Use of 1,2,4-Dithiazolidine-3,5-Dione (DtsNH) and 3-Ethoxy-1,2,4-Dithiazoline-5-One (EDITH) for Synthesis of Phosphorothioate-Containing Oligodeoxyribonucleotides

Abstract

Previous methods for the preparation of phosphorothioate-containing oligodeoxyribonucleotides rely on the reaction of phosphite triesters with sulfurizing reagents such as tetraethylthiuram disulfide (TETD) and 3H-1,2-benzodithiol-3-one 1,1-dioxide (Beaucage reagent). However, these and other sulfurizing reagents suffer from several disadvantages, and there is great impetus for the development of improved methods for sulfur transfer that are fully compatible with standard automated DNA synthesis. The present report describes the use of 1,2,4-dithiazolidine-3,5-dione (DtsNH) and 3-ethoxy-1,2,4-dithiazoline-5-one (EDITH) as effective sulfurizing reagents that meet these needs. Both reagents are easily prepared, and are stable upon prolonged room temperature storage in acetonitrile solution. The reagents are used at low concentrations (0.05 M) and for short reaction times (30 s). The methodology has been proven for the automated synthesis on 0.2-1.0 micromol scales of oligodeoxyribonucleotides, of length 6-20 bases, containing the phosphorothioate substitution at either a single site or at all positions.

Separation of Synthetic Oligonucleotide Dithioates from Monothiophosphate Impurities by Anion-Exchange Chromatography on a Mono-Q Column

“…The thiophosphite triesters were oxidized with 3H-1,2-benzodithiole-3-one, 1,1-dioxide (34) or EDITH reagent (35). Deprotection of PS2 analogues was according to the literature (22).…”

Detection and minimization of H-phosphonate side reaction during phosphopeptide synthesis by a post-assembly global phosphorylation strategy

“…Subsequent oxidation converted the trivalent phosphorus intermediate to the pentavalent protected phosphate form. Gel-phase NMR [21][22][23] observation of 31p was used to monitor resin-bound phosphorus chemistry (Fig. 1, Tables 1 and 2).…”

Alternative syntheses of linear polyurethanes using masked isocyanate monomers

“…A more applicable masked isocyanate is the alkyl-free heterocyclic disulfide, 1,2,4-dithiazolidine-3,5-dione 1 (see Scheme 1), which is not only stable under a variety of conditions, but also requires mild deprotection conditions. This disulfide 1 is also a highly effective sulfurization reagent [14], amine protecting group [15] and a protected form of ammonia [16]. Alkylation of the disulfide 1 can be achieved readily using alkyl halides [17], thus providing easy access to a wide range of complex masked isocyanates and monomers.…”