NMDA receptor modulators and uses thereof

A compound of the Formula Ic:

• or a pharmaceutically acceptable salt thereof, wherein
• R1 is selected from the group consisting of hydrogen, halogen, C1-6alkyl, C2-6alkenyl, C2-6alkynyl, C1-6alkoxy, C3-6cycloalkyl, —C(O)OH, —C(O)OC1-6alkyl, (C3-6) cycloalkyl and phenyl (optionally substituted by one, two or three substituents each selected from halogen, C1-6alkyl, C1-6alkoxy, —C(O)OH, —C(O)OC1-6alkyl and NRaRb);
• R4 is selected from the group consisting of hydrogen, C1-6alkyl, C2-6alkenyl, C2-6alkynyl, —CO2H, —CO2C1-6alkyl, —CO2 NRaRb, NRaRb, C3-6cycloalkyl and phenyl (optionally substituted by one or two substituents each selected from halogen or methyl);
• R5 independently for each occurrence is selected from the group consisting of hydrogen, C1-6alkyl, C1-6alkoxy, halogen, cyano, OH, C2-6alkenyl, C2-6alkynyl, C3-6cycloalkyl, heteroaryl, phenyl, —NRaRb, —C(O)OH, C1-6alkylcarbonyl, C1-6alkoxycarbonyl, (NRaRb) carbonyl-, C1-6alkyl-S(O)w— (where w is 0, 1 or 2), and RaRbN—SOw— (where w is 0, 1 or 2);
• wherein heteroaryl and phenyl may optionally be substituted by one, two or three substituents each selected from the group consisting of halogen, cyano, C1-6alkyl, C1-6alkoxy, and —NRaRb;
• wherein one or more carbon atoms of said C3-6cycloalkyl may be optionally replaced by N or O;
• or two R5, together with two adjacent carbons on ring A to which they are attached, form a 5-7 membered unsaturated, partially unsaturated or saturated carbocyclic or heterocyclic ring;
• R6 for each occurrence is independently selected from the group consisting of hydrogen, C1-6alkyl, C3-6cycloalkyl, —C(O)—C1-6alkyl, and phenyl (optionally substituted by one or two substituents each selected from halogen or methyl);
• Ring A is pyridinyl, pyrimidinyl or pyridazinyl;
• RC is selected from the group consisting of cyano, hydrogen, halogen, S(C1-6) alkyl, S(O)(C1-6) alkyl, SO2(C1-6)alkyl, C(O)NRaRb, —C(O)OH, —C(O)O(C1-6)alkyl, (C1-6)alkyl, (C2-6) alkenyl, (C2-6) alkynyl and heteroaryl (optionally substituted by C1-4alkyl or halogen);
• Ra and Rb are independently selected, for each occurrence, from the group consisting of:
• hydrogen, C1-4alkylcarbonyl, C1-6alkoxycarbonyl, cyclopropyl, and C1-3alkyl;
• wherein C1-3alkyl may optionally be substituted on a carbon not bound to the nitrogen by one or more substituents each selected from the group consisting of fluorine, cyano, oxo and hydroxyl;
• or Ra and Rb, together with the nitrogen to which they are attached, form a 4-6 membered heterocyclic ring which may have an additional heteroatom selected from O, S, or N (optionally substituted by one or two methyl groups);
• and wherein the 4-6 membered heterocyclic ring may optionally be substituted on a carbon not bound to the nitrogen by one or more substituents;
• and
• p is 0, 1, 2 or 3.