- Violuric acid and preparation method thereof
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The invention provides violuric acid and a preparation method thereof. The preparation method comprises the following steps: S1, providing an alkaline water solution of barbituric acid; S2, adding a nitrite water solution into the alkaline water solution of the barbituric acid to form a mixed solution; S3, dropwise adding inorganic acid or an inorganic acid water solution into the mixed solution;carrying out chemical reaction to obtain the violuric acid. According to the preparation method of the violuric acid, provided by the embodiment of the invention, the high-purity violuric acid can beobtained; the method is simple to operate and can be operated at room temperature; the method has high safety and is suitable for industrialized production; meanwhile, raw materials are easy to obtainand the cost is relatively low.
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Paragraph 0055; 0061; 0068; 0075
(2018/09/12)
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- Complexes with 6-amino-5-nitroso-2-thiouracil and violuric acid derivatives containing the fac-ReI(CO)3 core: Synthesis, XRD structural and photoluminescence characterization
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The fac-tricarbonylrhenium(I) complexes of the 6-amino-1,3-dimethyl-5- nitroso-2-thiouracil (DANTU) and violuric acid (VIO) and its mono- (MVIO) and dimethyl (DVIO) derivatives have been prepared. The complexes have been characterized by elemental analysis, IR, 1H and 13C NMR spectral methods and luminescence spectroscopy. The structures of [ReCl(CO) 3(DANTU)], [Re(H2O)(CO)3(VIOH-1)] and [Re(H2O)(CO)3(DVIOH-1)] complexes were solved from single-crystal X-ray diffraction experiments. The coordination environment around the Re(I) may be described as a distorted octahedron in which the ligand behaves in a bidentate fashion through the nitrogen atom of the nitroso group and an adjacent carbonylic oxygen, making a five-membered chelate ring. The coordination sphere is completed with three carbonyl groups in fac-arrangement and one chlorine atom (DANTU complex) or water molecule (VIO complexes). The higher acidity of violuric acids, if compared with DANTU one, may explain both synergic deprotonation and chloride substitution in the [ReCl(CO)3]+ moiety to form the Re-violurato complexes.
- Illán-Cabeza, Nuria A.,García-García, Antonio R.,Moreno-Carretero, Miguel N.
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experimental part
p. 262 - 267
(2011/04/12)
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- Enol nitrosation revisited: determining reactivity of ambident nucleophiles
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Enols are one of the most Important types of ambident nucleophiles being widely used as reagents in organic chemistry, The relevance of enols has led to considerable interest in developing methods to determine the reactivity of their nucleophilic centers, In this sense, the mainstream, literature works on this topic make use of a. combination of overall rate constants together with the analysis of the reaction products, By knowing the product ratio it is possible to determine the ratio between the reaction rates on each site, Thus, the reactivity for each, nucleophilic position can be obtained, This is a reliable approach as long as the isolation or in situ characterization of the reaction products can be carried out, In the case of unstable and/or interconvertible products where the use of identification techniques is not possible, an alternative methodology must be found, For that: reason, our research group has developed a model that allows us to study and quantify separately the reaction rates of enol nucleophilic centers even if only one final reaction product is obtained, This model is based on the fact: that nitrosation of enols shows well-differentiated behavior depending on whether the reaction proceeds through the carbon or the oxygen atom, The present study provides insights into the ambident nature of enols as well as a methodology for determining the chemical reactivity of their nucleophilic centers.
- Garcia-Rio, Luis,Mejuto, Juan C.,Parajo, Mercedes,Perez-Lorenzo, Moises
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supporting information; experimental part
p. 4525 - 4533
(2010/01/16)
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