Synthesis and biological evaluation of ortho-carborane containing benzoxazole as an inhibitor of hypoxia inducible factor (HIF)-1 transcriptional activity

ortho-Carborane and adamantane containing benzoxazoles were synthesized by intramolecular dehydration of the corresponding phenoxyacetanilides. Among the compounds synthesized, ortho-carborane containing benzoxazole 2b which has a carboxylic group on the benzoxazole ring, exhibited significant inhibition of hypoxia-induced HIF-1 transcriptional activity with the IC50 value of 14.4 μM toward HeLa cell-based reporter gene assay.