Nucleophilic Displacements of Imidazoles.I. Oxygen,Nitrogen and Carbon Nucleophiles

Article abstract of DOI:10.1071/CH9871399

4(5)-Bromo- and -iodo-imidazoles, activated by an adjacent nitro substituent, undergo nucleophilic displacement with methoxide, phenoxide, cyclic secondary amines and cyanide.The regiochemistry of the reactions of 5-iodo-4-nitroimidazole with methoxide has been confirmed by spectroscopic and X-ray methods, and a number of erroneous structures from the literature have been revised.Some apparently anomalous reactions of methoxide with 5-halo-1,2-dimethyl-4-nitroimidazoles, and of cyanide with 4-halo-1-methyl-5-nitroimidazole have been noted.The crystal and molecular structure of 5-methoxy-1-methyl-4-nitroimidazole has been determined by direct methods.Crystals are monoclinic, P2₁/c, a 10.929(3), b 8.899(2), c 7.290(2) Angstroem; β 92.87(2) deg; Z 4.The structure was refined to R=0.095 for 818 reflections (I.2?I).