5142-74-5Relevant academic research and scientific papers
A Novel Electro-organic Synthesis of Pyrrolopyrazole Derivatives
Fahmy, Hussein M.,Sharaf, Mohey E.,Aboutabl, Mohammed A.,Ramiz, Mahmoud M. M.,El-Azzem, Magdi Abdel,El-Rahman, Hassan Abd
, p. 1607 - 1613 (2007/10/02)
The polarographic reduction of two series of pyrazolone derivatives, namely ethyl 4-arylazo-5-oxo-4,5-dihydropyrazol-3-ylacetate derivatives (1a-d) and ethyl 4-arylazo-5-oxo-1-phenyl-4,5-dihydropyrazol-3-ylacetate derivatives (2a-d), is reported in detail for aqueous buffered media at a dropping mercury electrode (DME).Controlled-potential electrolysis (CPE) on four members showed that the products of electrolysis were ethyl 4-amino-5-oxo-4,5-dihydropyrazol-3-ylacetate (5a), 3,5-dioxo-2,3,3a,4,5,6-hexahydropyrrolopyrazole (6a), ethyl 4-amino-5-oxo-1-phenyl-4,5-dihydropyrazol-3-ylacetate (5b), and 3,5-dioxo-2-phenyl-2,3,3a,4,5,6-hexahydropyrrolo-pyrazole (6b).These were isolated and identified through IR, 1H NMR, and MS analyses.Also, the acid dissociation constants pKa1 and pKa2 were determined spectrophotometrically and a mechanism has been suggested and discussed for the electrode and ionization processes.Finally the results were shown to be predicted through Hammett correlations.
