Patent ID: 7786259

Claim:
A method of preparing an immobilized peptide derivative of formula (Vb): comprising: (a) reacting a functionalized solid support of general formula Sub(L)X, wherein Sub is a solid support, L is a cleavable linker, and X is a leaving group, wherein (L)X comprises a group of formula wherein a bond bisected by a wavy line indicates a bond connecting L to Sub, with a compound of formula: H 2 N—A—C(O)OtBu, wherein tBu is a tert-butyl group, and wherein the N—A—C(O) group is a residue of an amino acid or of a peptide composed of independently selected amino acid residues, to yield an immobilized peptide derivative of formula: Sub-(L)—NH—A—C(O)OtBu; then, (b) contacting the immobilized peptide derivative of the formula: Sub-(L)—NH—A—C(O)OtBu with compound of the formula RHN—A—C(O)OH, wherein the RHN—A—C(O) group is the residue of a N-protected α-amino acid, in the presence of a coupling agent, to yield an immobilized peptide derivative of the formula (Vb):