The present invention relates to novel derivatives of 3-hydroxyanthranilic acid, 3-HANA, of the general formula I ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and selected from H and alkyl; X and Y are the same or different and selected from alkoxy, aryloxy, alkyl, alkylthio, arylthio, fluoroalkyl, halogen, cyano, OCF.sub.3 and SCF.sub.3 with the proviso that the compound of formula I wherein R.sub.1 and R.sup.2 =H, X=Br and Y=Me is excluded;or a pharmaceutically acceptable salt thereof, methods and intermediates for their preparation, novel pharmaceutical compositions and the use thereof for inhibiting the enzyme 3-hydroxyanthranilate oxygenase, 3-HAO, responsible for the production of the endogenous neurotoxin quinolinic acid, QUIN.