Abstract: A class of phosphonomethyl-imidazo[1,2-a]pyrimidine-2-carboxylic acid compounds is described for treatment to reduce neurotoxic injury associated with anoxia or ischemia which typically follows stroke, cardiac arrest, hypoglycemia or perinatal asphyxia. The treatment includes administration of a compound of this class alone or in a composition in an amount effective as an antagonist to inhibit excitotoxic actions at major neuronal excitatory amino acid receptor sites. Compounds of most interest are those of the formula: ##STR1## wherein each of R.sup.1, R.sup.2 and R.sup.6 is independently selected from hydrido, alkyl, allyl, cycloalkyl, cycloalkylalkyl, phenyl and benzyl; wherein Y.sub.m is --CH.sub.2 -- or --CH.sub.2 --CH.sub.