Amnesia-reversal activity of a series of 5-alkoxy-1-arylsulfonyl-2-pyrrolidinones

Abstract

A series of 5-alkoxy-1-arylsulfonyl-2-pyrrolidinones were prepared by condensation of arylsulfonyl chlorides with 5-alkoxy-2-pyrrolidinones. Most compounds reversed electroconvulsive shock-induced amnesia in mice, showing the typical inverted U-shaped dose-response curve. The results for 58 compounds indicate that the potency is maximal when there is a 5-ethoxy group and progressively declines as the ether alkyl chain is either elongated or shortened. Substitution on the phenyl ring or its replacement with heterocyclic rings or its hydrogenation decreases the activity. The most promising compounds, with anti-amnesic properties superior in many respects (greater potency, greater efficacy and broader active dose-range) to those of piracetam and aniracetam were further evaluated for reversing scopolamine-induced amnesia and for their anti-hypoxic activity. 5-Ethoxy-1-phenylsulfonyl-2-pyrrolidinone (1) and 5-(1-methylethoxy)-1-/3-(trifluoromethyl) phenylsulfonyl/-2-pyrrolidinone (41) were selected for further evaluation because of their potent anti-amnesic and/or antihypoxic activity. © 1991.