Subunit selective nmda receptor potentiators for the treatment of neurological conditions

A pharmaceutical composition comprising a compound of the following formula:

• or pharmaceutically acceptable salts or esters thereof wherein,
• R1-R6 are selected independently from H, OMe, OH, SH, SMe, Cl, F, I, Br, C1-6 alkyl, C6-10aryl, alkylaryl, and arylalkyl, and substituted versions of the alkyl, aryl, aralkyl, and alkylaryl moieties;
• X is O;
• Y is selected from S and O;
• wherein a substituted alkyl, aryl, aralkyl, and alkylaryl is alkyl, aryl, aralkyl, and alkylaryl with one or more substituent, wherein a substituent is fluoro, chloro, bromo, iodo, hydroxy, heterocyclic, heteroaryl, carboxy, alkoxy, NH2, N(alkyl)2, NH(alkyl), alkoxycarbonyl, —N(H or alkyl)C(O)(H or alkyl), —N(H or alkyl)C(O)N(H or alkyl)2, —N(H or alkyl)C(O)O(H or alkyl), —OC(O)N(H or alkyl)2, —S(O)n—(H or alkyl), —C(O)—N(H or alkyl)2, cyano, alkenyl, cycloalkyl, acyl, hydroxyalkyl, heterocyclic, heteroaryl, aryl, aminoalkyl, oxo, carboxyalkyl, —C(O)—NH2, —C(O)—N(H)O(H or alkyl), —S(O)2—NH2, —S(O)n—N(H or alkyl)2 and/or —S(O)2—N(H or alkyl)2.