(S)-PHENYL(HETEROCYCLE)METHANOL-BASED COMPOUNDS, COMPOSITIONS COMPRISING THEM AND METHODS OF THEIR USE

1 . A stereomerically pure compound of formula I:

or a pharmaceutically acceptable salt thereof, wherein:

A is an optionally substituted piperidine;

X is optionally substituted pyrimidine;

each R 1 is independently hydrogen, halogen, cyano, R A , OR A , C(O)R A , C(O)OR A , C(O)N(R A R B ), N(R A R B ), or SO 2 R A ;

each R 2 is independently hydrogen, halogen, cyano, R A , OR A , C(O)R A , C(O)OR A , C(O)N(R A R B ), N(R A R B ), or SO 2 R A ;

each R A is independently hydrogen or optionally substituted alkyl, aryl, arylalkyl, alkylaryl, heterocycle, heterocycle-alkyl, or alkyl-heterocycle; and

each R B is independently hydrogen or optionally substituted alkyl, aryl, arylalkyl, alkylaryl, heterocycle, heterocycle-alkyl, or alkyl-heterocycle.

2 . The compound of claim 1 , wherein A is unsubstituted.

3 . The compound of claim 1 , wherein X is of the formula:

wherein:

each R 4 is independently hydrogen, halogen, cyano, R A , OR A , C(O)R A , C(O)OR A , C(O)N(R A R B ), N(R A R B ), or SO 2 R A .

4 . The compound of claim 1 , which is of the formula:

wherein:

each R 1 is independently hydrogen, halogen, cyano, R A , OR A , C(O)R A , C(O)OR A , C(O)N(R A R B ), N(R A R B ), or SO 2 R A ;

each R 2 is independently hydrogen, halogen, cyano, R A , OR A , C(O)R A , C(O)OR A , C(O)N(R A R B ), N(R A R B ), or SO 2 R A ;

each R 4 is independently hydrogen, halogen, cyano, R A , OR A , C(O)R A , C(O)OR A , C(O)N(R A R B ), N(R A R B ), or SO 2 R A ;

each R 5 is independently halogen, cyano, R 5A , OR 5A , C(O)R 5A , C(O)OR 5A , C(O)N(R 5A R 5B ), N(R 5A R 5B ), or SO 2 R 5A ;

each R A is independently hydrogen or optionally substituted alkyl, aryl, arylalkyl, alkylaryl, heterocycle, heterocycle-alkyl, or alkyl-heterocycle;

each R B is independently hydrogen or optionally substituted alkyl, aryl, arylalkyl, alkylaryl, heterocycle, heterocycle-alkyl, or alkyl-heterocycle;

each R 5A is independently hydrogen or optionally substituted alkyl, aryl, arylalkyl, alkylaryl, heterocycle, heterocycle-alkyl, or alkyl-heterocycle;

each R 5B is independently hydrogen or optionally substituted alkyl, aryl, arylalkyl, alkylaryl, heterocycle, heterocycle-alkyl, or alkyl-heterocycle; and

n is 0-5.

5 . The compound of claim 1 , which is:

(S)-2-(4-((3′-chlorobiphenyl-4-yl)(hydroxy)methyl)piperidin-1-yl)pyrimidin-5-ol;

(S)-(3′-chlorobiphenyl-4-yl)(1-(pyrimidin-2-yl)piperidin-4-yl)methanol;

(S)-(3-amino-3′-chlorobiphenyl-4-yl)(1-(pyrimidin-2-yl)piperidin-4-yl)methanol;

(S)—N-(3′-chloro-4-(hydroxy(1-(pyrimidin-2-yl)piperidin-4-yl)methyl)biphenyl-3-yl)acetamide;

(S)—N-{3′-chloro-4-[hydroxyl-(1-pyrimidin-2-yl-piperidin-4-yl)-methyl]-biphenyl-3-yl}-acetamide; or

(S)-3′-chloro-4-[hydroxy-(1-pyrimidin-2-yl-piperidin-4-yl)-methyl]-biphenyl-3-ol.

6 . A method of improving the cognitive performance of a human patient, which comprises administering to the patient an amount of a compound of claim 1 sufficient to improve the cognitive performance.

7 . A method of treating or managing a disease or disorder in a patient, which comprises administering to the patient a therapeutically or prophylactically effective amount of a compound of claim 1 , wherein the disease or disorder is age-associated memory impairment, Alzheimer's disease, Attention-Deficit/Hyperactivity Disorder, autism, Down syndrome, Fragile X syndrome, Huntington's disease, Parkinson's disease, or schizophrenia.