93251-33-3Relevant academic research and scientific papers
ACYLOTROPIC TAUTOMERISM. XVII. TAUTOMERISM OF 5-METHYL-1,2,3,4-TETRAMETHOXYCARBONYLCYCLOPENTADIENE AND ITS ARYLAZO DERIVATIVES
Mikhailov, I. E.,Dushenko, G. A.,Minkin, V. I.,Olekhnovich, L. P.
, p. 1509 - 1514 (2007/10/02)
In the nitroarylazo derivatives of 5-methyl-1,2,3,4-tetramethoxycarbonylcyclopentadiene fast reversible intramolecular migrations of the arylazo groups around the perimeter of the cyclopentadiene ring were detected by the dynamic NMR method.The rate of the rearrangements depends on the number of nitro groups in the arylazo fragment and on the nature of the solvent (ΔG 15-19 kcal/mole).The prototropy of 5-methyl-1,2,3,4-tetramethoxycarbonylcyclopentadiene and 1,2,3,4,5-pentamethoxycarbonylcyclopentadiene was investigated.In contrast to 1,2,3,4,5-pentamethoxycarbonylcyclopentadiene, which exists in solutions exclusively in the form of the tautomer with the fulvene structure where the mobile proton is fixed at the oxygen centers, the cyclopentadiene CH-tautomeric form is also present in solutions of 5-methyl-1,2,3,4-tetramethoxycarbonylcyclopentadiene.
