SYNTHESIS OF PYRAZOLONES FROM α-KETO AND α-CYANO ESTERS

1952 ◽  
Vol 30 (11) ◽  
pp. 904-914 ◽  
Author(s):  
Paul E. Gagnon ◽  
Jean L. Boivin ◽  
Alexander Chisholm
Keyword(s):  
Acid Medium ◽  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Amino Group ◽  
Keto Esters ◽  
Curtius Degradation

1,4-Dimethyl-3-amino-5-pyrazolone and 4-methyl- and 4-ethyl-3-amino-1-phenyl-5-pyrazolones were synthesized from α-keto esters and methyl- and phenylhydrazines. The hydrazones first obtained were transformed into pyrazolones having a carbethoxy group in position 3, which was converted into an amino group by a Curtius degradation. 2,4-Dimethyl-3-amino-5-pyrazolone was obtained directly from methylhydrazine and ethyl α-cyanopropionate. A series of 3-imino-2-methyl-5-pyrazolones monosubstituted in position 4 with pentyl, hexyl, heptyl, and octyl groups and another series disubstituted in position 4 with butyl, hexyl, and heptyl groups were also prepared from the corresponding mono- and disubstituted cyanoacetates and methylhydrazine.The ultraviolet absorption spectra were determined in neutral and acid medium.

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.

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.

FAR ULTRAVIOLET ABSORPTION SPECTRA OF N3AND N2+GENERATED BY ELECTRONS IMPACTING GASEOUS N2

2013 ◽  
Vol 779 (1) ◽  
pp. 40 ◽  
Author(s):  
Yu-Jong Wu ◽  
Hui-Fen Chen ◽  
Shiang-Jiun Chuang ◽  
Tzu-Ping Huang
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption ◽  
Far Ultraviolet

scholarly journals ULTRAVIOLET ABSORPTION SPECTRA AT REDUCED TEMPERATURES

1950 ◽  
Vol 187 (1) ◽  
pp. 299-312
Author(s):  
R.L. Sinsheimer ◽  
J.F. Scott ◽  
J.R. Loofbourow
Keyword(s):  
Absorption Spectra ◽  
Ultraviolet Absorption

ULTRAVIOLET ABSORPTION SPECTRA AND ACIDITIES OF ISOMERIC THIATRIAZOLE AND TETRAZOLE DERIVATIVES

1959 ◽  
Vol 37 (3) ◽  
pp. 563-574 ◽  
Author(s):  
Eugene Lieber ◽  
J. Ramachandran ◽  
C. N. R. Rao ◽  
C. N. Pillai
Keyword(s):  
Absorption Spectra ◽  
Absorption Maximum ◽  
Dipole Moments ◽  
Ring System ◽  
Ultraviolet Absorption ◽  
Characteristic Absorption ◽  
Tetrazole Derivatives

The ultraviolet absorption spectra of 5-(substituted)amino-1,2,3,4-thiatriazoles and the corresponding isomeric 1-substituted-tetrazoline-5-thiones have been studied. The spectra and the dipole moments of the 5-(substituted)amino-1,2,3,4-thiatriazoles eliminate the possibility of meso-ionic structures for these compounds. The dipole moments of 5-amino-, 5-methylamino-, and 5-dimethylamino-1,2,3,4-thiatriazole were all high but approximately of the same value (5.77 to 5.84 D). This suggests that the amino thiatriazoles are best represented by conventional covalent structures with significant ionic resonance contributions. The thiatriazole ring system exhibits a characteristic absorption maximum at 250–255 mμ and an electron-withdrawing effect approximately equal to the tetrazolyl ring system. The tetrazolinethionolyl ring system is similarly electron-withdrawing. The relative acidities of the 1-substituted-tetrazoline-5-thiones and the 5-alkylmercaptotetrazoles have also been studied and the results support the observations made on the basis of their ultraviolet absorption spectra.

Ultraviolet absorption spectra of monomer and dimer of benzoic acid

1962 ◽  
Vol 8 (1-6) ◽  
pp. 257-275 ◽  
Author(s):  
Haruo Hosoya ◽  
Jiro Tanaka ◽  
Saburo Nagakura
Keyword(s):  
Benzoic Acid ◽  
Absorption Spectra ◽  
Ultraviolet Absorption
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