80588-72-3Relevant academic research and scientific papers
TAUTOMERISM IN THE SERIES OF N,N-DISUBSTITUTED HYDRAZONES OF 3-ETHOXALYLCARBOXYLIC ESTERS
Yakimovich, S. I.,Khrustalev, V. A.,Yusupov, V. D.
, p. 1851 - 1856 (2007/10/02)
The N,N-disubstituted hydrazones of ethyl α-ethoxalyl carboxylic esters exist as tautomeric mixtures of the imine and enamine forms; the imine form is represented by two configurational isomers, and the enamine form has the Z configuration stabilized by an intramolecular hydrogen bond.The tautomeric equilibrium is shifted toward the enamine form with increase in the volume of the substituents at the second nitrogen atom.In the methylarylhydrazones of ethoxalylacetic ester the enamine form is favored by the introduction of electron-withdrawing substituents into the aromatic r ing at the second nitrogen atom.In the series of hydrazones of the same type there is an irregular variation of the tautomeric composition with succesive increase in the volume of the α substituent with the largest content of the enamine form in the derivatives of α-ethoxalylpropionic ester.
