Reaction Of Uracil Research Articles

Unexpected Reaction Products of Uracil and Its Methyl Derivatives with Acetic Anhydride and Methylene Chloride.

New acetyl derivatives of uracil, 6-methyluracil, and thymine were obtained in the course of an unconventional synthesis in methylene chloride. It was shown that products with the acetyloxymethyl fragment are formed according to a mechanism different from that for products with the acetyloxyethyl group. In particular, for uracil it was proven that the reaction with Ac2O, TEA, and CH2Cl2 leads to 1-acetyloxymethyluracil, where the N1 substituent is composed of the -CH2- fragment that originated from CH2Cl2 and the 1-acetyloxy moiety from Ac2O. The reaction of uracil with Ac2O, TEA, CH2Cl2, and DMAP leads to an acetyloxyethyl derivative in which the -CH2-CH2- fragment originates from TEA and the 1-acetyloxy moiety from Ac2O. A possible mechanism for the formation of new compounds was suggested and supported by the density functional theory/B3LYP quantum mechanical calculations. New compounds (39 in total, including seven deuterated) were fully characterized by nuclear magnetic resonance and high-resolution mass spectrometry techniques.

Synthesis of N-1-Skatyl Uracil Derivatives

N-1 skatyl derivatives were obtained in moderate yields via the reaction of uracil, 5-fluorouracyl, and cytosine with gramine N-oxide or its methyl iodide. Gramine N-oxide was converted into gramine in good yield upon microwave irradiation in DMF solution. Gramine was also formed in DMF solution in the presence of DBU from gramine methyl iodide although microwave irradiation did not affect the yield of gramine. Gramine did not form from its methyl iodide upon microwave irradiation without DBU.

Synthesis of Cyclobutane Nucleosides 2-Preparation of Thymine and Uracil Analogues

1-(2-Oxocyclobutyl-4-benzoyloxymethyl)-2,4(1H,3H)-pyrimidinedione and 1-(2-oxocyclobutyl-4-benzoyloxymethyl)-5-methyl-2,4(1H,3H)-pyrimidinedione can be prepared by reaction of uracil and thymine, respectively, with 3-benzoyloxymethyl-2-bromocyclobutanone. The N-alkylation gave both cis and trans isomers with the trans isomer predominating for uracil whereas the trans isomer was the only product which could be isolated for thymine. Both series were subjected to borohydride reduction followed by transesterification with methoxide giving the corresponding uracil and thymine nucleoside analogues. The uracil derivative 1-(2-oxocyclobutyl-4-benzoyloxymethyl)-2,4(1H,3H)-pyrimidinedione was irradiated in aqueous acetonitrile to generate isonucleoside analogues.

Fragmentation of uracil after electron capture by doubly charged ions

Single electron capture from molecular uracil (C4H4N2O2) by doubly-charged He2+, C2+, and O2+ atomic ions followed by the fragmentation of uracil ions has been studied using time-of-flight mass-spectrometry at the collision velocity range 0.13–0.65 a.u. The uracil ion fragmentation mechanism has been clarified by the arrival time correlation analysis for all ion-fragments produced in a single collision. Electron capture with ionization cross section has been determined from experiment. As shown, single electron capture in reaction of uracil with C2+ leads to high fragmentation probability of the resulting uracil ion. The role of electron core rearrangement in the C2+ and O2+ atomic ions is discussed.

ChemInform Abstract: Synthesis of Some Novel Functionalized Dihydropyrido[2,3‐d]pyrimidines via a One‐Pot Three‐Component Reaction Catalyzed by InCl3.

AbstractThe reaction of uracils, aryl halides and 3‐cyanoacetyl indole produces the pharmaceutically interesting title compounds (IV) and (VII).

ChemInform Abstract: Reactions of Uracils. Part 25. An Efficient Synthesis of Thioisomuenchnones Derived from Uracils and Uridine: Novel Type of Mesoionic Nucleosides.

ChemInform Abstract: Reactions of Uracils. Part 25. An Efficient Synthesis of Thioisomuenchnones Derived from Uracils and Uridine: Novel Type of Mesoionic Nucleosides.

Preparation and reaction of uracil substituted cyclen and cyclam: formation of tricyclic guanidinium and dihydroimidazolium salts

Di-uracil substituted cyclen derivatives were prepared by the reaction of cyclen with 6-chloro-1-methyluracil or 6-chloro-1,3-dimethyluracil. The reaction of cyclam with 6-chloro-1,3-dimethyluracil gave a similar di-uracil substituted cyclam. The 1,7-di-uracil substituted cyclen was converted to the tricyclic guanidinium salt and acylurea upon heating in DMSO in the presence of weak acid. The 1,8-di-uracil substituted cyclam gave a tricyclic dihydroimidazolium salt under the same conditions. These reactions can be explained by an intramolecular uracil ring-breaking reaction mechanism.

Unimolecular Reactivity of Uracil–Cu2+ Complexes in the Gas Phase

The gas-phase interaction of copper(II) ions with uracil are studied by means of mass spectrometry and B3LYP/6-311+G(2df,2p)//B3LYP/6-31G(d) calculations. Positive-ion electrospray spectra show that the reaction of uracil with copper(II) gives rise to singly charged species, whereby the [Cu(uracil--H)](+) complex is the most intense ion in the spectra at low concentration. Mass spectrometry/mass spectrometry (MS/MS) experiments show that the loss of HNCO and NCO are the dominant fragmentation processes, accompanied by a minor loss of CO. A systematic study of the spectra obtained with different labeled species, namely, 2-(13)C- (m/z 175), 2-(13)C,1,3-(15)N(2)- (m/z 177) and 3-(15)N-uracil (m/z 175), concludes unambiguously that both the loss of HNCO and NCO involve exclusively C2 and N3, whereas only C4 is involved in the loss of CO. Suitable mechanisms for these fragmentation processes are proposed through a theoretical survey of the corresponding potential energy surface. In these mechanisms, pi complexes, which lie high in energy with respect to the global minimum, play a significant role in the loss of NCO; this explains why both products, HNCO and NCO involve the same atoms of the ring.

Formation of a Rare Tautomeric Form of 5-Hydroxy-6-Methyluracil in Complexation with Copper(II) and Manganese(II) Chlorides in Alkaline Media

Reactions of uracils with metals have been reviewed in [1, 2]. Although uracil and its 5and 6-substituted derivatives can theoretically exist as six tautomers [3, 4], X-ray diffraction analysis revealed that complexation involves their dilactam form only [1, 2]. The exceptions are complexes with the lactim form of 1-methyluracil, 1-methylthymine, and unsubstituted uracil [5–7]. In this study, based on the IR spectra of copper(II) and manganese(II) complexes with 5-hydroxy-6-methyluracil, we assumed for the first time stabilization of the lactim tautomer by the metal ion. Synthesis of a(e 5 c 5 N 2 e 3 ) 2 · 2c 2 e (a = Cu , Mn ) . A weighed sample of 5-hydroxy-6-methyluracil (HL) was dissolved in an equimolar aqueous solution of NaOH to complete homogenization. Then, a corresponding metal chloride was added (HL : MCl 2 = 2 : 1). The resulting solution was stirred at room temperature for 20 min. The complexes were obtained as powdered yellow-green (M = Cu) or yellow (M = Mn) precipitates in 51 and 82% yields, respectively. The compositions of the complexes ML 2 · 2 H 2 O were determined by elemental analysis.

Influence of Noncovalent Interactions on Uracil Tautomer Selection: Coordination of Both N1 and N3 Uracilate to the Same Metal in the Solid State

The reaction of uracil and [Zn(H2O)6](NO3)2 in aqueous ammonia solution produces, after treatment with iProOH, the complex [Zn(uracilate-κN1)(uracilate-κN3)(NH3)2]. This compound in the solid state presents a complete set of hydrogen bonds and electrostatic interactions including those mediating the self-recognition of the uracilate groups. The unique characteristics of this complexsmall size and the presence of both N1 and N3 uracil tautomers among otherseliminate possible factors in uracil tautomer selection, demonstrating the overriding importance of noncovalent interactions in tautomer selection during crystallization. This result can probably be extended to other, uracil-related ligands.

Reactions of Uracils, 24. Multiple Anellation to Uracils and their Analogs - An Approach to Nevirapine-Type Tricycles

Starting with 6-amino-1,3-dimethyluracil 1 a structural analog of the NNRTI Nevirapine 16 is synthesized in a sequence of two ring anellations and a Beckmann rearrangement. The anellation behavior of 3 is studied in general leading to the anellated systems 5, 7s-c, 12 a-c.

A new method for the synthesis of N-phenyl-uracil and -pyrimidine nucleosides

Reaction of uracil or pyrimidine nucleosides with iodobenzene in the presence of cuprous oxide in 2,4,6-trimethylpyridine for 20 h gave N1,N3-diphenyluracil 1 or N3-phenylpyrimidine nucleosides 4, 7. The identity of these products were confirmed by comparison of their physical and spectroscopic data with those of 2,4-diphenoxypyrimidine 2 or 4-phenoxypyrimidin-2(1H)-one nucleoside 5b.

Reactions of uracils. 21. Zwitterionic heteropolycyclic uracils by a novel three-component reaction: iminophosphorane, isocyanate, heteroarene

The novel three-component reaction of (uracil-6-ylimino)phosphorane 1, isocyanate 2, and (susbtituted) pyridines gives, in a one-pot procedure, a variety of new pyrido[1',2':3,4]pyrimido[4,5-d]pyrimidines 3-11. The zwitterionic ground state of these new ring systems is i.a. established by means of solvatochromism, Hammett correlations, NMR, and X-ray analysis. Replacement of the pyridine by isoquinoline and phthalazine gives access to the novel ring systems pyrimido[4',5':4,5]pyrimido[6,1-a]isoquinoline and -phthalazine, which are formed as dihydro derivatives (14, 15) or as zwitterions (13, 17), depending on the reaction conditions. Oxidative cleavage of the phthalazine 15 in nitrobenzene affords the pyrimido[4,5-d]pyrimidines 16

Amidoalkylation of pyrimidine bases of nucleic acids

The reaction of uracil, thymine, and cytosine with acid N-α-chloroalkylamides gave N-substituted derivatives of these compounds. Conditions for the selective amidoalkylation of pyrimidine bases in the 1 position were found.

ChemInform Abstract: Reaction of Uracils with Trimethyl Phosphates and Sodium Diphenyl Phosphate.

AbstractReaction of the uracils (I) with trimethyl phosphate (II) gives the corresponding 1‐methylated derivatives only if R is a electron‐withdrawing substituent.

ChemInform Abstract: Reactions of Uracils. Part 15. 7‐Ethoxypyrimido(4,5‐d)pyrimidines via a Uracil‐Carbodiimide Derivative and Their Products of Aminolysis and Pyrolysis.

AbstractReaction of the 6‐(phosphoranylideneamino)uracil‐5‐carboxylate (I) with the isocyanates (II) yields the title compounds (III) which are converted into the 7‐amino derivatives (V) by displacement of the ethoxy group with the amines (IV).

ChemInform Abstract: Dihalogenotriphenylphosphoranes in Heterocyclic Synthesis. Part 10. Reactions of Uracils. Part 10. Novel Michael Adducts of Uracils and New Synthesis of Imidazo(5,1‐f)(1,2,4)triazines.

AbstractThe uracil derivative (I) is coupled with (II) or (IV) to yield the 6‐substituted uracils (III) and (V) respectively.

Oxidation of Thymines and Uracils with Sodium Peroxodisulfate

Abstract Reaction of thymines with Na2S2O8 in water resulted in selective oxidation of the methyl group at 5-position of thymines. Oxidation of thymines with Na2S2O8 in hydrochloric acid gave 5-chloro-6-hydroxy-5,6-dihydrothymines and in acetic acid containing NaCl gave 6-acetoxy-5-chloro-5,6-dihydrothymines which were converted to 6-alkoxy-5-chloro-5,6-dihydrothymines with alcohols. The reaction of uracils also gave similar products together with 5-chlorouracils.

ChemInform Abstract: Reactions of Uracils. Part 7. Synthesis and Novel Consecutive Thermal [1,5]‐Sigmatropic Rearrangements of 6‐(Alkylamino)‐5‐ethenyluracils.

AbstractUnder basic conditions in the presence of catalytic amounts of DBN the compounds (II) are cyclized to the pyridopyrimidine triones (III), while the thermal reaction with Dowtherm A (followed by chromatography on silica with CHCl3/methanol being last eluent) or in refluxing xylene results in the formation of the dealkylated (and rearranged) uracil derivative (IV).

Dihalogenotriphenylphosphoranes. 10. Reactions of uracils. 10. Novel Michael adducts of uracils and new synthesis of imidazo[5,1-f][1,2,4]triazines

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDihalogenotriphenylphosphoranes. 10. Reactions of uracils. 10. Novel Michael adducts of uracils and new synthesis of imidazo[5,1-f][1,2,4]triazinesHeinrich Wamhoff and Winfried SchuppCite this: J. Org. Chem. 1986, 51, 14, 2787–2789Publication Date (Print):July 1, 1986Publication History Published online1 May 2002Published inissue 1 July 1986https://doi.org/10.1021/jo00364a032RIGHTS & PERMISSIONSArticle Views98Altmetric-Citations29LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (380 KB) Get e-Alerts Get e-Alerts