Abstract
A kinetic study shows that the hydrolysis of thiomidate esters in the presence of hyrogen ions at pH ≲ 2 is promoted by mercury(II) ions. Methyl thiobenzimidate leads to benzonitrile and methyl N-cyclohexyl thiobenzimidate to N-cyclohexylbenzamide. The N-protonated forms of the esters, like their analogue the 1-[α-(methylthio)-benzylidene]piperidinium ion, are unreactive towards mercury(II) ions: the rate of reaction therefore falls as [H3O+] rises. Mechanisms of the mercury-promoted reactions are given which are compatible with the observed reaction orders. The hydrolysis of the imidate esters at pH ≲ 2, in the absence of heavy metal ions, which leads predominantly to the thiol ester, is also inhibited by an increase in [H3O+] and the explanation of this effect is disscussed. Unlike mercury(II) ions, silver ions have no detectable effect on the rate of hydrolysis of thioimidate esters at pH ≲ 2, but do affect the isolable products since they rapidly convert the thiol ester to the carboxylic acid.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the Chemical Society, Perkin Transactions 2
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
