Hagedorn_1976_Arzneimittelforschung_26_1515

Application of Wittig reaction to 4-pyridinecarboxaldehyde leads to 4-beta-formylvinylpyridine (62%). The corresponding oxime (4-(2)) can be quaternized with alpha,alpha'-bis-(chloromegonin), and with methyliodide one to 4-PAM (4-(3)). In this case the formal insertion of an ethylenic double bond between the pyridinium ring and the aldoxime group decreases the ability to reactivate phosphorylated acetylcholinesterase (AChE).