6965-92-0Relevant academic research and scientific papers
Kinetics of the Multistage Reactions of 6-Substituted Purine Nucleosides with Aqueous Alkalies
Loennberg, Harri,Kaeppi, Rainer,Lehikoinen, Pertti,Oivanen, Mikko
, p. 34 - 40 (2007/10/02)
Reactions of some 6-substituted 9-(β-D-ribofuranosyl)purines with aqueous sodium hydroxide have been studied by liquid chromatography.The main reaction pathway for the decomposition of 6-chloro, 6-methyl and 6-methylthio derivatives has been shown to consist of three consecutive reactions: an attack of hydroxide ion on C8 atom with rapid subsequent openingof the imidazole ring and anomerization of the glycone moiety, deformylation of the resulting 5-formamido-4-ribosylaminopyrimidines, and clevage of the N-glicosidic bond.With the 6-chloro derivative, the first step is irreversible, while with the 6-methyl and 6-methylthio derivatives, recyclization to purine ribosides competes with the deformylation of 5-formamido-4-ribosylaminopyrimidines. 6-Chloro- and 6-methylthio-9-(β-D-ribofuranosyl)purines also yield some inosine, but this reaction is of minor importance.In contrast, 6-methoxy-9-(β-D-ribofuranosyl)purine is converted quantitatively to inosine.The rate constants for the different partial reactions have been determined at several concentrations of hydroxide ion.The kinetic data, and those reported earlier for adenosine and 9-(β-D-ribofuranosyl)purine, have been used to evaluate the susceptibility of the consecutive steps to the polar nature of the 6-substituent.
Mechanisms for the Solvolytic Decompositions of Nucleoside Analogues. IX. Pathways for the Alkyline Hydrolysis of 6-Substituted 9-(1-Ethoxyethyl)purines
Loennberg, Harri,Lehikoinen, Pertti,Neuvonen, Kari
, p. 707 - 712 (2007/10/02)
A few 6-substituted 9-(1-ethoxyethyl)purines have been prepared and the rates of their base-catalyzed hydrolysis were measured by UV spectroscopy.The product mixtures were fractionated by preparative TLC and characterized by NMR and UV spectroscopy.The results obtained suggest that the alkaline cleavage of 9-(1-ethoxyethyl)purines generally proceeds by nucleophilic attack of hydroxide ion on C8 of the purine moiety, resulting in formation of appropriate 4,5-diaminopyrimidine and 8-methylpurine as final products.With 6-methoxy, 6-methylthio, and 6-chloro derivatives nucleophilic attack of hydroxide ion of C6 giving 9-(1-ethoxyethyl)hypoxanthine competes with this reaction.
