Chemical reactivity and electronic structure of N-methyl derivatives of xanthine
Abstract
Calculations of electron density and other indices of reactivity have been performed for N-methyl-substituted xanthines using the Hückel, Del Re, and CNDO/2 methods. The considerable difference in chemical reactivity of theophylline, theobromine, and caffeine is probably due either to steric repulsion of the van der Waals type or to the electrostatic effects of a positively charged methyl group in position 7.