The present invention relates to compounds, pharmaceutical compositions and methods of using compounds of formula (I) in the treatment and/or prevention of certain diseases or conditions. In formula (I), A is chosen from ortho substituted aryl or heteroaryl species, X is chosen from --OH, --SH, NHR and R.sup.1 or R.sup.2 is chosen from --(CH.sub.2).sub.n L wherein L may be selected from a variety of substituents including aryl, heteroaryl and heterocyclic groups. The compounds are useful in treating and/or preventing neurological disorders associated with excitatory amino acids. ##STR1##