13C NMR spectra of p- and m-substituted phenyl N-methyl- and phenyl N,N-dimethyl-carbamates

✍ Scribed by Chisako Yamagami; Narao Takao; Takaaki Nishioka; Toshio Fujita; Yoshito Takeuchi

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 564 KB
• Volume: 22
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270220709

✦ Synopsis

NMR spectra of p and rn-substituted phenyl N-methylcarbamates, phenyl Nfl-dimethylcarbamates and p and m-suhstituted phenyl propionates were recorded, and their para -C SCS (substituent chemical shW) were analysed by DSP (dual substituent parameters) and DSP-NLR (non-linear resonance) equations. It was found that the 6xed substituent Y, --oCONHCH,, -OCON(CH& and --oCWH,, were all mild in the sense that DSP analysis gave a good correlation, leaving little room for improvement by the DSP-NLR treatment. Further, the three series of compounds gave similar p, and p~ values (para derivatives, 3.2-3.3 and 17.7-18.0; meta derivatives, 5.1-5.2 and 21.8-22.0). Examma * tion of the corresponding analyses of similar compounds indicated that the p, and p~ values and, hence, their ratio p&, =A, depended primarily on the nature of the atom through which the fixed substituent Y (e.g. OK, a-N and a-0) was bonded to the aromatic ring when the Y substituents are mild. The extent of this tendency for compounds with active tixed substituents is also discussed. ' ,J(CF) = 9.6 Hz.

'J(CF) = 3.5 Hz.