Correlation and Multivariate Analyses of the Spectroscopic Data in 4'-Substituted 4-Nitro-difhenylsulfones

Molecular descriptors such as quantum chemical indices, substituent constants, substituent chemical shifts values of monosubstituted benzenes, and different data analyses (linear regression, dual substituent parameters, and multivariate analysis) have been comparatively used in order to rationalize the electronic substituent effects and to predict C-13 nuclearmagnetic resonance (NMR) and vibrational spectroscopy (IR) data of the 14 title compounds. The results have been compared with those previously obtained for the biologically active 4'-substituted 4-aminodiphenylsulfones, inhibitors of the dihydropteroate synthase enzyme. Both the 4-nitro and the 4-amino sulfone series show similar transmission of the electronic substituent effects through the C(1)-SO2-C(1') moiety by a hyperconjugative mechanism. Good predictions of the spectroscopic data are obtained with the different models considered. However, the partial least-squares method and principal componenent analysis seem to be the most powerful predictive tools.