The present correlation for the series of compounds listed in Table I does not include the q of the nitrogen atom because every compound in this series has the same (C2H&N (CH1) 2- group. Therefore, a constant q of the nitrogen is assumed. For other series of compounds with N-alkyl derivatives, the q of the nitrogen must be considered as variable, because heteroatoms are considered as active centers for binding with the receptors. However, the ...