Halogenated derivatives of morphinans and uses thereof

1. A compound of Formula IC, wherein the compound is the (+)-isomers of Formula IC or a pharmaceutically acceptable salt thereof:

wherein:

R 1 is selected from the group consisting of hydroxyl, alkoxy, and aryloxy;

R 2 is selected from the group consisting of hydrogen, alkyl, alkynyl, alkenyl, alkoxy, hydrocarbyl, substituted hydrocarbyl, cycloalkyl, alkylaryl, substituted alkylaryl

Y is selected from the group consisting of hydrogen and hydroxy;

X is fluorine; and

Z is hydrogen; provided that when R 1 is hydroxyl, R 2 is not cyclopropylmethyl.

2. The compound of claim 1 , wherein Y is hydrogen.

3. The compound of claim 1 , wherein Y is hydroxy.

4. The compound of claim 1 , wherein R 1 is hydroxyl or methoxy.

5. The compound of claim 1 , wherein R 2 is cyclopropylmethyl, propenyl, or phenethyl.

6. A compound of formula:

or a pharmaceutically acceptable salt thereof.

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

or a pharmaceutically acceptable salt thereof.

8. A compound of Formula IC, wherein the compound is the (+)-isomer of Formula IC, or a pharmaceutically acceptable salt thereof:

wherein R 1 is methoxy, R 2 is cyclopropyl, Y is hydrogen, X is fluorine, and Z is hydrogen.

9. The compound of claim 1 , wherein the (+)-isomer of Formula IC is of the formula:

or a pharmaceutically acceptable salt thereof.

10. The compound of claim 1 , wherein the compound of Formula IC is selected from the group consisting of:

and pharmaceutically acceptable salts thereof.

11. A method for potentiating the analgesic effects of an opioid in a subject comprising administering to the subject an effective amount of the compound of claim 1 .

12. A method for reducing the risk of developing an opioid dependency in a subject during opioid therapy, comprising the step of administering to the subject who is on opioid therapy an effective amount of the compound of claim 1 .

13. A method for treating a subject with a clinical condition associated with Toll-like receptor (TLR) glial activation comprising the step of administering to the subject an effective amount of the compound of claim 1 ; wherein the clinical condition is acute nociceptive pain, neuropathic pain, pain associated with neurological diseases, pain associated with neuronal damage, pain caused by burns, pain caused by osteoarthritis, pain caused by chemotherapy, pain caused by trauma, acute and repetitive opioid analgesia, the reward effects of drug abuse, chronic pain, or other pain associated with opioid dependency.

14. A method for treating a subject suffering from or susceptible to neuropathic pain, the method comprising administering to the subject an effective amount of the compound of claim 1 .

15. A method for treating a subject suffering from or susceptible to nociceptive pain, the method comprising administering to the subject an effective amount of the compound of claim 1 .

16. The method of claim 14 , wherein the neuropathic pain is due to a condition selected from the group consisting of spinal cord injury, multiple sclerosis, stroke, diabetes, sciatica, herpes zoster infection, HIV, neuralgia, nutritional deficiencies, toxins, tumors, immune mediated disorders, physical trauma to a nerve trunk, cancer, chemotherapy, radiation injury, invasive medical procedures, surgery, non-specific lower back pain, carpal tunnel syndrome, fibromyalgia, and a chronic inflammatory condition.

17. The method of claim 14 , wherein the neuropathic pain is due to multiple sclerosis.

18. The method of claim 14 , wherein the neuropathic pain is due to cancer.

19. The method of claim 14 , wherein the neuropathic pain is due to chemotherapy.

20. The method of claim 13 , wherein the Toll-like receptor is TLR-4.

21. The compound of claim 1 , wherein R2 is hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, isobutyl, n-pentyl, neopentyl, tert-pentyl, isopentyl, sec-pentyl, 3-pentyl, sec-isopentyl, n-hexyl, hexyl, cyclopropylmethyl, dicyclopropylmethyl, 1-cyclopropylethyl, 2-propenyl, cyclohexyl, 1-phenylethyl, 1-methyl-2-phenyl-ethyl, benzyl,