Phthalazine degradation

Although there has been interest recently in phthalazine quaternary salts, no work has been reported on the position of quatemization since the classic studies of Gabriel and co-workers. For the sake of completeness, it may be noted that 4-methylphthalazine (59) and methyl iodide gave the salt 60 alkaline degradation of 60 gave a... 

Some authors used a completely different approaeh HA or the degradation products of HA were not directly detected, but the competition between HA and another (exogenously added) compound for the HO radicals was used as a measure of reactivity. In this context, the luminol-amplified chemiluminescence was often used [251] Luminol (5-amino-2,3-dihydro-phthalazine-l,4-dione) reacts with HO radicals under the emission of light. When luminol is present in excess over the generated radicals, the intensity of light... 

These substrates have been used extensively with two-carbon synthons to make phthalazines, apparently via nonisolable cyclic adducts that are degraded spontaneously with or without loss of hydrogen sulfide. Some typical examples follow. 

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