- Direct Chemoselective Synthesis of N-3-Substituted Pyrimidinones in a Microwave-Assisted Method
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Synthesis of selectively N-3-substituted pyrimidine nucleobases or pyrimidinones has always been a challenge because of poor regioselectivity and chemoselectivity. In this article we demonstrate a single-step, de novo synthesis of selectively N-3-substitu
- Laxminarayana, Burgula,Kundu, Lal Mohan
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- A2B ADENOSINE RECEPTOR ANTAGONISTS
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Disclosed are novel compounds that are A2B adenosine receptor antagonists having the following structure (I) wherein R1 and R2 are independently chosen from hydrogen, optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted aryl, and optionally substituted heteroaryl, and R4 is an optionally substituted heteroaryl moiety. The compounds of the invention are useful for treating various disease states, including asthma, chronic obstructive pulmonary disorder, pulmonary inflammation, emphysema, diabetic disorders, inflammatory gastrointestinal tract disorders, immunological/inflammatory disorders, cardiovascular diseases, neurological disorders, and diseases related to angiogenesis.
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Page/Page column 34
(2008/06/13)
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- Polyfunctional derivatives of isocytosine. Effect of hydration on prototropic tautomerism of 2-(2-hydroxyethyl)amino-6-methylpyrimidin-4(3H)-one
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Hydration of 2-(2-hydroxyethyl)amino-6-methylpyrimidin-4(3H)-one forms an equilibrium mixture of 4-oxo-3,4-dihydro and 4-hydroxy tautomers. The intermediate in mutual transitions of these tautomers has a zwitter ionic structure. The equilibrium shifts to the 4-oxo-3,4-dihydro form as the polarity of the medium decreases. 2005 Pleiades Publishing, Inc.
- Erkin,Krutikov
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p. 639 - 644
(2008/02/01)
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- HSAB driven chemoselectivity in alkylation of uracil derivatives. A high yielding preparation of 3-alkylated and unsymmetrically 1,3-dialkylated uracils
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A qualitative hardness scale (N134) has been found for the conjugated bases of 2-methoxy-4(3H)-pyrimidinones 1-3 and applied to high yielding chemoselective N3 methylation, ethylation and benzylation reactions. Removal of the 2-methoxy group followed by a second alkylation affords unsymmetrically 1,3-disubstituted uracils.
- Gambacorta, Augusto,Farah, Mohamed Elmi,Tofani, Daniela
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p. 12615 - 12628
(2007/10/03)
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- Kinetics and Mechanisms of Hydrolytic Reactions of Methylated Cytidines under Acidic and Neutral Conditions
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First-order constants have been determined for acidic hydrolysis, and for acidic and acid buffer-catalysed, deamination of cytidine and a number of its methylated derivatives.Rate constants for deamination under neutral conditions (frequently referred to as spontaneous deamination) have also been determined.N4-Methyl groups retard both deamination and hydrolysis, the former influence being much larger.A 6-methyl substituent retards deamination even more markedly, but accelerates hydrolysis.The effect of a 5-methyl group on the rates of both reactions is minor.The mechanisms of the deamination reactions under various conditions are discussed on the basis of structural effects, rates of hydrogen exchange at C5 and kinetic α-secondary isotope effects.Relevance of the data to enzyme-catalysed deamination and non-enzymatic deamination of cytosine residues in nucleic acids is briefly discussed.
- Kusmierek, Jaroslav,Kaeppi, Rainer,Neuvonen, Kari,Shugar, David,Loennberg, Harri
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p. 196 - 202
(2007/10/02)
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- 6-ALKYL AND 5,6-DIALKYL-2-METHOXY-4(3H)-PYRIMIDINONES IN THE TRANSFORMATIONS OF PYRIMIDINES-2 SYNTHESIS AND CONVERSION INTO ALKYLURACILS AND 2-ALKOXY-4(3H)-PYRIMIDINONES
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The synthesis of 6-alkyl and 5,6-dialkyl-2-methoxy-4(3H)-pyrimidinones 3 is described.Their versatility to be transformed into 6-alkyl and 5,6-dialkyluracils 4(a-h), 6-alkyl and 5,6-dialkyl-3-methyluracils 7(a,e,f) and 6-alkyl and 5,6-dialkyl-2-alkoxy-4(3H)-pyrimidinones 5(a-i) is also shown.
- Botta, M.,Cavalieri, M.,Ceci, D.,Angelis, F. De,Finizia, G.,Nicoletti, R.
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p. 3313 - 3320
(2007/10/02)
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