
%0 Journal Article
%A Swan, JM 
%T Thiohydantoins. I. The Preparation of Some 2-Thiohydantoins from Amino Acids and Acylamino Acids
%J Australian Journal of Chemistry
%D 1952/12/01
%V 5
%N 4
%P 711-720
%K 
%R https://doi.org/10.1071/CH9520711
%U https://www.publish.csiro.au/paper/CH9520711 
%X A reinvestigation of the stepwise degradation of peptides and proteins by the Schlack and Kumpf (1926) procedure, which involves conversion of the terminal carboxyl residue to a 5-substituted-2-thiohydantoin; has been undertaken. The following amino acids or their aoetyl derivatives have been converted by warming with acetic anhydride and ammonium thiocyanate into the corresponding 1-acetyl-2-thio-hydantoins: valine, methionine, isoleucine, &#945;-aminophenylacetic acid, tryptophane, histidine, and tyrosine. These new 1-acetyl-2-thiohydantoins, as well as others, have been deacetylated by an improved procedure. Certain 1-acyl-5-carbethoxy-2-thio- hydantoins on hydrolysis give 2-thiohydantoin only. N-acetylthreonine, acetic anhydride, and ammonium thiocyanate produce 5-ethylidene-2-thiohydantoin, also obtained by the condensation of acetaldehyde with 2-thiohydantoin or its 1-acyl derivatives, or from the interaction of ammonium thiocyanate with 2-phenyl-4-ethylideneoxazol-5-one. This type of rearrangement occurs in other cases. 
