SIMULATION OF C-13 NUCLEAR-MAGNETIC-RESONANCE SPECTRA OF INDOLES

Linear models are developed to predict the C-13 NMR chemical shifts of carbons in indole moieties based on a critical review. These models f ill a gap in the spectral simulation database which is used to simulat e the C-13 NMR spectra of a wide range of organic compounds, illustrat ing that this is a viable method for the expansion of the database. Th e models are based on calculated numerical parameters (descriptors) wh ich encode the topological and topological-electronic environments of the eight indole carbons. The 56 indoles in the reference set have a m ean r.m.s. error of 0.93 ppm and the 42 indoles in the prediction set have an error of 2.04 ppm. The spectral error for N-substituted indole s is higher than that of N-unsubstituted indoles.