
%0 Journal Article
%A Swan, JM 
%T Thiohydantoins. III. Anhydride Intermediates in the Formation of 1-Acyl-2-thiohydantoins from Acylamino Acids
%J Australian Journal of Chemistry
%D 1952/12/01
%V 5
%N 4
%P 728-735
%K 
%R https://doi.org/10.1071/CH9520728
%U https://www.publish.csiro.au/paper/CH9520728 
%X Linear anhydrides are formed by the action of acetic anhydride on p-toluene-sulphonylglycine and carbobenzyloxy-glycine, -phenylalanine, and -&#946;-alanine. The anhydrides from the first two acids yield the corresponding 2-thiohydantoin with ammonium thiocyanate in acetic acid. Other methods for the preparation of l-p-toluenesulphonylglycine anhydride, and its 2-thiohydantoin, are also given.   Hippuric acid, with ethyl chlorocarbonate and triethylamine yields ethyl hippurate, probably via the mixed anhydride and 2-phenyloxazol-5-one. The inclusion of ammonium thiocyanate gives 1-benzoyl-2-thiohydantoin in high yield. The N-carboxy anhydride of phenylalanine (4-benzyloxazolid-2,5-dione) also reacts with ammonium thiocyanate to give carbon dioxide and 5-benzyl-2-thiohydantoin. 
