Electronic Effects of Aryl and Heteroaryl Groups on the Rate of Nucleophilic Displacement of Chlorine from 5-Heteroaryl(or Aryl)-2-chloropyrimidines by Piperidine
2014
Allen, David W. | Buckland, David J. | Hutley, Barrie G.
The kinetics of nucleophilic displacement of chlorine from a series of 2-chloro-5-heteroaryl(or aryl)pyrimidines by piperidine have been studied in order to assess the electronic effects of the 5-substituent. The observed order of reactivity is 5-(1-methylpyrrol-2-yl) < 5-p-anisyl < 5-p-tolyl < 5-phenyl < 5-(2-thienyl) < 5-(2-furyl) < 5-(m-chlorophenyl). The reactions are enthalpy-controlled and the rate data can be explained as a consequence of the electron-withdrawing or electron-donating ability of the 5-substituent. Synthetic routes to the compounds studied are also described.
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