Synlett 2014; 25(15): 2229-2230
DOI: 10.1055/s-0034-1378535
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© Georg Thieme Verlag Stuttgart · New York

Imidazole-1-sulfonyl Azide Hydrochloride

Maksim Fomich
Institute of Physical Organic Chemistry, The National Academy of Sciences of Belarus, 13 Surhanava Street, Minsk 220072, Belarus   Email: mfomich@gmail.com
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Further Information

Publication History

Publication Date:
11 August 2014 (online)

Introduction

Imidazole-1-sulfonyl azide hydrochloride (1) is a white, slightly hygroscopic solid (mp 100–102 °C) that is soluble in water, acetonitrile, DMSO, DMF, and lower alcohols. It was reported by Goddard-Borger and Stick as a crystalline, shelf-stable, and easily prepared alternative to triflyl azide (TfN3) in diazotransfer reactions.[1] It is widely used to prepare organic azides from aminosugars, aminoacids, and anilines because of its solubility in water. In addition, this reagent allows conversion of substrates with activated methylene groups into diazo compounds.[1] [2]

The preparation of imidazole-1-sulfonyl azide is conducted by a convenient two-step procedure (Scheme [1]).[1] First, sulfuryl chloride is reacted with NaN3 to give ClSO2N3, which then reacts with imidazole. The crude base product is precipitated by ethanolic HCl.

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Scheme 1 Goddard-Borger’s synthesis

To minimize explosion risks, a safer synthesis starting from sulfuryl diimidazole was developed (Scheme [2]).[3]

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Scheme 2 Wang’s synthesis