N4-Benzoylcytosine

Synthesis and biological evaluation of 3'-C-ethynyl and 3'-C-(1,4-disubstituted-1,2,3-triazolo) double-headed pyranonucleosides.[Pubmed:22530902]

Med Chem. 2012 May;8(3):320-9.

A novel series of 3'-C-ethynyl and 3'-C-(1,4-disubstituted-1,2,3-triazolo) double-headed pyranonucleosides has been designed and synthesized. Reaction of 3-keto glucoside 1 with ethynyl magnesium bromide gave the desired precursor 3-C-ethynyl-1,2:5,6-di-O-isopropylidene-alpha-D-allofuranose (2). Hydrolysis followed by acetylation led to the 1,2,4,6-tetra-O-acetyl-3-C-ethynyl-beta-D-allopyranose (3). Compound 3 was condensed with silylated 5-fluorouracil, uracil, thymine, N4-Benzoylcytosine and N6-benzoyladenine, respectively and deacetylated to afford the target 1-(3'-C-ethynyl-beta-D-allopyranosyl)nucleosides 5a-c,f,g. Copper-Catalyzed Azide-Alkyne Cycloaddition (CuAAC) reaction was utilized to couple the 3'-C-ethynyl pyranonucleoside derivatives with azidoethyl adenine, 5-fluorouracil and thymine, respectively to afford novel triazole double-headed nucleoside analogs 8a-h. 3'-C-Ethynyl pyranonucleosides and the new double-headed analogues were evaluated for their antiviral and cytostatic activities. Although none of the compounds showed pronounced cytostatic activity and were devoid of a significant antiviral potential, the double-headed nucleoside derivatives 8a, 8c and 8e showed a moderate cytostatic activity against human cervix carcinoma HeLa cells which may be the basis for the synthesis of analogous derivatives with improved cytostatic potential.

A novel pseudo-complementary PNA G-C base pair.[Pubmed:21686250]

Artif DNA PNA XNA. 2011 Jan;2(1):33-37.

Pseudo-complementary oligonucleotide analogues and mimics provide novel opportunities for targeting duplex structures in RNA and DNA. Previously, a pseudo-complementary A-T base pair has been introduced. Towards sequence unrestricted targeting, a pseudo-complementary G-C base pair consisting of the unnatural nucleobases n6-methoxy-2,6-diaminopurine (previously described in a DNA context) and N4-Benzoylcytosine is now presented for design of pseudo-complementary PNA oligomers (pcPNAs).

Nucleosides and nucleotides. 232. Synthesis of 2'-C-methyl-4'-thiocytidine: unexpected anomerization of the 2'-keto-4'-thionucleoside precursor.[Pubmed:16438048]

Nucleosides Nucleotides Nucleic Acids. 2005;24(10-12):1789-800.

The synthesis of 2'-C-methyl-4'-thiocytidine (16) is described. Since the 2'-keto-4'-thiocytidine derivative 2beta unexpectedly isomerized to 2alpha and the methylation of 2beta proceeded predominantly from the less hindered alpha-face to give 7, the desired product 16 was synthesized via the Pummerer reaction of the sulfoxide 14 and N4-Benzoylcytosine.

Phosphoralaninate pronucleotides of pyrimidine methylenecyclopropane analogues of nucleosides: synthesis and antiviral activity.[Pubmed:16438046]

Nucleosides Nucleotides Nucleic Acids. 2005;24(10-12):1763-74.

The Z- and E-thymine and cytosine pronucleotides 3d, 4d, 3e, and 4e of methylenecyclopropane nucleosides analogues were synthesized, evaluated for their antiviral activity against human cytomegalovirus (HCMV), herpes simplex virus 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), human immunodeficiency virus type 1 (HSV-1), and hepatitis B virus (HBV) and their potency was compared with the parent compounds 1d, 2d, 1e, and 2e. Prodrugs 3d and 4d were obtained by phosphorylation of parent analogues 1d or 2d with reagent 8. A similar phosphorylation of N4-Benzoylcytosine methylenecyclopropanes 9a and 9b gave intermediates 11a and 11b. Deprotection with hydrazine in pyridine-acetic acid gave pronucleotides 3e and 4e. The Z-cytosine analogue 3e was active against HCMV and EBV The cytosine E-isomer 4e was moderately effective against EBV.

Diastereocontrolled synthesis of dinucleoside phosphorothioates using a novel class of activators, dialkyl(cyanomethyl)ammonium tetrafluoroborates.[Pubmed:11982352]

J Am Chem Soc. 2002 May 8;124(18):4962-3.

A novel class of activators, dialkyl(cyanomethyl)ammonium tetrafluoroborates 1a-c, has been developed and applied to the condensations of diastereopure 5'-O-tert-butyldiphenylsilylthymidine 3'-cyclic phosphoramidites 3a-d with 3'-O-tert-butyldimethylsilylthymidine (4a). Among them, the condensation of 3a with 4a in the presence of 1a completed within 5 min and gave only one diastereoisomer of the corresponding phosphite 5a. After sulfurization and deprtection, almost diastereopure (Rp)-TpsT 7 was obtained (d.r. = 99:1). Next the 5'-O-(DMTr)nucleoside 3'-phosphoramidites 8a-d containing thymine, N6-benzoyladenine, N4-Benzoylcytosine, and N2-phenylacetylguanine have been synthesized and allowed to condense with 3'-O-protected thymidine and 2'-deoxyadenosine. The 5'-O-DMTr group and the N-acyl groups of the nucleobases were compatible with the reaction conditions and the condensations completed quickly with excellent diastereoselectivity.

Synthesis and anti-HIV and anti-HBV activities of 2'-fluoro-2', 3'-unsaturated L-nucleosides.[Pubmed:10197975]

J Med Chem. 1999 Apr 8;42(7):1320-8.

The synthesis of L-nucleoside analogues containing 2'-vinylic fluoride was accomplished by direct condensation method, and their anti-HIV and anti-HBV activities were evaluated in vitro. The key intermediate 8, the sugar moiety of our target compounds, was prepared from 1,2-O-isopropylidene-L-glyceraldehyde via (R)-2-fluorobutenolide intermediate 5 in five steps. Coupling of the acetate 8 with the appropriate heterocycles (silylated uracil, thymine, N4-Benzoylcytosine, N4-benzoyl-5-fluorocytosine, 6-chloropurine, and 6-chloro-2-fluoropurine) in the presence of Lewis acid afforded a series of 2'-fluorinated L-nucleoside analogues (15-18, 23-26, 36-45). The newly synthesized compounds were evaluated for their antiviral activities against HIV-1 in human peripheral blood mononuclear (PBM) cells and HBV in 2.2.15 cells. Cytosine 23, 5-fluorocytosine 25, and adenine 36 derivatives exhibited moderate to potent anti-HIV (EC50 0.51, 0.17, and 1.5 microM, respectively) and anti-HBV (EC50 0.18, 0.225, and 1.7 microM, respectively) activities without significant cytotoxicity up to 100 microM in human PBM, Vero, CEM, and HepG2 cells.

Studies on 2',3'-dideoxy-2',3'-didehydropyrimidine nucleosides. II. N4-benzoyl-2',3'-dideoxy-2',3'-didehydrocytidine as a prodrug of 2',3'-dideoxy-2',3'-didehydrocytidine (DDCN).[Pubmed:2557984]

Chem Pharm Bull (Tokyo). 1989 Sep;37(9):2547-9.

N4-Benzoyl-2',3'-dideoxy-2',3'-didehydrocytidine (Bz-DDCN) was synthesized as a novel prodrug of 2',3'-dideoxy-2',3'-didehydrocytidine (DDCN), which is a reverse transcriptase inhibitor and is considered to be a potential anti-acquired immunodeficiency syndrome agent. Chemical and enzymatic regeneration of DDCN from the prodrug has been investigated in both in vitro and in vivo experiments. Bz-DDCN regenerated DDCN under basic conditions (greater than pH 8), while cleavage of the N-glycosidic linkage and production of N4-Benzoylcytosine were observed under acidic conditions (less than pH 6). DDCN was enzymatically regenerated from the prodrug in the presence of several enzyme preparations, including human plasma. DDCN and Bz-DDCN were intravenously administered to mice and the plasma concentrations of DDCN and the prodrug were measured. Though DDCN levels following direct DDCN administration decreased exponentially with a half-life of 14.5 min, the plasma levels of DDCN following the prodrug administration were sustained above 2 microM for over 3 h.