556-99-0Relevant articles and documents
Synthesis of N4-amino and N4-hydroxy derivatives of 5-azacytidine. A facile rearrangement of the N4-amino derivative to 5-(3-β-D-ribofuranosylureido)-1H-1,2,4-triazole
Piskala, Alois,Hanna, Naeem B.,Masojidkova, Milena,Fiedler, Pavel,Votruba, Ivan
, p. 905 - 917 (2004)
Treatment of methoxyribosyltriazinone 4 with hydrazine in methanol afforded crude 4-hydrazino-1-β-D-ribofuranosyl-1,3,5-triazin-2(1H)-one (N 4-amino-5-azacytidine) (2), which rearranged rapidly to isomeric 5-ribosylureidotriazole 6. The rearrangement proceeds easily also in water solutions of 2. Alkaline hydrolysis of 6 gave a mixture of 5-ureidotriazole 7 and 5-aminotriazole 8. Acid hydrolysis of 6 afforded only 7. This compound was also prepared by thermal rearrangement of 5-amino-1-carbamoyltriazole 9 or on reaction of cyano(formyl)guanidine 10 with hydrazine hydrochloride. Treatment of benzoylated methoxyribosyltriazinone 4a with hydrazine in methanol gave only the rearranged product 6a. Reaction of tribenzoylribosyl isocyanate 12 with aminotriazole 8 gave 1-triazolecarboxamidotribenzoylribose 13, which afforded by methanolysis oxazoloribofuranose 14 and aminotriazole 8. Compound 14 was also obtained by methanolysis of blocked ribosylcarbamate 16. Reaction of methoxyribosyltriazinone 4 with hydroxylamine in methanol afforded 4-hydroxylamino-1-β-D-ribofuranosyl-1,3,5-triazin-2(1H)-one (N 4-hydroxy-5-azacytidine) (3), which on the action of excess hydroxylamine yielded 1-cyano-1-hydroxy-5-β-D-ribofuranosylisobiuret (19). Treatment of methoxy-1,3,5-triazinone 18 with a solution of hydroxylamine in methanol gave 4-hydroxylamino-1-methyl-1,3,5-triazin-2(1H)-one (N 4-hydroxy1-methyl-5-azacytosine) (17). Heating of cyano(formyl)guanidine 10 with hydroxylamine hydrochloride in water lead to the formation of triuret (21). The mechanisms of the reactions of methoxyribosyltriazinone 4 with hydrazine and hydroxylamine are discussed. Compounds 2, 6 and 19 exhibited no significant antibacterial or cytostatic activity.
Preparation of NIR absorbing axial substituted tin(iv) porphyrins and their photocytotoxic properties
Babu, Balaji,Amuhaya, Edith,Oluwole, David,Prinsloo, Earl,Mack, John,Nyokong, Tebello
, p. 41 - 48 (2019/01/30)
Sn(iv) porphyrins ([Sn(iv)TTP(3PyO)2] (5) and [Sn(iv)TPP(3PyO)2] (6) [tetrathienylporphyrin (TTP), tetraphenylporphyrin (TPP), and pyridyloxy (PyO)]) were prepared and characterized and their photocytotoxicity upon irradiation with 625 nm light has been studied. The presence of the 3PyO axial ligands was found to limit the aggregation and enhance the solubility of 5 and 6 in DMF/H2O (1?:?1). The photophysical properties and photodynamic therapy (PDT) activity of the meso-2-thienyl and meso-phenyl-substituted Sn(iv) porphyrins are compared. 5 and 6 were found to be photocytotoxic in MCF-7 cancer cells when irradiated with a Thorlabs M625L3 LED at 625 nm but remained nontoxic in the dark. The PDT activity of Sn(iv) meso-tetra-2-thienylporphyrin 5 was found to be significantly enhanced relative to its analogous tetraphenylporphyrin 6. There is a marked red-shift of the Q00 band of 5 into the therapeutic window due to the meso-2-thienyl rings, and 5 has an unusually high singlet oxygen quantum yield value of 0.83 in DMF. The results demonstrate that readily synthesized axially ligated Sn(iv) meso-arylporphyrins are potentially suitable for use as singlet oxygen photosensitizers in biomedical applications and merit further in depth investigation in this context.
Zinc monoglycerolate as a catalyst for the conversion of 1,3- and higher diols to diurethanes
Kulasegaram, Sanjitha,Shaheen, Uzma,Turney, Terence W.,Gates, Will P.,Patti, Antonio F.
, p. 47809 - 47812 (2015/06/16)
A green methodology exploring the scope of diurethane synthesis from diols and urea in the presence of a homogeneous catalyst is described. Past reactions of diurethanes have relied heavily on environmentally corrosive reagents such as phosgene. Prior to this work, we have utilized metal glycerolates as homogeneous catalysts in the glycerolysis of urea. Here we explore the synthetic scope of this system with a variety of diols. The conversion to diurethanes is proposed to proceed via an intermediate zinc bound isocyanate ligand, which rearranges to form the terminal urethane in the case of 1,3- and higher diols in good selectivity and yields. With butane 1,2,4-triol the selectivity is exclusively for the 5-membered carbonate, suggesting that the proximity of the second hydroxyl group is critical in forming the ring.
Reactions of peroxynitrite with uric acid: Formation of reactive intermediates, alkylated products and triuret, and in vivo production of triuret under conditions of oxidative stress
Gersch, Christine,Palii, Sergiu P.,Imaram, Witcha,Kim, Kyung Mee,Karumanchi, S. Ananth,Angerhofer, Alexander,Johnson, Richard J.,Henderson, George N.
experimental part, p. 118 - 149 (2009/06/20)
Hyperuricemia is associated with hypertension, metabolic syndrome, preeclampsia, cardio-vascular disease and renal disease, all conditions associated with oxidative stress. We hypothesized that uric acid, a known antioxidant, might become prooxidative following its reaction with oxidants; and, thereby contribute to the pathogenesis of these diseases. Uric acid and 1,3-15N2-uric acid were reacted with peroxynitrite in different buffers and in the presence of alcohols, antioxidants and in human plasma. The reaction products were identified using liquid chromatography-mass spectrometry (LC-MS) analyses. The reactions generate reactive intermediates that yielded triuret as their final product. We also found that the antioxidant, ascorbate, could partially prevent this reaction. Whereas triuret was preferentially generated by the reactions in aqueous buffers, when uric acid or 1,3-15N2-uric acid was reacted with peroxynitrite in the presence of alcohols, it yielded alkylated alcohols as the final product. By extension, this reaction can alkylate other biomolecules containing OH groups and others containing labile hydrogens. Triuret was also found to be elevated in the urine of subjects with preeclampsia, a pregnancy-specific hypertensive syndrome that is associated with oxidative stress, whereas very little triuret is produced in normal healthy volunteers. We conclude that under conditions of oxidative stress, uric acid can form reactive intermediates, including potential alkylating species, by reacting with peroxynitrite. These reactive intermediates could possibly explain how uric acid contributes to the pathogenesis of diseases such as the metabolic syndrome and hypertension. Copyright Taylor & Francis Group, LLC.
Methods And Devices For Preparing Biuret And Cyanuric Acid
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Page/Page column 5, (2008/06/13)
Provided are methods and devices for preparing biuret and cyanuric acid by thermal decomposition of urea. Specifically, a product of thermal decomposition is cooled to precipitate a crystal and the precipitated crystal is dissolved using an alkali aqueous solution and cooled to obtain biuret having high purity. Furthermore, the cyanuric acid that is one of byproducts by the thermal decomposition of urea is effectively recovered with high purity.
Nitration of 2-substituted pyrimidine-4,6-diones, structure and reactivity of 5,5-gem-dinitropyrimidine-4,6-diones
Langlet, Abraham,Latypov, Nikolaj V.,Wellmar, Ulf,Bemm, Ulf,Goede, Patrick,Bergman, Jan,Romero, Ivan
, p. 7833 - 7838 (2007/10/03)
Nitration of some 2-substituted pyrimidine-4,6-diones in sulfuric acid was studied, which afforded previously unknown 5,5-gem-dinitropyrimidine-4,6-diones in high yields. The gem-dinitro products were easily attacked by nucleophiles with concomitant formation of gem-dinitroacetyl derivatives, which in turn could be further hydrolyzed to salts of dinitromethane and triureas.
Microwave assisted pyrolysis of urea supported on graphite under solvent-free conditions
Chemat, Farid,Poux, Martine
, p. 3693 - 3695 (2007/10/03)
The coupling of graphite (support) with microwaves (energy source) is responsible for a high temperature gradient leading to increased reaction rates as compared to conventional procedures. A rapid one-pot preparation of cyanuric acid is described that proceeds from urea by pyrolysis using microwave heating in the absence of water and organic solvents.
