Imidazopyridines pyrimidines and triazines for enhancing cognition as gaba-a-alphas 5 receoptor subtype ligands

A pharmaceutical composition comprising a compound of formula I or a pharmaceutically acceptable salt thereof:

• wherein:
• X and Y independently represent CH or N, with the proviso that if X is CH then Y is also CH;
• R1 represents hydrogen, hydrocarbon, a heterocyclic group, halogen, cyano, trifluoromethyl, nitro, —ORa, —SRa, —SORa, —SO2Ra, —SO2NRaRb, —NRaRb, —NRaCORb, —NRaCO2Rb, —CORa, —CO2Ra, —CONRaRb or —CRa═NORb;
• Ra and Rb independently represent hydrogen, hydrocarbon or a heterocyclic group;
• V and W are independently selected from H, halogen, C1-6alkyl, OH and C1-6alkoxy;
• Z represents H, halogen, CN, NO2, CF3, OCF3, CF2H, SCF3, R2, OR3, SR3, (CH2)pN(R3)2, O(CH2)pN(R3)2, SO2R2, SO2N(R3)2, COR4, CO2R3, CON(R3)2, NHCOR4, NR′(CH2)nheteroaryl or O(CH2)nheteroaryl where the heteroaryl is optionally substituted by one, two or three groups chosen from C1-6alkyl, benzyl, (CH2)pN(R3)2, halogen and CF3, R′ is C1-6alkyl, n is 1 or 2 and p is 0, 1 or 2;
• with the proviso that at least one of V, W and Z is other than H;
• R2 represents C1-6alkyl, C3-6cycloalkyl, C3-6cycloalkylC1-4alkyl, C2-6alkenyl, C2-6alkynyl or heteroaryl, any of which may bear a substituent selected from halogen, CN, NO2, CF3, OCF3, CF2H, SCF3, OH, C1-4alkoxy, C1-4alkoxycarbonyl, amino, C1-4alkylamino, or di(C1-4alkyl)amino;
• R3 represents H or R2;
• or two R3 groups bonded to the same nitrogen atom may complete a 5-7 membered nonaromatic heterocyclic ring;
• and
• R4 represents R3 or heteroaryl;
• in a pharmaceutically acceptable carrier.

A method for treating an individual suffering from diminished cognition which comprises administering to that individual a therapeutically effective amount of a compound of formula I or a pharmaceutically acceptable salt thereof:

• wherein:
• X and Y independently represent CH or N, with the proviso that if X is CH then Y is also CH;
• R1 represents hydrogen, hydrocarbon, a heterocyclic group, halogen, cyano, trifluoromethyl, nitro, —ORa, —SRa, —SORa, —SO2Ra, —SO2NRaRb, —NRaRb, —NRaCORb, —NRaCO2Rb, —CORa, —CO2Ra, —CONRaRb or —CRa═NORb;
• Ra and Rb independently represent hydrogen, hydrocarbon or a heterocyclic group;
• V and W are independently selected from H, halogen, C1-6alkyl, OH and C1-6alkoxy;
• Z represents H, halogen, CN, NO2, CF3, OCF3, CF2H, SCF3, R2, OR3, SR3, (CH2)pN(R3)2, O(CH2)pN(R3)2, SO2R2, SO2N(R3)2, COR4, CO2R3, CON(R3)2, NHCOR4, NR′(CH2)nheteroaryl or O(CH2)nheteroaryl where the heteroaryl is optionally substituted by one, two or three groups chosen from C1-6alkyl, benzyl, (CH2)pN(R3)2, halogen and CF3, R′ is C1-6alkyl, n is 1 or 2 and p is 0, 1 or 2;
• with the proviso that at least one of V, W and Z is other than H;
• R2 represents C1-6alkyl, C3-6cycloalkyl, C3-6cycloalkylC1-4alkyl, C2-6alkenyl, C2-6alkynyl or heteroaryl, any of which may bear a substituent selected from halogen, CN, NO2, CF3, OCF3, CF2H, SCF3, OH, C1-4alkoxy, C1-4alkoxycarbonyl, amino, C1-4alkylamino, or di(C1-4alkyl)amino;
• R3 represents H or R2;
• or two R3 groups bonded to the same nitrogen atom may complete a 5-7 membered nonaromatic heterocyclic ring;
• and
• R4 represents R3 or heteroaryl.