The chemical shifts of pyrroles can be estimated using substituent chemical shifts (SCS)
for the substituents in α (2/5) and β (3/4) positions.
The SCS values used for the calculations are taken from .
"Carbon-13 Nuclear Magnetic Resonance Spectra of Some Substituted Pyrroles"
Abraham RJ, Lapper RD, Smith KM and Unsworth JF
J. Chem. Soc., Perkin II (1974) 1004-1009