title: New useful reagents for peptide synthesis. Insoluble active esters of polystyrene-bound 1-hydroxybenzotriazole.
abstract: Insoluble 1-hydroxbenzotriazole-bound polystyrene was prepared through a series of chemical modifications of commercially available polystyrene. Reaction of 3-nitro-4-chlorobenzyl alcohol or of 3-nitro-4-chlorobenzyl bromide with polystyrene in the presence of aluminium trichloride yielded (3-nitro-4-chloro)benzylated polystyrene. Upon reaction with hydrazine it was converted to (3-nitro-4-hydrazine) benzylated polystyrene which was cyclized, by acidolysis, to yield 1-hydroxybenzotriazole-bound polystyrene. This was coupled, using N, N' -dicyclohexylcarbodiimide as the coupling agent, to many N-blocked amino acid derivatives, yielding polymeric polystyrene-bound active esters. Such derivatives are highly reactive and their efficacy in the synthesis of several peptides, including that of the tetrapeptide Boc-L-Leu-L-leu-L-Val-0bzl-L-Tyr-0Bzl and of thyrotropin-releasing hormone was demonstrated.
mesh_terms: D004151:Dipeptides / Q000138:chemical synthesis; D007202:Indicators and Reagents; D008722:Methods; D009842:Oligopeptides / Q000138:chemical synthesis*; D011137:Polystyrenes; D012995:Solubility; D014230:Triazoles
chemical_list: D004151:Dipeptides; D007202:Indicators and Reagents; D009842:Oligopeptides; D011137:Polystyrenes; D014230:Triazoles; C011852:1-hydroxybenzotriazole