Table 2. Solid-Phase Synthesis of Gly-Ψ[CH(CF3)NH]-Peptides.

| entry | FmocNH-Gly-Ψ[CH(CF3)NH]-dipeptide | peptide sequence | purity (%)e | mass, mg (yield, %) | calculated mass | observed mass |
|---|---|---|---|---|---|---|
| 1 | 4ca | H2N-Tyr-GlyΨ[CH(CF3)NH]-Phe-Ala-OH, 6c | 96 | 9.4 (34) | 510.51 | 511.2 [M + H]+ |
| 2 | 4ib | H2N-Tyr-GlyΨ[CH(CF3)NH]-Asp-Ala-OH, 7c | 97 | 10.3 (38) | 478.17 | 479.2 [M + H]+ |
| 3 | 4jb | H2N-Tyr-GlyΨ[CH(CF3)NH]-Lys-Ala-OH, 8c | 95 | 8.4 (32) | 491.51 | 492.2 [M + H]+ |
| 4 | 4hb | H2N-Tyr-GlyΨ[CH(CF3)NH]-Arg-Ala-OH, 9c | 96 | 20.3 (45) | 519.53 | 520.3 [M + H]+ |
| 5 | 4ca | H2N-Tyr-Gly-GlyΨ[CH(CF3)NH]-Phe-Leu-OH, 10d | 96 | 15.3 (28) | 609.65 | 610.4 [M + H]+ |
| 6 | 4jb | Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-GlyΨ[CH(CF3)NH]-Lys-Pro-Val-CONH2, 11d | 95f | 19.9 (25) | 1719.82 | 859.9 [M + H]2+ |
Treated with 30% TFA in DCM to form the free carboxylic acid from the precursor tert-Bu ester.
Treated with 2% TFA in DCM to form the free carboxylic acid from the precursor cumyl ester.
Synthesis performed manually in a single vial.
Synthesis performed in an automated synthesizer.
Determined by reverse phase HPLC.
Improved to >98% after a second purification.