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The reaction of amino-acid N-carboxyanhydrides with hydrochlorides of aminobenzoic acids and of aminooxy-acids gave amino-acid amides in a one-step synthesis. The coupling of L-alanine N-carboxyanhydride with anthranilic and with p-aminobenzoic acid hydrochloride gave peptide-like compounds of high optical activity. indicating the presence of little or no racemate. Glycyl and DL-phenylalanyl amides with aminobenzoic acid were obtained in this way, and trimers were formed by reaction of the N-carboxyanhydrides with p-aminobenzoyl-L-glutamic acid hydrochloride.Parallel procedures led to the u-, p-, and r-amido-oxy-peptides of amino-oxy-acetic, -propionic, and -butyric acid, respectively.

The a-amino-group of homocysteine thiolactone shows a reactivity analogue to that of homoserine lactone ; in a-benzyloxycarbonylamino-y-thiobutyrolactone the reactivity of the carbonyl group to nucleophilic attacks is much less than that of the analogous O-lactone.By using homocysteine thiolactone as aminating agent, peptide y-thiolactones have been synthesised from N-protected amino-acids. By using or-benzyloxycarbonylamino-y-thiobutyrolactone, amides and mixed dioxopiperazines of homocystine have been obtained.

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