3-hydroxy anthanilic acid derivatives

PCT No. PCT/SE94/00152 Sec. 371 Date May 4, 1995 Sec. 102(e) Date May 4, 1995 PCT Filed Feb. 22, 1994 PCT Pub. No. WO94/19315 PCT Pub. Date Sep. 1, 1994 (I) The present invention relates to novel derivatives of 3-hydroxyanthranilic acid, 3-HANA of general formula (I), wherein R1 and R2 are the same or different and selected from H and alkyl; X is selected from alkylthio, arylthio, aryloxy, halogen and cyano; R3, R4 are the same or different and selected from halogen, methyl, fluoroalkyl, cyano and Z-R5 wherein Z is selected from CHn, NHm, O, S, SO2 and CO wherein n=1 or 2; m=0 or 1 and R5 is selected from alkyl, aryl and fluoroalkyl; or R3 and R4 together form a saturated or unsaturated ring system Y-V-Z wherein Y and Z, independently of each other, are as defined for Z above and V is selected from C1-C3 alkylene or alkenylene, -N=, -N=N- and (a), wherein R7=H or alkyl; or a pharmaceutically acceptable salt thereof, methods and intermediates for their preparation, novel pharmaceutical compositions and the use thereof for inhibiting the enzyme 3-hydroxy-anthranilate oxygenase, 3-HAO, responsible for the production of the endogenous neurotoxin quinolinic acid, QUIN.