Fig. 7
Synthetic procedures and molecular structures of BODIPY 1. a Ethyl 2-cyanoacetate, hexamethylenetetramine; reflux in dry toluene for 2 h; b benzaldehyde, trifluoroacetic acid, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, triethylamine, BF3•Et2O.
