Reaction of 4(5)-bromo-2-methyl-5(4)-nitroimidazole with phenacyl bromide d
erivatives led to 4-bromo-2-methyl-1-phenacyl-5-nitro- and 5-bromo-2-methyl
- 1-phenacyl-4-nitroimidazoles. Treatment of the latter isomers with potass
ium tert-butoxide in dry THF yielded imidazo[5, 1-b]oxazoles.