Patent ID: 8003702

Claim:
A compound of formula: wherein R1 is alkylsulfonyl; each of R 2 and R 3 is independently selected from hydrogen, carboxy, nitro, alkylsulfonyl, aminosulfonyl, alkyl aminosulfonyl, halogen, cyano, C 1-4 alkyl, C 1-4 alkoxy, NR′R″, aryl, aryl-C 1-4 alkyl, or aryl-C 1-4 alkoxy, and each of R′ and R″ is independently H or C 1-4 alkyl, or R′═R″═ClCH 2 CH 2 , or NR′R″ constitutes a saturated heterocyclic ring containing 3-8 ring members; X is: —(CH 2 ) n —Y— wherein Y is: >NH; n is 0-4; and any carbon of the —(CH 2 ) n — may be substituted by 1-2 substituents independently selected from halogen, carboxy, CO 1-4 alkyl, C 1-4 alkoxy, OH, NH 2 or acyl; and Ar is a kynurenine/kynuramine metabolite of a 3-indole: wherein each R 5 independently is hydrogen, halogen, C 1-4 alkyl, C 1-4 alkoxy, OH, NR′R″ as defined above, nitro, aryl, aryl-C 1-4 alkyl, or aryl-C 1-4 alkoxy; or a pharmaceutically acceptable salt thereof.