The invention had the object of finding novel compounds having valuable properties, in particular those which can be used for the preparation of medicaments. 
The present invention relates to compounds and to the use of compounds in which the inhibition, regulation and/or modulation of signal transduction by kinases, in particular tyrosine kinases and/or serine/threonine kinases, plays a role, furthermore to pharmaceutical compositions which comprise these compounds, and to the use of the compounds for the treatment of kinase-induced diseases. 
In particular, the present invention relates to compounds and to the use of compounds in which the inhibition, regulation and/or modulation of signal transduction by Met kinase plays a role. 
One of the principal mechanisms by which cellular regulation is effected is through the transduction of extracellular signals across the membrane that in turn modulate biochemical pathways within the cell.  Protein phosphorylation represents one course by which intracellular signals are propagated from molecule to molecule resulting finally in a cellular response.  These signal transduction cascades are highly regulated and often overlap, as is evident from the existence of many protein kinases as well as phosphatases.  Phosphorylation of proteins occurs predominantly at serine, threonine or tyrosine residues, and protein kinases have therefore been classified by their specificity of phosphorylation site, i.e. serine/threonine kinases and tyrosine kinases.  Since phosphorylation is such a ubiquitous process within cells and since cellular phenotypes are largely influenced by the activity of these pathways, it is currently believed that a number of disease states and/or diseases are attributable to either aberrant activation or functional mutations in the molecular components of kinase cascades.  Consequently, considerable attention has been devoted to the characterisation of these proteins and compounds that are able to modulate their activity (for a review see: Weinstein-Oppenheimer et al.  Pharma. &  Therap.,  2000, 88, 229-279). 
The role of the receptor tyrosine kinase Met in human oncogenesis and the possibility of inhibition of HGF (hepatocyte growth factor) dependent Met activation are described by S. Berthou et al.  in Oncogene, Vol.  23, No.  31, pages 5387-5393 (2004).  The inhibitor SU11274 described therein, a pyrrole-indoline compound, is potentially suitable for combating cancer.  Another Met kinase inhibitor for cancer therapy is described by J. G. Christensen et al.  in Cancer Res.  2003, 63(21), 7345-55. 
A further tyrosine kinase inhibitor for combating cancer is reported by H. Hov et al.  in Clinical Cancer Research Vol.  10, 6686-6694 (2004).  The compound PHA-665752, an indole derivative, is directed against the HGF receptor c-Met.  It is furthermore reported therein that HGF and Met make a considerable contribution to the malignant process of various forms of cancer, such as, for example, multiple myeloma. 
The synthesis of small compounds which specifically inhibit, regulate and/or modulate signal transduction by tyrosine kinases and/or serineIthreonine kinases, in particular Met kinase, is therefore desirable and an aim of the present invention. 
It has been found that the compounds according to the invention and salts thereof have very valuable pharmacological properties while being well tolerated. 
The present invention specifically relates to compounds of the formula I which inhibit, regulate and/or modulate signal transduction by Met kinase, to compositions which comprise these compounds, and to processes for the use thereof for the treatment of Met kinase-induced diseases and complaints, such as angiogenesis, cancer, tumour formation, growth and propagation, arteriosclerosis, ocular diseases, such as age-induced macular degeneration, choroidal neovascularisation and diabetic retinopathy, inflammatory diseases, arthritis, thrombosis, fibrosis, glomerulonephritis, neurodegeneration, psoriasis, restenosis, wound healing, transplant rejection, metabolic diseases and diseases of the immune system, also autoimmune diseases, cirrhosis, diabetes and diseases of the blood vessels, also instability and permeability and the like in mammals. 
Solid tumours, in particular fast-growing tumours, can be treated with Met kinase inhibitors.  These solid tumours include monocytic leukaemia, brain, urogenital, lymphatic system, stomach, laryngeal and lung carcinoma, including lung adenocarcinoma and small-cell lung carcinoma. 
The present invention is directed to processes for the regulation, modulation or inhibition of Met kinase for the prevention and/or treatment of diseases in connection with unregulated or disturbed Met kinase activity.  In particular, the compounds of the formula I can also be employed in the treatment of certain forms of cancer.  The compounds of the formula I can furthermore be used to provide additive or synergistic effects in certain existing cancer chemotherapies, and/or can be used to restore the efficacy of certain existing cancer chemotherapies and radiotherapies. 
The compounds of the formula I can furthermore be used for the isolation and investigation of the activity or expression of Met kinase.  In addition, they are particularly suitable for use in diagnostic methods for diseases in connection with unregulated or disturbed Met kinase activity. 
It can be shown that the compounds according to the invention have an antiproliferative action in vivo in a xenotransplant tumour model.  The compounds according to the invention are administered to a patient having a hyperproliferative disease, for example to inhibit tumour growth, to reduce inflammation associated with a lymphoproliferative disease, to inhibit transplant rejection or neurological damage due to tissue repair, etc.  The present compounds are suitable for prophylactic or therapeutic purposes.  As used herein, the term “treatment” is used to refer to both prevention of diseases and treatment of pre-existing conditions.  The prevention of proliferation is achieved by administration of the compounds according to the invention prior to the development of overt disease, for example to prevent the growth of tumours, prevent metastatic growth, diminish restenosis associated with cardiovascular surgery, etc.  Alternatively, the compounds are used for the treatment of ongoing diseases by stabilising or improving the clinical symptoms of the patient. 
The host or patient can belong to any mammalian species, for example a primate species, particularly humans; rodents, including mice, rats and hamsters; rabbits; horses, cows, dogs, cats, etc.  Animal models are of interest for experimental investigations, providing a model for treatment of human disease. 
The susceptibility of a particular cell to treatment with the compounds according to the invention can be determined by in vitro tests.  Typically, a culture of the cell is combined with a compound according to the invention at various concentrations for a period of time which is sufficient to allow the active agents to induce cell death or to inhibit migration, usually between about one hour and one week.  In vitro testing can be carried out using cultivated cells from a biopsy sample.  The viable cells remaining after the treatment are then counted. 
The dose varies depending on the specific compound used, the specific disease, the patient status, etc.  A therapeutic dose is typically sufficient considerably to reduce the undesired cell population in the target tissue while the viability of the patient is maintained.  The treatment is generally continued until a considerable reduction has occurred, for example an at least about 50% reduction in the cell burden, and may be continued until essentially no more undesired cells are detected in the body. 
For identification of a signal transduction pathway and for detection of interactions between various signal transduction pathways, various scientists have developed suitable models or model systems, for example cell culture models (for example Khwaja et al.,  EMBO, 1997, 16, 2783-93) and models of transgenic animals (for example White et al.,  Oncogene, 2001, 20, 7064-7072).  For the determination of certain stages in the signal transduction cascade, interacting compounds can be utilised in order to modulate the signal (for example Stephens et al.,  Biochemical J., 2000, 351, 95-105).  The compounds according to the invention can also be used as reagents for testing kinase-dependent signal transduction pathways in animals and/or cell culture models or in the clinical diseases mentioned in this application. 
Measurement of the kinase activity is a technique which is well known to the person skilled in the art.  Generic test systems for the determination of the kinase activity using substrates, for example histone (for example Alessi et al.,  FEBS Lett.  1996, 399, 3, pages 333-338) or the basic myelin protein, are described in the literature (for example Campos-González, R. and Glenney, Jr., J. R. 1992, J. Biol.  Chem.  267, page 14535). 
For the identification of kinase inhibitors, various assay systems are available.  In scintillation proximity assay (Sorg et al.,  J. of Biomolecular Screening, 2002, 7, 11-19) and flashplate assay, the radioactive phosphorylation of a protein or peptide as substrate with γATP is measured.  In the presence of an inhibitory compound, a decreased radioactive signal, or none at all, is detectable.  Furthermore, homogeneous time-resolved fluorescence resonance energy transfer (HTR-FRET) and fluorescence polarisation (FP) technologies are suitable as assay methods (Sills et al.,  J. of Biomolecular Screening, 2002, 191-214). 
Other non-radioactive ELISA assay methods use specific phospho-antibodies (phospho-ABs).  The phospho-AB binds only the phosphorylated substrate.  This binding can be detected by chemiluminescence using a second peroxidase-conjugated anti-sheep antibody (Ross et al.,  2002, Biochem.  J.). 
There are many diseases associated with deregulation of cellular proliferation and cell death (apoptosis).  The conditions of interest include, but are not limited to, the following.  The compounds according to the invention are suitable for the treatment of various conditions where there is proliferation and/or migration of smooth muscle cells and/or inflammatory cells into the intimal layer of a vessel, resulting in restricted blood flow through that vessel, for example in the case of neointimal occlusive lesions.  Occlusive graft vascular diseases of interest include atherosclerosis, coronary vascular disease after grafting, vein graft stenosis, peri-anastomatic prosthetic restenosis, restenosis after angioplasty or stent placement, and the like.