Selective antagonists of A

1. A compound of formula Ia or Ib or stereoisomer or a pharmaceutically acceptable salt thereof:

wherein:

the (CH 2 ) portions of (CH 2 ) n and (CH 2 ) q are independently substituted with 0-2 groups selected from OH, ═O, C 1-4 alkyl, C 3-6 cycloalkyl, and benzyl;

Q is O or S;

X is CH or N;

Y is selected from the group consisting of O, NY 1 , OCH 2 CH 2 OCH 2 , OCH 2 CH 2 OCH 2 CH 2 OCH 2 , OCH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 OCH 2 , NY 1 CH 2 CH 2 OCH 2 , NY 1 CH 2 CH 2 OCH 2 CH 2 OCH 2 , and NY 1 CH 2 CH 2 OCH 2 CH 2 OCH 2 CH 2 OCH 2 ;

alternatively, Y is a bond;

Y 1 is selected from the group consisting of H, C 1-4 alkyl, benzyl, C 3-6 cycloalkyl, and (C 3-6 cycloalkyl)C 1-4 alkylene;

Z is selected from the group consisting of aryl and heteroaryl, wherein Z is attached via a carbon atom and is substituted with 1-4 Z 1 groups;

Z 1 is independently selected from the group consisting of F, Cl, Br, I, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , and OCF 3 ;

R a is independently selected from the group consisting of H, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 3-8 cycloalkyl, (C 3-8 cycloalkyl)C 1-8 alkylene, aryl, (aryl)C 1-8 alkylene, heteroaryl, and (heteroaryl)C 1-8 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NR c —;

R 1 is independently selected from the group consisting of H, C 1-8 alkyl, C 3-8 cycloalkyl, (C 3-8 cycloalkyl)C 1-8 alkylene, aryl, (aryl)C 1-8 alkylene, heteroaryl, (heteroaryl)C 1-8 alkylene, (aryl)(aryl)-C 1-8 alkylene, (heteroaryl)(heteroaryl)-C 1-8 alkylene, and (aryl)(heteroaryl)C 1-8 alkylene, wherein the alkyl and cycloalkyl optionally may be interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NR c —, and the groups of R 1 are substituted with 0-4 groups independently selected from the group consisting of F, Cl, Br, I, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , and OCF 3 ;

R 2 is selected from the group consisting of H, C 1-6 alkyl, OR a , N(R a ) 2 , C 3-8 cycloalkyl, aryl, heterocycle, and heteroaryl, wherein the alkyl, cycloalkyl, aryl, heterocycle, and heteroaryl optionally are substituted with 1-2 groups independently selected from the group consisting of F, Cl, I, Br, CH 3 , CF 3 , and CH 3 O;

R 3 is a bond or is C 1-8 alkylene, wherein the alkylene group optionally is interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NH—;

R 3 is unsubstituted or is substituted with 1-2 groups selected from the group consisting of F, Cl, Br, I, —OR d , —SR d , —N(R d ) 2 , C 3-6 cycloalkyl, (C 3-6 cycloalkyl)C 1-4 alkylene, aryl, (aryl)C 1-4 alkylene, heteroaryl, and (heteroaryl)C 1-4 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted by 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 —, and —NR c —;

R 4 is selected from the group consisting of C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl, C 3-12 cycloalkyl, (C 3-12 cycloalkyl)C 1-8 alkylene, aryl, (aryl)C 1-8 alkylene, heteroaryl, (heteroaryl)C 1-8 alkylene, CF 3 , —CO 2 R b , R b C(O)—, (R b ) 2 NC(O)—, R b OC(S)—, R b C(S)—, and R b S(═O)—, wherein the alkyl and cycloalkyl optionally are interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NH—, and the alkyl, alkenyl, alkynyl, cycloalkyl, aryl, and heteroaryl are unsubstituted or are substituted with 1-4 groups independently selected from the group consisting of F, Cl, Br, I, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , OCF 3 , and —OS(O 2 )R a ;

alternatively, when R 3 is present, R 4 is additionally selected from the group consisting of H, F, Cl, Br, I, N(R b ) 2 , OR b , SR b , —CN, NO 2 , CF 3 O, R b C(O)O—, —OCO 2 R b , (R b ) 2 NC(O)O—, R b OC(O)NR b —, R b C(O)NR b —, (R b ) 2 NC(O)NR b —, and (R b ) 2 NC(S)NR b —;

provided that when R 2 is H and R 3 is a bond, then R 4 is other than

 wherein:

(a) “*” is the point of attachment;

(b) R z is —CH 2 OR, —CO 2 R, —OC(O)R, —CH 2 OC(O)R, —CH 2 SR, —C(S)OR, —CH 2 OC(S)R, —CH 2 NRR, —C(S)NRR, and, —C(O)NRR; and,

(c) R is H or a substituent;

R b is independently selected from the group consisting of H, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 3-8 cycloalkyl, (C 3-8 cycloalkyl)C 1-8 alkylene, aryl, (aryl)C 1-8 alkylene, heteroaryl, and (heteroaryl)C 1-8 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NH— and wherein the alkyl, cycloalkyl, aryl, and heteroaryl are substituted with 0-4 substituents selected from the group consisting of F, Cl, Br, I, C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , and OCF 3 ;

R c is independently selected from the group consisting of H, C 1-6 alkyl, and benzyl;

R d is independently selected from the group consisting of H, C 1-6 alkyl, C 3-6 cycloalkyl, (C 3-6 cycloalkyl)C 1-4 alkylene, phenyl, and benzyl;

R 5 is independently selected from the group consisting of H, F, Cl, Br, I, —OR c , —N(R c ) 2 , C 1-6 alkyl, C 3-6 cycloalkyl, aryl, and (aryl)C 1-4 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted by 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 —, and —NR b —;

R 6 is selected from the group consisting of CH 2 CH 2 , CH═CH, and C≡C;

a is independently selected from the group consisting of 0, 1, and 2;

n is independently selected from the group consisting of 0, 1, and 2;

p is independently selected from the group consisting of 0, 1, and 2;

q is independently selected from the group consisting of 0, 1, and 2; and,

r is independently selected from the group consisting of 0, 1, and 2.

2. The compound according to claim 1 , wherein the compound is of formula IIa or IIIa:

wherein:

Y is selected from the group consisting of O, NY 1 , OCH 2 CH 2 OCH 2 , and, NY 1 CH 2 CH 2 OCH 2 ;

alternatively, Y is a bond;

Y 1 is selected from the group consisting of H and CH 3 ;

Z is selected from the group consisting of 5-6 membered heteroaryl and phenyl, wherein Z is attached via a carbon atom and is substituted with 1-4 Z 1 groups;

Z 1 is independently selected from the group consisting of F, Cl, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , and OCF 3 ;

R a is independently selected from the group consisting of H, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, C 3-6 cycloalkyl, (C 3-6 cycloalkyl)C 1-2 alkylene, aryl, (aryl)C 1-2 alkylene, heteroaryl, and (heteroaryl)C 1-2 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NR c —;

R 1 is independently selected from the group consisting of H, C 1-4 alkyl, C 3-6 cycloalkyl, (C 3-6 cycloalkyl)C 1-4 alkylene, aryl, (aryl)C 1-4 alkylene, heteroaryl, (heteroaryl)C 1-4 alkylene, (aryl)(aryl)-C 1-4 alkylene, (heteroaryl)(heteroaryl)-C 1-4 alkylene, and (aryl)(heteroaryl)C 1-2 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NR c — and the aryl and heteroaryl rings are substituted with 0-2 groups independently selected from the group consisting of F, Cl, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , and OCF 3 ;

R 2 is selected from the group consisting of H, C 1-4 alkyl, OR a , N(R a ) 2 , C 3-6 cycloalkyl, aryl, heterocycle, and heteroaryl, wherein the alkyl, cycloalkyl, aryl, heterocycle, and heteroaryl are substituted with 0-2 groups independently selected from the group consisting of F, Cl, CH 3 , CF 3 , and CH 3 O;

R 4 is selected from the group consisting of C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, C 3-6 cycloalkyl, (C 3-6 cycloalkyl)C 1-2 alkylene, aryl, (aryl)C 1-2 alkylene, heteroaryl, (heteroaryl)C 1-2 alkylene, CF 3 , —CO 2 R b , R b C(O)—, (R b ) 2 NC(O)—, R b OC(S)—, R b C(S)—, and R b S(═O)—, wherein the alkyl and cycloalkyl optionally are interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NH—, and the alkyl, alkenyl, alkynyl, cycloalkyl, aryl, and heteroaryl are substituted with 0-3 groups independently selected from the group consisting of F, Cl, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , OCF 3 , and —OS(O 2 )R a ;

alternatively, when R 3 is at least 1, R 4 additionally may be selected from the group consisting of H, F, Cl, N(R b ) 2 , OR b , SR b , —CN, NO 2 , CF 3 O, R b C(O)O—, —OCO 2 R b , (R b ) 2 NC(O)O—, R b OC(O)NR b —, R b C(O)NR b —, (R b ) 2 NC(O)NR b —, and (R b ) 2 NC(S)NR b —;

provided that when R 2 is H and R 3 is a bond, then R 4 is other than

 wherein:

(a) “*” is the point of attachment;

(b) R z is —CH 2 OR, —CO 2 R, —OC(O)R, —CH 2 OC(O)R, —CH 2 SR, —C(S)OR, —CH 2 OC(S)R, —CH 2 NRR, —C(S)NRR, and, —C(O)NRR; and,

(c) R is H or a substituent;

R b is independently selected from the group consisting of H, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, C 3-6 cycloalkyl, (C 3-6 cycloalkyl)C 1-2 alkylene, aryl, (aryl)C 1-2 alkylene, heteroaryl, and (heteroaryl)C 1-2 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted with 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 — and —NH— and wherein the alkyl, cycloalkyl, aryl, and heteroaryl are substituted with 0-2 substituents selected from the group consisting of F, Cl, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, —(CH 2 ) a OR a , —(CH 2 ) a NR a R a , —(CH 2 ) a NHOH, —(CH 2 ) a NR a NR a R a , —(CH 2 ) a NO 2 , —(CH 2 ) a CN, —(CH 2 ) a CO 2 R a , —(CH 2 ) a C(O)R a , —(CH 2 ) a OC(O)R a , —(CH 2 ) a CONR a R a , CF 3 , and OCF 3 ;

R 3 is a bond or is C 1-4 alkylene, wherein the alkylene group optionally is interrupted with a heteroatom selected from the group consisting of —O—, —S(O) 0-2 — and —NH—;

R 3 is substituted with 0-1 groups selected from the group consisting of F, Cl, —OR d , —SR d , —N(R d ) 2 , C 3-6 cycloalkyl, (C 3-6 cycloalkyl)C 1-2 alkylene, aryl, (aryl)C 1-2 alkylene, heteroaryl, and (heteroaryl)C 1-2 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted by 1-2 heteroatoms selected from the group consisting of —O—, —S(O) 0-2 —, and —NR c —;

R c is independently selected from the group consisting of H and C 1-4 alkyl;

R d is independently selected from the group consisting of H, C 1-4 alkyl, (C 3-6 cycloalkyl)C 1-2 alkylene, and benzyl;

R 5 is independently selected from the group consisting of H, F, Cl, —N(R c ) 2 , C 1-4 alkyl, C 3-6 cycloalkyl, aryl, and (aryl)C 1-2 alkylene, wherein the alkyl and cycloalkyl optionally are interrupted by 1 heteroatom selected from the group consisting of —O—, —S(O) 0-2 —, and —NR b —;

a is independently selected from the group consisting of 0 and 1;

n is independently selected from the group consisting of 0 and 1;

p is independently selected from the group consisting of 0 and 1;

q is independently selected from the group consisting of 0 and 1; and,

r is independently selected from the group consisting of 0 and 1.

3. The compound according to claim 2 , wherein:

Y is selected from the group consisting of 0 and OCH 2 CH 2 OCH 2 ;

alternatively, Y is a bond;

Z is selected from the group consisting of phenyl, pyridyl, and pyrimidyl, wherein Z is attached via a carbon atom and is substituted with 1-3 Z 1 groups;

Z 1 is independently selected from the group consisting of F, Cl, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, OR a , NHOH, NR a NR a R a , NO 2 , CO 2 R a , C(O)R a , OC(O)R a , CONR a R a , CF 3 , and OCF 3 ;

R 1 is independently selected from the group consisting of H, C 1-4 alkyl, (cyclopropyl)CH 2 —, benzyl, pyridyl-CH 2 —, (phenyl)(phenyl)-C 1-4 alkylene, (pyridyl)(pyridyl)-C 1-4 alkylene, and (phenyl)(pyridyl)C 1-4 alkylene, wherein the aryl and heteroaryl rings are substituted with 0-2 groups independently selected from the group consisting of F, Cl, CH 3 , OH, OCH 3 , NH 2 , NHCH 3 , N(CH 3 ) 2 , NHOH, NHNH 2 , NO 2 , CN, CO 2 CH 3 , C(O)CH 3 , CONH 2 , C(O)NHCH 3 , C(O)N(CH 3 ) 2 , CF 3 , and OCF 3 ;

R 2 is selected from the group consisting of H, OR a , N(R a ) 2 , phenyl, and 5-6 membered heteroaryl, wherein the aryl, and heteroaryl are substituted with 0-2 groups independently selected from the group consisting of F, Cl, CH 3 , CF 3 , and CH 3 O;

R 3 is a bond or is C 1-2 alkylene;

R 4 is selected from the group consisting of C 2-4 alkenyl, C 2-4 alkynyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, heteroaryl, wherein the cycloalkyls optionally are interrupted with a heteroatom selected from the group consisting of —O—, —S(O) 0-2 — and —NH—, and the alkenyl, alkynyl, cycloalkyl, aryl, and heteroaryl are substituted with 0-2 groups independently selected from the group consisting of F, Cl, CH 3 , OH, OCH 3 , NH 2 , NHCH 3 , N(CH 3 ) 2 , NHOH, NHNH 2 , NO 2 , CN, CO 2 CH 3 , C(O)CH 3 , CONH 2 , C(O)NHCH 3 , C(O)N(CH 3 ) 2 , CF 3 , and OCF 3 ;

R 5 is independently selected from the group consisting of H and CH 3 ;

n is 1;

p is 1;

q is independently selected from the group consisting of 0 and 1; and,

r is independently selected from the group consisting of 0 and 1.

4. The compound according to claim 3 , wherein:

Z is selected from the group consisting of phenyl, pyridyl, and pyrimidyl, wherein Z is attached via a carbon atom and is substituted with 1 Z 1 group: and,

Z 1 is independently selected from the group consisting of F, Cl, CH 3 , CH 2 CH 3 , OH, OCH 3 , NH 2 , NHCH 3 , N(CH 3 ) 2 , NHOH, NHNH 2 , NO 2 , CN, CO 2 CH 3 , C(O)CH 3 , CONH 2 , C(O)NHCH 3 , C(O)N(CH 3 ) 2 , CF 3 , and OCF 3 .

5. The compound according to claim 2 , wherein the compound is of formula IIa.

6. The compound according to claim 5 , wherein p is 1.

7. The compound according to claim 6 , wherein r is 0.

8. The compound according to claim 7 , wherein Y is O.

9. The compound according to claim 8 , wherein the compound is of formula IIb:

10. The compound according to claim 2 , wherein the compound is of formula IIIa.

11. The compound according to claim 10 , wherein p is 1.

12. The compound according to claim 11 wherein r is 0.

13. The compound according to claim 12 , wherein Y is O.

14. The compound according to claim 13 , wherein the compound is of formula IIIb:

15. A compound selected from:

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 2-benzyloxy-ethyl ester;

4-[3-(6-Amino-9-cyclopentyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 2-benzyloxy-ethyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 3-trifluoromethyl-phenyl ester;

4-[3-(6-Amino-9-cyclopentyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 3-trifluoromethyl-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 2-fluoro-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 4-nitro-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 4-methoxycarbonyl-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 4-chloro-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 4-methoxy-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 4-methyl-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 4-nitro-benzyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 2-chloro-phenyl ester;

4-[3-(6-Amino-9-prop-2-ynyl-9H-purin-2-yl)-prop-2-ynyl]-piperidine-1-carboxylic acid 2-methoxy-phenyl ester;

2-{3-[1-((3,4-Dimethyl)phenoxycarbonyl)piperidin-4-yl]propyn-1-yl}-9-propargyladenine;

2-{3-[1-((3,4-Difluoro)phenoxycarbonyl)piperidin-4-yl]propyn-1-yl}-9-propargyladenine; and,

2-{3-[1-((3,4-Dichloro)phenoxycarbonyl)piperidin-4-yl]propyn-1-yl}-9-propargyladenine.

16. A compound selected from a compound of Table A:

TABLE A

Ex. No.

R

X

R 9

1

Phenyl

O

Propargyl

2

Phenyl

O

Cyclopentyl

3

—CH 2 CH 2 OBn

O

Propargyl

4

—CH 2 CH 2 OBn

O

Cyclopentyl

5

3-Trifluoromethylphenyl

O

Propargyl

6

3-Trifluoromethylphenyl

O

Cyclopentyl

7

4-Fluorophenyl

O

Propargyl

8

4-Nitrophenyl

O

Propargyl

9

O

Propargyl

10

4-Chlorophenyl

O

Propargyl

11

4-Methoxyphenyl

O

Propargyl

12

4-Methylphenyl

O

Propargyl

13

4-Nitrobenzyl

O

Propargyl

14

2-Chlorophenyl

O

Propargyl

15

2-Methoxyphenyl

O

Propargyl

16

3,4-Dimethylphenyl

O

Propargyl

17

3,4-Difluorophenyl

O

Propargyl

18

3,4-Dichlorophenyl

O

Propargyl.

17. A pharmaceutical composition comprising: a therapeutically effective amount of a compound of claim 1 and a pharmaceutically acceptable carrier.

18. A pharmaceutical composition comprising: a therapeutically effective amount of a compound of claim 15 and a pharmaceutically acceptable carrier.

19. A pharmaceutical composition comprising: a therapeutically effective amount of a compound of claim 16 and a pharmaceutically acceptable carrier.