A NIR BODIPY dye bearing 3,4,4a-trihydroxanthene moieties

A novel 3,4,4a-trihydroxanthene-fused pyrrole 2 was synthesized by the reaction of 2,3,4,4a-tetrahydro-1H-xanthen-1-one with 3-phenyl-2H-azirine in the presence of LDA. Utilizing this pyrrole 2, a NIR BODIPY 1 (lambda(abs) = 732 nm, lambda(em) = 747 nm) has been prepared. The new BODIPY 1 was stable, non-cytotoxic, and suited to labeling living cells for imaging assay in the NIR region.