. Boc-Arg(Tos) -Gly-OH (2), obtained from the catalytic hydrogenation of 1, reacted with HC1-Asp(OcHex)-OBzl (3a) to give the protected RGD tripeptide in the yields of 76.4% (DCC/HOSu), 64.7% ~ 8.3% (DCC/HOBt) and 66.7% -77. 9% (EDCI/HOBt), respectively. C-Terminal dipeptide Boc-Gly-Asp(OcHex)- OBzl (4) was prepared by the coupling of Boc-Gly-OH with HC1 o Asp (OcHex)-OBzl (3a) with the coupling reagents of DCC/HOBt and GDI (81.2%, 89.5% yield ). Deprotecting Boc group, 4 reacted with Boc-Arg(Tos)-OH through the coupling reagents of DCC/HOBt, EDCI/HOBt, GDI and DCC/HOSu to form the target molecule in the yields of 40.4%, 73.8%, 67.8% and 84.4%, respectively.

Key words: PEPTIDE, ARGININE, GLYCINE, ASPARTIC ACID, SYNTHESIS