Infrared, 1H and 13C NMR Spectral Studies on Di- and Tri-substituted N-Aryl Amides, 2,6-X2C6H3NHCOCH3 – IXi and 2,4,6-X3C6H2NHCOCH3 – IXi (X = Cl or CH3 and I = 0, 1, 2 or 3)

2004 ◽  
Vol 59 (1-2) ◽  
pp. 69-76 ◽  
Author(s):  
B. Thimme Gowda ◽  
K. M. Usha ◽  
K. Jyothi
Keyword(s):  
General Formula ◽  
Benzene Ring ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Spectral Studies ◽  
Side Chain ◽  
1H And 13C Nmr ◽  
Stretching Vibrations ◽  
Absorption Frequencies ◽  
C Nmr

Several di- and tri-substituted amides of the general formula, 2,6-X2C6H3NHCOCH3−iXi and 2,4,6-X3C6H2NHCOCH3−iXi (X = Cl or CH3 and i = 0, 1, 2, or 3) are prepared, characterised, and their infrared spectra in the solid state and 1H and 13C NMR spectra in solution are studied. The C=O stretching vibrations of N-(2,6-dichlorophenyl)- and N-(2,6-dimethylphenyl)-amides appear as strong absorptions in the ranges 1707 - 1658 cm−1 and 1700 - 1647 cm−1, respectively, while the N-H stretching vibrations of N-(2,6-dichlorophenyl)- and N-(2,6-dimethylphenyl)-amides appear as strong vibrations in the ranges 3271 - 3209 cm−1 and 3285 - 3214 cm−1, respectively. The N-H stretching vibrations of N-(2,4,6-trichlorophenyl)- and N-(2,4,6-trimethylphenyl)- amides also appear as strong absorptions in the ranges 3370 - 3212 and 3283 - 3225 cm−1, respectively, while those of the C=O vibrations appear in the ranges 1688 - 1617 and 1704 - 1647 cm−1. The analysis of the C=O and N-H absorption frequencies of all amides of the general formula XiC6H5−iNHCOCH3−iXi (where X = Cl or CH3, and i = 0, 1, 2 or 3) indicates that their variations do not show regular trends with substitution either in the phenyl ring or in the side chain. The chemical shifts of both the aromatic protons and the aromatic carbons of all the amides are calculated in two ways, either by adding the incremental shifts due to -COCH3−iXi groups and the substituents in the benzene ring to the chemical shifts of the corresponding aromatic protons or carbons of the parent aniline, or by adding the incremental shifts due to -NHCOCH3−iXi groups and the substituents in the benzene ring to the chemical shift of the benzene proton or carbon. The calculated chemical shifts of the aromatic protons and carbons of all the substituted amides by both methods lead to almost the same values in most cases and agree well with the observed chemical shifts, indicating that the principle of additivity of the substituent effects is valid in these compounds.

Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2/3/4-Substituted Phenyl)-2,4-Disubstituted Benzenesulphonamides, 2,4-(CH3)2/2-CH3-4-Cl/2,4-Cl2C6H3SO2NH(i-XC6H4) (i-X = H, 2-CH3, 3-CH3, 4-CH3, 2-Cl, 3-Cl, 4-Cl, 4-F, 4-Br)

2006 ◽  
Vol 61 (10-11) ◽  
pp. 600-606
Author(s):  
Savitha M. Basappa ◽  
Basavalinganadoddy Thimme Gowda
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
Benzene Rings ◽  
Stretching Vibrations ◽  
Absorption Frequencies ◽  
C Nmr

Twenty six N-(2/3/4-substituted phenyl)-2,4-disubstituted benzenesulphonamides of the general formulae 2,4-(CH3)2C6H3SO2NH(i-XC6H4), 2-CH3-4-ClC6H3SO2NH(i-XC6H4) and 2,4- Cl2C6H3SO2NH(i-XC6H4), where i-X = H, 2-CH3, 3-CH3, 4-CH3, 2-Cl, 3-Cl, 4-Cl, 4-F or 4-Br, have been prepared, characterized and their infrared spectra in the solid state and 1H and 13C NMR spectra in solution studied. The infrared N-H stretching vibrational frequencies vary in the range 3298 - 3233 cm−1. Asymmetric and symmetric SO stretching vibrations appear in the ranges 1373 - 1311 cm−1 and 1177 - 1140 cm−1, respectively, while C-S, S-N and C-N stretching absorptions vary in the ranges 840 - 812 cm−1, 972 - 908 cm−1 and 1295 - 1209 cm−1, respectively. The various 1H and 13C NMR chemical shifts are assigned to the protons and carbon atoms of the two benzene rings in line with those for similar compounds. The incremental shifts due to the groups in the parent compounds have been computed by comparing the chemical shifts of the protons or carbon atoms in these compounds with those of benzene or aniline, respectively. The computed incremental shifts and other data were used to calculate the 1H and 13C NMR chemical shifts of the substituted compounds in three different ways. The calculated chemical shifts by the three methods compared well with each other and with the observed chemical shifts. It is observed that there are no particular trends in the variation of either the infrared absorption frequencies or the chemical shifts with the nature or site of substitution.

1H and 13C NMR Spectral Studies on N-(Aryl)-Substituted Acetamides, C6H5NHCOCH3-iXi and 2/4-XC6H4NHCOCH3-iXi (where X = Cl or CH3 and i = 0, 1, 2 or 3)

2003 ◽  
Vol 58 (12) ◽  
pp. 801-806 ◽  
Author(s):  
B. Thimme Gowda ◽  
K. M. Usha ◽  
K. L. Jayalakshmi
Keyword(s):  
Chemical Shift ◽  
Benzene Ring ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
Side Chain ◽  
1H And 13C Nmr ◽  
Methyl Group ◽  
Solution State

35 N-(Phenyl)-, N-(2/4-chlorophenyl)- and N-(2/4-methylphenyl)-substituted acetamides are prepared, characterised and their NMR spectra studied in solution state. The variation of the chemical shifts of the aromatic protons in these compounds follow more or less the same trend with changes in the side chain. The chemical shifts remain almost the same on introduction of Cl substituent to the benzene ring, while that of methyl group lowers the chemical shifts of the aromatic protons. But only 13C-1 and 13C-4 chemical shifts in these compounds are sensitive to variations of the side chain. The incremental shifts in the chemical shifts of the aromatic protons and carbons due to -COCH3−iXi or NHCOCH3−iXi groups in all the N-(phenyl)-substituted acetamides, C6H5NHCOCH3−iXi (where X = Cl or CH3 and i = 0, 1, 2 or 3) are calculated. These incremental chemical shifts are used to calculate the chemical shifts of the aromatic protons and carbons in all the N-(2/4-chlorophenyl)- and N-(2/4-methylphenyl)-substituted acetamides, in two ways. In the first way, the chemical shifts of aromatic protons or carbons are computed by adding the incremental shifts due to -COCH3−iXi groups and the substituents at the 2nd or 4th position in the benzene ring to the chemical shifts of the corresponding aromatic protons or carbons of the parent aniline. In the second way, the chemical shifts are calculated by adding the incremental shifts due to -NHCOCH3−iXi groups and the substituents at the 2nd or 4th position in the benzene ring to the chemical shift of a benzene proton or carbon, respectively. Comparison of the two sets of calculated chemical shifts of the aromatic protons or carbons of all the compounds revealed that the two procedures of calculation lead to almost the same values in most cases and agree well with the experimental chemical shifts.

scholarly journals Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2-/3-Substituted Phenyl)-4-Substituted Benzenesulphonamides, 4-X’C6H4SO2NH(2-/3-XC6H4), where X’ = H, CH3, C2H5, F, Cl or Br, and X = CH3 or Cl

2005 ◽  
Vol 60 (1-2) ◽  
pp. 106-112 ◽  
Author(s):  
B. Thimme Gowda ◽  
Mahesha Shetty ◽  
K. L. Jayalakshmi
Keyword(s):  
Solid State ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
1H And 13C Nmr ◽  
Methyl Group ◽  
Benzene Rings ◽  
Stretching Vibrations ◽  
C Nmr

Twenty three N-(2-/3-substituted phenyl)-4-substituted benzenesulphonamides of the general formula, 4-X’C6H4SO2NH(2-/3-XC6H4), where X’ = H, CH3, C2H5, F, Cl or Br and X = CH3 or Cl have been prepared and characterized, and their infrared spectra in the solid state, 1H and 13C NMR spectra in solution were studied. The N-H stretching vibrations, νN−H, absorb in the range 3285 - 3199 cm−1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1376 - 1309 cm−1 and 1177 - 1148 cm−1, respectively. The S-N and C-N stretching vibrations absorb in the ranges 945 - 893 cm−1 and 1304 - 1168 cm−1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbons of the two benzene rings. Incremental shifts of the ring protons and carbons due to -SO2NH(2-/3-XC6H4) groups in C6H5SO2NH(2-/3-XC6H4), and 4- X’C6H4SO2- and 4-X’C6H4SO2NH- groups in 4-X’C6H4SO2NH(C6H5) are computed and employed to calculate the chemical shifts of the ring protons and carbons in the substituted compounds, 4-X’C6H4SO2NH(2-/3-XC6H4). The computed values agree well with the observed chemical shifts.

scholarly journals 1H and 13C NMR Spectral Studies on N-(j, k-Dichlorophenyl)- and N-(j, k-Dimethylphenyl)-acetamides and Substituted Acetamides

2007 ◽  
Vol 62 (1-2) ◽  
pp. 84-90 ◽  
Author(s):  
Shilpa Gowda ◽  
Basavalinganadoddy Thimme Gowda
Keyword(s):  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
Side Chain ◽  
Aryl Group ◽  
1H And 13C Nmr ◽  
Methyl Substitution ◽  
Methods Of Calculation ◽  
Experimental Values ◽  
C Nmr

70 N-( j,k-Dichlorophenyl / j,k-dimethylphenyl)-acetamides and substituted acetamides of the general formula j,k-X′2C6H3NH-CO-CH3−iXi ( j,k = 2,3; 2,4; 2,5; 3,4 or 3,5; X, X′ = Cl or CH3; i = 0, 1, 2 or 3) have been synthesized and their 1H and 13C NMR spectra in solution were studied. The influence of Cl and methyl substitution in the side chain as well as in the aryl group was ystematically investigated and discussed in detail. Chemical shifts of all aromatic protons and carbon atoms were computed by adding the substituent contributions in three different ways to those of the unsubstituted molecules. The agreement with the experimental values is discussed in detail for the three different methods of calculation.

Synthetic and Spectroscopic Studies on N-(i,j-Disubstituted Phenyl)-4- Substituted Benzenesulphonamides, 4-X’C6H4SO2NH(i,j-X2C6H3), where X’ = H, CH3, C2H5, F, Cl or Br; i, j = 2, 3; 2, 4; 2, 5; 2, 6 or 3, 4; and X = CH3 or Cl

2005 ◽  
Vol 60 (1-2) ◽  
pp. 113-120 ◽  
Author(s):  
Mahesha Shetty ◽  
B. Thimme Gowda
Keyword(s):  
General Formula ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Spectroscopic Studies ◽  
Methyl Group ◽  
Methods Of Calculation ◽  
Benzene Rings ◽  
Stretching Vibrations ◽  
C Nmr

Fifty four N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides of the general formula 4-X’C6H4SO2NH(i,j-X2C6H3), where X’ = H, CH3, C2H5, F, Cl or Br; i,j = 2,3; 2,4; 2,5; 2,6 or 3, 4; and X = CH3 or Cl, are prepared and characterized and their infrared, 1H and 13C NMR spectra in solution are studied. The N-H stretching vibrations νN−H absorb in the range 3305 - 3205 cm−1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1377 - 1307 cm−1 and 1184 - 1128 cm−1, respectively. The N-(i,j-disubstituted phenyl)-4-substituted benzenesulphonamides show C-S, S-N and C-N stretching vibrations in the ranges 844 - 800 cm−1, 945 - 891 cm−1 and 1309 - 1170 cm−1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts ofare assigned to protons and carbon atoms of the two benzene rings. Incremental shifts of the ring protons and carbon atoms due to -SO2NH(i,j-X2C6H3) groups in C6H5SO2NH(i,j-X2C6H3) and 4-X’C6H4SO2NH- groups in 4-X’C6H4SO2NH(C6H*) are computed and employed to calculate the chemical shifts of the ring protons and carbon atoms in the substituted compounds 4-X’C6H4SO2NH(i,j-X2C6H3). The different methods of calculation lead to almost the same values in most cases and agree well with the observed chemical shifts, indicating the validity of the principle of additivity of the substituent effects with chemical shifts in these compounds.

scholarly journals Substituent Effects on NMR Spectroscopy of 2,2-Dimethylchroman-4-one Derivatives: Experimental and Theoretical Studies

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2061
Author(s):  
Daniela Iguchi ◽  
Davide Ravelli ◽  
Rosa Erra-Balsells ◽  
Sergio M. Bonesi
Keyword(s):  
Density Functional ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Heterocyclic Ring ◽  
Functional Theory ◽  
1H And 13C Nmr ◽  
Meta Position ◽  
Experimental And Theoretical Studies ◽  
Nmr Signals ◽  
C Nmr

The attribution of 1H and 13C NMR signals of a library of 5-, 6- and 7-substituted 2,2-dimethylchroman-4-one derivatives is reported. Substituent effects were interpreted in terms of the Hammett equation, showing a good correlation for carbons para- to the substituent group, not for the meta- ones. Similarly, the Lynch correlation shows the additivity of the substituent chemical shifts in the case of both H and C nuclei, again with the exception of the carbons in the meta- position. Density Functional Theory (DFT)-predicted 1H and 13C chemical shifts correspond closely with experimentally observed values, with some exceptions for C NMR data; however, the correlation is valid only for the aromatic moiety and cannot be extended to the heterocyclic ring of the chroman-4-one scaffold.

Increments for 1H and 13C NMR chemical shifts in pinacol arylboronates

2012 ◽  
Vol 90 (1) ◽  
pp. 71-74
Author(s):  
Di Qiu ◽  
Zhitong Zheng ◽  
Fanyang Mo ◽  
Yan Zhang ◽  
Jianbo Wang
Keyword(s):  
Benzene Ring ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
Cross Coupling Reactions ◽  
C Nmr

Arylboronates are important compounds widely used in cross-coupling reactions. By analyzing the NMR spectra data of a variety of pinacol arylboronates, we have determined the increments for 1H and 13C NMR chemical shifts caused by a pinacol boronate substituent in the benzene ring. These data can be used in the estimation of chemical shifts of aromatic pinacol boronates.

Synthetic, Infrared, 1H And 13C NMR Spectral Studies on Potassium Salts of N-Chloroarylsulphonamides

2004 ◽  
Vol 59 (1-2) ◽  
pp. 64-68
Author(s):  
K. Jyothi ◽  
B. Thimme Gowda
Keyword(s):  
Infrared Spectra ◽  
Phenyl Ring ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Spectral Studies ◽  
Empirical Correlations ◽  
Potassium Salts ◽  
1H And 13C Nmr ◽  
Stretching Vibrations ◽  
Electron Donating Groups

Several N-chloroarylsulphonamides of the configuration, 4-X-C6H4SO2(K)NCl・xH2O (where X = H, CH3, C2H5, F, Cl or Br) and i-X, j-YC6H3SO2(K)NCl・xH2O (where i-X, j-Y = 2,3-(CH3)2; 2,4- (CH3)2; 2,5-(CH3)2; 2-CH3,4-Cl; 2-CH3,5-Cl; 3-CH3,4-Cl; 2,4-Cl2 or 3,4-Cl2) are prepared, characterised, and their infrared spectra in the solid state and NMR spectra in solution are measured and correlated. Comparison of the infrared spectra of the potassium salts of N-chloro-arylsulphonamides with the corresponding arylsulphonamides shows that the strong absorptions in the range 947 - 933 cm−1 are due to N-Cl stretching vibrations. The effect of ring substitution on the N-Cl frequencies is non-uniform. The frequencies in the ranges 1404 - 1370 cm−1 and 1149 - 1125 cm−1 are respectively assigned to S=O asymmetric and symmetric vibrations. The effect of substitution in the phenyl ring in terms of electron withdrawing and electron donating groups is non-systematic. Empirical correlations relating the chemical shifts to the structures are considered. The chemical shifts of aromatic protons and carbons in all the N-chloroarylsulphonamides have been calculated by adding substituent contributions to the shift of benzene, as per the principle of substituent addition. Considering the approximation made, the agreement between the calculated and experimental chemical shifts is reasonably good.

Synthetic, Infrared, 1Hand 13CNMR Spectral Studies on N-(p-Substituted Phenyl)-p-Substituted Benzenesulphonamides, p-X’C6H4SO2NH- (p-XC6H4), where X’ or X = H, CH3, C2H5, F, Cl or Br

2004 ◽  
Vol 59 (4-5) ◽  
pp. 239-249
Author(s):  
B. Thimme Gowda ◽  
K. L. Jayalakshmi ◽  
Mahesha Shetty
Keyword(s):  
Solid State ◽  
General Formula ◽  
Infrared Spectra ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Vibrational Frequencies ◽  
Spectral Studies ◽  
Benzene Rings ◽  
Electron Donating Groups ◽  
C Nmr

Thirty N-(p-substituted phenyl)-p-substituted benzenesulphonamides of the general formula, p-X’C6H4SO2NH(p-XC6H4), where X’ or X = H, CH3, C2H5, F, Cl or Br, are synthesised and their infrared spectra in the solid state and 1H and 13C NMR spectra in solution are measured. The N-H stretching vibrational frequencies, νN−H vary in the range 3334 - 3219 cm−1, while the asymmetric and symmetric SO2 vibrations appear in the ranges 1377 - 1311 cm−1 and 1182 - 1151 cm−1, respectively. The compounds exhibit S-N and C-N stretching vibrational absorptions in the ranges 937 - 898 cm−1 and 1310 - 1180 cm−1, respectively. There are no particular trends in the variation of these frequencies on substitution with either electron withdrawing or electron donating groups. The 1H and 13C chemical shifts of N-(p-substituted phenyl)-p-substituted benzenesulphonamides,are assigned to various protons and carbons of the two benzene rings. Further, incremental shifts of the ring protons and carbons due to -SO2NH(p-XC6H4) groups in the compounds of the formula, C6H5SO2NH(p-XC6H4), and p-X’C6H4SO2- and p-X’C6H4SO2NH- groups in the compounds of the formula, p-X’C6H4SO2NH(C6H5) are computed and used to calculate the 1H and 13C chemical shifts of the parallely substituted compounds of the general formula p-X’C6H4SO2NH(p-XC6H4). The computed values agree well with the observed chemical shifts. The above incremental shifts are found to correlate with the Hammett substituent parameters.

Infrared, 1H and 13C NMR Spectral Studies of some 4-([1,1′-Biphenyl]-4-yl)-6-(Substituted Phenyl)-5,6-Dihydro-4H-1,3-Oxazine-2-Amines: Assessment of Substituent Effects

2015 ◽  
Vol 50 ◽  
pp. 9-16
Author(s):  
G. Thirunarayanan ◽  
V. Sathiyendiran ◽  
Ganesan Vanangamudi ◽  
R. Arulkumaran ◽  
V. Manikandan ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Statistical Analysis ◽  
Chemical Shifts ◽  
Substituent Effects ◽  
Spectral Studies ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
Substituent Constants ◽  
Infrared Frequencies ◽  
C Nmr

About ten titled compounds were prepared by microwave assisted silica-phosphoric acid catalysed cyclization of substituted styryl 4-biphenyl ketones and urea under solvent-free conditions. The infrared frequencies (ν, cm-1) of NH2, C=N, COC stretches, NMR spectral chemical shifts (δ, ppm) of NH2, H4-6, C=N, and C4-6 were assigned and correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the results of statistical analysis, the effect of substituents on the infrared frequencies (ν, cm-1) and NMR chemical shifts (δ, ppm) has been studied.

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