Synthesis, Characterization, and Application of Substituted Pyrazolopyrimidine Nucleosides
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- Abstract
- Table of Contents
- Materials
- Figures
- Literature Cited
Abstract
This unit describes, in detail, the preparation of 3?aminopropyl?substituted pyrazolo[3,4?d]pyrimidine analogs of the purines deoxyadenosine (dA) and deoxyguanosine (dG). Phosphoramidite reagents of these so?called aminopropyl?PPA and ?PPG nucleosides (AP?PPA and AP?PPG, respectively) allow introduction of amino linkers into internal positions of synthetic DNA strands. Synthesis of suitably protected AP?PPA and AP?PPG phosphoramidites are described. The stepwise alkynylation, hydrogenation, selective protection, and phosphoramidite synthesis is similar for both the PPA and PPG analogs. To demonstrate the application of these reagents, a protocol is given in which a simple DNA strand is synthesized and conjugated to a lipophilic activated ester (dabcyl?SE) to form a stable amide linkage. Utility of this chemistry for preparing internally modified DNA conjugates is discussed.
Table of Contents
- Basic Protocol 1: Preparation of Protected Aminopropyl‐PPG Phosphoramidite
- Basic Protocol 2: Preparation of Protected Aminopropyl‐PPA Phosphoramidite
- Basic Protocol 3: Synthesis of DNA Conjugates Using AP‐PPA and AP‐PPG Phosphoramidites
- Reagents and Solutions
- Commentary
- Literature Cited
- Figures
Materials
Basic Protocol 1: Preparation of Protected Aminopropyl‐PPG Phosphoramidite
Materials
Basic Protocol 2: Preparation of Protected Aminopropyl‐PPA Phosphoramidite
Materials
Basic Protocol 3: Synthesis of DNA Conjugates Using AP‐PPA and AP‐PPG Phosphoramidites
Materials
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Figures
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Figure 1.8.1 Preparation of AP‐PPG phosphoramidite (S.1 ). Abbreviations: DMF, N , N ‐dimethylformamide; DMTr⋅Cl, N , N ′‐dimethoxytrityl chloride. View Image -
Figure 1.8.2 Preparation of AP‐PPA phosphoramidite (S.2 ). Abbreviations: DMF, N , N ‐dimethylformamide; DMTr⋅Cl, N , N ′‐dimethoxytrityl chloride. View Image -
Figure 1.8.3 Synthesis of dabcyl conjugate at internal AP‐PPA linker position in a 9‐mer oligonucleotide. View Image -
Figure 1.8.4 Reversed‐phase HPLC chromatograms and UV‐Vis spectra of AP‐PPA‐modified oligonucleotides (S.9 ; dashed lines) and dabcyl conjugate (S.10 ; solid lines). The large difference in retention time simplifies isolation and analysis of the lipophilic conjugate. View Image
Videos
Literature Cited
Literature Cited | |
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