31P NMR study of the desulfurization of oligonucleoside phosphorothioates effected by "aged" trichloroacetic acid solutions.
When employing phosphoramidites 1a-d in the solid-phase synthesis of oligonucleoside phosphorothioates, the thermolytic 2-[N-methyl-N-(2-pyridyl)]aminoethyl thiophosphate protecting group is lost to a large extent during the course of the synthesis. The resulting phosphorothioate diesters are then substantially desulfurized upon recurring exposure to a commercial solution of deblocking reagent during chain assembly. This problem is caused by the secondary decomposition product(s) of the reagent and is alleviated by using a fresh solution of the deblocking reagent prepared from solid trichloroacetic acid.
Cieślak
Jacek
J
Division of Therapeutic Proteins, Center for Drug Evaluation and Research, Food and Drug Administration/NIH, 8800 Rockville Pike, Bethesda, MD 20892, USA.
Ausín
Cristina
C
Chmielewski
Marcin K
MK
Kauffman
Jon S
JS
Snyder
John
J
Del-Grosso
Alfred
A
Beaucage
Serge L
SL
D001483:Base Sequence; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D010755:Organophosphates / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D010759:Phosphorus Isotopes; D013455:Sulfur / Q000737:chemistry; D013873:Thionucleotides / Q000737:chemistry; D014238:Trichloroacetic Acid / Q000737:chemistry
D009838:Oligodeoxyribonucleotides; D010755:Organophosphates; D010710:Phosphates; D010759:Phosphorus Isotopes; D013873:Thionucleotides; D014238:Trichloroacetic Acid; D013455:Sulfur