Chemical Studies on Amino Acids and Peptides. III. 4, 5-Diaryl-4-oxazolin-2-one Derivatives as an Amino Protecting Group

Abstract

4, 5-Diaryl-4-oxazolin-2-one [V : R=CH₃O (AOX) and R=Cl (COX)] derivatives of amino acids were prepared by condensation of 4, 5-diaryl-1, 3-dioxol-2-one (III : R=CH₃O and R=Cl) with amino acids. These oxazolinone derivatives were stable to NaOH-aq. EtOH and liquid hydrogen fluoride at room temperature, but were cleaved by hydrogenolysis over pd-carbon. Pentagastrin protected with AOX group, AOX-Gly-Trp-Met-Asp-Phe-NH₂, was prepared and its biological effect was examined on gastric secretion in young chicken.