Tubulin polymerization inhibitors with a fluorinated phthalimide skeleton derived from thalidomide

4,7-Difluoro-2-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione [4,7FPP-33 (14)] has a potent tubulin-polymerization-inhibiting activity comparable with those of the known tubulin-polymerization inhibitors rhizoxin and colchicine. The structure–activity relationship for fluorine substitution was elucidated.