An Improved Protection-Free One-Pot Chemical Synthesis of 2′-Deoxynucleoside-5′-Triphosphates

A facile, straightforward, reliable, and an efficient method for the gram-scale chemical synthesis of both purine deoxynucleotides such as 2 ′-deoxyguanosine-5 ′-triphosphate (dGTP) and 2 ′-deoxyadenosine-5 ′-triphosphate (dATP) and pyrimidine deoxynucleotides such as 2 ′-deoxycytidine-5 ′-triphosphate (dCTP), thymidine-5 ′-triphosphate (TTP), and 2 ′-deoxyuridine-5 ′-triphosphate (dUTP) starting from the corresponding nucleoside is described. This improved “one-pot, three step” Ludwig synthetic strategy involves the monophosphorylation of nucleoside followed by reaction with tributylammonium pyrophosphate and hydrolysis of the resulting cyclic intermediate to provide the corresponding dNTP in good yields (65%–70%).     

Efficient Synthesis of 2′-Amino-2′-deoxypyrimidine 5′-Triphosphates

Abstract

The synthesis of 2′-amino-2′-deoxypyrimidine 5′-triphosphates is described. The 2′-amino-2′-deoxyuridine 5′-triphosphate is obtained from uridine in four steps with 25% overall yield. The 2′-amino-2′-deoxycytidine 5′-triphosphate is obtained from uridine in seven steps with 13% overall yield.     

Efficient Synthesis of 5-Carboxy-2′-Deoxypyrimidine Nucleoside 5′-Triphosphates

An efficient P(V)–N activation method for the synthesis of 5-carboxy-2′-deoxyuridine and 5-carboxy-2′-deoxycytidine triphosphates directly from the corresponding phosphoropiperidate precursors has been developed.     

Facile Protection-Free One-Pot Chemical Synthesis of Nucleoside-5′-Tetraphosphates

A new, straightforward, reliable, and convenient protection-free one-pot method for the synthesis of 2′-deoxynucleoside-5′-tetraphosphate and ribonucleoside-5′-tetraphosphate is reported. The present synthetic strategy involves the monophosphorylation of a nucleoside followed by reaction with tris-(tri-n-butylammonium) triphosphate and subsequent hydrolysis of the putative cyclic tetrametaphosphate intermediate to provide nucleoside-5′-tetraphosphate in moderate yield with high purity. A plausible mechanism is proposed to account for the formation of product.     

An Efficient and Scalable Synthesis of Arabinosylguanine and 2′-Deoxy-2′-Fluoro-guanosine

Abstract

An efficient conversion from commercially available 2, 6-diaminopurine-2′, 3′, 5′-tri-O-benzyl arabinoside to arabinosylguanine and its further transformation to 2′-deoxy-2′-fluoro-guanosine is outlined. This process has been used to produce more than one hundred grams of final product.     

An Efficient Protection-Free One-Pot Chemical Synthesis of Modified Nucleoside-5′-Triphosphates

A simple, reliable, and an efficient “one-pot, three step” chemical method for the synthesis of modified nucleoside triphosphates such as 5-methylcytidine-5′-triphosphate (5-MeCTP), pseudouridine-5′-triphosphate (pseudoUTP) and N¹-methylpseudouridine-5′-triphosphate (N¹-methylpseudoUTP) starting from the corresponding nucleoside is described. The overall reaction involves the monophosphorylation of nucleoside, followed by the reaction with pyrophosphate and subsequent hydrolysis of the cyclic intermediate to furnish the corresponding NTP in moderate yields with high purity (>99.5%).     

Efficient Large-Scale Synthesis of 5′-O-Dimethoxytrityl-N 4-Benzoyl-5-Methyl-2′-Deoxycytidine

An efficient process to synthesize 5′-O-dimethoxytrityl-N⁴-benzoyl-5-methyl-2 ′-deoxycytidine in high yield and quality is described. Final benzoylation was improved by developing a method to selectively hydrolyze benzoyl ester impurities. This inexpensive approach was scaled up to multi-kilogram quantities for routine use in oligonucleotide therapeutics.     

Highly Efficient and Facile Synthesis of 5-Azido-2′-Deoxyuridine

Previously reported syntheses of the photoaffinity label 5-azido-2′-deoxyuridine are rather inefficient and involve the tedious preparation of a 5-nitro intermediate. To overcome these inconveniences, we have developed a new approach from the commercially available 5-bromo-2′-deoxyuridine nucleoside. Our synthetic route makes use of a benzylamination reduction sequence. Using this strategy, the 5-azido-2′-deoxyuridine photolabel is prepared in three steps and quantitative yields.     

Facile Synthesis of Base-Labile 2′-Deoxyribonucleosides: An Improved Synthesis of 2′-Deoxy-5-aza-Cytidine

Abstract

The use of the Fmoc group for the protection of the hydroxy functions of the sugar moiety gave an improved overall yield of 2′-deoxy-5-azacytidine (6β), due to the mildly-basic conditions required for its removal from the protected nucleoside.     

Synthesis of 4-Substituted Pyrimidine 2′,3′-Dideoxynucleosides

Abstract

Reaction of 5′-0-(4,4′-dimethoxytriphenylmethyl)-3′-deoxythy-midine with triphenylphosphine/carbon tetrachloride, followed by deprotection of the 5′-hydroxyl group, afforded the 4-chloro derivative 3 from which some 4-substituted pyrimidin-2(1H)one-2′, 3′-dideoxyribosides were obtained by nucleo-philic substitution under very mild conditions.     

A Stereospecific Synthesis of Pyrimidine β-D-2′-Deoxyribonucleosides

Abstract

A stereospecific route for the synthesis of pyrimidine 2′-β-D-deoxyribonucleosides has been developed using suitably modified methyl 2-deoxy-D-ribofuranosides. The stereochemistry of the nucleoside bond is dictated by the chirality at C-4 of the pentofuranose. A novel palladium hydroxide catalyzed alcholysis of a nucleoside bond has been discovered. Preliminary studies of the mechanism and limitations of this reaction are described.     

Synthesis of 5′-Thioalkyl,Sulfoxide and Sulfone Pyrimidine Nucleosides

Abstract

The preparation of 5′-thioalkyl, sulfoxide and sulfone pyrimidine nucleosides is [4–11] is described. The key steps of this synthesis are the nucleophilic displacements of a chlorine by a thioalkyl sodium salt or the direct introduction of the thioalkyl group under Mitsunobu conditions.     

A Direct and Efficient Synthesis of 5′-Deoxy-2′, 3′-

Abstract

A direct and efficient synthesis of 5′-deoxy-2′,3′-O-isopropylideneinosine, 7, from readily available inosine is described. An example of a potentially general synthesis of N -substituted-5′-deoxyadenosines from 7 is also described.     

An Improved Synthesis of 3′-Keto-5′-Tritylthymidine

Abstract

The title compound is prepared in consistently high yield and purity by molecular sieve catalyzed pyridinium dichromate oxidation of 5′-0-tritylthymidine. Shortcomings of other preparations are described, and properties of the title compound are reported.     

Ribosylation of Pyrimidine 2′-Deoxynucleosides

Abstract

The previously developed method for the preparation of 2′-O-D-ribofuranosyl-nucleosides is extended to ribosylation of 2′-deoxynucleosides. The scope and limitations of this reaction are discussed.     

Concise and Efficient Synthesis of 3′-O-Tetraphosphates of 2′-Deoxyadenosine and 2′-Deoxycytidine

We describe concise and efficient synthesis of biologically very important 3′-O-tetraphosphates namely 2′-deoxyadenosine-3′-O-tetraphosphate (2′-d-3′-A4P) and 2′-deoxycytidine-3′-O-tetra-phosphate (2′-d-3′-C4P). N⁶-benzoyl-5′-O-levulinoyl-2′-deoxyadenosine was converted into N⁶-benzoyl-5′-O-levulinoyl-2′-deoxyadenosine-3′-O-tetraphosphate in 87% yield using a one-pot synthetic methodology. One-step concurrent deprotection of N⁶-benzoyl and 5′-O-levulinoyl groups using concentrated aqueous ammonia resulted 2′-d-3′-A4P in 74% yield. The same synthetic strategy was successfully employed to convert N⁴-benzoyl-5′-O-levulinoyl-2′-deoxycytidine into 2′-d-3′-C4P in 68% yield.     

An Improved Procedure for the Synthesis of 2′-0-Methylnucleoside 5′-Diphosphate

2′-0-Methyladenosine 5′-diphosphate has been chemically synthesized with an overall yield of 48% by adopting the direct phosphorylation of the nucleoside by phosphoryl chloride in step 1 and the morpholidate procedure in step 2 of the following scheme: Am¹ - pAm¹ (step 1) - ppAm (step 2). The method has been successfully used in the synthesis of 2′-O-methyluridine 5′-diphosphate and 2′-O-methylcytidine 5′-diphosphate and is applicable to the synthesis of nucleoside 5′-diphosphates in general.     

An Improved Synthesis of 2′,3′-Dideoxycytidine

Abstract

A convenient synthesis of 2′,3′-dideoxycytidine (ddC, 6) from 2′-deoxycytidine (1) has been achieved employing a base-catalyzed elimination of 3′-O?methanesulfonyl group as the key step.     

Efficient Synthesis of 2′-Deoxynucleoside 3′-C-Phosphonates: Reactivity of Geminal Hydroxyphosphonate Moiety

Abstract

In this report we present a novel, simple way for the synthesis of 3′-C-phosphonate derivatives of all four basic 2′-deoxynucleosides in both fully protected and deprotected forms. The reactivity of the geminal hydroxy phosphonate moiety located at the 3′-carbon atom of the nucleoside was studied with respect to the use of this type of nucleoside phosphonic acid for the preparation of short oligonucleotides, namely, dinucleoside monophosphate analogues.     

Synthesis and Antiviral Evaluation of 2′,3′-Dideoxy-2′-fluoro-3′-C-hydroxymethyl-β-D-arabinofuranosyl Pyrimidine Nucleosides

Abstract

The synthesis and anti-HBV and anti-HIV activity of a number of 2′,3′-dideoxy-2′-fluoro-3′-C-hydroxymethyl-β-D-arabinofuranosyl pyrimidine nucleosides are reported.