Abstract: (S)-alpha-ethyl-2-oxo-1-pyrrolidineacetamide, its preparation and pharmaceutical compositions containing the same. It can be prepared either by reacting (S)-alpha-ethyl-2-oxo-1-pyrrolidineacetic acid successively with an alkyl haloformate and with ammonia, or, by cyclizing an (S)-2-amino-butanamide of the formula X--CH.sub.2 CH.sub.2 -NHCH (C.sub.2 H.sub.5)CONH.sub.2 wherein Y is a --CH.sub.2 --radical when X represents a ZOOC--radical and Y is a --CO-- radical when X represents a HalCH.sub.2 --radical, Z being a C.sub.1 -C.sub.4 alkyl radical and Hal a halogen atom.This laevorotatory enantiomer has been found to have significantly higher protective activity against hypoxia and ischemia than the corresponding racemate.