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Carbon‐13 NMR chemical shifts of 1‐alkyl‐3(5)‐cyano‐1 H ‐pyrazole‐4‐carboxylic acid esters
Author(s) -
Babbitt George E.,
Lynch Michael P.,
Beck James R.
Publication year - 1990
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260280117
Subject(s) - chemistry , chemical shift , pyrazole , ring (chemistry) , structural isomer , carbon fibers , carbon 13 nmr , alkyl , medicinal chemistry , nuclear magnetic resonance spectroscopy , stereochemistry , organic chemistry , materials science , composite number , composite material
A compilation of 13 C NMR chemical shifts for 13 pairs of 3‐ and 5‐cyano‐substituted pyrazole regioisomers is reported. All of the ring carbon and cyano carbon 13 C chemical shifts show a regular, predictable correlation with the particular isomer, whether 3‐cyano or 5‐cyano. These shifts occurred in very narrow ranges, precluding any confusion of assignment within the group of compounds studied. x‐ray crystallographic analysis was performed on one of the samples.