A method of predicting the site of alkylation of heterocyclic polyazines from kinetic data on model compounds

A method is presented which enables calculation of isomer ratios resulting from the N-methylation of polyazines in dimethyl sulfoxide. The method assumes that substituent and annular nitrogen atom effects on reactivity are additive in the absence of steric factors. Kinetic studies on model azines provide rate factors which are employed in the calculations. Observed and calculated isomer ratios are compared for a number of polyazines. An extension to N-oxidation is suggested.