SYNTHESIS AND REACTIVITY OF NUCLEOSIDE SULFILIMINES

Abstract

Treatment of 3′- and 5′-protected deoxycytidine and deoxyadenosine with bis-[α,α-bis(trifluoromethyl)benzyloxy]diphenylsulfur resulted in the formation of the corresponding 4-N- and 6-N-diphenylsulfilimine derivatives in good yields. The 4-N- and the 6-N-dimethylsulfilimines of these nucleosides were obtained using DMSO/trifluoroacetic anhydride. These dimethyl- and diphenylsulfilimine derivatives were found to have characteristic UV absorbances at 284-296 nm. Stability tests of the nucleoside dimethylsulfilimine and diphenylsulfilimine under the conditions commonly used in oligonuclotide chemistry by the H-phosphonate approach were executed, and possible applications of these compounds have been discussed.

Keywords:

• H-phosphonate
• nucleoside
• nucleotide labeling
• sulfilimine
• synthesis

We thank the Swedish Natural Science Research Council for support.

Notes

^a The values given in the table correspond to the percentage of the intact sulfilimine as determined by straight-phase HPLC (mean error ± 3%).

^b As a solution in collidine/water/MeCN.

^c Prepared by mixing equal volumes of Capping A and B solutions, containing Ac₂O/ collidine/MeCN 2:3:5 (v/v/v) and 6% 4-(N,N-dimethylamino)pyridine (DMAP) in MeCN (w/v), respectively.

^a The values given in the table correspond to the percentage of the intact sulfilimine as determined by straight-phase HPLC (mean error ± 3%).

^b As a solution in collidine/water/MeCN.

^c Prepared by mixing equal volumes of Capping A and B solutions, containing Ac₂O/collidine/MeCN 2:3:5 (v/v/v) and 6% DMAP in MeCN (w/v), respectively.

^a The values given in the table correspond to the percentage of the intact sulfilimine as determined by reversed- phase HPLC (mean error ± 3%).