- Systematic assignment of NMR spectra of 5-substituted-4-thiopyrimidine nucleosides
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Unambiguous characterization of 5-substituted-4-thiopyrimidine nucleosides (ribonucleosides and 2'-deoxynucleosides) was performed using NMR spectroscopy. Assignments of all proton and carbon signals of 5-bromo-4-thiouridine and related nucleosides were systematically carried out and firmly established by COSY and HMQC techniques. The NMR data of various 4-thiopyrimidine nucleosides are compared, and the key contributing factors discussed. The approach presented here is applicable to other modified nucleosides and nucleotides, as well as nucleobases. Copyright
- Zhang, Xiaohui,Wang, Jian,Xu, Yao-Zhong
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p. 523 - 529
(2013/09/02)
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- Synthesis and properties of DNA containing cyclonucleosides
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Here, we present efficient syntheses of the R and S diastereomers of 8,5′-cyclo-2′-deoxyadenosine and 6,5′-cyclo-2′- deoxyuridine. We incorporated these interesting nucleosides into DNA to study how the cyclo linkage affects the stability of duplex formation.
- Yueh, Han,Yu, Hongchuan,Theile, Christopher S.,Pal, Ayan,Horhota, Allen,Greco, Nicholas,Christianson, Carl V.,McLaughlin, Larry W.
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p. 661 - 679
(2012/11/07)
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- Ionic liquid mediated synthesis of 5-halouracil nucleosides: Key precursors for potential antiviral drugs
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Synthesis of antiviral 5-halouracil nucleosides, also used as key precursors for the synthesis of other potential antiviral drugs, has been demonstrated using ionic liquids as convenient and efficient reaction medium.
- Kumar, Vineet,Malhotra, Sanjay V.
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experimental part
p. 821 - 834
(2010/08/20)
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- A mild and efficient methodology for the synthesis of 5-halogeno uracil nucleosides that occurs via a 5-halogeno-6-azido-5,6-dihydro intermediate
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A mild and efficient methodology for the synthesis of 5-halogeno (iodo, bromo, or chloro) uracil nucleosides has been developed. 5-Halo-2'-deoxyuridines 4a-c (84-95%), 5-halouridines 7a-c (45-95%), and 5-haloarabinouridines 8a-c (65-95%) were synthesized in good to excellent yields by the reaction of 2'-deoxyuridine (2), uridine (5) and arabinouridine (6), respectively with iodine monochloride, or N-bromo (or chloro)succinimide, and sodium azide at 25-45°C. These C-5 halogenation reactions proceed via a 5-halo-6-azido-5,6-dihydro intermediate (3), from which HN3 is eliminated, to yield the 5-halogeno uracil nucleoside. The 5-halo-6-azido-5,6-dihydro intermediate products (10a, 10b) could be isolated from the reaction of 3',5'-di-O-acetyl-2'-deoxyuridine (9) with iodine monochloride or N-bromosuccinimide and sodium azide at 0°C. The isolation of 10a, 10b indicates that the C-5 halogenation reaction proceeds via a 5-halo-6-azido-5,6-dihydro intermediate.
- Kumar,Wiebe,Knaus
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p. 2005 - 2010
(2007/10/02)
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- In-cell Indirect Electrochemical Halogenation of Pyrimidine Bases and their Nucleosides to 5-Haloderivatives
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Reaction of anodically generated "halonium" species (LiX or Bu4NX, LiClO4, MeCN, Pt/Pt; I2, LiClO4, MeCN) with pyrimidine bases and their nucleosides leads to 5-halo compounds in good yields.
- Palmisano, G.,Danieli, B.,Santagostino, M.,Vodopivec, B.,Fiori, G.
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p. 7779 - 7782
(2007/10/02)
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- Cerium(IV)-Mediated Halogenation at C-5 of Uracil Derivatives
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Treatment of protected uracil nucleosides 1 or 2 with elemental iodine or metal halogenides and ceric ammonium nitrate (CAN) at 80 deg C gave the corresponding protected 5-halouracil nucleosides 3a-f in excellent yields.Treatment of the resulting crude 3a-f with 0.1 M NaOMe/MeOH at ambient temperature gave the corresponding 5-halouridines 4a-f in high overall yields from 1 or 2.Further, 5-halouraciles 9a-f were prepared in good yields by treatment of 1,3-dimethyluracil (7) or uracil (8) with elemental iodine, metal halogenides, or hydrochloric acid and CAN.Halouridines 4a-e also were obtained in good yields by treatment of unprotected uracil nucleosides 5 or 6 with halogen sources as above and CAN.
- Asakura, Jun-ichi,Robins, Morris J.
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p. 4928 - 4933
(2007/10/02)
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- SYNTHESIS OF 6,5'-cyclo-2',5'-DIDEOXYPYRIMIDINE NUCLEOSIDES ( NUCLEOSIDES AND NUCLEOTIDES. LXXII )
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6,5'-cyclo-2',5'-dideoxyuridine and 6,5'-cyclo-5'-deoxythymidine, pyrimidine deoxynucleosides fixed in the anti conformation were synthesized.The key intermediate, 3'-O-acetyl-5-chloro-2',5'-dideoxy-5'-iodouridine ( 12 ), prepared from 2'-deoxyuridine, was cyclized by treatment with tributyltin hydride to the 6,5'-cyclo derivative ( 13 ), then dehydrochlorinated to furnish, after de-O-acetylation, 6,5'-cyclo-2',5'dideoxyuridine ( 14 ).For the synthesis of 6,5'-cyclothymidine, 3'-O-acetyl-2',5'-dideoxy-5'-iodo-5-phenylthiomethyluridine ( 22 ) was prepared from 2'-deoxyuridine and this compound was cyclized by treatment with tributyltin hydride to yield, after de-O-acetylation 6,5'-cyclo-5'-deoxythymidine ( 24 ).Keywords - cyclonucleoside; C-cyclouridine; 6,5'-cyclo-2',5'-dideoxyuridine; 6,5'-cyclo-5'deoxythymidine; 5-bromo-6,5'-cyclo-2',5'-dideoxyuridine; radical cyclization; tributyltin hydride; NMR; CD
- Suzuki, Yukari,Matsuda, Akira,Ueda, Tohru
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p. 1085 - 1092
(2007/10/02)
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