- A diversity of alkylation/acylation products of uracil and its derivatives: Synthesis and a structural study
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tert-Butyl dicarbonate (Boc2O) and ethyl iodide (EtI) reactions with uracil (U), thymine (T) and 6-methyluracil (6-MU) were performed following routine procedures in pyridine/DMF solvents and with DMAP as the catalyst. Among 20 synthesized compounds, a derivative of 6-methyluracil substituted by the Boc-pyridine moiety at the C5 position appeared unexpectedly. The NMR spectra confirmed the molecular structure of all uracil derivatives. Parallel quantum mechanical DFT calculations supported the experimental findings.
- Michalak, Olga,Cmoch, Piotr,Krzeczyński, Piotr,Cybulski, Marcin,Le?, Andrzej
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p. 354 - 362
(2019/01/10)
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- HSAB-driven chemoselective N1-alkylation of pyrimidine bases and their 4-methoxy- or 4-acetylamino-derivatives
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The lithium salts of the conjugated bases of 4-methoxy- and 4-acetylamino-2(1H)-pyrimidinones 1-3 undergo highly chemoselective N1-methylation or ethylation when treated with methyl- or ethylsulfate (hard electrophiles) in dry dioxane, while the use of DMF as solvent results in competitive O2-alkylation. Potassium salts of the same bases in DMF undergo prevalent O2-attack. Under the same conditions, a similar but less chemoselective behaviour is observed in alkylation of thymine and uracil, where some N3-attack occurs. This can be rationalised in terms of the HSAB principle.
- Gambacorta, Augusto,Tofani, Daniela,Loreto, Maria Antonietta,Gasperi, Tecla,Bernini, Roberta
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p. 6848 - 6854
(2007/10/03)
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- Alkylation des pyrimidines en catalyse par transfert de phase
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Nous rapportons ici, la premiere etude concernant l'alkylation simple et efficace, en catalyse par transfert de phase, de dianions pyrimidiques ambidents derives de l'uracile, de la thymine, du nitro-5 uracile, du fluoro-5 uracile, du chloro-6 uracile, de la tetrahydro-1,2,3,4 dioxo-2,4 quinazoline, conduisant selectivement et avec de hauts rendements, aux derives N1,N3-dialkyles correspondants.
- Hedayatullah, Mir
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p. 339 - 342
(2007/10/02)
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