The Synthesis of Some 5-Vinyluracil-Nucleoside Analogues

Abstract

The reaction of 5-iodouridine with esters of acrylic acid in the palladium-catalysed Heck reaction was used to generate a series of esters of the acid (E) -5- (2-carboxyvinyl)uridine in poor to moderate yield. An alternative method starts from the acid by protection of the sugar moiety followed by in situ generation of the acid chloride then ester formation followed by simultaneous sugar deprotection. Treatment of the methyl ester with ammonia and methylamine gave the corresponding amides, while treatment with dimethylamine gave 5-(1-dimethylamino-2-carboxy)ethyluridine as the major product.     

Synthesis of Some New Nucleoside Analogues as Potential Antiviral Agents

Abstract

A novel series of pyrimidine nucleoside analogues was synthesized. 2,3-Dideoxy-2,3-anhydro-β-D-lyxofuranose was opened by sodium azide to give the corresponding azido compound, which was reduced by lithium aluminium hydride to lead to 2,3-dideoxy-2,3-epimino-β-D-ribofuranose. Pyrimidine bases were glycosylated with this synthon to give potential antiviral molecules: 1-(2,3-dideoxy-2,3-epimino-β-D-ribofuranosyl)pyrimidines.     

Synthesis of cis-Disubstituted Cyclobutenyl Nucleoside Analogues

Abstract

cis-Disubstituted cyclobutene nucleosides analogues were prepared by a linear synthesis starting from cis-cyclobutene dicarboxylic anhydride. This strategy involved mild reaction conditions with intent to restrict the thermal electrocyclic ring opening into (Z,E)-dienes.     

Synthesis of New Thiazolidinone Nucleoside Analogues

Abstract

The synthesis of new thiazolididone nucleoside analogues is described. Among the different proposed synthetic pathways, the condensation of various nucleic bases using TMSOTf and Et₃N as coupling reagents on a key sulfoxide thiazolidinone intermediate led to the desired compounds in a one-pot procedure. Analytical data and NMR studies confirmed the proposed structure assignment for these compounds.     

Synthesis of Imidazo[1, 2-a]pyrazine Nucleoside Analogues

Abstract

A synthesis of imidazo[1, 2-a]pyrazine nucleoside analogues is described.     

Synthesis of Nucleoside Analogues Using Immobilised N-Deoxyribosyltransferases

Crude N-deoxyribosyltransferase from Lactobacillus leichmannii was immobilised by hydrophobic interaction on octyl-Sepharose or by covalent attachment to poly(acrylamide-co-N-acryl-oxysuccinimide) (PAN). Little enzyme activity was retained by entrapment in K-carrageenan. N-deoxyribosyltransferase immobilised on PAN was used to prepare 2'-deoxy-2-thiouridine.     

Unsaturated Nucleoside Analogues: Synthesis and Antitumor Activity

Abstract

Five classes of unsaturated nucleoside analogues were investigated as inhibitors of growth of murine leukemia L 1210 culture. The structural types include E ole-fins 1, Z-olefins 2, acetylene derivatives 3, allenes 4 and oxacyclopentenes 5. Compounds of the type 1-3 (X = Cl) were obtained by alkylation of the respective nucleic acid bases or 2-amino-6-chloropurine with E and Z-1,4-dichloro-2-butene or 1,4-di-chloro-2-butyne. Acid hydrolysis of intermediates 1, 2 and 3 (X = CI) led to the corresponding alcohols 1, 2 and 3 (X = OH). Chloroallene 4 (B = Ade, X = CI) was obtained by chlorination of adenallene (B = Ade, X = OH). Compounds of the type 5 were obtained by base-catalyzed cyclization of the respective 2-butynes. A prolonged hydrolysis of compound 2 (B = 2-amino-6-chloropurine, X = CI) gave tricyclic derivative 7. Similar cyclization of 2 (B = Ade, X = CI) afforded a 3, g-bridged adenine 8. Alcohol 2 (B = Ade, X = OH) is a poor substrate for adenosine deaminase as contrasted with compounds 1, 3 and 4 (B = Ade. X = OH). 4-Hydroxybutyl derivative 6 (B = Ade, X = CI) was completely inert.     

Novel Bicyclic Nucleoside Analogues Related to Natural Griseolic Acids

Abstract

Methodologies for the synthesis of novel isomeric nucleosides related to the natural, biologically-active griseolic acids are described. The carbohydrate precursor for the synthesis, 1,4:3,6-dianhydro-d-glucitol, can be prepared easily from d-glucitol.     

Novel Synthesis of a 2, 5'-O-Cycloimidazole Nucleoside

Abstract

A novel conversion of ethyl 5-amino-1 -(2, 3, 0-isopropylidene-β-D-ribofuranosyl)imidazole-4-carboxylate (2) to the corresponding 2, 5'-cyclo derivative (4) occurs with alkaline hypobromite or N-chlorosuccinimide and alkali.     

Synthesis of Bridged Pyrimidine Nucleosides and Triazo [4, 3-c] Pyrimidine Nucleoside Analogues

Abstract

The synthesis and the spectral characterization of a number of N⁴-N⁴ bridged pyrimidine nucleosides and triazo [4, 3-c] pyrimidine nucleoside analogues are reported.     

Synthesis of Novel Olefinic Carbocyclic Purine Nucleoside Analogues

Abstract

The synthesis of optically pure unsaturated carbocyclic nucleoside analogues is described. (3,4S)-Bis(t-butyldiphenyl silyloxymethyl)-1R and 1S cyclopent-2-en-1-ol were coupled with 6-chloropurine and 2-amino-6-chloropurine respectively, using a modified Mitsunobu reaction. The products were reacted further using standard procedures to give compounds 12, 14, 16 and 18.     

Synthesis of Carbocyclic 2-Substituted Adenine Nucleoside and Related Analogs

2-Iodonoraristeromycin, 2-iodoaristeromycin and related analogs were synthesized to investigate their inhibitory activities against human and Plasmodium falciparum S-adenosyl-L-homocysteine hydrolases.     

Synthesis of Novel Fluoro Carbocyclic Purine Nucleoside Analogues

Abstract

ABSTRACT: The synthesis of four isomerically pure fluoro-carbocyclic adenosine and guanosine analogues is described.     

Novel Nucleoside Analogues: First Synthesis of Pyridine-4-Thioglycosides and Their Cytotoxic Evaluation

The reaction of sodium 2,2-dicyanoethene-1,1-bis(thiolate) with 2-cyano-N-arylacetamides afforded sodium pyridine-4-thiolates, coupling of the latters with 2,3,4,6-tetra-O-acetyl-D-gluco- and D-galactopyranosyl bromides, respectively, afforded new pyridine-4-thioglycosides. Ammonolysis of the latter compounds afforded the free thioglycosides. The antitumor activities of the synthesized compounds were tested against human tumor cell lines; lung (A549), colon (HCT116), liver (HEPG2), and prostate (PC3).     

Synthesis of Novel Acyclic Nucleoside Analogues with Anti-Retroviral Activity

A series of novel acyclic thymine nucleoside analogues were prepared by the Mitsunobu reaction from appropriately protected chiral triols. The enantiomeric triols were obtained from substituted γ-lactone acids, prepared by asymmetric oxidation of 3-substituted-1,2-cyclopentanediones. The cytotoxic activity of new analogues was evaluated on MCF-7 human breast cancer and HeLa cells, and antiviral activities on human immunodeficiency virus type 1 and hepatitis C virus models. The synthesized compounds revealed specific anti-retroviral activity and no cytotoxic side effects.     

Asymmetric Synthesis of Optically Active 1,3-Oxathiolane Nucleoside Analogues

Abstract

A ready asymmetric synthesis of 3′-oxa-4′-thionucleosides has been accomplished in three main steps from benzoyloxyethanal. The synthesis is characterized by high overall yield and appreciable enantiomeric excesses. It represents a general synthetic scheme to prepare a wide range of heterosubstituted sulfur-containing nucleoside analogues.     

Synthesis and Biological Evaluation of 2-Oxo/Thioxoquinoxaline and 2-Oxo/Thioxoquinoxaline-Based Nucleoside Analogues

Several O- and S-quinoxaline glycosides have been prepared by glycosidation of 3-methyl-2-oxo(thioxo)-1,2-dihydroquinoxalines 1a,b with α-D-glucopyranosyl, α-D-galactopyranosyl, and α-D-lactosyl bromide in the presence of K₂CO₃ followed by deacetylation with Et₃N/H₂O. Furthermore, alkylation of 1a,b with 4-bromobutyl acetate, 2-acetoxyethoxymethyl bromide, and 3-chloropropanol afforded the corresponding O- and S-acycloquinoxaline nucleosides. Reaction of 1b with chloroacetic acid followed by condensation with sulfacetamide and sulfadiazine in the presence of Et₃N/THF and ethyl chloroformate gave the corresponding sulfonamide derivatives 14 and 15, respectively. The structures of new compounds were confirmed by using IR, ¹H, ¹³C NMR spectra and microanalysis. Some of these compounds were screened in vitro for antitumor and antifungal activities.     

Carbocyclic Nucleoside Analogues. Synthesis and Properties of 1-(4-Hydroxymethyl-2-cyclopenten-1-YL)-Thymine

Abstract

The title compound, a potential anti-Aids drug, was prepared via construction of the thymine ring on a suitably substituted aminocyclopentene. NOE difference spectroscopy was used for establishing the stereochemistry of the products.     

The Convenient Synthesis of Unsaturated Nucleoside Analogues in Water under Microwave Irradiation

A convenient method for the regioselective synthesis of unsaturated nucleoside analogs in water under microwave irradiation was developed. All pyrimidine and purine nucleoside derivatives were exclusively alkylated at N1 and N9 respectively in good to excellent yields. In addition, this system could tolerate a broad range of functional groups, such as chloro, bromo, iodo, alkyl, amino, and hydroxyl groups. More importantly, the reaction scale could be enlarged to 50 mmol which made this route attractive for industrial application.     

Short Synthesis and Antiviral Activity of Acyclic Phosphonic Acid Nucleoside Analogues

An efficient route for synthesizing novel allylic and cyclopropanoid phosphonic acid nucleoside analogues is described. The condensation of the bromine derivatives 6 and 18 with nucleoside bases (A, U, T, C, G) under standard nucleophilic substitution and deprotection conditions, afforded the target phosphonic acid nucleoside analogues. These compounds were evaluated for their antiviral properties against various viruses. Cyclopropanoid phosphonic adenine nucleoside analogue 23 showed significant anti-HIV activity.