Phenylsulfonyl-1 -tetrazole

1-Phenylsulfonyl-1//-tetrazole (1) has been used as a condensing reagent in deoxyoligonucleotide solution synthesis by the phosphotriester method. It activates 5 -dimethoxytrityl (DMT) 

A list of General Abbreviations appears on the front Endpapers 

Although (1) has not been used in solid-phase oligonucleotide synthesis, another more stable arylsulfonyl derivative, l-(mesityl-sulfonyl)-3-nitro-l,2,4-triazole (MSNT), is commonly used in that strategy by the phosphotriester approach.  

Dugaiezyk, A. Itakura, K., Cold Spring Harbor Symp. Quant. Biol. 1982, 47, 383 Chem. Abstr. 1983, 99, 22 773a). 

Steven A. Kates Fernando Albericio Millipore Corporation, Bedford, MA, USA 

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In the case of activated isothiocyanates such as phenylsulfonyl and pyridyl isothiocyanates the enhanced reactivity of the isothiocyanate again only results in reaction at the C=S bond rather than the N=C bond which would have given rise to tetrazoles <77CCC1557>. Floch et al. have found that replacement of hydrazoic acid with trimethylsilylazide in 80% aqueous ethanol at 20 °C leads to a much faster reaction (2 days vs. 20 days) and good yields (60-80%) <77CCC2945>. 

This procedure is also efficient for the synthesis of other fused tetrazoles, such as ethyl l,5-dihydro-5-oxo-7-phcnyl-8-(phenylsulfonyl)tetrazolo[ 1,5- pyridine-6-carboxy late <2000J(P1)3686>. At the same time, the unexpected azido-tetrazolo tautomerization and reversible tetrazolo transformation of 3,6-diazido-l,2,4,5-tetrazine are remarkable compared to all other polyazido heteroaromatic high-nitrogen C-N compounds <2005JA12537>. 

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