75703-66-1Relevant academic research and scientific papers
Etude i.r. et NMR de diaryl-2,4 diethoxycarbonyl-5,5Δ1pyrrolines
Robert, J. F.,Koch, J.,Xicluna, A.,Panouse, J. J.
, p. 535 - 542 (1980)
The spectroscopic properties (i.r., NMR) of 2,4-diaryl-5,5-diethoxycarbonyl-Δ1-pyrrolines has been studied.Chemical shifts and coupling constants of pyrrolinic protons are affected by effect of substitution on phenyl rings.In all cases, we have noted the conservation of magnetic non-equivalence of ethyl ester and methylene groups.Examination of these NMR data gives conformational approach of these pyrrolines.
The Synthesis and Chemistry of Azolenines. Part 4. Preparation and Rearrangement of some 3,5-Diaryl-2H-pyrrole-2,2-dicarboxylic Esters
Sammes, Michael P.,Chung, Margaret W. L.,Katritzky, Alan R.
, p. 1773 - 1780 (2007/10/02)
Oxidation of diethyl 3,5-diaryl-3,4-dihydro-2H-pyrrole-2,2-dicarboxylates (3) with chloranil in refluxing xylene gives not the 3,5-diaryl-2H-pyrrole-2,2-dicarboxylates (4) as reported by an earlier group, but instead the rearranged, isomeric, 1H-pyrrole-1,2-dicarboxylates (5). 2H-Pyrroles (4) may be obtained from the dihydropyrroles (3) using DDQ in benzene at room temperature; they rearrange to the isomers (5) in boiling xylene via an acyl -sigmatropic shift from carbon to nitrogen, a novel process in the 2H-pyrrole series.Thermal analyses indicate that the rearrangement is concerted with negligible charge separation in the transition state.Other novel 3,5-diaryl-1H-pyrrole-2-carboxylic acid derivatives are described.
