US Patent 7244815 Attachment and elaboration strategies for inverse peptide synthesis

The present invention provides a process for preparing a peptide of formula I):Sub-[L]-[N(R1)-A-C(O)]p—[NH-A-C(O)]n+m—OH  (I)comprising:(a) reacting an immobilized compound of formula (II):Sub-(L)-[N(R1)-A-C(O)]p—[NH-A-C(O)]n—OH  (II)with an amino acid ester or peptide derivative of formula (III):H—[NH-A-C(O)]m—O(tBu)  (III)in the presence of a coupling agent to yield a peptide compound of general formula (IV):Sub-[L]-[N(R1)-A-C(O)]p—[NH-A-C(O)]n+m—O(tBu);  (IV)(b) removing the tBu (t-butyl) group to produce a solid-support bound carboxylic acid or peptide derivative of general formula (I);wherein n is a positive integer, e.g., 1–10, preferably 1–5; m is a positive integer, and P is 0–1.