R. Welz, S. Müller
Jan 28, 2002
Citations
1
Influential Citations
65
Citations
Journal
Tetrahedron Letters
Abstract
An improved method for the preparation of 5-(benzylmercapto)-1H-tetrazol as activator in RNA synthesis is described. Reaction of benzylthiocyanate with azide delivers the corresponding tetrazole with 72% yield under optimised conditions. We demonstrate that 5-(benzylmercapto)-1H-tetrazol is a superior activator of 2′-O-TBDMS phosphoramidite building blocks. Compared to routinely used 1H-tetrazol, application of a 0.25 M 5-(benzylmercapto)-1H-tetrazol solution in acetonitrile allows for higher coupling yields (>99%), lower coupling times (3 min) and reduced excess of phosphoramidites in solution over the solid-phase nucleotides (8-fold).