- 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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supporting information
p. 1342 - 1353
(2015/05/26)
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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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- Heterocyclic Transformations. Part 6. Studies on the Reactions of 3-Benzyl-6-methyl-1,3-oxazine-2,4(3H)-dione with α-Amino and Hydroxy Amides
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Amide nitrogen-induced reactions of α-amino and hydroxy amides with 3-benzyl-6-methyl-1,3-oxazine-2,4(3H)-dione 1 give 6-substituted-5-acetyluracils 2; a competitive reaction initiated by the amine nitrogen of an amino amide in some cases also yields 1-su
- Singh, Harjit,Singh, Palwinder,Chimni, Swapandeep Singh,Kumar, Subodh
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p. 364 - 365
(2007/10/03)
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- Heterocyclic Transformations Part 4: A Facile Transformation of 3-Alkyl-6-methyl-1,3-oxazine-2,4(3H)-diones to 6-Substituted 5-acetyluracils and 6-Thioxo-1,3,5-triazine-2,4(1H,3H,5H)-diones
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3-Benzyl-6-methyl-1,3-oxazine-2,4(3H)-dione 1 (R = CH2Ph) reacts under phase-transfer catalytic conditions with amides and thioamides to give 6-substituted 5-acetyluracils and with malonamide to give a bicyclic pyridopyrimidine system.Similar reactions of 1 with thioureas provide 6-thioxo-1,3,5-triazine-2,4(1H,3H,5H)-diones, but with ureas, the substituents influence the mode of the reaction and the nature of the products.The synthetic scope and utility of these reactions has been examined.
- Singh, Harjit,Aggarwal, Pawan,Kumar, Subodh
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p. 1139 - 1144
(2007/10/02)
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- A facile synthesis of 6-substituted-5-acetyluracils via ring transformations of 3-benzyl-6-methyl-1,3-oxazine-2,4(3H)-dione with amides
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Phase transfer catalysed reaction of alkyl-/aryl-amides and thioamides with 3-benzyl-6-methyl-1,3-oxazine-2,4(3H)-dione give 6-alkyl/aryl-5-acetyl-3-benzyluracil derivatives.
- Singh, Harjit,Aggarwal, Pawan,Kumar, Subodh
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p. 1083 - 1084
(2007/10/02)
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- A useful methodology for the regioselective deprotection of 1,3-dibenzyluracils
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A practical, regioselective N-1 deprotection of 1,3-dibenzyl uracils 2 a-e is described. The same experimental procedure and longer reaction time afforded the complete deprotection of the uracils.
- Botta,Summa,Saladino,Nicoletti
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p. 2181 - 2187
(2007/10/02)
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