79815-55-7Relevant academic research and scientific papers
A Facile Synthesis of 1-Oxo-1H-pyrazolopyrazol-4-ium-3-olates
Kappe, Thomas,Kos, Carlo
, p. 629 - 630 (2007/10/02)
The thermal condensation at 200-300 deg C of pyrazoles 1a-c with substituted diethyl malonates 2a-c or triethyl methanetricarboxylate 2d yields the 1-oxo-1H-pyrazolo-pyrazol-4-ium-3-olates 3a-h.
Cross-Conjugated and Psaeudo-Cross-Conjugated Mesomeric Betaines. 1. Synthesis and Characterization
Potts, Kevin T.,Murphy, Peter M.,Kuehnling, William R.
, p. 2889 - 2898 (2007/10/02)
Reaction of pyrazoles, 1,2,3-triazoles, and 1,2,4-triazoles with aryl(chlorocarbonyl)ketenes, alkylmalonyl dichlorides, or carbon suboxide results in a series of cross-conjugated mesomeric betaines, characterized by the presence of distinct cationic and anionic segments. 1-Substituted imidazoles, suitably substituted 1,2,4-triazoles, and pyridine with the above reagents give rise to pseudo-cross-conjugated mesomeric betaines which, in addition to charge separation, are characterized by the presence of the 2-oxyallyl cation 1,3-dipole.Alternative syntheses of cross-conjugated mesomeric betaines which allow the introduction of more diverse substituents are also described.
Studies on Paraionic Compounds. Anhydro-1-hydroxy-3-oxopyrazolopyrazolium Hydroxides. Formation and Stability of a Novel Series of 4n? Heterocyclic Betaines.
Zvilichovsky, Gury,David, Mordechai
, p. 295 - 300 (2007/10/02)
Different substituted anhydro-1-hydroxy-3-oxopyrazolopyrazolium hydroxides were prepared by the reaction of 1,3-dicarbonyl compounds with derivatives of 4-phenyl-3,5-dihydroxypyrazole.These diazapentalene derivatives belong to new series of 4n? cyclic betaines which are named "paraionic" heterocycles.The effects of substituents on the stability of both the anionic and the cationic rings were kinetically studied.Selective cleavage of either the anionic or the cationic ring was achieved by varying the conditions of the reaction with morpholine.Electron releasing groups on the cationic ring and electron attracting groups on the anionic ring enhance the stability of the bicyclic system.They also cause a hypsochromic shift of the visible light absorption.
