Phthalic acid hydrazide, methylation

That the donor and the fluorescing part of the molecules in (19) and (22) actually are separated can be demonstrated. As mentioned above unsubstituted phthalic acid hydrazide does not chemiluminesce, neither does 4-methyl phthalic hydrazide [36]. A mixture of phthalic acid hydrazide and N-methyl acridone gives no light on oxidation. The conjugate (19) chemiluminesces in the aprotic system with 8% of the luminol quantum yield (ca. 1 x 10" ), the emission matching... 

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