Potentials of glutamate receivers.

A compound of formula I ** (See formula) ** in which R1 is C1-C5 alkyl; R2 is selected from the group consisting of C1-C5 alkyl, halo and C1-C3 fluoralkyl X is selected from the group consisting of O, S (O) m, and NR3; Y is C1-C3 alkanediyl; Ar1 Ar2 are independently phenylene or pyridinediyl; L is selected from the group consisting of -G-O-J-, -G-S (O) p-J, and -G-N (R4) -J; G is a link; J is independently selected from the group consisting of a bond and C1-C3 alkanediyl; R3 is independently hydrogen or C1-C5 alkyl; R4 is independently selected from the group consisting of hydrogen, C1-C5 alkyl, C (= O) R3, C (= O) R3, C (= O) NR3R3 and SO2R3; Z is selected from the group consisting of (CH2) n COOH and ** (See formula) ** m and p are independently 0, 1, or 2; n and q are 0 and their pharmaceutically acceptable salts.