Evaluation of Sulfur-Transfer Reagents for Large Scale Synthesis of Oligonucleotide Phosphorothioate Analogues

Abstract

Several sulfur-transfer reagents have been evaluated for large scale synthesis of oligonucleotide phosphorothioate analogues, in which 3-ethoxy-1, 2-dithiazoline-5-one (EDITH, 5) shows potential as an alternative to Beaucage reagent.

Notes

Beaucage reagent (1) was purchased from R. I. Chemical (Orange, CA); TETD (2) was from Applied Biosystems (Foster City, CA); dibenzoyl tetrasulfide (3)⁶ and bis(O, O-diisopropoxyphosphinothioyl) disulfide (S-Tetra, 4)⁷ were prepared by literature's procedure; benzyltriethyl-ammonium tetrathiomolybate (BTTM, 5) was provided by Aronex Pharmaceuticals (The Woodlands, TX); EDITH (6) was provided by PerSeptive Biosystems (Framingham, MA).