| abstract |
(57) The present invention relates to a compound of the formula I wherein X represents O, S or two hydrogen atoms which do not form a bridge; A 1 / A 2 independently of one another Or B means a 6-membered heterocyclic ring containing one or two nitrogen atoms; B is a group represented by the formula (A), wherein Y is -O-, -S- or a bond; Z is- Or B represents a 5-membered heterocycle of the formula (a, b, c or d)). These compounds can be used as glutamate receptor ligands in the suppression or prevention of acute and / or chronic nervous system disorders. |