NEW 2,5-DIHYDROIMIDAZOLE-1-OXYLS WITH FUNCTIONAL SIDE-GROUPS (N, O, SDONORS)

A series of functionalized -dihydro-1-hydroxy-2-R(1)-2-R(2)-4-R(3)-imi dazoles were prepared by cyclocondensation of alpha-oxo hydroxylamines with ketones R(1)R(2)C=O in the presence of ammonia (R(1) = R(2) = 2- pyridyl, 4,5-diazafluoren-9-ylene, R(3) = Me; R(1) = CH(2)OCOMe, CH(2) OCOPh, 2-thienyl, CH2OH, CO2K, R(2) = R(3) = Me; R(1) = Py, R(2) = Me, R(3) = Ph; R(1) = R(2) = CH(2)OCOPh, CH2OH, R(3) = Me) and oxidized t o the corresponding nitroxide radicals. The structures of 5'-trimethyl spiro[4,5-diazafluoren-9,2'-imidazole] (2) and of l)-2,5-dihydro-2,4,5 ,5-tetramethylimidazole-1-oxyl (14) were determined by X-ray diffracti on. In the crystal 2 forms one-dimensional chains through hydrogen bon ding between N atoms of the hydroxylamine and imidazoline groups.