The conversion of furan-, thiophene- and selenophene-2-carbonyl azides into isocyanates: a DSC analysis

Abstract

Abstract:The Curtius Rearrangement (CR) of five heteroaroyl azides to the corresponding isocyanates was studied by Differential Scanning Calorimetry. The five compounds selected were the furan 1, the thiophene 2, 5-methylthiophene 3, 5-(trimethylsilyl)thiophene 4, and selenophene-2-carbonyl azide 5. For each compound, the heat of the transition from the heteroaroyl azide to the isocyanate was measured by DSC under a set of standard conditions both in the absence and presence of an inert medium.

Regioselectivity of [3+2] Cycloadditions of Heteroaryl Azides and Ethyl‐Vinyl Ether

“…The molecular peak at m/z 233 in the MS spectrum, the presence of a broad singlet at δ=7.54 ppm which accounts for an amide proton, and the set of signals for the ethoxy group in the 1 H NMR spectrum are in agreement for the proposed structure. Furthermore, comparison of 1 H NMR data of compound 19 (see below) with an analogous compound (dodecyl N ‐(2‐selenophenyl)carbamate) reported in the literature, [28] furnishes an ulterior confirmation of this structure.…”