Crystal Structure of 2-Ethylimidazole-1-sulfonyl Azide: A New Azidation Reagent

Abstract

Abstract:Crystalline 2-ethylimidazole-1-sulfonyl azide was designed as a convenient reagent with improved thermal stability for electrophilic azidation of carbanions. The compound crystallized in the monoclinic space group P2 1 /c. The molecules are arranged into chains by short C-H ... O contacts along a two-fold screw axis. The quaternary 1-azidosulfonyl-2-ethyl-3-methylimidazolium tetrafluoroborate crystallized in Fdd2 with two independent ion pairs which engage in C-H ... F interactions.

CuAAC: An Efficient Click Chemistry Reaction on Solid Phase

“…In 2010, Katritzky et al 131 synthesized the crystalline benzotriazole-1-yl-sulfonyl azide (Table 2, entry 4) as a new stable and widely available diazo-transfer reagent that efficiently provides N-(α-azidoacyl) benzotriazoles with CuSO 4 •5H 2 O as copper source. Crystalline 2-ethylimidazole-1-sulfonyl azide (Table 2, entry 5) was designed by Schottenberger et al 132 as a convenient reagent to improve thermal stability for the azidation of electrophilic carbanions.…”

A Safe and Facile Route to Imidazole-1-sulfonyl Azide as a Diazotransfer Reagent

“…While maintaining good diazotransfer activity, this new reagent demonstrated a reduced tendency for explosion than TfN 3 and could even be isolated as a solid of the chloride salt. Additionally, structual modifications of compound 2 or its salt have been investigated. − Listed in Figure are the newly reported solid diazotransfer reagents with improved chemical properties or an increased safety threshold. Nevertheless, the synthetic procedures were not optimized, which all engaged compound 1 as a key intermediate.…”