Synthesis of boradiazaindacene-imidazopyrazinone conjugate as lipophilic and yellow-chemiluminescent chemosensor for superoxide radical anion

As a chemiluminescent chemosensor that emits yellow light on reacting with a superoxide radical anion (O(2)(center dot-)) and has a lipophilic character, a 6-phenylimidazo[1,2-a]pyrazin-3(7H)-one derivative possessing a boradiazaindacene (BODIPY) at the para position of 6-phenyl (1) was synthesized. The lipophilicity of 1 was investigated by reversed-phase liquid chromatography, and its log P(ow) value was found to be 3.57. This value was Much higher than that of 2-methyl-6-(4-methoxypheyl)imidazo [ 1,2-a]pyrazin-3(7H)-one (MCLA, log P(ow)=1.19) and 6-[4-[2-{N'-(5-fluoresceinyl)thioureido}ethoxy]phenyl]-2-methylimidazo[1,2-a]pyrazin-3(7H)-one (FCLA, log P(ow)=-0.08), and it was comparable to that of benzenoid hydrocarbons. The O(2)(center dot-)-induced chemiluminescence of 1 was investigated using the hypoxanthine/xanthine oxidase system as the source of O(2)(center dot-), and as a result, yellow emission was observed. The maximum wavelength was observed at 542 nm, and it was longer than that of FCLA. (C) 2009 Elsevier Ltd, All rights reserved.