Acetylcholinesterasereactivators are crucial antidotes for the treatment of organophosphate intoxication. Eighteen monoquaternaryreactivators of acetylcholinesterase with modified sidechain were developed in an effort to extend the properties of pralidoxime. The known reactivators (pralidoxime, HI-6, obidoxime, trimedoxime, methoxime) and the prepared compounds were tested in vitro on a model of