Potentiators of glutamate receptors

A compound of formula I

• wherein
• R1 is selected from the group consisting of C1-C5 alkyl, C3-C7 cycloalkyl, C4-C8 cycloalkylalkyl, phenyl and substituted phenyl;
• R2 is selected from the group consisting of hydrogen, C1-C5 alkyl, substituted C1-C5 alkyl, halo, phenyl, substituted phenyl, C1-C3 fluoroalkyl, CN, CO2R3, thiophenyl, substituted thiophenyl, thiazolyl, substituted thiazoyl, furanyl, substituted furanyl, pyridinyl, substituted pyridinyl, oxazolyl, substituted oxazloyl, isothiazolyl, substituted isothiazoyl, isoxazolyl, substituted isoxazolyl, 1,2,4-oxadiazolyl, substituted 1,2,4-oxadiazolyl, pyrimidinyl, substituted pyrimidinyl, pyridazinyl, and substituted pyridazinyl;
• X is selected from the group consisting of O, S(O)m, and NR3;
• Y is selected from the group consisting of C1-C3 alkanediyl and substituted C1-C3 alkanediyl;
• Ar1 is 1,2,4-oxadiazole-3,5-diyl;
• Ar2 is phenylene or substituted phenylene;
• L is selected from the group consisting of C1-C5 alkanediyl, substituted C1-C5 alkanediyl, and -G-C(═W)-J-;
• W is CR3R3, O or NR3;
• G and J are independently selected from the group consisting of a bond and C 1-C3 alkanediyl;
• R3 is independently hydrogen or C1-C5 alkyl;
• Z is selected from the group consisting of (CH2)nCOOH,
• m is 0, 1, or 2;
• n and q are independently 0, 1, 2 or 3;
• and
• pharmaceutically acceptable salts thereof.