Oxidation Of Pyrimidines Research Articles

Pyrimidine derivatives and related compounds. Part 41. Reactions of 1,3,6-trimethyl-5-nitrouracil and its 6-bromomethyl analogue with amines and hydrazines. Synthesis of pyrazolo[4,3-d]pyrimidine N-oxides and their ring expansion to pyrimido[5,4-d]pyrimidines

Reactions of 1,3,6-trimethyl-5-nitrouracil (1) and 6-bromomethyl-1,3-dimethyl-5-nitrouracil (4) with amines and hydrazines have been studied with the aim of synthesising fused-ring pyrimidines. Treatment of compound (4) with primary amines afforded 2-substituted pyrazolo[4.3-d]pyrimidine 1-oxides (6a–I). Of these, compounds (6h–I) were converted into pyrimido[5,4-d]pyrimidines (11) by treatment with sodium ethoxide. Although treatment of compound (1) with hydrazines caused the known ring transformation giving pyrazolones (2a and b), a new type of denitration reaction was found when compound (4) reacted with hydrazines yielding 6-hydrazonomethyl-1,3-dimethyluracils (15a and b). Treatment of the 6-(substituted methyl)-1,3-dimethyl-5-nitrouracils (13b–d) and (14)[prepared from (4)] with hydrazines also gave (15a and b). Mechanisms for the formation of compounds (6), (11), and (15) are discussed.

Nucleophilic addition reactions of [1,2,5]oxadiazolo[3,4-d] pyrimidine 1-oxides (pyrimidofuroxans)

5-Dimehtylamino-[1,2,5]oxadiazolo[3,4-d]pyrimidine 1-oxide reacts preferentially at the C-7 Position of the pyrimidine ring with nucleophilic reagents (water, alcohols, amines, and the hydride ion) giving readily isolable covalent adducts in which the furoxan ring remains intact but in the case of the water adduct this ring can be opened oxidatively under mild conditions to afford the corresponding 5,6-dinitropyrimidin-4(3H)-one derivative.

ChemInform Abstract: 1,3‐DIPOLAR CYCLOADDITION OF A THIAZOLO(5,4‐D)PYRIMIDINE 1‐OXIDE TO DIMETHYL ACETYLENEDICARBOXYLATE. NEW RING TRANSFORMATION TO A PYRROLO(3,2‐D)PYRIMIDINE VIA A PYRIMIDO(4,5‐B)(1,4)THIAZINE

AbstractDer Mercaptoester (I) bildet mit der Nitroverbindung (II) unter Kondensation das N‐Oxid (III), das mit Acetylenen (IV) bzw. (VIII) ein Gemisch der Verbindungen (V)‐(VII) bzw. (IX) und (X) liefert.

A Conversion of [1,2,5]-Oxadiazolo [3,4-d]pyrimidine 1-Oxides into Purines

A Conversion of [1,2,5]-Oxadiazolo [3,4-d]pyrimidine 1-Oxides into Purines

1,3-Dipolar cycloaddition of a thiazolo [5,4-d]pyrimidine 1-oxide to dimethyl acetylenedicarboxylate. New ring transformation to a pyrrolo-[3,2-d]pyrimidine via a pyrimido [4,5-b][1,4]thiazine

1,3-Dipolar cycloaddition of a thiazolo[5,4-d]-pyrimidine 1-oxide to dimethyl acetylenedicarboxylate resulted in the ring transformation of the thiazole moiety to give a pyrrolo [3,2-d] pyrimidine via a pyrimido [4,5-b]thiazine.

Studies on pyrimidine derivatives. XVIII. Reaction of active methyl groups on pyrimidine N-oxides.

Knoevenagel-type condensation and the Mannich reaction were investigated with various pyridine N-oxides having an active methyl group. For example, 6-methyl-4-phenylpyrimidine 1-oxide (Va) readily reacted with benzaldehyde in an aqueous ethanolic solution of potassium hydroxide, while 4-methyl-6-phenylpyrimidine (IVa) failed to react with benzaldehyde under the same conditions. When Va was treated with piperidine hydrochloride and paraformaldehyde, bis piperidinomethylation occurred at the 6-methyl group. The product was transformed into 4-phenyl-6-(2-piperidinoethyl) pyrimidine 1-oxide (XXIIa) by treatment with 5% sulfuric acid at 90°.

ChemInform Abstract: STUDIES ON PYRIMIDINE DERIVATIVES. VIII. RING‐CLEAVAGE REACTION OF 4,6‐DIMETHYLPYRIMIDINE 1‐OXIDE

AbstractDas Dimethylpyrimidinoxid (I) reagiert im Gegensatz zu Chinolin‐ und Isochinolin‐N‐oxiden unter Ringöffnung mit den aktivierten Methylenverbindungen (II) zu den Verbindungen (III).

Studies on pyrimidine derivatives. VIII. Ring-cleavage reaction of 4,6-dimethylpyrimidine 1-oxide.

Unlike quinoline and isoquinoline N-oxides, 4, 6-dimethylpyrimidine 1-oxide reacted with active methylene compounds such as malononitrile, ethyl cyanoacetate, and ethyl ethoxycarbonylacetimidate to give ring-opened products. In these cases, none of pyrimidine derivatives with a substituent at the 2-position were isolated. On the other hand, the pyrimidine 1-oxide was condensed with 5-amino-3-methyl-isoxazole to give 2-(5-amino-3-methyl-4-isoxazolyl)-4, 6-dimethylpyrimidine. Comparing these two reactions, the driving force of the ring-fission of the reaction intermediates was discussed.

ChemInform Abstract: NEW SYNTHESIS OF PYRAZOLO(4,3‐D)PYRIMIDINES

AbstractDie Amine (II) reagieren mit dem Brommethylnitrouracil (I) in Essigsäureäthylester bei 0°C zu den Aminoderivaten (III) und in siedendem Ethanol zu den Pyrazolopyrimidinen (IV), von denen letztere auch durch Cyclisierung von (III) in siedendem Ethanol zugänglich sind.

New synthesis of pyrazolo[4,3-d]pyrimidines

Treatment of 6-bromomethyl-1,3-dimethyl-5-nitrouracil with various primary amines gave the respective 2-substituted pyrazolo[4,3-d]pyrimidine 1-oxides.

ChemInform Abstract: PYRIMIDINES. LVI. RING TRANSFORMATION IN REACTIONS OF HETEROCYCLIC COMPOUNDS WITH NUCLEOPHILES. XIV. A NEW SYNTHESIS OF PYRIMIDINE 1‐OXIDES

Chemischer InformationsdienstVolume 7, Issue 49 Heterocyclic Compounds ChemInform Abstract: PYRIMIDINES. LVI. RING TRANSFORMATION IN REACTIONS OF HETEROCYCLIC COMPOUNDS WITH NUCLEOPHILES. XIV. A NEW SYNTHESIS OF PYRIMIDINE 1-OXIDES F. ROETERDINK, F. ROETERDINKSearch for more papers by this authorH. C. VAN DER PLAS, H. C. VAN DER PLASSearch for more papers by this author F. ROETERDINK, F. ROETERDINKSearch for more papers by this authorH. C. VAN DER PLAS, H. C. VAN DER PLASSearch for more papers by this author First published: December 7, 1976 https://doi.org/10.1002/chin.197649222Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume7, Issue49December 7, 1976 RelatedInformation

Heterocyclic polyfluoro-compounds. Part XXIII. Reaction of some 2-, 3-, and 4-substituted pyridine 1-oxides, 5-methylpyrimidine 1-oxide, and quinoline 1-oxide with perfluoropropene, and of pyridine 1-oxide with perfluoro-(2-methylpent-2-ene): synthesis of 2-(1,2,2,2-tetrafluoroethyl)-pyridines or -pyrimidines and their N-oxides and of 2,2,3-trifluoro-2,3-dihydro-3-trifluoromethylfuro[3,2-b]pyridine

Perfluoropropene reacts thermally with 2-chloro-, 2-cyano-, and 2-(1,2,2,2-tetrafluoroethyl)-pyridine 1-oxide and with 4-methyl-, 4-methoxy-, and 4-nitro-pyridine 1-oxide to yield carbonyl fluoride and the corresponding 2- or 4-substituted 6-(1,2,2,2-tetrafluoroethyl)pyridines. Thermal deoxygenation of 3-bromo-, 3-chloro-, or 3-fluoro-pyridine 1-oxide with perfluoropropene yields a mixture of the corresponding 3- and 5-halogeno-2-(1,2,2,2-tetrafluoroethyl)pyridines plus 2,2,3-trifluoro-2,3-dihydro-3-trifluoromethylfuro[3,2-b]pyridine and, in the cases of 3-bromo- and 3-chloro-pyridine 1-oxide, 3- and 5-fluoro-2-(1,2,2,2-tetrafluoroethyl)pyridine. Oxidation of the 2-(1,2,2,2-tetrafluoroethyl)pyridines 2-(CF3·CHF)C5H3NX (X = H, 3-Br, 3-Cl, 3-F, 4-Me, 4-NO2, 5-Br, 6-Cl, 6-CN, or 6-Me) with peroxy-acid yields the corresponding 1-oxides; 2,2,3-trifluoro-2,3-dihydro-3-trifluoromethylfuro[3,2-b]pyridine 4-oxide can be prepared similarly. Deoxygenation of pyridine 1-oxide with perfluoro-(2-methylpent-2-ene) yields 2-(2H-hexafluoroisopropyl)pyridine.Reaction of 5-methylpyrimidine 1-oxide with perfluoropropene yields 5-methyl-4- and 5-methyl-2-(1,2,2,2-tetrafluoroethyl)pyrimidine; oxidation of the former with peroxy-acid gives predominantly 5-methyl-4-(1,2,2,2-tetrafluoroethyl)pyrimidine 1-oxide.

Direct acylamination of quinoline, isoquinoline, benzimidazole, pyridazine, and pyrimidine 1-oxides. Novel 1,5-sigmatropic shift

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect acylamination of quinoline, isoquinoline, benzimidazole, pyridazine, and pyrimidine 1-oxides. Novel 1,5-sigmatropic shiftR. A. Abramovitch, R. B. Rogers, and G. M. SingerCite this: J. Org. Chem. 1975, 40, 1, 41–47Publication Date (Print):January 1, 1975Publication History Published online1 May 2002Published inissue 1 January 1975https://doi.org/10.1021/jo00889a009RIGHTS & PERMISSIONSArticle Views435Altmetric-Citations31LEARN 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 (959 KB) Get e-Alerts Get e-Alerts

S-Triazolo-N-oxides from sulphimides and nitrile oxides. Valence tautomerism of 5,7-dimethyl-2-p-tolyl-s-triazolo[1,5-α]pyrimidine 1-oxide

The pyrido-, pyrimidino-, and amidino-sulphimides (1)–(3) react with nitrile oxides at room temperature to give the s-triazolo-N-oxides (4)–(6); the N-oxide (5c) undergoes a reversible, degenerate valence tautomerism at 90–110°.

Reaction of some 4-chloro-5-nitropyrimidines with sodium azide. Oxadiazolo[3,4-d]pyrimidine 1-oxides

Reaction of some 4-chloro-5-nitropyrimidines with sodium azide. Oxadiazolo[3,4-d]pyrimidine 1-oxides

Studies on the Synthesis of 4-Methoxypyrimidine 1-Oxide and its Reissert Reaction.

4-Methoxypyrimidine 1-oxide was prepared and its Reissert reaction afforded 4-methoxypyrimidine-2-carbonitrile, which was derived to 2, 4-dimethoxypyrimidine to confirm the structure. At the same time, difference in the nucleophilic activity of the 2-and 4-positions in pyrimidine 1-oxide was clarified. During the course of this work, a simple process for the preparation of 4-methoxypyrimidine was established.