
%0 Journal Article
%A Crow, WD 
%A Gosney, I 
%T Isothiazole chemistry. III. Kinetics and mechanism of cyclization of <I>cis</I>-3-Thiocyanoacrylamide
%J Australian Journal of Chemistry
%D 1966/09/01
%V 19
%N 9
%P 1693-1699
%K 
%R https://doi.org/10.1071/CH9661693
%U https://www.publish.csiro.au/paper/CH9661693 
%X The cyclization of cis-3-thiocyanoacrylamide to isothiazol-3-one has been studied over the pH range 0-5.5 and it is shown that two cyclization mechanisms exist. Within the pH range 5.5-3.5, the only important mechanism is one involving a rapid, unimolecular cyclization of the thiocyanoacrylamide anion, while at pH less than 3.00, the process is essentially a slow cyclization of the neutral molecule, followed by rapid proton loss. The large rate difference between the two mechanisms is ascribed to a lowering of &#916;F* in the anion cyclization mechanism by a more favourable T&#916;S* term, and possible reasons for this are discussed. 
