WO2008011485A2 - Methods for treating chronic pain - Google Patents

Abstract

Disclosed herein are methods of treating a patient suffering from one or more types of chronic pain.

Description

METHODS FOR TREATING CHRONIC PAiN

BACKGROUND OF THE INVENTION

The present invention is directed to methods of treating a patient suffering from one or more types of chronic pain. Several compounds falling within one or more of the general definitions as "derivatives of 3-aryl-3-hydroxy-2-amino-propionic acid amides, of 3- heteroaryl-3-hydroxy-2-amino-propionic acid amides, of 1 ~aryl-1 -hydroxy-2,3- diamino-propyl amines, 1 -heteroaryl-1 -hydroxy-2,3-diamino-propyl amines" are known in the patent and scientific literature. For example, United States Patent Application Publications US

2003/0153768; US 2003/0050299 disclose several examples of the above- mentioned known compounds. The /V-acyl compounds of these references are said to be useful as /V-acylsphingosine glucosyltransferase inhibitors, the amide and the reduced compounds are described as intermediates in their preparations.

illustrative specific examples of compounds of these references are shown below:

⁼ ri_j π Λ — vJ

The publication Shin et al. Tetrahedron Asymmetry, 2000, 11 , 3293-3301 discloses the following compounds:

<1 fl,2fl)-2-((S)-1-phenylethylamino)-3- (1 f?,2f?)-2-amino-3-morpholino-1- morpholino-1 -phenylpropan-1 -ol phenylpropan-1-ol

D-threo-PDMP

L-threo-PDMP and some other known compounds used in the methods of this invention are commercially available, in pure enantiomeric and racemic forms, as applicable, from Matreya, LLC Pleasant Gap, Pennsylvania.

L-fftreo-PDMP

United States Patent Nos. 5,945,442; 5,952,370; 6,030,995 and 6,051 ,598, which are all related to each other as being based on same or related disclosures, describe compounds which are structurally similar to the known compounds shown above. The compounds of these U.S. patent references are said to be inhibitors of the enzyme glucosylceramide (GlcCer) synthethase.

A publication in Journal of Labelled Compounds &

Radiopharmaceuticals (1996), 38{3), 285-97 discloses the compound of the formula

Published PCT application WO 01/38228 discloses

in connection with a chromatographic method.

Kastron et at. in Latvijas PSR Zinatnu Akademijas Vestis, Kimtjas Serija (1965) (4), 474-7 disclose the following compound.

SUMMARY OF THE INVENTION

The present invention is directed to methods of treating a patient suffering from one or more types of chronic pain using the compounds below;

(±)-trans

COMPOUND 19;

COMPOUND 50 where R₄ is H₁ alkyi of 1 to 6 carbons or CO-R₅ where R₅ is alkyl of 1 to 6 carbons;

COMPOUND 70

(±) HCI

Compound 49

where R₄ is H, alkyl of 1 to 6 carbons or CO-R₅ where R₅ is alkyl of 1 to 6 carbons;

(±) Compound 300 where R₄ is H, alky! of 1 to 6 carbons or CO-R₅ where R₅ is alkyl of 1 to 6 carbons;

Compound 301 where R₄ is H, alkyl of 1 to 6 carbons or CO-R₅ where R₅ is alkyl of 1 to 6 carbons;

2.HCI (±ythreo Compound 302 where R₄ is H, alky! of 1 to 6 carbons or CO-R₅ where R₅ is alkyl of 1 to 6 carbons, and all pharmaceutically acceptable saits of said compounds.

Any of the compounds described here may be used to treat a patient suffering from one or more types of chronic pain including neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain.

DETAILED DESCRIPTION OF THE INVENTION Several compounds of the invention contain one or more asymmetric centers, such that the compounds may exist in enantiomeric as well as in diastereomeric forms. In fact, most of the compounds of the present invention have two asymmetric carbons adjacent to one another and therefore can exist in erythro or threo form, with each of these two forms having dextrorotatory (D) or ievorotary (L) enantiomers. Although the threo form is generally preferred in accordance with the present invention for analgesic activity, unless it is specifically noted otherwise, the scope of the present invention includes all enantiomers, diastereomers and diastereomeric and racemic mixtures. In light of the foregoing, it should be clearly understood that the designation "DL" or "(+/-)" or "(±)" in this application includes the pure dextrorotatory enantiomer, the pure levorotatory enantiomer and all racemic mixtures, including mixtures where the two enantiomers are present in equal or in unequal proportions. Moreover, for simplicity sake in many of the structural formulas, such as in the example below, only one of the enantiomers is actually shown but when the designation "DL" (or "(+/-)" or "(±)") appears it also includes the enantiomeric form (mirror image) of the structure actually shown in the formula. For example:

(±) HCi

Thus, in the example above, only one enantiomer is shown, but because the designation "DL" (or "(+/-)" or "(±)") appears below the formula, its optical isomer

HCl and all racemic mixtures of the two optical isomers are also included. In the case of some compounds of the present invention one enantiomer of the threo, and in some cases of the erythro, is significantly more active as an analgesic than the other enantiomer of the same pair. For this reason the isolated enantiomer which is significantly more active than the other is considered a novel and inventive composition even if the racemic mixture or one single enantiomer of the same compounds have already been described in the prior art.

Some of the novel compounds of the present invention may contain three or more asymmetric centers. Keeping the foregoing examples in mind a person of ordinary skill in the art should readily understand the scope of each described example, although in a broad sense all isomers, enantiomers and racemic mixtures are within the scope of the invention. The term "alkyl" in the general description and definition of the compounds includes straight chain as well as branch-chained alkyl groups,

Generally speaking the compounds of the invention may form salts with pharmaceutically acceptable acids or bases, and such pharmaceutically acceptable salts of the compounds are also within the scope of the invention. Referring now to the novel compounds of the invention the R₄ group shown above and in the claims, is preferably H.

The presently most preferred novel compounds of the invention are disclosed with their structural formulas in the ensuing Table and or description, showing activity of exemplary compounds relevant to their ability to act as analgesics.

BIOLOGICAL ACTIVITY, MODES OF ADMINISTRATION The compounds described here may be used to treat a patient suffering from one or more types of chronic pain, including neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain.

To "treat," as used here, means to deal with medically. It includes, for example, administering a compound of the invention to prevent a pain, to alleviate its severity, and to prevent its reoccurance.

The term "pain," as used here, means any unpleasant sensory experience, usually associated with a physical disorder. The physical disorder may or may not be apparent to a clinician. Pain is of two types: chronic and acute. An "acute pain" is a pain of short duration having a sudden onset. One type of acute pain, for example, is cutaneous pain felt on injury to the skin or other superficial tissues, such as caused by a cut or a burn. Cutaneous nociceptors terminate just below the skin, and due to the high concentration of nerve endings, produce a well-defined, localized pain of short duration. "Chronic pain" is a pain other than an acute pain. Chronic pain includes neuropathic pain, inflammatory pain, headache pain, somatic pain visceral pain and referred pain.

/. Neuropathic Pain

The compounds of the invention may be used to treat pain caused by 5 or otherwise associated with any of the following neuropathic pain conditions. "Neuropathic pain" means abnormal sensory input, resulting in discomfort, from the peripheral nervous system, central nervous systems, or both,

A. Symptoms of neuropathic pain

Symptoms of neuropathic pain can involve persistent, spontaneous 10 pain, as well as ailodynia (a painful response to a stimulus that normally is not painful), hyperalgesia (an accentuated response to a painful stimulus that usually causes only a mild discomfort, such as a pin prick), or hyperpathia {where a short discomfort becomes a prolonged severe pain).

B. Causes of neuropathic pain

] 5 Neuropathic pain may be caused by any of the following.

1. A traumatic insult, such as, for example, a nerve compression injury (e.g., a nerve crush, a nerve stretch, a nerve entrapment or an incomplete nerve transsection); a spinal cord injury (e.g., a hemisection of the spinal cord); a limb amputation; a contusion; an inflammation (e.g., an inflammation 0 of the spinal cord); or a surgical procedure.

2. An ischemic event, including, for example, a stroke and heart attack.

3. An infectious agent

4. Exposure to a toxin, including, for example, a drug, an alcohol, a heavy metal (e.g., lead, arsenic, mercury), an industrial agent (e.g., a solvent, 5 fumes from a glue) or nitrous oxide.

5. A disease, including, for example, an inflammatory disorder, a neoplastic tumor, an acquired immune deficiency syndrome (AIDS), Lymes disease, a leprosy, a metabolic disease, a neurodegenerative disease, a spinal stenosis, a mononeuropathy, a polyneuropathy, and a peripheral nerve 0 disorder, such as a neuroma.

C. Types of neuropathic pain 1. Neuralgia. A neuralgia is a pain that radiates along the course of one or more specific nerves usually without any demonstrable pathological change in the nerve structure. The causes of neuralgia are varied. Chemical irritation, inflammation, trauma (including surgery), compression by nearby structures (for instance, tumors), and infections may all lead to neuraigia. In many cases, however, the cause is unknown or unidentifiable. Neuralgia is most common in elderly persons, but it may occur at any age, A neuralgia, includes, without limitation, a trigeminal neuralgia, a spinal stenosis, a post-herpetic neuralgia, a postherpetic neuralgia, a glossopharyngeal neuralgia, pain associated with nerve entrapment disorders, a sciatica and an atypical facial pain.

Neuralgia is a painful disorder of the cranial nerves. Falling under the category of neuralgia are trigeminal neuralgia (TN), atypical facial pain, and postherpetic neuralgia (caused by shingles or herpes). The affected nerves are responsible for sensing touch, temperature and pressure in the facial area from the jaw to the forehead. The disorder generally causes short episodes of excruciating pain, usually for less than two minutes and on only one side of the face. The pain can be described in a variety of ways such as "stabbing," "sharp," "like lightning," "burning," and even "itchy". In the atypical form of TN, the pain can also present as severe or merely aching and last for extended periods. The pain associated with TN is recognized as one the most excruciating pains that can be experienced.

Simple stimuli such as eating, talking, washing the face, or any light touch or sensation can trigger an attack (even the sensation of a gentle breeze). The attacks can occur in clusters or as an isolated attack. Symptoms include sharp, stabbing pain or constant, burning pain located anywhere, usually on or near the surface of the body, in the same location for each episode; pain along the path of a specific nerve; impaired function of affected body part due to pain, or muscle weakness due to concomitant motor nerve damage; increased sensitivity of the skin or numbness of the affected skin area (feeling similar to a local anesthetic such as a Novacaine shot); and any touch or pressure is interpreted as pain. Movement may also be painful. Trigeminal neuralgia is the most common form of neuralgia. It affects the main sensory nerve of the face, the trigeminal nerve ("trigeminal" literally means "three origins", referring to the division of the nerve into 3 branches). This condition involves sudden and short attacks of severe pain on the side of the face, along the area supplied by the trigeminal nerve on that side. The pain attacks may be severe enough to cause a facial grimace, which is classically referred to as a painful tic (tic douloureux). Sometimes, the cause of trigeminal neuralgia is a blood vessel or small tumor pressing on the nerve. Disorders such as multiple sclerosis (an inflammatory disease affecting the brain and spinal cord), certain forms of arthritis, and diabetes (high blood sugar) may also cause trigeminal neuralgia, but a cause is not always identified. In this condition, certain movements such as chewing, talking, swallowing, or touching an area of the face may trigger a spasm of excruciating pain. A related but rather uncommon neuralgia affects the glossopharyngeal nerve, which provides sensation to the throat. Symptoms of this neuralgia are short, shock-like episodes of pain located in the throat.

Neuralgia may occur after infections such as shingles, which is caused by the varicella-zoster virus, a type of herpesvirus. This neuralgia produces a constant burning pain after the shingles rash has healed. The pain is worsened by movement of or contact with the affected area. Not all of those diagnosed with shingles go on to experience postherpetic neuralgia, which can be more painful than shingles. The pain and sensitivity can last for months or even years. The pain is usually in the form of an intolerable sensitivity to any touch but especially light touch. Postherpetic neuralgia is not restricted to the face; it can occur anywhere on the body but usually occurs at the location of the shingles rash. Depression is not uncommon due to the pain and social isolation during the illness.

Postherpetic neuralgia may be debilitating long after signs of the original herpes infection have disappeared. Other infectious diseases that may cause neuralgia are syphilis and Lyme disease. Diabetes is another common cause of neuralgia. This very common medical problem affects almost 1 out of every 20 Americans during adulthood. Diabetes damages the tiny arteries that supply circulation to the nerves, resulting in nerve fiber malfunction and sometimes nerve loss. Diabetes can produce almost any neuralgia, including trigeminal neuralgia, carpal tunnel syndrome (pain and numbness of the hand and wrist), and meralgia paresthetica (numbness and pain in the thigh due to damage to the lateral femoral cutaneous nerve). Strict control of blood sugar may prevent diabetic nerve damage and may accelerate recovery in patients who do develop neuralgia.

Other medical conditions that may be associated with neuralgias are chronic renal insufficiency and porphyria - a hereditary disease in which the body cannot rid itself of certain substances produced after the normal breakdown of blood in the body. Certain drugs may also cause this problem. 2. Deafferentation.

Deafferentation indicates a loss of the sensory input from a portion of the body, and can be caused by interruption of either peripheral sensory fibres or nerves from the central nervous system. A deafferentation pain syndrome, includes, without iimitation, an injury to the brain or spinal cord, a post-stroke pain, a phantom pain, a paraplegia, a brachial plexus avulsion injuries, lumbar radiculopathies.

3. Complex regional pain syndromes (CRPSs)

CRPS is a chronic pain syndrome with two forms. CRPS 1 currently replaces the term "reflex sympathetic dystrophy syndrome". It is a chronic nerve disorder that occurs most often in the arms or legs after a minor or major injury. CRPS 1 is associated with severe pain; changes in the nails, bone, and skin; and an increased sensitivity to touch in the affected limb. CRPS 2 replaces the term causalgia, and results from an identified injury to the nerve. A CRPS, includes, without limitation, a CRPS Type I (reflex sympathetic dystrophy) and a CRPS Type Ii (causalgia).

4. Neuropathy. A neuropathy is a functional or pathological change in a nerve and is characterized clinically by sensory or motor neuron abnormalities.

Central neuropathy is a functional or pathological change in the central nervous system. Peripheral neuropathy is a functional or pathological change in one or more peripheral nerves. The peripheral nerves relay information from your central nervous system (brain and spinal cord) to muscles and other organs and from your skin, joints, and other organs back to your brain, Peripheral neuropathy occurs when these nerves fail to carry information to and from the brain and spinal cord, resulting in pain, loss of sensation, or inability to control muscles, In some cases, the failure of nerves that control blood vessels, intestines, and other organs results in abnormal blood pressure, digestion problems, and loss of other basic body processes. Risk factors for neuropathy include diabetes, heavy alcohol use, and exposure to certain chemicals and drugs. Some people have a hereditary predisposition for neuropathy.

Prolonged pressure on a nerve is another risk for developing a nerve injury. Pressure injury may be caused by prolonged immobility (such as a long surgical procedure or lengthy illness) or compression of a nerve by casts, splints, braces, crutches, or other devices. Polyneuropathy implies a widespread process that usually affects both sides of the body equally. The symptoms depend on which type of nerve is affected. The three main types of nerves are sensory, motor, and autonomic. Neuropathy can affect any one or a combination of all three types of nerves. Symptoms also depend on whether the condition affects the whole body or just one nerve (as from an injury). The cause of chronic inflammatory polyneuropathy is an abnormal immune response. The specific antigens, immune processes, and triggering factors are variable and in many cases are unknown. It may occur in association with other conditions such as HIV, inflammatory bowel disease, lupus erythematosis, chronic active hepatitis, and blood cell abnormalities. Peripheral neuropathy may involve a function or pathological change to a single nerve or nerve group (monneuropathy) or a function or pathological change affecting multiple nerves (polyneuropathy). Peripheral neuropathies Hereditary disorders

Charcot-Marie-Tooth disease Friedreich's ataxia

Systemic or metabolic disorders

Diabetes (diabetic neuropathy )

Dietary deficiencies (especially vitamin B-12)

Excessive alcohol use (alcoholic neuropathy ) Uremia (from kidney failure )

Cancer (including bone cancer and other cancers) Infectious or inflammatory conditions

AIDS

Hepatitis Colorado tick fever

Diphtheria

Guillain-Barre syndrome

HIV infection without development of AIDS

Leprosy Lyme disease

Polyarteritis nodosa

Rheumatoid arthritis

Sarcoidosis

Sjogren's syndrome Syphilis

Systemic Lupus erythematosus amyloid Exposure to toxic compounds

Sniffing glue or other toxic compounds Nitrous oxide

Industrial agents -- especially solvents

Heavy metals (lead, arsenic, mercury, etc.) Neuropathy secondary to drugs like analgesic nephropathy Rhabdomyolysis Macrohagic myofasciitis

Highly Active Anti-Retrviral Therapy (HAART)-induced neuropathy Chemotherapy lncuced Neuropathy Miscellaneous causes

Ischemia (decreased oxygen/decreased blood flow) Prolonged exposure to cold temperature a. Polyneuropathy Polyneuropathy is a peripheral neuropathy involving the loss of movement or sensation to an area caused by damage or destruction to multiple peripheral nerves. Polyneuropathic pain, includes, without limitation, post-polio syndrome, postmastectomy syndrome, diabetic neuropathy, alcohol neuropathy, amyloidosis, toxin exposure, AIDS, hypothyroidism, uremia, vitamin deficiencies, chemotherapy-induced pain, 2',3'-didexoycytidine (ddC) treatment, exposure to the anticonvulsant phenytoin, exposure to antibiotics including chloramphenicol, nitrofurantoin and sulfonamineds, exposure to sedatives including barbital and hexobarbital, Guillain-Barre syndrome, Fabry's disease or polyneuropathy secondary to cancers such as multiple myeloma. b. Mononeuropathy

Mononeuropathy is a peripheral neuropathy involving loss of movement or sensation to an area caused by damage or destruction to a single peripheral nerve or nerve group. Mononeuropathy is most often caused by damage to a local area resulting from injury or trauma, although occasionally systemic disorders may cause isolated nerve damage (as with mononeuritis multiplex). The usual causes are direct trauma, prolonged pressure on the nerve, and compression of the nerve by swelling or injury to nearby body structures. The damage includes destruction of the myelin sheath (covering) of the nerve or of part of the nerve cell (the axon). This damage slows or prevents conduction of impulses through the nerve. Mononeuropathy may involve any part of the body. Mononeuropathic pain, includes, without limitation, a sciatic nerve dysfunction, a common peroneal nerve dysfunction, a radial nerve dysfunction, an ulnar nerve dysfunction, a cranial mononeuropathy Vl, a cranial mononeuropathy VlI, a cranial mononeuropathy !Ii (compression type), a cranial mononeuropathy IE) (diabetic type), an axillary nerve dysfunction, a carpal tunnel syndrome, a femoral nerve dysfunction, a tibial nerve dysfunction, a Beli's palsy, a thoracic outlet syndrome, a carpal tunnel syndrome, and a sixth (abducent) nerve palsy. c. Generalized peripheral neuropathies Generalized peripheral neuropathis are symmetrica!, and usually due to various systematic illnesses and disease processes that affect the peripheral nervous system in its entirety. They are further subdivided into several categories: i. Distal axonopathies are the result of some metabolic or toxic derangement of neurons. They may be caused by metabolic diseases such as diabetes, renal failure, deficiency syndromes such as malnutrition and alcoholism, or the effects of toxins or drugs. Distal axonopathy (aka dying back neuropathy) is a type of peripheral neuropathy that results from some metabolic or toxic derangement of peripheral nervous system (PNS) neurons. it is the most common response of nerves to metabolic or toxic disturbances, and as such may be caused by metabolic diseases such as diabetes, renal faiiure, deficiency syndromes such as malnutrition and alcoholism, or the effects of toxins or drugs. The most common cause of distal axonopathy is diabetes, and the most common distal axonopathy is diabetic neuropathy. ii. Myelinopathies are due to a primary attack on myelin causing an acute failure of impulse conduction. The most common cause is acute inflammatory demyelinating polyneuropathy (AIDP; aka Guillain-Barre syndrome), though other causes include chronic inflammatory demyelinating syndrome (CIDP), genetic metabolic disorders (e.g., leukodystrophy), or toxins. Myelinopathy is due to primary destruction of myelin or the myelinating Schwann cells, which leaves the axon intact, but causes an acute failure of impulse conduction. This demyelination slows down or completely blocks the conduction of electical impulses through the nerve. The most common cause is acute inflammatory demyelinating polyneuropathy (AIDP, better known as Guiliain-Barre syndrome), though other causes include chronic inflammatory demyelinating polyneuropathy (CIDP), genetic metabolic disorders (e.g., leukodystrophy or Charcot-Maπe-Tooth disease), or toxins. iii. Neuronopathies are the result of destruction of peripheral nervous system (PNS) neurons. They may be caused by motor neurone diseases, sensory neuronopathies (e.g., Herpes zoster), toxins or autonomic dysfunction. Neurotoxins may cause neuronopathies, such as the chemotherapy agent vincristine. Neuronopathy is dysfunction due to damage to neurons of the peripheral nervous system (PNS), resulting in a peripheral neuropathy. It may be caused by motor neurone diseases, sensory neuronopathies (e.g., Herpes zoster), toxic substances or autonomic dysfunction. A person with neuronopathy may present in different ways, depending on the cause, the way it affects the nerve cells, and the type of nerve cell that is most affected. iv. Focal entrapment neuropathies (e.g., carpal tunnel syndrome) represent an additional category of generalized peripheral neuropathies.

//. Inflammatory pain The compounds of the invention may be used to treat pain caused by or otherwise associated with any of the following inflammatory conditions.

A. Arthritic disorder

Arthritic disorders include, for example, a rheumatoid arthritis; a juvenile rheumatoid arthritis; a systemic lupus erythematosus (SLE); a gouty arthritis; a scleroderma; an osteoarthritis; a psoriatic arthritis; an ankylosing spondylitis; a Reiter's syndrome (reactive arthritis); an adult Still's disease; an arthritis from a viral infection; an arthritis from a bacterial infection, such as, e.g., a gonococcal arthritis and a non-gonococcal bacterial arthritis (septic arthritis); a Tertiary Lyme disease; a tuberculous arthritis; and an arthritis from a fungal infection, such as, e,g_M a blastomycosis

B. Autoimmune diseases Autoimmune diseases include, lor example, a Guillain-Barre syndrome, a Hashimoto's thyroiditis, a pernicious anemia, an Addison's disease, a type i diabetes, a systemic lupus erythematosus, a dermatomyositis, Sjogren's syndrome, a lupus erythematosus, a multiple sclerosis, a myasthenia gravis, a Reiter's syndrome, a Grave's disease, and a rheumatoid arthritis. C.

Connective tissue disorder

Connective tissue disorders include, for example, a spondyloarthritis a dermatomyositis, and a fibromyalgia syndrome ,

D. Injury Inflammation caused by injury, including, for example, a crush, puncture, stretch of a tissue or joint, may cause chronic inflammatory pain.

E. Infection

Inflammation caused by infection, including, for example, a tuberculosis or an interstitial keratitis may cause chronic inflammatory pain. Infection may also result in inflammatory bowel diseases and irritable bowel syndromes.

F. Neuritis

Neuritis is an inflammatory process affecting a nerve or group of nerves. Symptoms depend on the nerves involved, but may include pain, paresthesias, paresis, or hypesthesia (numbness). Examples include: a. Brachial neuritis b. Retrobulbar neuropathy, an inflammatory process affecting the part of the optic nerve lying immediately behind the eyeball. c. Optic neuropathy, an inflammatory process affecting the optic nerve causing sudden, reduced vision in the affected eye. The cause of optic neuritis is unknown, The sudden inflammation of the optic nerve (the nerve connecting the eye and the brain) leads to swelling and destruction of the myelin sheath. The inflammation may occasionally be the result of a viral infection, or it may be caused by autoimmune diseases such as multiple sclerosis. Risk factors are related to the possible causes. d. Vestibular neuritis, a viral infection causing an inflammatory process affecting the vestibular nerve. G. Joint inflammation

Inflammation of the joint, such as that caused by bursitis or tendonitis, for example, may cause chronic inflammatory pain.

///. Headache Pain The compounds of the invention may be used to treat pain caused by or otherwise associated with any of the following headache conditions. A headache (medically known as cephalgia) is a condition of mild to severe pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. It may indicate an underlying local or systemic disease or be a disorder in itself.

A. Muscular/myogenic headache

Muscular/myogenic headaches appear to involve the tightening or tensing of facial and neck muscles; they may radiate to the forehead. Tension headache is the most common form of myogenic headache. A tension headache is a condition involving pain or discomfort in the head, scalp, or neck, usually associated with muscle tightness in these areas. Tension headaches result from the contraction of neck and scalp muscles. One cause of this muscle contraction is a response to stress, depression or anxiety. Any activity that causes the head to be held in one position for a long time without moving can cause a headache. Such activities include typing or use of computers, fine work with the hands, and use of a microscope. Sleeping in a cold room or sleeping with the neck in an abnormal position may also trigger this type of headache. A tension-type headache, includes, without limitation, an episodic tension headache and a chronic tension headache. B. Vascular headache

The most common type of vascular headache is migraine. Other kinds of vascular headaches include cluster headaches, which cause repeated episodes of intense pain, and headaches resulting from high blood pressure 1. Migraine A migraine is a heterogeneous disorder that generally involves recurring headaches. Migraines are different from other headaches because they occur with other symptoms, such as, e.g., nausea, vomiting, or sensitivity to light. In most people, a throbbing pain is felt only on one side of the head. Clinical features such as type of aura symptoms, presence of prodromes, or associated symptoms such as vertigo, may be seen in subgroups of patients with different underlying pathophysiological and genetic mechanisms. A migraine headache, includes, without limitation, a migraine without aura (common migraine), a migraine with aura (classic migraine), a menstrual migraine, a migraine equivalent (acephalic headache), a complicated migraine, an abdominal migraine and a mixed tension migraine. 2. Cluster headache Cluster headaches affect one side of the head (unilateral) and may be associated with tearing of the eyes and nasal congestion. They occurs in clusters, happening repeatedly every day at the same time for several weeks and then remitting. D. High blood pressure headache E. Traction and inflammatory headache

Traction and inflammatory headaches are usually symptoms of other disorders, ranging from stroke to sinus infection.

F. Hormone headache

G. Rebound headache Rebound headaches, also known as medication overuse headaches, occur when medication is taken too frequently to relieve headache. Rebound headaches frequently occur daily and can be very painful. H. Chronic sinusitis headache

Sinusitis is inflammation, either bacterial, fungal, viral, allergic or autoimmune, of the paranasal sinuses. Chronic sinusitis is one of the most common complications of the common cold. Symptoms include: Nasal congestion; facial pain; headache; fever; general malaise; thick green or yellow discharge; feeling of facial 'fullness' worsening on bending over. In a small number of cases, chronic maxillary sinusitis can also be brought on by the spreading of bacteria from a dental infection. Chronic hyperplastic eosinophilic sinusitis is a noninfective form of chronic sinusitis. I. An organic headache J. lctal headaches lctal headaches are headaches associated with seizure activity.

IV, Somatic pain

The compounds of the invention may be used to treat pain caused by or otherwise associated with any of the following somatic pain conditions. Somatic pain originates from ligaments, tendons, bones, blood vessels, and even nerves themselves. It is detected with somatic nociceptors. The scarcity of pain receptors in these areas produces a dull, poorly-localized pain of longer duration than cutaneous pain; examples include sprains and broken bones. Additional examples include the following. A. Excessive muscle tension

Excessive muclse tension can be caused, for example, by a sprain or a strain.

8. Repetitive motion disorders Repetitive motion disorders can result from overuse of the hands, wrists, elbows, shoulders, neck, back, hips, knees, feet, legs, or ankles. C. Muscle disorders

Muscle disorders causing somatic pain include, for example, a polymyositis, a dermatomyositis, a lupus, a fibromyalgia, a polymyalgia rheumatica, a macrophagic myofascitis, and a rhabdomyolysis. Muscle pain can also be secondary to neurological and neuromuscular disorders including without limitation Parkinson's disease, Huntington's chorea, dystonias, tardive dyskinesias, drug-induced dyskinesias and dystonias, dyskinesias (paroxysmal), amyotrophic lateral sclerosis, multiple sclerosis, myoclonus, progressive supranuclear patsy, corticobasal degeneration, choreoathetosis, spasticity, Wilson disease, multiple system atrophy (including Shy-Drager syndrome, striatonigral degeneration and olivopontocerebellar atrophy), and hereditary spastic paraplegia (including familial spastic paraparesis, familial spastic paraplegia, hereditary spastic paraparesis, Strumpell-Lorraine syndrome, and Strumpell's disease). D. Myalgia

Myalgia is muscle pain and is a symptom of many diseases and disorders. The most common cause for myalgia is either overuse or overstretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections. Longer-term myalgias may be indicative of a metabolic myopathy, some nutritional deficiencies or chronic fatigue syndrome.

E. Infection

Infection can cause somatic pain. Examples of such infection include, for example, an abscess in the muscle, a trichinosis, an influenza, a Lyme disease, a malaria, a Rocky Mountain spotted fever, Avian influenza, the common cold, community-acquired pneumonia, meningitis, monkeypox, Severe Acute Respiratory Syndrome, toxic shock syndrome, trichinosis, typhoid fever, and upper respiratory tract infection, F. Drugs

Drugs can cause somatic pain. Such drugs include, for example, cocaine, statins for lowering cholesterol (such as atorvastatin, simvastatin, and lovastatin), and ACE inhibitors for lowering blood pressure (such as enalapril and captopril). G. Prolonged nociceptive pain including without limitation to bone fracture pain, spinal stenosis, and post-surgical pain.

V. Visceral pain

The compounds of the invention may be used to treat pain caused by or otherwise associated with any of the following visceral pain conditions. Visceral pain originates from body's viscera, or organs. Visceral nociceptors are located within body organs and internal cavities. The even greater scarcity of nociceptors in these areas produces pain that is usually more aching and of a longer duration than somatic pain. Visceral pain is extremely difficult to localise, and several injuries to visceral tissue exhibit "referred" pain, where the sensation is localised to an area completely unrelated to the site of injury.

Examples of visceral pain include the following. A. Functional visceral pain Functional visceral pain includes, for example, an irritable bowel syndrome and a chronic functional abdominal pain (CFAP), a functional constipation and a functional dyspepsia, a non-cardiac chest pain (NCCP) and a chronic abdominal pain. B, Chronic gastrointestinal inflammation

Chronic gastrointestinal inflammation includes, for example, a gastritis, an inflammatory bowel disease, e.g., a Crohn's disease, an ulcerative colitis, a microscopic colitis, a diverticulitis and a gastroenteritis; an interstitial cystitis; an intestinal ischemia; a cholecystitis; an appendicitis; a gastroesophageal reflux; an ulcer, a nephrolithiasis, an urinary tract infection, a pancreatitis and a hernia.

C. Autoimmune pain

Autoimmune pain includes, for example, a sarcoidosis and a vasculitis.

D. Organic visceral pain Organic visceral pain includes, for example, pain resulting from a traumatic, inflammatory or degenerative lesion of the gut or produced by a tumor impinging on sensory innervation,

E. Treatment-induced visceral pain

Treatment-induced visceral pain includes, for example, a pain attendant to chemotherapy therapy or a pain attendant to radiation therapy.

Vl. Referred pain

The compounds of the invention may be used to treat pain caused by or otherwise associated with any of the following referred pain conditions.

Referred pain arises from pain localized to an area separate from the site of pain stimulation. Often, referred pain arises when a nerve is compressed or damaged at or near its origin, In this circumstance, the sensation of pain will generally be felt in the territory that the nerve serves, even though the damage originates elsewhere. A common example occurs in intervertebral disc herniation, in which a nerve root arising from the spinal cord is compressed by adjacent disc material. Although pain may arise from the damaged disc itself, pain will also be felt in the region served by the compressed nerve (for example, the thigh, knee, or foot). Relieving the pressure on the nerve root may ameliorate the referred pain, provided that permanent nerve damage has not occurred. Myocardial ischaemia (the loss of blood flow to a part of the heart muscie tissue) is possibly the best known example of referred pain; the sensation can occur in the upper chest as a restricted feeling, or as an ache in the left shoulder, arm or even hand.

Pain Reversal

An art-accepted model or assay for measuring an analgesic effect of a compound in chronic pain (in particular peripheral neuropathy) is the model known as Kim and Chung 1992, Pain 150, pp 355-363 (Chung model). This model involves the surgical ligation of the L5 (and optionally the L6) spinal nerves on one side in experimental animals. Rats recovering from the surgery gain weight and display a level of general activity similar to that of normal rats. However, these rats develop abnormalities of the foot, wherein the hindpaw is moderately everted and the toes are held together. More importantly, the hindpaw on the side affected by the surgery appears to become sensitive to low-threshold mechanical stimuli and will perceive pain instead of the faint sensation of touch. This sensitivity to normally non-painful touch, called "tactile allodynia", develops within the first week after surgery and lasts for at least two months. The allodynia response includes lifting the affected hindpaw to escape from the stimulus, Sicking the paw and holding it in the air for many seconds. None of these responses is normally seen in the control group.

To produce the tactile allodynia, rats are anesthetized before surgery. The surgical site is shaved and prepared either with betadine or Novacaine. Incision is made from the thoracic vertebra XIII down toward the sacrum. Muscle tissue is separated from the spinal vertebra (left side) at the L4 - S2 levels. The L6 vertebra is located and the transverse process is carefully removed with a small rongeur to expose the L4 - L6 spinal nerves. The L5 and L6 spinal nerves are isolated and tightly ligated with 6-0 silk thread. The same procedure is done on the right side as a control, except no ligation of the spinal nerves is performed. After a complete hemostasis is confirmed, the wounds are sutured, A small amount of antibiotic ointment is applied to the incised area, and the rat is transferred to the recovery plastic cage under a regulated heat-temperature lamp. On the day of the experiment, at least seven days after the surgery, typically six rats per test group are administered the test drugs by intraperitoneal (Lp.) injection or oral gavage (p.o.). For i.p. administration, the compounds are formulated in H₂O and given in a volume of 1 ml/kg body weight by injecting into the intraperitoneal cavity. For p.o, administration, the compounds are formulated in H₂O and given in a volume of 1 ml/kg body weight using an 18-gauge, 3 inch gavage needle that is slowly inserted through the esophagus into the stomach.

Tactile allodynia is assessed via von Frey hairs, which are a series of fine hairs with incremental differences in stiffness. Rats are placed in a plastic cage with a wire mesh bottom and allowed to acclimate for approximately 30 minutes. To establish the pre-drug baseline, the von Frey hairs are applied perpendicularly through the mesh to the mid-plantar region of the rats' hindpaw with sufficient force to cause slight buckling and held for 6-8 seconds. The applied force has been calculated to range from 0.41 to 15.1 grams. If the paw is sharply withdrawn, it is considered a positive response, A normal animal will not respond to stimuli in this range, but a surgically ligated paw will be withdrawn in response to a 1 -2 gram hair. The 50% paw withdrawal threshold is determined using the method of Dixon, WJ., Ann. Rev. Pharmacol. Toxicol. 20:441 -462 (1980) hereby incorporated by reference. Tactile allodynia is measured prior to and 15, 30, and 60 minutes after drug administration. The post-drug threshold is compared to the pre-drug threshold and the percent reversal of tactile sensitivity is calculated based on a norma! threshold of 15.1 grams.

Table 1 below indicates the degree of pain reversal obtained in the Chung model with exemplary compounds of the invention. The intraperitonial (i.p.) and/or intravenous (iv) administration of the compounds was in doses ranging from 1 μg/kg to 300 μg/kg or 3 mg/kg PO and the peak percentage of reversal of allodynia was measured at 15, 30 or 60 minutes after administration, as is indicated in the table. Data are expressed as the highest % ailodynia reversal (out of 3 time points: 15 min, 30 min, or 60 min. post- drug) with a minimum of a 20% allodynia reversal in the rat Chung model. Comparisons between groups (drug treated vs. saline treated) were made using a two-tailed, 2-sampie, unpaired t-test. Compounds that are not shown which were not statistically analgesic following an IP dose of 300 ug/kg, but may still be analgesic. Compounds that do not exhibit significant analgesia at 100 mg/kg are not considered to be analgesic.

Modes of Administration:

The compounds of the invention may be administered at pharmaceutically effective dosages. Such dosages are normally the minimum dose necessary to achieve the desired therapeutic effect; in the treatment of chromic pain, this amount would be roughly that necessary to reduce the discomfort caused by the pain to tolerable levels. For human adults such doses generally will be in the range of 0.1 -5,000 mg/day; more preferably in the range of 1 to 3,000 mg/day, 10 mg to 500 mg/day, 500 to 1 ,000 mg/day, 1 ,000 to 1 ,500 mg/day, 1 ,500 to 2,000 mg/day, 2,000 to 2,500 mg/day, or 2,500 to 3,000 mg/day. However, the actual amount of the compound to be administered in any given case wiil be determined by a physician taking into account the relevant circumstances, such as the severity of the pain, the age and weight of the patient, the patient's general physical condition, the cause of the pain, and the route of administration.

The compounds are useful in the treatment of pain in a mammal; particularly a human being. Preferably, the patient will be given the compound orally in any acceptable form, such as a tablet, liquid, capsule, powder and the like. However, other routes may be desirable or necessary, particularly if the patient suffers from nausea. Such other routes may include, without exception, transdermal, intraperitonial, parenteral, subcutaneous, intranasal, intrathecal, intramuscular, intravenous and intrarectal modes of delivery. Another aspect of the invention is drawn to therapeutic compositions comprising the novel compounds of the invention and pharmaceutically acceptable salts of these compounds and a pharmaceutically acceptable excipient. Such an excipient may be a carrier or a diluent; this is usually mixed with the active compound, or permitted to dilute or enclose the active compound. If a diluent, the carrier may be solid, semi-solid, or liquid material that acts as an excipient or vehicle for the active compound. The formulations may also include wetting agents, emulsifying agents, preserving agents, sweetening agents, and/or flavoring agents. If used as in an ophthalmic or infusion format, the formulation will usually contain one or more salt to influence the osmotic pressure of the formulation.

In another aspect, the invention is directed to methods for the treatment of pain, particularly chronic pain, through the administration of one or more of the novel or otherwise known compounds of the invention, or of pharmaceutically acceptable salts thereof to a mammal in need thereof. As indicated above, the compound will usually be formulated in a form consistent with the desired mode of delivery.

SYNTHETIC METHODS FOR OBTAINING THE COMPOUNDS OF THE

INVENTION

The compound of the invention can be synthesized by utilizing the synthetic methods described in the experimental below, or such modifications of the below described experimental methods which will become readily apparent to those skilled in the art in light of the present disclosure. More specifically, the synthesis of each compound of the invention is described for the specific compounds wherein the variable R₄ is H, It will be readily understood by those skilled in the art that the compounds wherein the variable R₄ is alkyl of 1 to 6 carbons or CO-R₅ where R₅ is alkyl of 1 to 6 carbons can be readily made by processes well known in the art, such as alkylation or acylation, respectively. It will also be readily understood by those skilled in the art that for the performance of the alkylation or acylation of the hydroxy! group other groups, such as the amino group, may need to be protected and the protective group can be subsequently removed by processes well known in the art. In some cases the alkylation or acyiation of the hydroxy! group may be performed on an intermediate in the synthetic process leading to the compounds of the invention. GENERAL

¹H NMR spectra were recorded at ambient temperature with an Avance 300 (Bruker) spectrometer. The compounds were analyzed by reverse phase high performance iiquid chromatography (HPLC) using a Waters Autopurification System equipped with a Waters 2525 Pump, a Waters 2696 photodiode array detector, and a XTerra column (Part. No. 186000482, 5 μm, C18, 4.5 x 50 mm). The HPLC method used was a gradient of 5 % solvent B to 100 % in 7 min. Solvent A was H₂O with 0.05 % TFA and solvent B was CH₃CN with 0.05 % TFA (Method A).

Melting points were measured with a Bϋchi B-545 melting point apparatus and were uncorrected. To isolate reaction products the solvent were removed by evaporation using a vacuum rotatory evaporator, the water bath temperature not exceeding 40 ⁰C.

GENERAL SYNTHETIC ROUTES

The compound of the invention can be synthesized by utilizing the synthetic methods described in a general sense immediately below and in more detail in the experimental section of the present application, or by such modifications of the below described general and experimental methods which will become readily apparent to those skilled in the art in light of the present disclosure.

DETAILED DESCRIPTION OF THE SYNTHESIS OF PREFERRED

COMPOUNDS (EXPERIMENTAL) Preparation of Compound 19. 2-lsocvano-1 -(pyrrolidin-1 -yl)ethanone BLE 04098.

To stirred and cooled {0 ⁰C) methyl isocyanoacetate (96 % technical grade, 5,0 g, 47.8 mmol) was slowly added in 0.75 h pyrrolidine (6.5 mL, 78 mmol). The mixture was stirred for 1.5 h with continued cooling and then concentrated. The resulting oil was co-evaporated twice from CH₂CI₂:hexane to remove residual pyrrolidine. 2-lsocyano-1-(pyrrolidin-1-yl)ethanone BLE 04098 was obtained as a yellow solid (6.85 g, 98 % yield) and used in the next step without purification.

BLE 04098

MW: 138.17; Yield: 98 %; yellow solid; Mp (⁰C) = 73.9. 1H-NMR (CDCi₃, δ): : 1.81-2.08 (m, 4H₁ 2xCH_Ξ), 3.35-3.45 (m, 2H, N-CH₂), 3.50-3.60 (m, 2H, N-CH₂J, 4.23 (s, 2H₁ CH₂CO),

General Method B: Exemplified by the preparation of fraπs-(4,5-dihvdro-5- (pyridin-3-yl)oxazol-4-yl)(pyrrolidin-1 -yl)methanone BLE 0411QB.

To a stirred and cooled (0 °C) solution of potassium hydroxide (0.55 g,

9.80 mmol) in methanol (10 mL) were added a mixture of 3-pyridine carboxaldehyde (1.03 mL, 10.84 mmo!) and 2-isocyano-1 -(pyrrolidin-1 - yi)ethanone BLE 04098 (1.50 g, 10.86 mmol). The solution was stirred 3 h at 0 ⁰C and then concentrated. The residue was partitioned between ethyl acetate (100 mL) and water. The organic layer was combined with two additional ethyl acetate extracts (2x100 mL), washed with aqueous sodium chloride and dried over MgSO₄, filtered and evaporated. Concentration afforded a crude product which was purified by column chromatography on silica (CH₂Ci₂: MeOH = 98:2) to yield to fra/is-(4,5-dihydro-5-(pyridin-3- yl)oxazol-4-yl)(pyrrolidϊn-1 -yl)methanone BLE 04110B (0.95 g, 39 %) as a pale yellow pale solid.

BLE 0411 OB

MW: 245.28; Yield: 39 %; Yellow Pale Solid; Mp (⁰C): 107.0.

¹H-NMR (CDCI₃, δ): : 1.78-2.10 (m, 4H, 2xCH₂), 3.40-3.61 (m, 3H₁ CH₂N), 3.90-4.04 (m, 1 H, CH₂N), 4.59 (dd, 1 H₁ J = 7.7 Hz, J = 2.2 Hz, CH-N)₁ 6.21 (d,

1 H₅ J = 7.7 Hz, CH-O)₁ 7.04 (d, 1 H, J = 2.2 Hz, 0-CH=N), 7.33 (m, 1 H, ArH),

7.64 (m, 1 H, ArH), 8.59 (d, 2H, J= 2.8 Hz, ArH).

¹³C-NMR (CDCI₃, δ): : 24.2, 26.O₅ 46.4, 46.6, 75.7, 79.3, 123.7, 133.5, 135.3,

147.6, 149.9, 155.2, 166.2.

frans-(4,5-Dihvdro-5-(pyridin-4-yl)oxazoi-4-yl)(pyrrolidin-1-yl)methanone

Compound 19.

Compound 19 was prepared in accordance with method B using pyridine-4-carbaIdehyde (1.88 ml_, 19.76 mmol), KOH (1.01 g, 18.00 mmol) in methanol (18 mL) and 2-isocyano-1 -(pyrrolidin~1 -yl)ethanone BLE 04098

(2.73 g, 19.76 mmol). The residue was partitioned between ethyl acetate (200 mL) and water (150 mL), The organic layer was combined with additional ethyl acetate extracts (2 x 150 mL), washed with aqueous sodium chloride (2 x 150 mL) and dried over MgSO₄, filtered and evaporated. 7ra/7S-(4,5-dihydro- 5-(pyridin-4-yl)oxazol-4-yl)(pyrrolidin-1 -yl)methanone Compound 19 was obtained as a white solid (4.32 g, 98 % yield).

MW: 245.28; Yield: 98 %; White Solid; Mp (⁰C) = 69.2. R_f\ 0.65 (MeOH:CH₂CI₂ = 10:90). ¹H-NMR (CDCI₃, δ): : 1 ,78-2.06 (m, 4H₁ 2xCH_£), 3.44-3.60 (m, 3H, CH₂N),

3.90-4.01 (m, 1 H₁ CH₂Nj, 4.52 (eld, 1 H₅ J= 7.9 Hz₁ J= 2.2 Hz, CH-N), 6.19 (d, J = 7.9 Hz, 1 H₅ CH-O), 7.03 (d, 1 H, J = 2.2 Hz, N=CH-O), 7.24 {dd, 2H, J = 4.5 Hz, J = 1.5 Hz, ArH)₅ 8.61 (dd, 2H, J = 4.5 Hz, J = 1.5 Hz, ArH).

Preparation of Compound 50.

General Method C: Exemplified by the preparation of DL-tf?rβo-2-amino-3- hydroxy-3-(pyridin-3-yl)-1 -(pyrrolidin-1 -vi)propan-1 -one dihydrochloride

Compound 20. To a solution of frans-(4,5-dihydro-5-(pyridin-3-yi)oxazol-4- yl)(pyrrolidin-1 -yl)methanone BLE 0411 OB (0.932 g, 3.80 mmol) in MeOH (10 mL) was added hydrochloric acid 37 % (1.2 mL). After heating (50 ⁰C) the mixture for 2.25 h the reaction mixture was concentrated and the crude product was coevaporated twice with ethyl acetate. After trituration with ethyl acetate, filtration and drying DL-fftreo-2-amino-3-hydroxy-3-(pyridin-3-yl)-1 - (pyrrolidin-1 -yl)propan-1 -one dihydrochloride Compound 20 was obtained as a white solid (1.10 g, 94 % yield).

Compound 20 MW: 308.2; Yield: 94 %; White Solid; Mp (⁰C): 123.4.

¹H-NMR (CD3OD, δ): : 1.65-2.00 (m, 4H, 2xCH₂), 2.82-3.11 (m, 1 H, -CH₂N), 3.30-3.57 (m, 2H₁ C₂HN), 3.57-3.77 (m, 1 H, CH₂N), 4.54 (d, 1 H, J = 5.3 Hz₁ CH-N), 5.38 (d, 1 H₁ J = 5.3 Hz, CH-O), 8.15 (dd, 1 H, J= 7.6 Hz, J = 5.0 Hz, ArH), 8.68 (d, 1 H₁ J= 7.6 Hz, ArH), 8.89 (d, 1 H, J = 7,6 Hz, ArH), 8.96 (s, 1 H₁ ArH).

¹³C-NMR (CD3OD, δ): : 24.9, 26.9, 47.7, 48.2, 58.1 , 69.6, 128.7, 141.5, 141.6, 143,1 , 146.5, 165.4. DL-f/7feo-2-Amino-3-hydroxy-3-(pyridin-4-yl)-1 -(pyrrolidin-1 -yl)propan-1 -one dihydrochloride Compound 22.

Compound 22 was prepared following method C with trans-(4,5- dihydro-5-(pyrJdin-4-yt)oxazol-4-yi)(pyrrolidin-1 -yl)methanone Compound 19 (0.750 g, 3,07 mmol), hydrochloric acid 37 % (1.0 mL) and methanol (10 mL). After 3.0 h at 50 ⁰C and work-up DL-tf?reo-2-amino-3-hydroxy-3-(pyridin-4-yl)- 1 -(pyrrolidtn-1 -yl)propan-1 -one dihydrochloride Compound 22 was obtained as a white solid (0.935 g, 99 % yield).

Compound 22

MW: 308.28; Yield: 99 %; White Solid; Mp (⁰C): 117.0.

¹H-NMR (CD₃OD, δ): : 1.75-2.03 (m, 4H, 2XCH₂), 2.93-3.08 (m, 1 H, CH-N), 3.32-3.75 (m, 3H, 2xCH₂), 4.54 (d, 1 H₁ J = 5.9 Hz, CH-N)₁ 5.40 (d, 1 H₁ J = 5.9 Hz₅ CH-O), 8.21 (d, 2H, J = 5.8 Hz₁ ArH), 8.94 (d, 2H, J= 5.8 Hz₁ ArH). MS-ESl m/z {% rel. int.): 236.1 ([MH]+, 17), 219 (25), 148 (100).

HPLC: Method A, detection UV 254 nm, Compound 22 RT = 0.8 min, peak area 96.3 %.

tert-Butyl 5-(DL-threo-1 -hydroxy-3-oxo-1 -(pyridin-4-yl)-3-(pyrrolidin-1 - yl)propan-2-vicarbamoyl)pentylcarbamate EBE 06102.

To a suspension of DL-f/7reo-2-amino-3-hydroxy-3-(pyridin-4-yl)-1 - (pyrrolidin-1 -yl)propan-1 -one dihydrochloride Compound 22 (0.60 g, 1.77 mmoi) in CH₂CI₂ (12 mL) was added TEA (0.739 mL, 5.32 mmol) and the reaction mixture was stirred for 10 min and cooled in an ice bath with continuous stirring. A solution of Boc-aminohexanoic acid (0.451 g, 1.951 mmol) and BOP (1.05 g, 1.95 mmol) was pre-prepared in CH₂CI₂ and added dropwise for 5 min. The reaction mixture was stirred for 2 h at 0⁰C and 16 h at RT. After evaporation of the volatiles, the residue was dissolved in EtOAc, washed with NaH₂PO₄ pH 7.2, saturated NaHCO₃, dried over Na₂SO₄. The resulting white solid was purified by column chromatography on silica gel with 10 % EtOAc in EtOAc to give tert-butyl 5-(DL-fΛreo-1 -hydroxy-3-oxo-1 - (pyridin-4-yl)-3-(pyrrolidin-1 -yl)propan-2-ylcarbamoyl)pentylcarbamate EBE 06102 (0.41 g, 52 % yield) as a white solid.

EBE 06102

MW: 448.56; Yield: 52.0 %; White Solid.

R,: 0.10 (EtOAc:MeOH = 90:10).

¹H-NMR: (CDCI₃, 6): : 1.10-1.12(m, 2H, CH₂), 1.35-1.55 (m, 11 H, (CH₃)₃ & CH₂), 1.72-1.92 (m, 4H, CH₂), 2.05-2.22 (m, 2H, CH₂), 2.40 (d, 2H, J = 9.3 Hz,

CH₂), 3.05 (q, 2H, J = 6.6 Hz, CH₂), 3.20-3.28 (m, 1 H, NCH₂), 3.32-3.50 (m,

2H, NCH₂), 3.62-3.72(m₎ 1 H, NCH₂), 4.79 (bs, 1 H, NH), 4.97 (eld, 1 H₁ J = 8.7,

4.1 Hz, NCH), 5.07 (d, 1 H, J = 4.1 Hz, OCH), 5.40 (bs, 1 H, NH), 6.74 (d, 1 H, J

= 8.4 Hz, OH), 7.35 (d, 2H₁ J = 6.0 Hz, ArH), 8.56 (d, 2H, J = 6.0 Hz, ArH). ¹³C-NMR (CDCI₃, δ): : 24.0, 25.0, 26.1 , 28.4, 29.6, 35.9, 36.9, 40.3, 46.1 ,

46.9, 54.9, 72.9, 79.0, 121.3, 148.8, 149.6, 156.1 , 169.0, 173.2.

MS-ESI m/z (% rel. Int.): 449.1 ([MHf, 20).

HPLC: Method A, detection UV 254 nm, EBE 06102 RT = 4.1 min, peak area

99.9 %.

6-(5-((3af?,6S,6aS)-hexahvdro-2-oxo-1 H-thienor3.4-c/|Jmidazol-6- yl)pentanamido)-Λ/-ff1 R.2S)- & (1 S.2fl)-1 -hvdroxy-3-oxo-1 -(pyridin-4-yl)-3-

(pyrrolidin-1 -yl)propan-2-yl)hexanamides Compound 50.

To a solution of 5~(DL-f/7reo-1 -hydroxy-3-oxo-1 -(pyridin-4-yl)-3- (pyrrolidin-1 -yl)propan-2-ylcarbamoyl)penty!carbamate EBE 06102 (0.370 g,

0.824 mmol), in MeOH (1 ml) was added a solution of HCI (4.2 M) in EtOAc

(10 ml_). The reaction mixture was stirred for 2 h at RT and the volatiles were evaporated to yield a crude brown oil EBE 06104 (0.221 g, 63 % crude yield) that was used without purification in the next step. To a suspension of EBE 06104 (0.221 g, 0.522 mmol) in CH₂CI₂ (5 ml_) was added triethylamine (0.217 mL, 1.57 mmol) and the reaction mixture was stirred for 10 min and cooled in an ice bath with continuous stirring. A solution of biotin (0.14 g, 0.574 rnmol) and BOP (0.309 g, 0.574 mmoi) was pre-prepared in CH₂CI₂ (1 mL) and added dropwise for 5 min. The mixture was stirred for 2 h at 0⁰C and 16 h at RT. The reaction mixture was evaporated to dryness, partitioned between NaH₂PO₄ and π-Butanoi. The n-butanol phase was washed with saturated Na₂CO₃ and evaporated to dryness. The desired product was isolated using column chromatography (EtOAc:MeOH:NH₄OH = 70:28:2) to give Compound 50 (diastereoisomeric mixture in ratio 1 :1 , 0.160 g, 53 % yield) as a white solid.

Compound 50

MW: 574.74; Yield: 53 %; White Solid; Mp (⁰C): 64.3. R_f : 0.2 (EtOAc:MeOH:NH₄OH = 70:28:2).

¹H-NMR (CDCi₃, δ): : 1.17-1.32 (m, 2H), 1.40-1.60 (m, 4H)₁ 1.60-1.90 (m, 6H), 1 ,90-2.10 (m, 4H), 2.15-2.30 (m, 4H), 2.74 (d, 1 H₁ J = 12.6 Hz), 2.91 (dd, J = 4.8 Hz, 12.8 Hz)₅ 2.95-3.10 (m, 1 H), 3.10-3.45 ( m, 4H), 3.60-3.72 (m, 1 H), 4.34 (dd, 1 H J - 4.4 Hz J = 7.5 Hz), 4.50-4.58 (m, 1 H), 4.85-4.95 (m, 1 H), 5.02-5.08 (m, 1 H), 6.12 (s, 1 H), 6.50-6.15 (m, 1 H), 6.68 (s, 1 H), 7.36 (m, 2H), 7.67 (q, 1 H, J = 8.12 Hz), 8.55 (d, 2H₁ J = 5.8 Hz). MS-ESI m/z {% re!. Int.): 575.3 ([MH]⁺, 70).

HPLC: Method A, detection UV 254 nm, Compound 50 RT = 3.61 min, peak area 97.2 %.

Preparation of Compound 49. fraπs-(4,5-Dihvdro-5-(2-methoxypyridin-3-yl)oxazoi-4-yl)(pyrrolidin-1 - vDmethanone BAL 01014.

BAL 01014 was prepared in accordance with method D using 2- methoxy-3-pyridinecarboxaldehyde (0.64 ml, 5.43 mmol), KOH (0.305 mg, 5.43 mmol) in methanol (5 mL) and 2-isocyano-1 -(pyrrolidin-1 -yl)ethanone BLE 04098 (0.75 g, 5.43 mmol). After work-up frans-(4,5-dihydro-5-(2- methoxypyridin-3-yl)oxazol-4-yl)(pyrro!idin-1 -yl)methanone BAL 01014 was obtained (0.74 mg, 50 % yield) as a white solid.

BAL 01014

MW: 275.30; Yield: 50 %; White Solid; Mp (⁰C): 110.1.

Rf. 0.25 (EtOAc).

¹H NMR (CDCI₃, δ): : 1.82-2.10 (m, 4H, 2xCH₂), 3.40-3.62 (m, 3 H, CH₂N),

3.80-3.90 (m, 3 H, CH₂N), 3.93 (s, 3H, OMe), 4.61 <dd, 1 H, J = 7 Hz₁ J = 2 Hz, CH-N), 6.14 (d, 1 H, J= 7 Hz, CH-O)₁ 6.90 (dd, 1 H₁ J = 7.3 Hz, J = 5 Hz, ArH),

7.02 (d, 1 H, J= 2 Hz, OCH=N)₁ 7.60 (dd, 1 H, J = 7.3 Hz, J = 1.7 Hz, ArH),

8.13 (dd, 1 H, J = 5 Hz, J = 1.8 Hz, ArH).

¹³C-NMR (CDCI₃, 5): : 24,3, 26.1 , 46.3, 46.6, 53.5, 73.5, 78.1 , 116.8, 122.2,

135.2, 146.5, 155.3, 160.5 and 167.4. MS-ESI m/z (% rel. int.): 276.1 ([MH]⁺, 42).

HPLC: Method A, detection UV 254 nm, BAL 01014 RT = 3.63 min, peak area

97.2 %. 3-(DL-f/7reo-2-Amino-1 -hvdroxy-3-oxo-3-pyrrolidin-1 -yl-propyl)-1 H-pyridin-2- one hydrochloride Compound 49. fra/?s-(4,5-Dihydro-5-{2-methoxypyridin-3-yl)oxazol-4-yl)(pyrroIidin-1- yl)methanone BAL 01014 {0.684 g, 2.487 mmol) was dissolved in methanol (10 ml_). A solution of hydrochloric acid (37 %, 0.6 ml) was added via syringe at RT. The mixture was stirred for 22 h at reflux. The residue was concentrated, triturated with EtOAc and filtered to obtain a yellow pale solid 3- (DL~tf?reo-2 -amino- 1 -hydroxy-3-oxo-3-pyrrolidin-1 -yl-propyl)-1 H-pyridin-2-one hydrochloride Compound 49 (136 mg, 19.0 % yield).

W HCi

Compound 49

MW: 287.74; Yield: 19.0 %; Yellow Pale Solid; Mp (⁰C): 180.

¹H NMR (CD₃OD, δ): : 1.82-2.09 (m, 4H₁ CH₂), 3.35-3.80 (m, 4 H, CH₂N)₁ 4.63

(S₁ 1 H, CH-N), 5.17 (s, 1 H₁ CH-O)₁ 6.56 (t, 1 H, ArH) ), 7.5 (d, 1 H, J = 6.1 Hz, ArH), 7.86 (d, 1 H₁ J= 6.5 Hz, ArH).

¹³C-NMR (CD₃OD₁ δ): : 24.2, 26.0, 46.6, 46.6, 75.8, 79.7, 127.3, 127.5, 127.9,

129.4, 130.0, 132.3, 133.2, 148.1 , 148.4, 155.3, 166.2.

MS-ESl m/z (% rel. Int.): 252.1 ([MHf, 18), 163.0 (100).

HPLC: Method A, detection UV 254nm, Compound 49 RT = 1.13 min, peak area 84.0 %.

Preparation of Compound 300.

(±)-f/ireo-2-Phthalimide-3-hvdroxy-3-(pyridin-4-yl)-1 -(pyrrolidin-1 -yl)propan-1 - one hydrochloride Compound 300. (±)-#7reo-2-Amino-3-hydroxy-3-(pyridin-4-yl)-1 -(pyrrolidin-1 -yl)propan-1 - one dihydrochloride Compound 22 (0.51 g, 1.64 mmol) was treated by 20 mL of a 1 N aqueous solution of K₂CO₃ and extracted (5 x 40 mL) with a mixture CH₂CI₂:MeOH - 90:10. The solution was dried over MgSO₄, filtered and evaporated to obtain the free base of Compound 22 (0.323 g, 82.5 % yield) as a white solid. In a 10 ml_ round -bottom flask phtalic anhydride (0.203 mg, 1.373 mmol) was added to the free base of Compound 22 (0.323 g, 1 ,37 mmol) and the mixture was heated from 65 ⁰C to 145 ⁰C and stirred 5 mtn at 145 ⁰C. After cooling a yellow black gum was obtained as a crude product. This crude product was purified by coiumn chromatography (Siθ2, EtOAc:MeOH = 100:0 to 90:10). After evaporation of the solvents, a white solid (±)-threo-2- phthaltmide-3-hydroxy-3-(pyridin-4-yl)-1 -(pyrroiidin-1 -yl)propan-1 -one BLE 04156A was obtained as a white solid (0.15 g, 30 % yield). To {±)-threo-2- phthalimide-3-hydroxy-3-(pyridin~4-yi)-1 -(pyrroiidin-1 -yl)propan-1 -one BLE 04156A (0.135 g, 0.37 mmol) was added a solution 0.1 N of HC! in isopropanol (10 mL) and the mixture was evaporated to dryness at 28 ⁰C on a rotavapor then to high vacuum pump. (±)-ffrreo2-Phthalimide-3-hydroxy-3- (pyridin-4-yl)-1 -(pyrro!idin-1 -yl)propan-1 -one hydrochloride Compound 300 (0,147 g, 24.5 % yield) was obtained as a white solid.

W

Compound 300

MW: 401.84; Yield: 24.5 %; White Solid; Mp (⁰C): 201.8

¹H-NMR (CD₃OD₁): 1.60-1.90 (m, 4H, 2xCH₂), 2.95-3.09 (m, 1 H₁ CH₂N), 3.30-

3.47 (m, 3H, CH₂N)₅ 5.30 (d, 1 H, J = 7.9 Hz, CH), 5.82 (d, 1 H, J= 7.9 Hz, CH), 7.80 (m, 4H, ArH), 8.25 (d, 2H, J = 5.4 Hz, ArH), 8.81 (d, 2H₁ J= 5.2 Hz,

ArH).

¹³C-NMR (CD₃OD₁): 24.7, 27.1 , 47.7, 47.8, 58.0, 70.6, 124.8 (2xC), 127.5

(2xC), 132.6 (2xC), 136.1 (2xC), 142.5 (2xC), 164.9, 166.5, 168.8.

MS-ESI m/z (% rel. Int.): 366.0 ([MH]⁺, 22), 219.1 (100), 148.0 (47). HPLC: Method A, detection UV 254 nm, RT = 3.88 min, peak area 98.7 %.

Preparation of Compound 301. fe/f-butyl 5-((±)'threo-~\ -hvdroxy-3-oxo-1 -(pyridin-4-vi)-3-(pyrroliciin-1 - yi)propan~2-ylcarbamoyl)pentylcarbamate Compound 237.

To a solution of Λ/-Boc-aminohexanoic acid (342 mg, 1.48 mmol) in THF (10 mL) was added Λ/-methylmorpholine (163 IL, 1.48 mmoi). The solution was stirred for 5 min, cooled at -15 ⁰C and treated dropwise with isobutyl chloroformate (211 GL, 1 ,48 mmol). This solution was added via a stainless steal cannula to a solution of (±)-fftreo-2-amino-3-hydroxy-3-(pyridin- 4-yl)-1 -(pyrroSidin-1 -yl)propan-1 -one dihydrochloride Compound 22 (500 mg, 1.48 mmol) and /V-methyl-morpholine (489 mg, 1.47 mmol) in THF (10 mL) at -15 ⁰C. The reaction mixture was kept for 0.5 h at -15 ⁰C followed by 2 h at 25 ⁰C with continuous stirring. After evaporation of the solvent, the residue was partitioned between EtOAc and H₂O, washed with NaH₂PO₄, saturated aqueous NaHCOs₁ dried over sodium sulfate and purified by column chromatography (SiO₂) with a gradient of 0 % to 10 % [v/v] MeOH in EtOAc to give terf-butyl 5-((±)-tf?reo-1 -hydroxy-3-oxo-1 -(pyridin-4-yl)-3-(pyrrolidin-1 - y!)propan-2-ylcarbamoyl)pentylcarbamate Compound 237 (455 mg, 69 % yield) as a white solid.

Compound 237

MW: 448.6; Yield: 69 %; White Solid. R_/: 0.20 (EtOAc:MeOH = 90: 10).

¹H-NMR (CD₃OD, δ): 1.05-1.15 (m, 2H, CH₂), 1.35-1.55 (m, 13H, 2xCH₂ + C(CHg)₃), 1.75-1.95 (m, 4H, 2xCH₂), 2.00-2.20 (m, 2H, O=CCH₂), 3.05 (q, 2H₁ J = 6.7 Hz₅ N-CH₂), 3.20-3.35 (m, 1 H, N-CH)₁ 3.38-3.50 (m, 2H, N-CH₂), 3.65- 3.75 (m, 1 H, N-CH)₁ 4.72 (bs, 1 H, NH), 4.98 (dd, 1 H, J = 8.8 Hz, J = 3.6 Hz), 5.08 (d, 1 H, J = 3.3 Hz, OCH), 5.23 (bs, 1 H, OH), 6.50 (d, I H₁ J = 8.7 Hz, NH), 7.35 (d, 2H, J = 6.0 Hz₅ ArH), 8.58 (d, 2H, J = 4.6 Hz, J = 1.4 Hz, ArH). MS-ESI m/z (% rel. Int.): 449.2 ([MH] ⁺, 30), 349.2 (100).

HPLC: Method A, detection at 254 nm, RT = 4.03 min, peak area 99.9 %.

6-Amino-/V-((±)^/7reo-1-hvdroxy-3-oxo-1 -(pyridin-4-yl)-3-(pyrrolidin-1- y!)propan-2-yl)hexanamide Compound 238.

To a solution of terf-butyl 5-((±)-f/?reσ-1 -hydroxy-3-oxo-1 -(pyridin-4-yl)- 3-(pyrrolidin-1-y!)propan-2-y!carbamoyl)penty!carbamate Compound 237 (81 mg, 0.181 mmol) in CH₂CI₂ (8 mL) was added TFA (2 ml_) at 0 ⁰C and stirred for 2 h at 0 ⁰C. All the volatiles were evaporated to give a residue that was treated with a suspension of Amberlite-400 (OH^") in MeOH. After filtration, the filtrate was evaporated and the product was isolated by column chromatography (SiO₂) with CH₂Cl₂:MeOH:NH₄OH = 10:5:0.4 to afford 6- amino-Λ/-((±)-tf7røo-1 -hydroxy-3-oxo-1 -(pyridin-4-yl)-3-(pyrrolidin-1 -yl)propan- 2-yl)hexanamide Compound 238 (40 mg, 64 % yield) as a white solid.

Compound 238

MW: 448.6; Yield: 64 %; White Solid; Mp (X): 134.4

Rf, 0.30 (CH₂CI₂:MeOH:NH₄OH ^ 10:5:0.4).

¹H NMR (CDCI₃, δ): 1.12-1.30 (m, 2H₁ CH₂), 1.30-1.50(m, 2H, CH₂), 1.50-1.65 (m, 2H₁ CH₂), 1.65-1.95 (m, 4H₁ CH₂), 2.10-2.30 (m, 2H, CH₂), 2.55-2.70 (t,

2H, J = 6.9 Hz₁ CH₂), 3.10-3.20 (m, 2H, CH₂), 3.28-3.50 (m, 2H, CH₂), 3.60-

3.70 (m, 1 H, CH), 4.95 (dd, 1 H, J = 5.1 Hz, J= 8.4Hz, 0-CH), 5.02 (d, 1 H, J =

5.0 Hz, OH), 7.11 Hz (d, J= 8.48 Hz, 1 H, ArH), 7.35 (dd, 2H, J= 4.4 Hz, J =

1.5 Hz, ArH), 8.55 (dd, J = 1.5 Hz, J = 4.6 Hz₁ 2H, ArH). 1³C NMR (CDCI₃, δ): 24.0, 25.1 , 25.8, 25.9, 32.5, 35.8, 41.7, 46.0, 46.9, 55.6,

72.6, 121.3 (2xC), 149.2, 149.5 (2xC), 168.9, 173.7. (±)-f/?reo-{3-f3-(3-{5-f1 -(Hvdroxy-pyridin-4-yl-methvi)-2-oxo-2-pyrroiidin-1 -vi- ethvicarbamoyli-pentylcarbamovD-propylcarbamovD-propyicarbamovn- propyD-carbamic acid terf-butyl ester TTA 08156.

Boc-GABA-GABA-GABA-OH (354 mg, 0.95 mmol) was stirred in CHCI₃ (40 ml) with Et₃N (0.3 mL, 2.1 mrnol) and HOBT (145 mg, 1.05 mmol) at 4 ⁰C for 5 min under nitrogen, EDC (205 mg, 1 ,05 mrnol) was added and the mixture was stirred for 15 min at 4 ⁰C. 6-Amino-/V-((±)-f/?reo-1 -hydroxy-3-oxo- 1-(pyridin-4-yl)-3-(pyrrolidin-1-yl)propan-2-yl)hexanamide (333 mg, 0.95 mmol) in CHCb (20 ml_) was added dropwise and the mixture was stirred at 4 ⁰C for 2 h and 15 h at RT under nitrogen. Brine (30 ml_) was added and the product was extracted by CH₂Cb (200 ml_). The organic layer was washed with a solution of 2 N NaOH, brine and dried over MgSO₄. After filtration the solution was evaporated and dried to give a crude yellow oil (420 mg). After purification by column chromatography (SiO2, CH₂C^MeOH = 85:15) (±)- threo-{3-[3-(3-{5-[1 -(hydroxy-pyridin-4-yl-methyI)-2-oxo-2-pyrro!idin-1 -yl- ethylcarbamoyI]-pentylcarbamoyl}-propylcarbamoyS)-propylcarbamoyi]- propylj-carbamic acid terf-butyl ester TTA 08156 (260 mg, 39 % yield) was obtained as a pale yeliow oil.

TTA 08156

MW: 703.87; Yield: 39 %; Pale Yellow Oil.

R_f: 0.20 (CH₂CI₂:MeOH= 9:1 ),

¹H-NMR (CDCl₃, δ): 1.17-1.25 (m, 2H, CH₂), 1.40-1.56 (m, 13H, 2xCH_2>

3xCH₃) 1.73-1.85 (m, 10H, 5xCH₂), 2.13-2.29 (m, 8H, 4xCH₂CO), 2.40 (s, 1 H₁ OH), 3.09-3.67 (m, 12H, 6xCH₂-N), 4.91 (dd, 1 H, J = 4,9 Hz, J = 8.5 Hz, CH-

N), 5.05 (d, 1 H, J = 5.1 Hz, CH-O), 5.15 (t, 1 H, J = 5.8 Hz, NH)₁ 7.01-7.04 (m, 1 H₁ NH), 7.14 (t, 1 H, J = 5.6 Hz₁ NH), 7.33 (t, 1H, J = 5.6 Hz₁ NH), 7.37 (d,

2H₁ J = 6.0 Hz, ArH), 8.55 (d, 2H, J = 6.0 Hz, ArH).

¹³C-NMR (CD₃OD, δ): 24.0, 24.9, 25.6, 25.8, 26.1 , 26.5, 28.4 (3xC), 29.0, 33.5, 33.7, 35.8, 38.6, 38.8, 39.1 , 39.6, 46.1 , 46.8, 55.6, 72.7, 79.5, 121.5 (x2), 149.1 , 149.5 (x2), 156.7, 168.8, 173.1 , 173.3, 173.4, 173.5. MS-ESI m/z (% re!. Int.): 704.3 ([MH]⁺, 100).

HPLC: Method A, detection UV 254 nm, TTA 08156 RT = 3.90 min, peak area 99.0 %.

6-(5-((3aR6S,6aS)-hexahvdro-2-oxo-1 H-thienor3,4-cliimidazol-6-vπ- pentanoylamino)-butyrylamino-butyrylamSno-butyrylamino-/V-((1 f?,25)-& (1 S,2f?)-1 -hydroxy-3-oxo-1 -(pyridin-4-vO-3-(pyrrolidin-1 -yl)propan-2- vDhexanamides Compound 301.

(±)-f/7reo-{3-[3-(3-{5-[1 -(Hydroxy-pyridin-4-yl-methyi)-2-oxo-2-pyrrolidin- 1 -yi-ethylcarbamoyl]-pentylcarbamoyl}-propyicarbamoyl)-propylcarbamoyl]- propyij-carbamic acid tert-butyl ester TTA 08156 (260 mg, 0.37 mmol) was stirred in MeOH (5 mL) with HC! 37% (0.3 ml, 3.70 mmol) for 15 min at 40 ⁰C. MeOH was evaporated and the residue was dried in vacuum. Amberlite IRA- 400 (C!^') (6 mL, 8.4 mmo!) was washed successively with water (2x10 mL), NaOH 0.5 N (3x20 mL), water (2x10 mL) and MeOH (3x10 mL). The previously obtained residue and washed Amberlite were stirred in MeOH (30 mL) for 5 min at RT. After filtration, the MeOH was evaporated to give amine in the free base form (210 mg, 94 % yield). Biotin (95 mg, 0.38 mmole) was dissolved in a mixture CHCI₃/DMF (40 mL/10 mL) and Et₃N (0.11 mL, 0.77 mmol), HOBT (53 mg, 0.38 mmol) and EDC (75 mg, 0.38 mmol) were added and the solution stirred at RT for 2 h under nitrogen. The previously obtained amine (210 mg, 0.35 mmol) in CHCb (10 mL) was added dropwise and the mixture was stirred for 24 h at RT under nitrogen. Brine (40 mL), 2 N NaOH (10 mL), CHCI₃ (50 mL) were added and the product was extracted by 3 additional extractions of a mixture CHCI3/DMF (50 mL/10 mL). The combined organic layer was washed with brine, dried over MgSO₄, filtered, evaporated to give crude yeilow oil (160 mg, 52 % yield). The crude oil was purified by column chromatography (SiO₂, CH₂CI₂:MeOH:NH₃ = 95:5:0.1 to 85:15:0.3) to obtain after evaporation 6-(5-{(3aR,6S,6aS)-hexahydro-2-oxo-1 H-thieno[3,4- <^imida2ol-6-yi)-pentanoylamino)-butyrylamino-butyrylamino-butyrylamino-/V- ((1 R,2S)- & {1 S,2fl)-1 -hyclroxy-3-oxo-1-(pyriclin-4-yl)-3-(pyrrolidin-1 -yl)propan- 2-yl)hexanamides (diastereoisomeric mixture ratio 1 :1 ) as a pale yellow oil (45 mg, 15 % yield).

Compound 301 MW: 830.05; Yield: 15 %; Pale Yellow Oil. R/: 0.30 (CH₂CI₂:MeOH:NH₃ = 85:15:0.3). 1H-NMR (CD₃OD₁ 5): 1.26-1.82 (m, 22H, HxCH₂), 2,18-2.25 (m, 1OH,

5xCH₂CO), 2.70 (d, 1 H, J = 12.7 Hz, CH₂-S), 2.92 (dd, 1 H, J = 4.8 Hz₁ J = 12.7 Hz, CH₂S), 3.06-3.80 (m, 13H, BxCH₂-N, CH-S), 4.29 (dd, 1 H, J = 4.4 Hz₁ J = 7.8 Hz, CH-N), 4,48 (dd, 1 H₁ J = 4.9 Hz, J = 7.8 Hz, CH-N), 4.82 (d, 1 H, J = 6.4 Hz₁ CH-N), 5.01 (d, 1 H, J = 6.4 Hz, CH-O), 7.49 (d, 2H, J = 5.5 Hz, ArH), 8.5 (d, 2H₁ J= 4.6 Hz₅ ArH).

¹³C-NMR (CD₃OD, δ): 25.0, 26.5, 26.8, (2xC), 26.9 (2x0), 27.5, 29.5, 29.8, 30.1 , 34.3, 34.4 (2xC), 36.4, 36.8, 39.8, 39.9, 40.1 , 41.1 , 47.2, 47.3, 57.1 , 58.3, 61.6, 63.4, 73.1 , 74.2, 123.5 (2x0), 149.9 (2x0), 152.8, 166.1 , 170.0, , 175.3, 175.4 (2x0), 176.0, 176.1.

MS-ESl m/z (% rel. Int.): 830.2. ([MH]⁺, 85), 219.1 (100), HPLC: Method A, detection UV 254 nm, RT = 3.70 min, peak area 99.8 %.

Preparation of compound 302. (±)-^reo-2-Amino-3-hvdroxy-3-(pipehdin-4-yl)-1 -(pyrrolidin-1 -yl)propan-1 -one dihydrochloride Compound 302.

(±)-ffrrøo-2-Amino-3-hydroxy-3-(pyridin-4-yl)-1 -(pyrrolidin-1 -yl)propan-1 - one dihydrochloride Compound 22 (500 mg, 1 ,61 mmol) was stirred in AcOH (10 imL) with PtO₂ hydrate typical (Pt content 79-84%, 100 rng) under hydrogen at atmospheric pressure for 24 h at RT, After filtration on Celite^® 545, the filtrate was evaporated and the residue was dried under vacuum to give a beige solid (450 mg, 88.2 % yield). The crude product was stirred in MeOH (50 mL) with Amberlite (Cl-) IRA-400 (9 mL, 12.7 mmol washed beforehand by NaOH 0.5 N then water and MeOH) at RT for 15 min. The mixture was filtered off, the filtrate was evaporated and the free base form was purified by column chromatography (SiO₂, CH₂Cl₂:MeOH:20 % NH₃ in H₂O = 70:30:8) to give (±H/7reo-2-amino~3-hydroxy-3-(piperidin-4-yI)-1 - (pyrrolidin-1-yl)propan-1-one TTA 08144A (226 mg, 58% yield). HCI Treatment in MeOH gave (±)-f/7reo~2-amino-3-hydroxy-3-(piperidin-4-yl)-1 - (pyrrolidin-1 -yl)propan-1 -one dihydrochloride Compound 302 (190 mg, 28 % yield) as a white solid.

2.HCI

(±)-threo Compound 302

MW: 314.25; Yield: 28.0 %; White Solid; Mp (⁰C): 197.5

R_f: 0.20 (CH₂Cl₂:MeOH:20 % NH₃ in H₂O = 70:30:8, free base).

¹H-NMR (CD₃OD₃ δ): 1.57-2.00 (m, 9H, 4xCH₂ & CH), 2.94-3.08 (m, 2H₁ CH₂-

N)₅ 3.46-3.77 (m, 7H₅ 3xCH₂-N, CH-N), 4.33 (s, 1 H, CH-O). 1³C-NMR (CD₃OD, δ): 22.5, 23.4, 24.1 , 24,7, 35.2, 42.2, 42.5, 45.4, 45.5,

52.0, 69.8, 164.6.

MS-ESI m/z (% rel. Int.): 242.2 ([MH]⁺, 45), 129.1 (100).

HPLC: Method A, detection UV 214 nm, RT = 0.70 min, peak area 98.0 %. Preparation of Compound 70

Method D (in CH₂CI₂):

To a stirred solution of DL-tf?reo-2-amino-3-hydroxy-3-(pyridin-4-yl)-1- (pyrrolidin-1 -yl)propan-1 -one dihydrochloride Compound 22 (0.15 g, 0.49 mmol) in 10 mL of CH₂Cb at +4 ⁰C were added triethylamine (200 μl, 1.45 mmo!) and very slowly acid chloride in 3 mL of CH₂CI₂. The mixture was stirred overnight at RT under nitrogen and then partitioned between CH₂Cl₂ and 1 N aqueous sodium carbonate. The organic layer was evaporated and the obtained residue purified by column chromatography on silica

(EtOAc:MeOH = 95:5). The hydrochloride salt was obtained in MeOH at 0 ⁰C with 0.3 M HCI in diethylether to give after evaporation of solvents and drying the acylated compound.

Benzyl DL~f/7røo-3-hydroxy-1 -oxo-3-(pyridin-4-yl)-1 -(pyrroiidin-1 -yl)propan~2- ylcarbamate hydrochloride Compound 58.

The compound was prepared according to method D with benzyl chloroformate (91 mg, 0.53 mmol). After work-up benzyl DL-fftreo-3-hydroxy- 1 -oxo-3-(pyridin-4-yl)-1 -(pyrroltdin-1 -yl)propan-2-yicarbamate hydrochloride Compound 58 was obtained as a white solid (90 mg, 46 % yield).

Compound 58

MW: 405.9; Yield: 46.0 %; White SoNd; Mp (⁰C): 185.3. FV 0.38 (MeOH:EtOAc = 10:90) free base. 1H-NMR (CD₃OD₁ δ): : 1.87-2.03 (m, 4H₁ 2xCH2), 3.40-3.48 (m, 2H₁ CH₂N)₁ 3.56-3.62 (m, 2H, CH₂N), 4.85-5.04 (m, 3H₁ CH₂O, CHO), 5.39 (d, 1 H, J = 2.8 Hz, NH), 7.26-7.36 (m, 5H₁ ArH), 8.12 (d, 2H₅ J = 6.0 Hz, ArH), 8.69 (d, 2H, J = 6.0 Hz, ArH). ¹³C-NMR (CD₃OD, δ): : 25.0, 27.0_» 47.5, 48.0, 58.8, 67.9, 72.7, 126.6 (2xC),

129.1 , 129.2, 129.5, 138.1 , 141.9 (2xC), 158.1 , 164.4, 169.2. MS-ESI m/z (% rel. Int.): 370.1 ([MH]⁺, 15), 219.0 (100). HPLC: Method A, detection UV 254 nm, Compound 58 RT = 4.10 rriin, peak area 99.8 %.

frans-3-Methyl-5-pyridin-4-yl-4-fpyrrolidinβ-1-carbonyl)-oxazoiidin-2-one hydrochloride Compound 70.

To a stirred solution of DL-tf?reo-3-hydroxy-1 -oxo-3-(pyridin-4-yi)-1 - {pyrrolidin-1 -yl)propan-2-ylcarbamate Compound 58 free base (0.10 g, 0.27 mmol) in a mixture of DMSO:DMF (2 ml_:0.2 ml_) at 6 ⁰C were added slowly tert-BuOK (38 mg, 0.33 mmol) and dimethyl sulfate (26 μl_, 0.27 mmol). The mixture was stirred 15 h at RT under nitrogen and partitioned between ice water (5 ml_), 1 M Na2CO₃ (2 ml_) and ethyl acetate (100 mL). The organic phase was washed with brine (20 mL) and dried over MgSO₄. After removing ethyl acetate by evaporation, the crude product was dried to give the crude free base as an oil. The hydrochloride salt was obtained in MeOH at 0 ⁰C using a 0.3 M solution of HCI in diethylether. After precipitation in diethylether, frar)s-3-methyl-5-pyridin-4-yl-4-(pyrrolidine-1 -carbonyl)-oxazoIidin-2-one hydrochloride was obtained as a pale yellow solid (80 mg, 95 % yield). A further crystallization in EtOAc:MeOH (10:1) gave Compound 70 as a white solid (16 mg, 20 % yield).

Compound 70

MW; 311.76; Yield: 20 %; White Solid; Mp (⁰C): 168.6.

R^: 0.15 (EtOAc:MeOH = 95:5), free base.

¹H-NMR (CD₃OD, δ): 1.90-2.10 (m, 4H, 2xCH₂), 2.84 (s, 3H, CH₃), 3.47-3.70 (m, 4H, CH₂N)₁ 4.82 (m, 1 H, CH), 5.89 (m, 1 H₁ CH), 8.17 (m, 2H, ArH)₁ 8.97

(m, 2H₁ ArH).

¹³C-NMR (CD₃OD₅ δ): 24.9, 27.1 , 30.2, 48.1 , 64.9, 76.3, 125.6 (2xC), 143.8

(2xC), 159.1 , 160.1 , 167.3. MS-ESI m/z (% rel. Int.): 276.1 ([MHf, 25), 177.1 (100).

HPLC: Method A, detection UV 254 nm, Compound 70 RT = 2.00 min, peak area 97.0 %.

Claims

WHAT IS CLAIMED IS:

1 , The use of a compound in the manufacture of a medicament for treating a condition selected from the group consisting of neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain, wherein the compound has the following structure:

or a pharmaceutically acceptable salt of said compound. 2. The use of a compound in the manufacture of a medicament for treating a condition selected from the group consisting of neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain, wherein the compound has a structure selected from the group consisting of structures (i) and (ii):

(I) (») wherein R₄ is H, alkyl of 1 to 6 carbons or CO-R₅ wherein R₅ is alkyl of 1 to 6 carbons, or a pharmaceutically acceptable salt of said compound. 3. The use according to claim 2, wherein R₄ is H.

4. The use of a compound in the manufacture of a medicament for treating a condition selected from the group consisting of neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain, wherein the compound has the following structure:

or any other pharmaceutically acceptable salt of said compound.

5. The use of a compound in the manufacture of a medicament for treating a condition selected from the group consisting of neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain, wherein the compound has the following structure:

(±) HCl wherein R₄ is H, alkyl of 1 to 6 carbons or CO-R₅ wherein R₅ is alkyl of 1 to 6 carbons or any other pharmaceutically acceptable salt of said compound. 6. The use according to claim 5, wherein R₄ is H. 7. The use of a compound in the manufacture of a medicament for treating a condition selected from the group consisting of neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain, wherein the compound has the following structure:

(±) wherein R₄ is H, alkyl of 1 to 6 carbons or CO-R₅ wherein R₅ is alkyl of 1 to 6 carbons or a pharmaceutically acceptable salt of said compound.

8. The use according to Claim 7, wherein R₄ is H.

9. The use of a compound in the manufacture of a medicament for treating a condition selected from the group consisting of neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain, wherein the compound is has a structure selected from the group consisting of structures (i) and (ii):

(0 (») wherein R₄ is H, alkyl of 1 to 6 carbons or CO-R₅ wherein R₅ is alkyl of 1 to 6 carbons or a pharmaceutically acceptable salt of said compound.

10. The use according to Claim 9, wherein R₄ is H.

11. The use of a compound in the manufacture of a medicament for treating a condition selected from the group consisting of neuropathic pain, inflammatory pain, headache pain, somatic pain, visceral pain, and referred pain, wherein the compound has the following structure:

2.HCI

(±)- threo wherein R₄ is H₅ alkyl of 1 to 6 carbons or CO-R₅ wherein R₅ is alkyl of 1 to 6 carbons or any other pharmaceutically acceptable salt of said compound. 12. The use according to Claim 11 , wherein R₄ is H.