Kinetic assessment of N-methyl-2-methoxypyridinium species as phosphonate anion methylating agents

Organophosphate nerve agents and pesticides are potent inhibitors of acetylcholinesterase (AChE). Although oxime nucleophiles can reactivate the AChE-phosphyl adduct, the adduct undergoes a reaction called aging. No compounds have been described that reactivate the aged-AChE adduct. A family of 2-methoxypyridinium species which reverse aging in a model system is presented. A kinetic study of this system, which includes an SAR analysis, demonstrates that the reaction is highly tunable based on the ring substituents.