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

For three series of mono-, di-, and trisubstituted pyridines, respectively, available incremental methods and calculation programs for estimating the corresponding 13 C 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 AROSIM 1,2 ), the calculation method of Fürst and Pretsch 3-6 (Carbon-13 module for ChemWindows), SPECAL from Specinfo 7 (a database founded calculation program), CSPEC2, 8,9 gNMR, 10 CNMR, 11 and HyperNMR, 12 respectively.