Rapid and efficient synthesis of the penta-peptide of elastin protein and peptides containing highly hindered α,α-dialkyl amino acids employing Fmoc-amino acid chlorides under microwave irradiation in solution phase

General Papers ARKIVOC 2006 (i) 21-30 Table 2. List of peptides made by the zinc dust mediated coupling microwave irradiation method Sl. Peptide* M.P. Yield Time [a]25 D No. (oC) (%) (sec) 1. Fmoc-Phg-Phe-OMe 190-92 93 30 -22.5 (c 0.5, DMF) 2. Fmoc-Phe-Ala-OMe 183-85 89 30 -18.0 (c1, CHCl3) 3. Fmoc-D-Phe-Ala-OMe 186-88 92 30 +18.3 (c1, CHCl3) 4. Fmoc-Ile-Pro-OMe 65-67 93 30 +19.6 (c1,CHCl3) 5. Fmoc-Gly-Phe-OMe 131-34 92 30 -16.0 (c1, MeOH) 6. Fmoc-Met-Val-OMe 90-93 80 30 -12.3 (c1, EtOH) 7. Fmoc-Tyr(Bzl)-Phe-OMe 171-73 91 35 +16.3 (c1, CHCl3) 8. Fmoc-Pro-Gly-OBzl 60-62 79 30 -27.7 (c1, CHCl3) 9. Fmoc-Leu-Val-OBzl 125-28 81 40 -11.8 (c0.5, CHCl3) 10. Fmoc-Phe-Leu-OBzl 155-58 88 35 -24.9 (c1, DMF) 11. Fmoc-Val-Gly-OBzl 182-84 90 30 -32.2 (c1, CHCl3) 12. Fmoc-Gly-Val-Gly-OBzl 176-79 88 25 -30.4 (c1, CHCl3) 13. Fmoc-Pro-Gly-Val-Gly-OBzl 158-60 78 30 -24.2 (c1, CHCl3) 14. Fmoc-Val-Pro-Gly-Val-Gly-OBzl 93-95 67 30 -29.2 (c1, CHCl3) *1H NMR of all the peptides obtained was satisfactory Figure 2. The HPLC of Fmoc-Val-Pro-Gly-Val-Gly-OBzl detection at 210 nm; eluents: acetonitrile (60 %) and water (40 %); flow rate of 1.0 mL/min.; Rt value : 9.06 min., purity >90% ISSN 1424-6376 Page 24 ©ARKAT