¹³C NMR Chemical Shift Calculations for Some Substituted Pyridines: A Comparative Consideration

Abstract

For three series of mono-, di-, and trisubstituted pyridines, respectively, available incremental methods and calculation programs for estimating the corresponding 13C NMR chemical shifts were employed and compared with the results obtained. The following methods and programs were used for testing them for their accuracy: simple pyridine increments, a simplified increment calculation on the base of benzene increments (program AROSIM1,2), the calculation method of Fürst and Pretsch3-6 (Carbon-13 module for ChemWindows), SPECAL from Specinfo7 (a database founded calculation program), CSPEC2,8,9 gNMR,10 CNMR,11 and HyperNMR,12 respectively.