Heteropolycyclic compounds and their use as metabotropic glutamate receptor antagonists

A pharmaceutical composition comprising a pharmaceutically acceptable excipient and a compound of Formula II or a pharmaceutically acceptable salt thereof:

• wherein
• X and Y are N,
• Z is O;
• Ar1 is 2-pyridyl;
• Ar2 is phenyl;
• and wherein
• at least one of the Ar1 and Ar2 moieties are substituted with one or more moieties selected from the group consisting of —F, —Cl, —Br, —I, —SR, —SOR, —SO2R, —SO2NRR′, —OCOR, —OCONRR′, —NRCOR′, —NRCO2R′, —CN, —CO2R, —CONRR′, —C(O)R, —CH(OR)R′, —CH2(OR), CF3, C1-C10 alkyl, cycloalkyl, alkyl-aryl, heterocycloalkyl, and aryl;
• R and R′ are independently selected from the group consisting of H, CF3, C1-C10 alkyl, cycloalkyl, alkyl-aryl, heterocycloalkyl, aryl;
• R and R′ may combine to form a ring;
• with the proviso that the compound is not 3-(2-Pyridyl)-5-(2-chlorophenyl)-1,2,4-oxadiazole or 3-(2-Pyridyl)-5-[3-(trifluoromethyl)phenyl]-1,2,4-oxadiazole.