Sulphonamides. II. Structure and Tautomerism of Sulphapyridine, Sulphathiazole, and Sulphanilylbenzamidine

1951 ◽  
Vol 4 (1) ◽  
pp. 93 ◽  
Author(s):  
SJ Angyal ◽  
WK Warburton
Keyword(s):  
Absorption Spectra ◽  
Structural Features ◽  
Ultraviolet Absorption ◽  
Amino Group ◽  
Dilute Solution ◽  
Methyl Derivatives ◽  
Derivatives Of

By the study of ultraviolet absorption spectra and comparison with methyl derivatives of known structure it is shown that the two forms of arylsulphonylbenzamidines described by Barber (1943) are tautomers, the more stable one having structure I. In dilute solution, sulphathiazole is found to be mainly X, and sulphapyridine a mixture of XIII and XIV in a ratio which depends on the solvent and can be influenced by changes on the p-amino group. Bands of the spectra are assigned to structural features of these molecules.

Polarographic half-wave potentials and ultraviolet absorption spectra of some conjugated heteroenoid compounds

1969 ◽  
Vol 47 (21) ◽  
pp. 4076-4083 ◽  
Author(s):  
H. L. Holmes ◽  
D. J. Currie
Keyword(s):  
Absorption Spectra ◽  
Functional Groups ◽  
Ultraviolet Absorption ◽  
Half Wave ◽  
Active Methylene Compounds ◽  
Derivatives Of ◽  
Active Methylene ◽  
Hammett Relationship

The half-wave potentials of phenyl substituted derivatives for each series of conjugated heteroenoid compounds studied follow a Hammett relationship. The effect of change in the functional groups and of increase in length of the conjugated system upon half-wave potentials and ultraviolet absorption maxima is briefly discussed. Terephthalylidene derivatives of active methylene compounds function like the cinnamylidene derivatives.

THE ULTRAVIOLET ABSORPTION SPECTRA OF SOME CARBOXY DERIVATIVES OF NAPHTHALENE

1949 ◽  
Vol 27b (5) ◽  
pp. 437-461 ◽  
Author(s):  
Y. Hirshberg ◽  
R. Norman Jones
Keyword(s):  
Dicarboxylic Acid ◽  
Absorption Spectra ◽  
General Problem ◽  
Acid Anhydride ◽  
Ultraviolet Absorption ◽  
Dioxane Solution ◽  
Ethanolic Solution ◽  
Complex Molecules ◽  
Steric Inhibition Of Resonance ◽  
Derivatives Of

The ultraviolet absorption spectra of a variety of naphthalene compounds containing phenyl and carboxy substituents are described. The majority of the compounds contain either the naphthalene-1,2-dicarboxylic acid anhydride or the naphthalene-2,3-dicarboxylic acid anhydride ring systems. It is shown that in ethanolic solution the spectra of these anhydrides change over a period of a few hours. The spectra of the anhydrides in n-heptane or dioxane solution do not change on standing. The effects of the various substituents are discussed in terms of steric inhibition of resonance and of antagonistic and reinforcing actions of the substituents, dependent on the position of substitution. The significance of these data are considered in relation to the general problem of the interpretation of the ultraviolet absorption spectra of complex molecules.

STUDY OF 4-MONO- AND 4,4-DISUBSTITUTED-3-IMINO-2-BENZOYL-5-PYRAZOLONES

1952 ◽  
Vol 30 (1) ◽  
pp. 52-61 ◽  
Author(s):  
Paul E. Gagnon ◽  
Jean L. Boivin ◽  
Paul A. Boivin ◽  
Hugh M. Craig
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Amino Group ◽  
Imino Group ◽  
Benzoyl Group ◽  
Hydrolysis Of ◽  
Curtius Degradation

4-Mono- and 4,4-disubstituted-3-imino-2-benzoyl-5-pyrazolones have been prepared from the corresponding ethyl mono- or disubstituted cyanoacetates and N-benzoylhydrazine. The presence of the imino group in 4,4-disubstituted-3-imino-2-benzoyl-5-pyrazolones was ascertained by the hydrolysis of 4,4-dibenzyl-3-imino-2-benzoyl-5-pyrazolone into 4,4-dibenzyl-3-oxo-2-benzoyl-5-pyrazolone. In order to prove that the benzoyl group in these pyrazolones was not in Position 1, the synthesis of 4-benzyl-3-amino-1-benzoyl-5-pyrazolone was attempted from 4-benzyl-3-carbethoxy-1-benzoyl-5-pyrazolone through a Curtius degradation of the 3-carbethoxy substituent into a 3-amino group. It was found that the 1-benzoyl group was hydrolyzed at the same time as the 3-carbethoxyamino substituent. The ultraviolet absorption spectra of all these compounds are reported and discussed briefly.

Functional group and substituent effects, both steric and electronic, upon the ultraviolet absorption spectra of some N-alkyl- and N,N-dialkyl-derivatives of some cinnamamides and benzalcyanoacetamides

1969 ◽  
Vol 47 (17) ◽  
pp. 3278-3280 ◽  
Author(s):  
A. D. Delaney ◽  
D. J. Currie ◽  
H. L. Holmes
Keyword(s):  
Hydrogen Atom ◽  
Absorption Spectra ◽  
Functional Group ◽  
Substituent Effects ◽  
Ultraviolet Absorption ◽  
Long Wavelength ◽  
Wavelength Absorption ◽  
Derivatives Of

Conjugative and steric constants for N-substituted carboxyamide groups have been derived which allow the calculation of the long wavelength absorption maxima of N-alkyl- and N,N-dialkyl-derivatives of cinnamamide and benzalcyanoacetamide. Deviations between calculated and observed values indicate that there may be steric interference between bulky N,N-dialkylcarboxyamide groups and the benzylic hydrogen atom.

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