Morpholin-acetamide derivatives for the treatment of inflammatory diseases

This patent application is a divisional of U.S. patent application Ser. No. 11/284,544, filed Nov. 22, 2005, now allowed, which was a continuation of U.S. patent application Ser. No. 10/381,767 filed Aug. 15, 2003, now U.S. Pat. No. 7,101,882, which was a 371 Application of PCT/GB01/04345 filed Sep. 28, 2001, which claims priority to GB 0023902.0 filed on Sep. 29, 2000, and GB 0107644.7 filed Mar. 27, 2001 both in the United Kingdom.

This invention relates to novel chemical compounds, processes for their preparation, pharmaceutical formulations containing them and their use in therapy.

Inflammation is a primary response to tissue injury or microbial invasion and is characterised by leukocyte adhesion to the endothelium, diapedesis and activation within the tissue. Leukocyte activation can result in the generation of toxic oxygen species (such as superoxide anion), and the release of granule products (such as peroxidases and proteases). Circulating leukocytes include neutrophils, eosinophils, basophils, monocytes and lymphocytes. Different forms of inflammation involve different types of infiltrating leukocytes, the particular profile being regulated by the profile of adhesion molecule, cytokine and chemotactic factor expression within the tissue.

The primary function of leukocytes is to defend the host from invading organisms, such as bacteria and parasites. Once a tissue is injured or infected, a series of events occurs which causes the local recruitment of leukocytes from the circulation into the affected tissue. Leukocyte recruitment is controlled to allow for the orderly destruction and phagocytosis of foreign or dead cells, followed by tissue repair and resolution of the inflammatory infiltrate. However in chronic inflammatory states, recruitment is often inappropriate, resolution is not adequately controlled and the inflammatory reaction causes tissue destruction. There is increasing evidence that the bronchial inflammation which is characteristic of asthma represents a specialised form of cell-mediated immunity, in which cytokine products, such as IL-4 and IL-5 released by Th2 T lymphocytes, orchestrate the accumulation and activation of granulocytes, in particular eosinophils and to a lesser extent basophils. Through the release of cytotoxic basic proteins, pro-inflammatory mediators and oxygen radicals, eosinophils generate mucosal damage and initiate mechanisms that underlie bronchial hyperreactivity. Therefore, blocking the recruitment and activation of Th2 cells and eosinophils is likely to have anti-inflammatory properties in asthma. In addition, eosinophils have been implicated in other disease types such as rhinitis, eczema, irritable bowel syndrome and parasitic infections.

Chemokines are a large family of small proteins which are involved in trafficking and recruitment of leukocytes (for review see Luster, New Eng. J. Med., 338, 436-445 (1998)). They are released by a wide variety of cells and act to attract and activate various cell types, including eosinophils, basophils, neutrophils, macrophages, T and B lymphocytes. There are two major families of chemokines, CXC-(α) and CC-(β) chemokines, classified according to the spacing of two conserved cysteine residues near to the amino terminus of the chemokine proteins. Chemokines bind to specific cell surface receptors belonging to the family of G-protein-coupled seven transmembrane-domain proteins (for review see Luster, 1998). Activation of chemokine receptors results in, amongst other responses, an increase in intracellular calcium, changes in cell shape, increased expression of cellular adhesion molecules, degranulation and promotion of cell migration (chemotaxis).

To date, 9 members of CC chemokine receptors have been identified (CCR-1 to 9). Of particular importance to the current invention is the CC-chemokine receptor-3 (CCR-3), which is predominantly expressed on eosinophils, and also on basophils, mast cells and Th2 cells (Luster, 1998). Chemokines that act at CCR-3, such as RANTES, MCP-3 and MCP-4, are known to recruit and activate eosinophils. Of particular interest are eotaxin and eotaxin-2, which specifically bind to CCR-3. The localization and function of CCR-3 chemokines indicate that they play a central role in the development of allergic diseases such as asthma. Thus, CCR-3 is specifically expressed on all the major cell types involved in inflammatory allergic responses. Chemokines that act at CCR-3 are generated in response to inflammatory stimuli and act to recruit these cell types to sites of inflammation, where they cause their activation (e.g. Griffiths et al., J. Exp. Med., 179, 881-887 (1994), Lloyd et al., J. Exp. Med., 191, 265-273 (2000)). In addition, anti-CCR-3 monoclonal antibodies completely inhibit eotaxin interaction with eosinophils (Heath, H. et al., (1997) J. Clin. Invest. 99 (2), 178-184), while an antibody for the CCR-3 specific chemokine, eotaxin, reduced both bronchial hyperreactivity and lung eosinophilia in an animal model of asthma (Gonzalo et al., J. Exp. Med., 188, 157-167 (1998). Thus, many lines of evidence indicate that antagonists at the CCR-3 receptor are very likely to be of therapeutic use for the treatment of a range of inflammatory conditions.

A number of patent applications relating to CCR-3 antagonists have published before the filing date of this application. For example, EP 0 903 349, FR 2785902, WO 00/29377, WO 00/31032 and WO 00/31033 (all in the name of F. Hoffmann-La-Roche AG) disclose pyrrolidine, piperidine and piperazine based compounds which are all distinct from the compounds of the present invention.

WO 99/55324, WO 00/04003, WO 00/27800, WO 00/27835, WO 00/27843, WO 00/41685 and WO 00/53172 (all in the name of SmithKline Beecham Corporation) describe a variety of compounds as CCR-3 antagonists which are unrelated to the compounds of the present invention.

WO 00/34278 (Toray Industries Inc.) describe fused triazolo derived compounds as chemokine inhibitors.

WO 00/35449, WO 00/35451, WO 00/35452, WO 00/35453, WO 00/35454, WO 00/35876 and WO 00/35877 (Du Pont Pharmaceuticals Company) describe N-ureidoalkyl and heterocyclic piperidine compounds as CCR-3 antagonists.

WO 00/51607 and WO 00/51608 (Merck & Co. Inc.) describe a series of pyrrolidine modulators of chemokine receptor activity.

WO 00/53600 (Banyu Pharmaceutical Co. Ltd.) describes piperidine derivatives as inhibitors at the CCR-3 receptor.

WO 01/14333 (AstraZeneca UK Ltd.) describe substituted piperidine compounds as modulators of chemokine receptor activity.

EP 0 760 362 (Nisshin Flour Milling Co. Ltd.) describes morpholinoalkylurea derivatives which are disclosed as being useful in the treatment of digestive tract diseases.

JP 04208267A (Mitsui Seiyaku Kogyo KK) also describes morpholinoalkylurea derivatives which are disclosed as being useful as antiemetics, for activating peristalsis and ameliorating gastrointestinal function.

EP 243959A (Dainippon Pharm KK) describes O-substituted N-morpholinyl-alkyl-benzamide derivatives useful as gastrointestinal motility enhancing agents.

JO 1117-882-A (Dainippon Pharm KK) describes heterocyclic morpholinyl alkylenyl carboxamide derivatives useful as anti-emetics.

WO 00/71518 (Sepracor Inc.) describes morpholinoalkylamide derivatives useful in the treatment of pain, drug addiction and tinnitus.

WO 97/48695 and WO 97/48397 (Klinge Pharma Gmbh) describe pyridyl alkane, alkene and/or alkyne acid amide compounds useful as cytostatic, immunomodulatory or immuno-suppressive agents.

Kato et al., (1992) Chem. Pharm. Bull. 40(3), 652-660, Kato et al., (1991) J. Med. Chem. 34(2), 616-624 and Kato et al., (1990) J. Med. Chem. 33(5), 1406-1413 describe a series of morpholine benzamides which are disclosed as being selective and potent gastrokinetic agents.

We have now found a novel group of CCR-3 antagonist compounds which block migration/chemotaxis of eosinophils, consequently effecting anti-inflammatory properties. These compounds are therefore of potential therapeutic benefit, especially in providing protection from eosinophil, basophil and Th2-cell-induced tissue damage in diseases where such cell types are implicated, particularly allergic diseases, including but not limited to bronchial asthma, allergic rhinitis and atopic dermatitis.