SIMULATION OF C-13 NUCLEAR-MAGNETIC-RESONANCE SPECTRA OF QUINOLINES AND ISOQUINOLINES

The C-13 NMR spectra for a series of amino-, nitro-, dichloro-, and chloromethylquinolines and isoquinolines were simulated using computer-aided methodology. Numerical descriptors were calculated to encode structural features about each carbon center. Multiple linear regression techniques were used to generate four models relating these descriptors to the observed C-13 NMR chemical shifts, and these models were then used to simulate the complete observed C-13 NMR spectra. The resulting spectra had an rms error of 2.7 ppm and were matched with the experimental spectra during library searches. Simulated spectra for an external prediction set were generated and evaluated. The quality of the simulation results depends primarily on the ring substituents rather than the position of the nitrogen in the backbone.