Abstract
Imidazo [2, 1-b] benzoxazoles which have a new ring system were synthesized. Condensation reaction of 2-aminobenzoxazole (I) and bromoacetone afforded 2-imino-3-(2-oxopropyl)-2, 3-dihydrobenzoxazole (IIa). When phenacyl bromide was used instead of bromoacetone, 2-imino-3-phenacyl-2, 3-dihydrobenzoxazole (IVa) was obtained. Cyclization of these imino-derivatives afforded imidazo [2, 1-b] benzoxazoles. On the other hand, imidazo [2, 1-b] benzoxazole (XIII) was prepared from 1-(o-chlorophenyl)-2-hydroxyimidazole (XI) via benzyne intermediate.
