- Oxidation of 6-methyl-2,4-dioxypyrimidine with selenious acid
-
The yield orotic aldehyde at the oxidation of 6-methyl-2,4- dihydroxypyrimidine was found to increase when selenious acid is used as an oxidizer. A comparative analysis of 6-methyl-2,4-dioxypyrimidine oxidation with selenium dioxide and selenious acid was performed using the ab initio quantum chemical method in the 6-31G basis.
- Rakhimov,Shul'Man,Fedunov
-
-
Read Online
- 5 - Chloro -6 - [(2 - imino -1 - pyrrolidine) methyl] - 2, 4 (1 H, 3 H) - dione or its salt preparation method
-
The invention provides a preparation method of 5-chloro-6-[(2-imino-1-pyrrolidinyl)methyl]-2,4(1H,3H)-pyrimidine dione or salts thereof, which comprises the following steps: by using 6-methylpyrimidyl-2,4(1H,3H)-dione as an initial raw material, carrying out 6- site methyl oxidation and 5- site hydrogen chlorination, reducing the 6- site formyl group, carrying out condensation with 2-aminopyrrolidine or corresponding salts to obtain the target product. The method is simple to operate and stable in technique, is suitable for industrial production, and has the advantages of high yield, high purity and low cost.
- -
-
Paragraph 0035; 0036; 0037
(2018/11/03)
-
- Tipiracil hydrochloride and synthesis method of intermediate 6-(chloromethyl)uracil
-
The invention provides a synthesis method of 6-(chloromethyl)uracil. The synthesis method comprises the steps that 6-(methyl)uracil and copper oxide perform oxidizing reaction in a solvent to obtain 6-(formyl)uracil; the 6-(formyl)uracil is reduced to obtain 6-(hydroxymethyl)uracil; the 6-(hydroxymethyl)uracil is subjected to chlorination to obtain the 6-(chloromethyl)uracil, wherein the purity of the 6-(chloromethyl)uracil is high than 99.0%. The synthesis method of the 6-(chloromethyl)uracil is optimized, selenium dioxide is replaced by low-toxicity metal oxide to achieve a 6-(formyl)uracil oxidation process, environmental friendliness is improved, and meanwhile the yield and purity of the 6-(chloromethyl)uracil are improved. The invention further provides a synthesis method of tipiracil hydrochloride. The obtained 6-(chloromethyl)uracil obtained by adopting the process is an intermediate, the tipiracil hydrochloride is directly prepared through three steps of chloro, condensing and salifying reaction, the obtained raw material drug does not need any purifying process, and the purity ishigher than 99.0%.
- -
-
Paragraph 0080; 0081; 0082; 0083; 0084; 0085; 0086-0092
(2017/07/19)
-
- Preparation method of tipiracil intermediate
-
The invention provides a preparation method of a tipiracil intermediate which is 6-(chloromethyl)-2, 4-(1H, 3H)-pyrimidinedione. 6-methyl-2, 4-(1H, 3H)-pyrimidinedione as an initial raw material undergoes an iodine replacement reaction at the 5th site of a compound and then the product undergoes reduction and chlorination reactions at the 6th site to produce a desired product. The preparation method has the advantages of stable processes, high yield and low cost and is suitable for industrial production.
- -
-
Paragraph 0026; 0027; 0028; 0029
(2017/02/17)
-
- UV and visible light activated TiO2 photocatalysis of 6-hydroxymethyl uracil, a model compound for the potent cyanotoxin cylindrospermopsin
-
TiO2 photocatalyses of 6-hydroxymethyl uracil (6-HOMU) a model compound for the potent cyanotoxin, cylindrospermopsin (CYN), were carried out employing visible and UV irradiation using different non-metal doped TiO 2 materials, nitrogen and fluorine-TiO2 (NF-TiO 2), phosphorus and fluorine-TiO2 (PF-TiO2) and sulfur-TiO2 (S-TiO2). The model compound was readily degraded under UV TiO2 photocatalysis with pseudo-first-order rate constants (k) of 2.1, 1.0, and 0.44 h-1 for NF-TiO2, PF-TiO2 and S-TiO2, respectively. Under visible light activated (VLA), NF-TiO2 was the most active photocatalyst, PF-TiO2 was marginally active and S-TiO2 inactive. VLA NF-TiO2 was effective and increased the k with increasing pH from 3 to 9. The presence of humic acid (HA), Fe3+ and Cu2+ can enhance the degradation. However, at 20 ppm HA significant inhibition was observed, likely due to shadowing of the catalyst, quenching of ROS or blocking active sites of TiO2. We probed the roles of different reactive oxygen species (ROS) using specific scavengers and the results indicate that O2- plays an important role in VLA TiO2 photocatalysis. Our results demonstrate that NF-TiO2 photocatalysis is effective under UV and visible irradiation and over a range of water qualities. VLA NF-TiO2 photocatalysis is an attractive alternative technology for the CYN contaminated water treatment.
- Zhao, Cen,Pelaez, Miguel,Dionysiou, Dionysios D.,Pillai, Suresh C.,Byrne, John A.,O'Shea, Kevin E.
-
-
- Fragment-based approach to the design of 5-chlorouracil-linked-pyrazolo[1, 5-a][1,3,5]triazines as thymidine phosphorylase inhibitors
-
5-Chlorouracil-linked-pyrazolo[1,5-a][1,3,5]triazines were designed as new thymidine phosphorylase inhibitors based on the fragment based drug design approach. Multiple-step convergent synthetic schemes were devised to generate the target compounds. The intermediate 5-chloro-6-chloromethyluracil was synthesized by a 4-step reaction. A series of the second bicyclic intermediates, namely pyrazolo[1,5-a][1,3,5]triazin-2-thioxo-4-one, was obtained from various substituted 3-aminopyrazoles. These two intermediates were coupled finally in the presence of sodium ethoxide and methanol to yield the desirable target compounds. The methylthio coupling spacer was found to be suitable in enabling the interaction of the two fragments at the active site and allosteric site of the enzyme. The best coupled compound (9q) inhibited the thymidine phosphorylase with an IC50 value as low as 0.36 ± 0.1 μM. In addition, 9q demonstrated a mixed-type of enzyme inhibition kinetics, thus suggesting that it might indeed potentially bind at two different sites on the enzyme. Georg Thieme Verlag KG Stuttgart New York ISSN 0935-8943.
- Sun, Lingyi,Li, Jiarong,Bera, Hriday,Dolzhenko, Anton V.,Chiu, Gigi N.C.,Chui, Wai Keung
-
p. 400 - 410
(2013/11/19)
-
- 6-Substituted 5-fluorouracil derivatives as transition state analogue inhibitors of thymidine phosphorylase
-
A combination of mechanism-based and structure-based design strategies led to the synthesis of a series of 5- and 6-substituted uracil derivatives as potential inhibitors of thymidine phosphorlase/platelet derived endothelial cell growth factor (TP/PD-ECGF). Among those tested, 6-imidazolylmethyl-5- fluorouracil was found to be the most potent inhibitor with a K i-value of 51 nM, representing a new class of 5-fluoropyrimidines with a novel mechanism of action. Copyright Taylor & Francis, Inc.
- Kalman, Thomas I.,Lai, Li
-
p. 367 - 373
(2007/10/03)
-