
TY  - JOUR
A1  - Yamagami, C 
A1  - Sai, T 
A1  - Takao, N 
T1  - <sup>13</sup>C N.M.R. Spectra of <I>ortho</I>-Substituted Phenyl N,N-Dimethyl-Carbamates and N-Methyl Carbamates
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1987
VL  - 40
IS  - 12
SP  - 2005
EP  - 2014
KW  - 
UR  - https://doi.org/10.1071/CH9872005 
N2  - We measured 13C nuclear magnetic resonance spectra of O-substituted phenyl N,N- dimethyland N-methyl- carbamates and compared the results with those for the corresponding m- and p-substituted derivatives. The additivity relationship on the basis of the substituent chemical shift for monosubstituted benzenes ( scsphx ) did not hold well because of the ortho effect. However, the scs of C2(ipso), C3(ortho) and C5(para) was correlated excellently with scsphxX . Dual substituent parameter (DSP) analyses of the scs of C5 and the carbonyl carbon in the fixed side chain showed that correlation was very good for C5 but moderate for C=O. These observations suggested that the X substituent lay in almost the same plane as the aromatic ring, whereas the OCONMe2 group may have changed its conformation somewhat. In O-substituted derivatives, the carbon nucleus that is directly attached to the aromatic ring (&#947; to the oxygen; OCONMe2)had a pronounced upfield shift relative to the corresponding m- and p-substituents by 4-5 ppm . This phenomenon was explained by the &#947;-effect caused by the oxygen atom. 
ER  -

