31458-45-4Relevant academic research and scientific papers
Selective hydrolysis of 2,4-diaminopyrimidine systems: A theoretical and experimental insight into an old rule
Teixido,Borrell,Colominas,Deupi,Matallana,Falco,Martinez-Teipel
, p. 192 - 199 (2001)
Hydrolysis of the amino groups in condensed 2,4-diaminopyrimidine systems (1) has been used as a common method for the synthesis of oxo-substituted pyrimidines. In particular, the treatment with 6 M HCl usually yields exclusively the 2-amino-4-oxopyrimidine isomer (2). During our work we found that the hydrolysis of the amino groups present in some condensed 2,4-diaminopyrimidine systems unexpectedly afforded exclusively the 4-amino-2-oxopyrimidine isomer (3). In this paper, we present the experimental work and ab initio calculations carried out to understand this discrepancy. As a part of such study, eight compounds containing a 2,4-diaminopyrimidine moiety were calculated in gas phase and in aqueous solution, and some acid hydrolyses were reexamined. Results showed that the presence, of an electron-donating nitrogen linked to C6 of the 2,4-diaminopyrimidine ring changes the preferred hydrolysis site to yield the 4-amino-2-oxopyrimidine isomer.
Prebiotic Origin of Pre-RNA Building Blocks in a Urea “Warm Little Pond” Scenario
Menor Salván,Bouza, Marcos,Fialho, David M.,Burcar, Bradley T.,Fernández, Facundo M.,Hud, Nicholas V.
, p. 3504 - 3510 (2020/10/02)
Urea appears to be a key intermediate of important prebiotic synthetic pathways. Concentrated pools of urea likely existed on the surface of the early Earth, as urea is synthesized in significant quantities from hydrogen cyanide or cyanamide (widely accepted prebiotic molecules), it has extremely high water solubility, and it can concentrate to form eutectics from aqueous solutions. We propose a model for the origin of a variety of canonical and non-canonical nucleobases, including some known to form supramolecular assemblies that contain Watson-Crick-like base pairs.The dual nucleophilic-electrophilic character of urea makes it an ideal precursor for the formation of nitrogenous heterocycles. We propose a model for the origin of a variety of canonical and noncanonical nucleobases, including some known to form supramolecular assemblies that contain Watson-Crick-like base pairs. These reactions involve urea condensation with other prebiotic molecules (e. g., malonic acid) that could be driven by environmental cycles (e. g., freezing/thawing, drying/wetting). The resulting heterocycle assemblies are compatible with the formation of nucleosides and, possibly, the chemical evolution of molecular precursors to RNA. We show that urea eutectics at moderate temperature represent a robust prebiotic source of nitrogenous heterocycles. The simplicity of these pathways, and their independence from specific or rare geological events, support the idea of urea being of fundamental importance to the prebiotic chemistry that gave rise to life on Earth.
