| Autor: |
Krotz, A. H., Gorman, D., Mataruse, P., Foster, C., Godbout, J. D., Coffin, C. C., Scozzari, A. N. |
| Zdroj: |
Organic Process Research & Development; November 2004, Vol. 8 Issue: 6 p852-858, 7p |
| Abstrakt: |
In this report, we describe the design of an efficient and robust sulfurization step in the production process of phosphorothioate (PS) oligonucleotides by solid-phase synthesis. Average stepwise sulfurization efficiencies >99.9% were obtained with aged solutions of phenylacetyl disulfide (PADS) in the solvent system acetonitrile/3-picoline (0.2 M, 1:1, v/v). Preparation of the reagent at least 1 day prior to use yields PS-oligonucleotides with low-level phosphate (PO) diester content. The use of freshly prepared PADS solutions gave oligonucleotide products with increased PO-diester content (stepwise sulfurization efficiency 99.5−99.7%). Short aging periods combined with short sulfurization contact times lead to formation of oligonucleotide 4,4-dimethoxytrityl-C-phosphonate derivatives. Investigation of reagent stability and sulfurization efficiency revealed significant changes in solution composition over time caused by dissociation of the PADS molecule. The in situ formation of a reactive intermediate, presumably a polysulfide, appears to be crucial for optimal synthesis results. |
| Databáze: |
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