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An analysis of the 1H- and 13C-NMR spectra of a series of 1,2-diaryl-1H-4,5-dihydroimidazoles and comparisons with 4,5-dihydroimidazoles having differentsubstitution patterns are presented. The influence of different 1-aryl and 2-aryl groupsubstituents on spectroscopic parameters of the heterocyclic ring and on the contributionsof possible mesomeric structures in the system was determined. Spectroscopic featuresare coherent with the presence of two conjugated systems (Ar1-N and Ar2-C=N) whichcompete with the delocalization characteristics of the amidine system.

An easy and safe, though only moderately effective method is presented forpreparing (diacetoxyiodo)arenes, ArI(OAc)2, from iodoarenes, ArI, using thecommercially available and easily handled urea-hydrogen peroxide adduct (UHP) as theoxidant. The reactions take place in anhydrous AcOH/Ac2O/AcONa (a catalyst)mixtures, at 40 oC for 3.5 h to afford the purified ArI(OAc)2 in 37-78% yields. The fullyinterpreted 1H- and 13C-NMR spectra of the ArI(OAc)2 products are reported.