77083-75-1Relevant academic research and scientific papers
Versatile ligational behavior of azopyrazolone derived from hydralazine
Seth, Susannah,Aravindakshan
experimental part, p. 1493 - 1503 (2012/06/01)
Five complexes of 3-methyl-4-(phenylhydrazono)-1-phthalazinyl-2-pyrazolin- 5-one (LH) were synthesized. The ligand and complexes were characterized using elemental analyses and various analytical techniques such as IR, UV, NMR, mass spectra, magnetic susc
The effect of ortho and para substituents on the formation of the E and Z isomers of the arylhydrazones obtained from diazonium coupling with methyl 3-aminocrotonate and 3-aminocrotononitrile
Jollimore, Jason V.,Vacheresse, Marc,Vaughan, Keith,Hooper, Donald L.
, p. 254 - 262 (2007/10/03)
Reaction of arene diazonium salts with 3-aminocrotononitrile or methyl 3-aminocrotonate affords the 2-arylhydrazono-3-oxobutanenitrile (1 or 3 and 3′) or the methyl 2-arylhydrazono-3-oxobutanoate (2 and 2′ or 4 and 4′). A series of these hydrazones has been prepared with a range of electron-withdrawing and -donating substituents in the ortho or para position of the aryl moiety. The hydrazones have been characterized by spectroscopic methods, with emphasis on the 1 H NMR spectra, which have been used to determine the configuration of the hydrazones as E or Z or a mixture of the two. The para-substituted hydrazononitriles (1) are formed as a single species, namely the Z isomer, whereas the ortho isomers are formed as a mixture of E and Z configurations (3 and 3′). The hydrazonobutanoates (2 and 2′ or 4 and 4′) are formed as E/Z mixtures regardless of the position of the substituent in the aryl moiety. Complete assignments of all signals in the 1 H NMR spectra have been made on the basis of the ability of the various substituents to participate in intramolecular hydrogen bonding and a mechanism is proposed to account for the variations in the proportions of E and Z isomers and the effect of the nature of the substituent on this ratio. 13C NMR spectra of selected hydrazones have been recorded as an aid to structure assignment.
