Selective ligands for the dopamine 3 (D

1. A compound having a structural formula

wherein X is C═O or SO 2 , R 1 is C 1-6 alkyl, R 2 is unsubstituted or substituted and is aryl, heteroaryl, —(CH 2 ) 1-3 aryl, or —(CH 2 ) 1-3 heteroaryl, and n is 0 or 1, or a pharmaceutically acceptable salt thereof.

2. The compound of claim 1 wherein X is C═O.

3. The compound of claim 1 wherein X is SO 2 .

4. The compound of claim 1 wherein R 1 is C 1-4 alkyl.

5. The compound of claim 1 wherein R 1 is n-propyl.

6. The compound of claim 1 wherein R 2 is aryl.

7. The compound of claim 6 wherein R 2 is phenyl or naphthyl.

8. The compound of claim 1 wherein R 2 is heteroaryl.

9. The compound of claim 8 wherein R 2 is selected from the group consisting of pyridyl, pyrrolyl, indolyl, furanyl, benzofuranyl, thiophenyl, quinolinyl, isoquinolinyl, and pyrimidinyl.

10. The compound of claim 1 wherein R 2 is substituted with a group selected from the group consisting of halo, OC 1-3 alkyl, phenyl, OH, pyridinyl, pyrimidinyl, pyrazinyl, imidazolyl, pyrazolinyl, triazolyl, pyrazolyl, C 1-3 alkylphenyl, C 1-3 alkylpyrimidinyl, C 1-3 alkylpyridinyl, C 1-3 alkylOphenyl, HOphenyl, and halophenyl.

11. The compound of claim 10 wherein halo is chloro or fluoro and C 1-3 alkyl is methyl.

12. The compound of claim 1 wherein R 2 is selected from the group consisting of thienyl, furyl, oxazolyl, quinolyl, thiophenyl, isoquinolyl, indolyl, triazinyl, triazolyl, isothiazolyl, isoxazolyl, imidazolyl, benzothiazolyl, pyrimidinyl, thiazolyl, thiadiazolyl, pyridinyl, pyridazinyl, pyrazolyl, pyrazinyl, quinolyl, tetrazolyl, oxazolyl, pyrrolyl, benzimidazolyl, benzofuranyl, cinnolinyl, indazolyl, indolizinyl, phthalazinyl, triazinyl, isoindolyl, purinyl, oxadiazolyl, furazanyl, benzofurazanyl, benzothiophenyl, benzotriazolyl, benzothiazolyl, benzisothiazolyl, benzoxazolyl, benzisoxazolyl, benzimidazolyl, quinazolinyl, quinoxalinyl, napththyridinyl, dihydroquinolyl, tetrahydroquinolyl, dihydroisoquinolyl, tetrahydroisoquinolyl, benzofuryl, furopyridinyl, pyrrolopyrimidinyl, and azaindolyl.

13. The compound of claim 1 wherein

is selected from the group consisting of

14. The compound of claim 1 having a structural formula

15. A method of treating a disease or condition wherein modulation of dopamine D 3 receptors provides a benefit comprising administering a compound of claim 1 to an individual in need thereof, wherein the disease or condition is selected from the group consisting of symptoms of Parkinson's disease, restless leg syndrome, schizophrenia, depression, symptoms of Tourette's syndrome, and chronic pain.

16. The method of claim 15 further comprising administering a therapeutically effective amount of a second therapeutic agent useful in the treatment of the disease or condition.

17. The method of claim 15 wherein the compound of claim 1 and the second therapeutic agent are administered simultaneously.

18. The method of claim 15 wherein the compound of claim 1 and the second therapeutic agent are administered from a single composition.

19. The method of claim 15 wherein the compound of claim 1 and the second therapeutic agent are administered from separate compositions.

20. The method of claim 19 wherein the compound of claim 1 is administered prior to the second therapeutic agent.

21. The method of claim 19 wherein the compound of claim 1 is administered after the second therapeutic agent.

22. The method of claim 16 wherein the second therapeutic agent is selected from the group consisting of an antipsychotic agent, an antidepressant agent, a monoamine oxidase inhibitor, a 5-HT reuptake inhibitor, a serotonin-1 B antagonist, a serotonin-2A antagonist, a histamine-3 antagonist or agonist, and an antiparkinsonian agent.

23. The method of claim 16 wherein the second therapeutic agent is selected from the group consisting of clozapine, olanzapine, quetiapine, risperidone, ziprasidone, haloperidol, aripiprazole, a tricyclic antidepressant, amitriptyline, dothiepin, doxepin, trimipramine, butriptyline, clomipramine, desipramine, imipramine, iprindole, lofepramine, nortriptyline, protriptyline, isocarboxazid, phenelzine, tranylcyclopramine, fluvoxamine, sertraline, fluoxetine, paroxetine, elzasonan, eplivanserin, MDL-100907, cipralisant, ABT239, TISQ, GSK-189254A, a dopaminergic antiparkinsonian agent, and levodopa, alone or in combination with a peripheral decarboxylase inhibitor, benserazide, or carbidopa, or with a dopamine agonist, bromocriptine, lysuride, or pergolide, and mixtures thereof.

24. A kit comprising:

(a) a packaged composition comprising a compound of claim 1 ;

(b) optionally, a packaged composition comprising a second therapeutic agent useful in a treatment of a disease or condition wherein modulation of D 3 receptors provide a benefit;

(c) an insert providing instructions for a simultaneous or sequential administration of (a), or (a) and (b), to treat a disease or condition wherein modulation of D 3 receptors provide a benefit in a human;

(d) a container for (a), (b), and (c),

wherein the disease or condition is selected from the group consisting of symptoms of Parkinson's disease, restless leg syndrome, schizophrenia, depression, symptoms of Tourette's syndrome, and chronic pain.

25. A composition comprising (a) a compound of claim 1 , (b) a second therapeutic agent useful in the treatment of a disease or condition wherein modulation of D 3 receptors provide a benefit, and (c) an optional excipient and/or pharmaceutically acceptable carrier,

wherein the disease or condition is selected from the group consisting of symptoms of Parkinson's disease, restless leg syndrome, schizophrenia, depression, symptoms of Tourette's syndrome, and chronic pain.

26. The compound of claim 1 wherein R 2 is selected from the group consisting of

wherein R is selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-8 cycloalkyl, heterocycloalkyl, aryl, and heteroaryl.