Beilstein J. Org. Chem.2009,5, No. 80, doi:10.3762/bjoc.5.80
group was confirmed by its IRspectroscopy in which the peak at 1715 cm−1 was observed. Radical azidonation of aldehyde 7 with iodine azide generated in situ by the reaction of sodium azide with ICl) at room temperature gave an acyl azide and subsequent Curtius rearrangement provided isocyanate 10 in
Beilstein J. Org. Chem.2009,5, No. 62, doi:10.3762/bjoc.5.62
(n > 10) according to the chain length.
All imidazolium compounds (18–68, 110–610, 112–612, 114–614, 116–616) were purified by flash chromatography or crystallization. Their structural characterizations and their purities were established by 1H NMR, 13C NMR{1H}, FT-IRspectroscopy and elemental