SYNTHESIS AND ULTRAVIOLET ABSORPTION OF SOME PYRAZOLONES

1951 ◽  
Vol 29 (10) ◽  
pp. 843-847 ◽  
Author(s):  
P. E. Gagnon ◽  
B. Nolin ◽  
R. N. Jones
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Light ◽  
Alkaline Medium ◽  
Light Absorption ◽  
Ultraviolet Absorption ◽  
Acid Solutions

Thirteen 3-amino-5-pyrazolones substituted only in position 4 have been synthesized from the corresponding mono- or disubstituted cyanoacethydrazides or cyanoacetic esters in alkaline medium. Their ultraviolet light absorption spectra have been determined in neutral and acid solutions.

CONTRIBUTION TO THE STUDY OF PYRAZOLONES

1953 ◽  
Vol 31 (7) ◽  
pp. 673-684 ◽  
Author(s):  
Paul E. Gagnon ◽  
Jean L. Boivin ◽  
Méüde Tremblay
Keyword(s):  
Acetic Acid ◽  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Acid Solutions

1,4-Diphenyl-3-carbethoxy-5-aminopyrazole yielded 1,4-diphenyl-5-aminopyrazole by hydrolysis and decarboxylation. The phenylhydrazone of ethyl phenyloxalacetate gave a pyrazolone which was transformed into 1,4-diphenyl-3-amino-5-pyrazolone. The 2,4-diphenyl-3-amino-5-pyrazolone was obtained from ethyl phenylcyanoacetate and phenylhydrazine by heating in acetic acid. 4-Alkyl-3-hydroxy- and 3-amino-5-pyrazolones and 4,4-dialkyl-3-oxo- and 3-imino-5-pyrazolones, substituted in position 2 by carbanilino or α- or β-naphthyl groups, were prepared from ethyl mono- or disubstituted malonates and cyanoacetates, 4-phenylsemicarbazide, and α- and β-naphthylhydrazines. Ultraviolet absorption spectra were determined in neutral and acid solutions.

LIGHT ABSORPTION STUDIES: PART XV. THE ULTRAVIOLET ABSORPTION SPECTRA OF ANISOLES

1959 ◽  
Vol 37 (8) ◽  
pp. 1305-1314 ◽  
Author(s):  
J. C. Dearden ◽  
W. F. Forbes
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Atom ◽  
Absorption Spectra ◽  
Hydroxy Group ◽  
Light Absorption ◽  
Spectral Properties ◽  
Ultraviolet Absorption ◽  
Steric Interactions ◽  
Absorption Studies ◽  
Methoxy Groups

Anisoles, compared with phenols, possess similar spectral properties, except that properties determined mainly by the hydrogen atom of the hydroxy group are modified. In this way, comparison of the ultraviolet absorption spectra of phenols and anisoles permits, for example, the study of the spectral effects of hydrogen bonding and the study of steric interactions involving the hydroxy and methoxy groups.

LIGHT ABSORPTION STUDIES: PART II. ULTRAVIOLET ABSORPTION SPECTRA OF SUBSTITUTED BENZOIC ACIDS AND PHENYL BENZOATES

1955 ◽  
Vol 33 (12) ◽  
pp. 1829-1839 ◽  
Author(s):  
W. F. Forbes ◽  
M. B. Sheratte
Keyword(s):  
Absorption Spectra ◽  
Light Absorption ◽  
Ultraviolet Absorption ◽  
Steric Effects ◽  
Benzoic Acids ◽  
Absorption Studies ◽  
Substituted Benzoic Acids ◽  
Electronic And Steric Effects

The spectra of a number of substituted benzoic acids, acetanilides, and phenyl benzoates are discussed in terms of the electronic and steric effects of substituents.

LIGHT ABSORPTION STUDIES: PART XII. ULTRAVIOLET ABSORPTION SPECTRA OF BENZALDEHYDES

1958 ◽  
Vol 36 (10) ◽  
pp. 1362-1370 ◽  
Author(s):  
J. C. Dearden ◽  
W. F. Forbes
Keyword(s):  
Absorption Spectra ◽  
Light Absorption ◽  
Electronic Spectra ◽  
Spectral Properties ◽  
Ultraviolet Absorption ◽  
Benzene Derivatives ◽  
Formyl Group ◽  
Steric Interactions ◽  
Absorption Studies ◽  
Acetyl Group

The electronic spectra of benzaldehydes in the region 220–360 mμ are recorded and discussed in terms of previously stated hypotheses. The formyl group is shown to endow benzene derivatives with spectral properties similar to those of the acetyl group in acetophenones, except that steric interactions are slightly modified.

LIGHT ABSORPTION STUDIES: PART XI ELECTRONIC ABSORPTION SPECTRA OF NITROBENZENES

1958 ◽  
Vol 36 (10) ◽  
pp. 1350-1361 ◽  
Author(s):  
W. F. Forbes
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Light Absorption ◽  
Electronic Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Electronic Interactions ◽  
Absorption Studies

The spectra of nitrobenzenes are discussed in terms of previously proposed hypotheses relating electronic interactions and ultraviolet absorption spectra.

LIGHT ABSORPTION STUDIES: PART XVIII. THE ULTRAVIOLET ABSORPTION SPECTRA OF BROMOBENZENES

1961 ◽  
Vol 39 (5) ◽  
pp. 1131-1142 ◽  
Author(s):  
W. F. Forbes
Keyword(s):  
Spectral Data ◽  
Absorption Spectra ◽  
Light Absorption ◽  
Bromine Atom ◽  
Ultraviolet Absorption ◽  
Steric Effects ◽  
Benzene Derivative ◽  
Previous Part ◽  
Absorption Studies ◽  
Band Spectra

The ultraviolet absorption spectra of bromobenzene in various solvents, and the spectra of a series of substituted bromobenzenes in cyclohexane solution, are reported. The B-band spectral data confirm the hypotheses postulated for the B-band spectra of chlorobenzenes in the previous part of this series of papers. That is, the bromine atom usually gives rise to greater steric effects than the chlorine atom and the apparent mesomeric interaction as judged from these spectra increases with the size of the halogen substituent.Both bromobenzene and chlorobenzene C-band intensities are unusually small, and this is assumed to account for the frequent C-band similarity between the spectrum of a mono-substituted benzene derivative PhX, where X = OH, OCH3, NH2, and the spectrum of the corresponding chloro- or bromo-substituted PhX derivative.

LIGHT ABSORPTION STUDIES: PART V. THE RELATION OF MESOMERIC EFFECTS AND ULTRAVIOLET LIGHT ABSORPTION SPECTRA

1956 ◽  
Vol 34 (10) ◽  
pp. 1447-1456 ◽  
Author(s):  
W. F. Forbes ◽  
Audrey S. Ralph
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Light ◽  
Light Absorption ◽  
Absorption Data ◽  
Absorption Studies

A method for the determination of mesomeric effects from ultraviolet light absorption data is critically discussed. For halogen-substituted compounds, the method gives an order of mesomeric effects different from that which is usually accepted for the halogens.

LIGHT ABSORPTION STUDIES: PART XVI. THE ULTRAVIOLET ABSORPTION SPECTRA OF FLUOROBENZENES

1959 ◽  
Vol 37 (12) ◽  
pp. 1977-1985 ◽  
Author(s):  
W. F. Forbes
Keyword(s):  
Absorption Spectra ◽  
Light Absorption ◽  
Fluorine Atom ◽  
Ultraviolet Absorption ◽  
Mesomeric Effect ◽  
First Approximation ◽  
Absorption Studies

The ultraviolet absorption spectra of a series of fluorobenzenes are determined. It is found that as a first approximation a fluoro substituent does not appreciably affect the benzenoid absorption. The spectra are discussed on the assumption that the mesomeric effect of the fluorine atom is small.

THE FATE OF PHENOTHIAZINE IN THE GASTROINTESTINAL TRACT OF THE SHEEP

1950 ◽  
Vol 28d (3) ◽  
pp. 143-161 ◽  
Author(s):  
R. P. Harpur ◽  
W. E. Swales ◽  
O. F. Denstedt
Keyword(s):  
Free Radical ◽  
Gastrointestinal Tract ◽  
Bile Duct ◽  
Absorption Spectra ◽  
Light Absorption ◽  
Biological Materials ◽  
Postmortem Examination ◽  
Ultraviolet Absorption ◽  
Red Color

The methods for estimating phenothiazine and phenothiazone in biological materials have been investigated. It has been shown that when phenothiazine, or phenothiazone is treated with bromine (under the conditions described), a red color is produced which has absorption maxima at the following wavelengths: 240, 282, 291, 375, and 510 mμ. Phenothiazone, in 95% ethanol, has a spectrum with absorption maxima at 237, 273, 280, 288, 369, and 508 mμ. Thus the bromine method is not applicable for distinguishing between these two compounds. It is shown also that phenothiazine may interfere with the estimation of phenothiazone when the latter is measured by the light absorption of its free radical. The ultraviolet absorption spectra of phenothiazine and diphenylamine o-sulphoxide have been determined. The spectrum of the former compound has a maximum at 254 mμ (with a small maximum at 318 mμ), and that of the latter has maxima at 227, 272, 302, and 335 mμ. Leucophenothiazone also has a maximum at 254 mμ.While excretion studies on sheep confirm that 40% of the orally administered phenothiazine is lost in the urine, it is shown that the absorption of the drug from the intestine is not dependent upon oxidation to phenothiazone in the rumen. Indeed, the drug appears to be unchanged in this organ. In a postmortem examination of the gastrointestinal tract no phenothiazone was found proximal to the bile duct. It is suggested that phenothiazine is absorbed from the rumen unoxidized. In support of this it is confirmed that some phenothiazine may be recovered unchanged from the urine of the sheep.

LIGHT ABSORPTION STUDIES: PART XVII. THE ULTRAVIOLET ABSORPTION SPECTRA OF CHLOROBENZENES

1960 ◽  
Vol 38 (7) ◽  
pp. 1104-1112 ◽  
Author(s):  
W. F. Forbes
Keyword(s):  
Absorption Spectra ◽  
Chlorine Atom ◽  
Light Absorption ◽  
Fluorine Atom ◽  
Ultraviolet Absorption ◽  
Electronic Interaction ◽  
Mesomeric Effect ◽  
Spectral Changes ◽  
Absorption Studies ◽  
Solute Interactions

The ultraviolet absorption spectra of a series of chlorobenzenes are determined. The spectral data suggest that the apparent mesomeric effect of the chlorine atom is greater than that of the fluorine atom, that solvent–solute interactions are generally less important in chlorobenzenes than in fluorobenzenes, and that, as expected, the effective interference radius of the chlorine atom is large. Moreover, spectral changes in o-substituted chlorobenzenes are consistent with the assumption that maximum electronic interaction requires the chlorine atom to be in the same plane as the benzene ring. The conformations of o-chloroacetophenone and o-chlorophenol are briefly discussed.

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