- Meteorite-catalyzed intermoleculartrans-glycosylation produces nucleosides under proton beam irradiation
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Di-glycosylated adenines act as glycosyl donors in the intermoleculartrans-glycosylation of pyrimidine nucleobases under proton beam irradiation conditions. Formamide and chondrite meteorite NWA 1465 increased the yield and the selectivity of the reaction
- Bizzarri, Bruno Mattia,Fanelli, Angelica,Kapralov, Michail,Krasavin, Eugene,Saladino, Raffaele
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p. 19258 - 19264
(2021/06/03)
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- Synthesis method of beta-thymidine
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The invention discloses a synthesis method of beta-thymidine. The synthesis method takes trimethylchlorosilane and 5-methyluracil as raw materials to react; in a reaction line process, tetraacetylribose, trifluoromethanesulfonic acid, N,N-dimethylformamide and acetylchloride are introduced; then hydrogenation reaction and hydrolysis reaction are carried out to finally obtain a beta-thymidine finished product and the yield is 89 percent. Compared with an existing synthesis method, the synthesis method of the beta-thymidine has the advantages that the price of raw materials is low, the content of the beta-thymidine in the final product is high, and pollution to the environment in a production process is small; in a synthesis process, the content of generated impurities is less. According to the synthesis method disclosed by the invention, an obtained result is stable and the operation is simple; demands on equipment and preparation environments are not strict so that large-scale popularization is facilitated.
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- Method for preparing telbivudine
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The invention relates to a method for preparing telbivudine. The reaction mechanism is as shown in the specification specifically. Compared with a method of the prior art, the method provided by the invention has the advantages that firstly, all raw materials are low in cost and can be easily obtained from the market; secondly, reaction of different steps is normal reaction, and the reaction steps are simple and easy to implement; and thirdly, production requirements can be met by using normal preparation equipment, the production is easy to control, and industrial production can be achieved.
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Paragraph 0052; 0053; 0054
(2016/10/09)
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- Method for preparing high-purity telbivudine compound
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The invention belongs to the technical field of medicine and provides a method for preparing a high-purity telbivudine compound. The method includes the steps that an LTD-4 compound serves as the raw material and reacts with thymine subjected to silicification protection, and an intermediate, namely an LTD-5 compound, can be obtained; then, through deprotection reaction, the telbivudine compound is obtained after post-processing, wherein MeONa serves as an alkaline reagent of the deprotection reaction, and strong-acidity resin serves as a dealkalization reagent. The method simplifies the production process, the yield of each step is high, and a target product high in purity and yield is obtained. Please see the structural formula in the description.
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Paragraph 0046; 0047
(2017/01/02)
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- METHODS FOR THE TREATMENT OF HEPATITIS B AND HEPATITIS D VIRUS INFECTIONS
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It is disclosed a method for treating hepatitis B virus infection or hepatitis B virus/hepatits delta virus co-infection, the method comprising administering to a subject in need of such treatment a first pharmaceutically acceptable agent that comprises at least one phosphorothioated nucleic acid polymer and a second pharmaceutically acceptable agent that comprises at least one nucleoside/nucleotide analog HBV polymerase inhibitor.
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- PROCESS FOR PREPARING L-NUCLEIC ACID DERIVATIVES AND INTERMEDIATES THEREOF
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A novel method has been found to produce 2,2′-anhydro-1-(β-L-arabinofuranosyl)thymine as a novel useful intermediate compound. A novel method has been further found to produce thymidine from 2,2′-anhydro-1-(β-L-arabinofuranosyl)thymine. According to these methods, synthesis of various L-nucleic acid derivatives, synthesis of which has been difficult till now, is possible.
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Page/Page column 5-6
(2009/01/24)
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- Synthesis of L-2′-deoxypentofuranonucleoside derivatives of thymine from D-glucose
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Convergent synthesis of L-2′-deoxypentofuranonucleoside derivatives of thymine was carried out from D-glucose via 6-O-toluoyl-3-deoxy-1,2-O- isopropylidene-β-L-lyxo-hexofuranose as a key intermediate. Copyright Taylor & Francis Group, LLC.
- Sivets, Grigorii G.
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p. 1241 - 1244
(2008/09/19)
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- Synthesis of beta-L-2'-deoxy nucleosides
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An improved process for the preparation of 2′-modified nucleosides and 2′-deoxy-nucleosides, such as, β-L-2′-deoxy-thymidine (LdT), is provided. In particular, the improved process is directed to the synthesis of a 2′-deoxynucleoside that may utilize different starting materials but that proceeds via a chloro-sugar intermediate or via a 2,2′-anhydro-1-furanosyl-nucleobase intermediate. Where an 2,2′-anhydro-1-furanosyl base intermediate is utilized, a reducing agent, such as Red-Al, and a sequestering agent, such as 15-crown-5 ether, that cause an intramolecular displacement reaction and formation of the desired nucleoside product in good yields are employed. An alternative process of the present invention utilizes a 2,2′-anhydro-1-furanosyl base intermediate without a sequestering agent to afford 2′-deoxynucleosides in good yields. The compounds made according to the present invention may be used as intermediates in the preparation of other nucleoside analogues, or may be used directly as antiviral and/or antineoplastic agents.
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Page/Page column 35; 36
(2010/02/11)
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- 2'-deoxy-L-nucleosides
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This invention provides processes for the preparation of compounds having the structure: wherein X and Y are same or different, and H, OH, OR, SH, SR, NH2, NHR′, or NR′R″Z is H, F, Cl, Br, I, CN, or NH2. R is hydrogen, halogen, lower alkyl of C1-C6 or aralkyl, NO2, NH2, NHR′, NR′R″, OH, OR, SH, SR, CN, CONH2, CSNH2, CO2H, CO2R′, CH2CO2H, CH2CO2R′, CH═CHR, CH2CH═CHR, or C═CR. R′ and R″ are same or different, and lower alkyl of C1-C6. R13 is hydrogen, alkyl, acyl, phosphate (monophosphate, diphosphate, triphosphate, or stabilized phosphate) or silyl; and
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Page/Page column 37
(2010/02/11)
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- Methods of manufacture of 2'-deoxy-beta-L-nucleosides
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The present invention relates to the synthesis of 2′-deoxy-β-L-thymidine, 2′-deoxy-β-L-uridine and 2′-deoxy-β-L-cytidine, and their derivatives, such as the 3′-O-acyl or 3′,5′-O-diacyl prodrugs, including the 3′-O-L-aminoacyl and 3′,5′-O-L-diaminoacyl prodrugs, and particularly the 3′-O-L-valinyl and 3′,5′-O-L-divalinyl prodrugs.
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Page/Page column 23
(2008/06/13)
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- Regioselective enzymatic acylation of β-L-2′-deoxynucleosides: Application in resolution of β-D/L-2′-deoxynucleosides
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(Chemical Equation Presented) A practical synthesis of β-L-3′- and β-L-5′-O-levulinyl-2′-deoxynucleosides has been described for the first time through enzymatic acylation and/or hydrolysis processes. It is noteworthy that the different behavior exhibited by Pseudomonas cepacia lipase in the acylation of D- and L-nucleosides allows the parallel kinetic resolution of D/L-nucleosides.
- Garcia, Javier,Fernandez, Susana,Ferrero, Miguel,Sanghvi, Yogesh S.,Gotor, Vicente
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p. 3759 - 3762
(2007/10/03)
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- L-NUCLEIC ACID DERIVATIVES AND PROCESSES FOR THE SYNTHESIS THEREOF
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A novel method has been found to produce 2,2'-anhydro-1-(β-L-arabinofuranosyl)thymine as a novel useful intermediate compound. A novel method has been further found to produce thymidine from 2,2'-anhydro-1-(β-L-arabinofuranosyl)thymine. A novel method has been further found to L-2'-deoxyribose derivatives as a useful synthetic intermediate through L-2,2'-anhydro-5,6-dihydrocyclouridine derivative. According to these methods, synthesis of various L-nucleic acid derivatives, synthesis of which has been difficult till now.
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Page/Page column 19
(2008/06/13)
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- Process for preparing beta-L-2'deoxy-thymidine
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The present invention relates to a new, essentially four-step process for preparing beta-L-2′-deoxy-thymidine starting from L-arabinose. The process according to the invention is particularly important for mass production of beta-L-2′-deoxy-thymidine.
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- Synthesis and enzymatic digestion of an RNA nonamer in both enantiomeric forms
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The D- and L-RNA nonamers of the sequence r(GCUUCGGC)T have been synthesised for X-ray crystallographic purposes. In vitro digestion of the unnatural optical antipode by snake venom phosphodiesterase I takes place at an approximately 1800-fold slower rate than that of the natural D-nonamer. The digestion experiments showed - to our knowledge for the first time - that L-RNA can indeed be cleaved enzymatically when phosphodiesterase I from snake venom is used - as opposed to a number of cellular ribonucleases - which sheds an interesting light on the evolution and possibly structure/function relationship of venom versus cellular degradation enzymes. The broad substrate specificity of this enzyme could be taken advantage of to study and further optimise the resistance towards biodegradation of therapeutic L-RNA aptamers. (C) 2000 Elsevier Science Ltd.
- Moyroud, Elisabeth,Biala, Ewa,Strazewski, Peter
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p. 1475 - 1484
(2007/10/03)
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- L-ribonucileosides for racemic RNA
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Two L-ribosyl donors were synthesised from L-xylose, then submitted to a glycosidation reaction according to Vorbruggen's conditions to furnish L- ribonucleosides in high yield.
- Moyroud,Botta,Strazewski
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p. 693 - 695
(2007/10/03)
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- Ionization of purine nucleosides and nucleotides and their components by 193-nm laser photolysis in aqueous solution: Model studies for oxidative damage of DNA 1
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The effect of 20-ns pulses of 193-nm laser light on aqueous solutions of purine bases, (2′-deoxy)nucleosides, and (2′-deoxy)nucleotides was investigated, and monophotonic ionization was observed. Although (deoxy)ribose and (deoxy)ribose phosphates are also ionized by 193-nm light, the photoionization of the (deoxy)nucleosides and -tides takes place predominantly (90%) at the purine moiety, due to the much higher extinction coefficients at 193 nm of the bases as compared to the (deoxy)ribose phosphates. The quantum yields of photoionization (φPl) of the purines are in the range 0.01 to 0.08, based on φ(Cl-) at 193 nm of 0.46. As shown by comparison with data obtained from pulse radiolysis, the ionized purines, i.e., the radical cations, deprotonate in neutral solution, yielding neutral radicals. The radical cation of 1-methylguanosine, produced by photoionization in oxygen-saturated aqueous solution, deprotonates with the rate constant 3.5 × 105 s-1. In the absence of oxygen, the hydrated electrons resulting from the photoionization react with the untransformed purine derivatives to yield the corresponding radical anions. As these are rapidly protonated by water (as concluded from pulse radiolysis), the photoionization in deaerated neutral solution results in two different neutral radicals: a deprotonated radical cation and a protonated radical anion.
- Candeias,Steenken
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p. 699 - 704
(2007/10/02)
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