ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 17, Number 5
JKCSEZ 17(5)
October 20, 1973 

The rate constants of the nucleophilic addition of n-propyl-mercaptan to α-cyano-β-piperonylacrylic acid were determined at various pH and a rate equation which can be applied over wide pH range is obtained. The rate equation reveals that below pH 4.5 the reaction is initiated by the attack of n-propylmercaptan to α-cyano-β-piperonylacrylic acid. At pH 4.5~6.5, however, n-propylmercaptan is added to α-cyano-β-piperonylacrylate ion; at pH 7.04~9.5 the competitive reaction between n-propylmercaptan and n-propylmercaptide ion is anticipated to occur. Above pH 10 the addendum is n-propylmercaptide ion and the acceptor is α-cyano-β-piperonylacrylate ion.