WO2012050517A1

WO2012050517A1 - Imidazole substituted pyrimidine having a high gsk3 inhibiting potency as well as pan-kinase selectivity

Info

Publication number: WO2012050517A1
Application number: PCT/SE2011/051223
Authority: WO
Inventors: Anders Lindgren
Original assignee: Astrazeneca Ab
Priority date: 2010-10-14
Filing date: 2011-10-13
Publication date: 2012-04-19

Abstract

The present invention relates to a new compound of formula (I) as a free base or a pharmaceutically acceptable salt thereof, in an essentially pure and isolated form, a pharmaceutical composition containing a compound of formula (I), to the use of said active compound in therapy, to the use for the treatment of conditions associated with glycogen synthase kinase-3 related disorders, such as Alzheimer's disease, as well as for the method of treatment of said disorders, comprising administering to a mammal, including human in need of such treatment, a therapeutically effective amount of said compound.

Description

Imidazole substituted pyrimidine having a high GSK3 inhibiting potency as well as pan-kinase selectivity.

FIELD OF THE INVENTION

The present invention relates to a new compound of formula (I) or a pharmaceutically acceptable salt thereof, in a pure and isolated form, to pharmaceutical compositions containing said compound and to the use of said compound in therapy as well as a new intermediate compound.

BACKGROUND OF THE INVENTION

Glycogen synthase kinase 3 (GSK3) is a serine / threonine protein kinase composed of two isoforms (a and β), which are encoded by distinct genes but are highly homologous within the catalytic domain. GSK3 is highly expressed in the central and peripheral nervous system. GSK3 phosphorylates several substrates including tau, β-catenin, glycogen synthase, pyruvate dehydrogenase and elongation initiation factor 2b (eIF2b). Insulin and growth factors activate protein kinase B, which phosphorylates GSK3 on serine 9 residue and inactivates it (Kannoji et al, Expert Opin. Ther. Targets 2008, 12, 1443-1455).

Alzheimer's Disease (AD) dementias, and taupathies.

AD is characterized by cognitive decline, cholinergic dysfunction and neuronal death, neurofibrillary tangles and senile plaques consisting of amyloid-β deposits. The sequence of these events in AD is unclear, but is believed to be related. Glycogen synthase kinase 3β (GSK3P), or Tau phosphorylating kinase, selectively phosphorylates the microtubule associated protein Tau in neurons at sites that are hyperphosphorylated in AD brains. Hyperphosphorylated tau has lower affinity for microtubules and accumulates as paired helical filaments, which are the main components that constitute neurofibrillary tangles and neuropil threads in AD brains. This results in depolymerization of microtubules, which leads to death of axons and neuritic dystrophy. (Hooper et al, J. Neurochem. 2008, 104(6), 1433-1439). Neurofibrillary tangles are consistently found in diseases such as AD, amyotrophic lateral sclerosis, parkinsonism-dementia of Gaum, corticobasal degeneration, dementia pugilistica and head trauma, Down's syndrome, postencephalitic parkinsonism, progressive supranuclear palsy, Niemann-Pick's Disease and Pick's Disease. Addition of amyloid-β to primary hippocampal cultures results in hyperphosphorylation of tau and a paired helical filaments-like state via induction of GSK3P activity, followed by disruption of axonal transport and neuronal death (Imahori and Uchida, J. Biochem. 1997, 121,179- 188), while GSK3a has been postulated to regulate the production of amyloid-β itself (Phiel et al. Nature, 2003, 423, 435-439). GSK3P preferentially labels neurofibrillary tangles and has been shown to be active in pre-tangle neurons in AD brains. GSK3 protein levels are also increased by 50% in brain tissue from AD patients. Furthermore, GSK3P phosphorylates pyruvate dehydrogenase, a key enzyme in the glycolytic pathway and prevents the conversion of pyruvate to acetyl-Co-A (Hoshi et al, PNAS 1996, 93: 2719- 2723). Acetyl-Co-A is critical for the synthesis of acetylcholine, a neurotransmitter with cognitive functions. Accumulation of amyloid-β is an early event in AD. GSK transgenic mice show increased levels of amyloid-β in brain. Also, PDAPP(APpV717F) transgenic mice fed with lithium show decreased amyloid-β levels in hippocampus and decreased amyloid plaque area (Su et al, Biochemistry 2004, 43, 6899-6908). Likewise, GSK3 inhibition has been shown to decrease amyloid deposition and plaque-associated astrocytic proliferation, lower tau phosporylation, protect against neuronal cell death, and prevent memory deficincies in a double APP^sw-tau^vrw mouse model (Sereno et al, Neurobiology of Disease, 2009, 35, 359-367). Furthermore, GSK3 has been implicated in synaptic plasticity and memory function (Peineau et al, Neuron 2007, 53, 703-717; Kimura et al, PloS ONE 2008, 3, e3540), known to be impaired in AD patients.

In summary, GSK3 inhibition may have beneficial effects in progression as well as the cognitive deficits associated with Alzheimer's disease and other above-referred to diseases.

Acute Neurodegenerative Diseases

Growth factor mediated activation of the PI3K /Akt pathway has been shown to play a key role in neuronal survival. The activation of this pathway results in GSK3 inhibition. GSK3P activity is increased in cellular and animal models of neurodegeneration such as cerebral ischemia or after growth factor deprivation (Bhat et al., PNAS 2000, 97, 11074- 11079). Several compounds with known GSK3P inhibitory effect has been shown to reduce infarct volume in ischemic stroke model rats. A recent publication (Koh et al, BBRC 2008, 371, 894-899) demonstrated that GSK-3 inhibition decreased the total infarction volume and improved neurobehavioral functions by reducing ischemic cell death, inflammation, brain edema, and glucose levels, in a focal cerebral ischemia model. Thus GSK3P inhibitors could be useful in attenuating the course of acute

neurodegenerative diseases.

Bipolar Disorders (BD)

Bipolar Disorders are characterized by manic episodes and depressive episodes. Lithium has been used to treat BD based on its mood stabilizing effects. The disadvantage of lithium is the narrow therapeutic window and the danger of overdosing that can lead to lithium intoxication. The discovery that lithium inhibits GSK3 at therapeutic

concentrations has raised the possibility that this enzyme represents a key target of lithium's action in the brain (Stambolic et al., Curr. Biol. 1996, 68, 1664-1668; Klein and Melton; PNAS 1996, 93, 8455-8459; Gould et al, Neuropsychopharmacology, 2005, 30, 1223-1237). GSK3 inhibitor has been shown to reduce immobilization time in forced swim test, a model to assess on depressive behavior (O'Brien et al., J Neurosci 2004, 24, 6791- 6798). GSK3 has been associated with a polymorphism found in bipolar II disorder (Szczepankiewicz et al, Neuropsychobiology. 2006, 53, 51-56). Inhibition of GSK3P may therefore be of therapeutic relevance in the treatment of BD as well as in AD patients that have affective disorders.

Schizophrenia

Accumulating evidence implicates abnormal activity of GSK3 in mood disorders and schizophrenia. GSK3 is involved in signal transduction cascades of multiple cellular processes, particularly during neural development. (Kozlovsky et al, Am. J. Psychiatry, 2000, 157, 831-833) found that GSK3P levels were 41% lower in the schizophrenic patients than in comparison subjects. This study indicates that schizophrenia involves neurodevelopmental pathology and that abnormal GSK3 regulation could play a role in schizophrenia. Furthermore, reduced β-catenin levels have been reported in patients exhibiting schizophrenia (Cotter et al, Neuroreport 1998, 9, 1379-1383). Atypical antipsychotic such as olanzapine, clozapine, quetiapine and ziprasidone, inhibits GSK3 by increasing ser9 phosphorylation suggesting that antipsychotics may exert their beneficial effects via GSK3 inhibition (Li X. et al., Int. J.of Neuropsychopharmacol, 2007, 10, 7-19). Diabetes

Type 2 diabetes mellitus is characterized by insulin resistance and β-cell failure. Insulin stimulates glycogen synthesis in skeletal muscles via dephosphorylation and thus activation of glycogen synthase and therefore increased glucose disposal. Under resting conditions, GSK3 phosphorylates and inactivates glycogen synthase via

dephosphorylation. GSK3 is also over-expressed in muscles from Type II diabetic patients (Nikoulina et al, Diabetes 2000 Feb; 49(2), 263-71). Inhibition of GSK3 increases the activity of glycogen synthase thereby decreasing glucose levels by its conversion to glycogen. In animal models of diabetes, GSK3 inhibitors lowered plasma glucose levels up to 50 % (Cline et al, Diabetes, 2002, 51 : 2903-2910; Ring et al, Diabetes 2003, 52, 588- 595). Moreover, results obtained by using haploinsufficient GSK3P mice on a diabetic background indicated that reduced GSK3P activity also protects from β-cell failure (Tanabe et al, PloS Biology, 2008, 6(2), 307-318 GSK3 inhibition may therefore be of therapeutic relevance in the treatment of Type I and Type II diabetes to enhance insulin sensitivity and reduce β-cell failure and therefore also relevant therapy to reduce diabetic complications like diabetic neuropathy.

Alopecia

GSK3 phosphorylates and degrades β-catenin. β-Catenin is an effector of the pathway for keratonin synthesis. β-Catenin stabilization may be lead to increase hair development. Mice expressing a stabilized β-catenin by mutation of sites phosphorylated by GSK3 undergo a process resembling de novo hair morphogenesis (Gat et al, Cell, 1998, 95, 605- 14)). The new follicles formed sebaceous glands and dermal papilla, normally established only in embryogenesis. Thus, GSK3 inhibition may offer treatment for a variety of indications that lead to alopecia.

Inflammatory disease

The discovery that GSK3 inhibitors provide anti-inflammatory effects has raised the possibility of using GSK3 inhibitors for therapeutic intervention in inflammatory diseases. (Martin et al, Nat. Immunol. 2005, 6, 777-784; Jope et al, Neurochem. Res. 2007, 32, 577-595). Inflammation is a common feature of a broad range of conditions including Alzheimer's Disease and mood disorders. A recent publication (Kitazawa et al, Ann.

Neurol. 2008, 64, 15-24) indicates that GSK3P may play a role in inclusion body myositis (IBM).

Cancer

GSK3 is over expressed in ovarian, breast and prostate cancer cells and recent data suggests that GSK3P may have a role in contributing to cell proliferation and survival pathways in several solid tumor types. GSK3 plays an important role in several signal transduction systems which influence cell proliferation and survival such as WNT, PI3 Kinase and NFkB. GSK3 deficient MEFs indicate a crucial role in cell survival mediated NFkB pathway (Ougolkov AV and BiUadeau DD., Future Oncol. 2006 Feb, 2(1), 91-100.). Thus, GSK3 inhibitors may inhibit growth and survival of solid tumors, including pancreatic, colon and prostate cancer. Growth control of multiple myeloma cells has been demonstrated through inhibition of GSK3 (Zhou et al 2008 Leuk. Lymphoma, 48, 1946- 1953). A recent publication (Wang et al, Nature 2008, 455, 1205-1209) demonstrated that GSK3 inhibition was efficacious in a murine model of MLL leukemia. Thus, GSK3 inhibitors may also inhibit growth and survival of hematological tumors, including multiple myeloma.

Glaucoma

There is a possibility of using GSK3 inhibitors for therapeutic treatment of glaucoma. Elevated intraocular pressure (IOP) is the most significant risk factor for the development of glaucoma, and current glaucoma therapy focuses on reducing IOP, either by reducing aqueous humor production or by facilitating aqueous humor outflow. Recently published expression profiling experiments (Wang et al, J. Clin. Invest. 2008, 118, 1056-1064) have revealed that the soluble WNT antagonist sFRP-1 is overexpressed in ocular cells from glaucoma patients relative to control subjects. A functional link between WNT signaling pathways and glaucoma was provided through experiments in which addition of recombinant sFRP-1 to ex vzvo-cultured human eye anterior segments resulted in a decrease in aqueous humor outflow; in addition, in vivo experiments in mice demonstrated that over expression of sFRP-1 in ocular tissues resulted in increases in intraocular pressure, an effect that was antagonized by a small-molecule GSK3 inhibitor. Taken together, the results reported by Wang et al. (2008) suggest that activation of WNT signaling via inhibition of GSK3 may represent a novel therapeutic approach for lowering intraocular pressure in glaucoma.

Pain

A recent publication (WO2008/057933) indicates that GSK3beta inhibitors may play a role in the treatment of pain, particularly neuropatic pain, by modulation of glycogenolysis or glycolysis pathways.

Bone-related disorders and conditions

Genetic studies have established a link between bone mass in humans and Wnt signaling (Gong et al, Am. J. Hum. Genet 1996, 59, 146-51, Little et al, N. Engl. J. Med., 2002, 347, 943-4). Genetic and pharmacological manipulations of Wnt signaling in mice have since then confirmed the central role of this pathway in regulating bone formation. Of the pathways activated by Wnts, it is signaling through the canonical (i.e., Wnt/ -catenin) pathway that increases bone mass through a number of mechanisms including renewal of stem cells, stimulation of pre-osteoblast replication, induction of osteoblastogenesis, and inhibition of osteoblast and osteocyte apoptosis. Therefore, enhancing Wnt pathway signaling with GSK3 inhibitors alone or in combination with a suitable device could be used for the treatment of bone -related disorders, or other conditions which involve a need for new and increased bone formation for example osteoperosis (genetic, iatrogenic or generated through aging/hormone imbalance), fracture repair as a result of injury or surgery, chronic-inflammatory diseases that result in bone loss such as for example rheumatoid arthritis, cancers that lead to bone lesions, such as for example cancers of the breast, prostate and lung, multiple myeloma, osteosarcoma, Ewing's sarcoma,

chondrosarcoma, chordoma, malignant fibrous histiocytoma of the bone, fibrosarcoma of the bone, cancer induced bone disease, iatrogenic bone disease, benign bone disease and Paget's disease.

Regenerative medicine

Stem-cell expansion and differentiation are required for self-renewal and maintenance of tissue homeostasis and repair. The β-catenin-mediated canonical Wnt signaling pathway has been shown to be involved in controlling stem differentiation (Pinto et al., Exp. Cell Res., 2005, 306, 357-63). A physiological Wnt response may be essential for the regeration of damaged tissues. GSK3 inhibitors by enhancing Wnt signaling may be useful to modulate stem cell function to enhance tissue generation ex vivo or in vivo in diseases associated with tissue damage or reduced tissue repair.

WO2007/040440, published 12.04.2007, relates to imidazole and phenyl substituted pyrimidine compounds that are stated to have a selective inhibiting effect at GSK3 as well as a bioavailability.

DETAILED DESCRIPTION OF THE INVENTION

The object of the present invention is to provide a new compound having a high GSK3 inhibiting potency as well having pan-kinase selectivity, as demonstrated through CDK2 selectivity, and cell permeability in CaCo-2 cells.

A compound of the formula (I)

or a pharmaceutically acceptable salt thereof, in a pure and isolated form.

The compound of the present invention is 2-(2,5-difluoro-4-(5-fluoro-4-(2 -methyl- 1- (tetrahydro-2H-pyran-4-yl)-lH-imidazol-5-yl)pyrimidin-2-ylamino)benzylamino)ethanol in the form of a free base or a pharmaceutically acceptable salt thereof, in a pure and isolated form. One aspect of the invention is 2-(2,5-difluoro-4-(5-fluoro-4-(2 -methyl- 1 -(tetrahydro-2H- pyran-4-yl)-lH-imidazol-5-yl)pyrimidin-2-ylamino)benzylamino)ethanol, in the form of a free base in a pure and isolated form.

The compound of formula (I), 2-(2, 5-difluoro-4-(5-fluoro-4-(2 -methyl- l-(tetrahydro-2H- pyran-4-yl)-lH-imidazol-5-yl)pyrimidin-2-ylamino)benzylamino)ethanol, has been identified as a metabolite from N-(2,5-difluoro-4-(morpholinomethyl)phenyl)-5-fluoro-4- (2-methyl-l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5-yl)pyrimidin-2-amine in rat, dog, minipig, hamster and human in in-vitro and in-vivo studies.

Thus, a further object of the present invention is the compound of formula (I), 2-(2,5- difluoro-4-(5 -fluoro-4-(2 -methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 - yl)pyrimidin-2-ylamino)benzylamino)ethanol, when prepared ex-vivo.

In consequence, the compound 2-(2,5-difluoro-4-(5-fluoro-4-(2 -methyl- 1 -(tetrahydro-2H- pyran-4-yl)-l H-imidazol-5 -yl)pyrimidin-2-ylamino)benzylamino)ethanol may be useful for the prevention and/or treatment of conditions associated with glycogen synthase kinase-3 (GSK3) in mammals, including man.

Another aspect of the invention is a pharmaceutical composition comprising a compound of formula I) or a pharmaceutically acceptable salt thereof,

in association with a pharmaceutically acceptable adjuvant, diluents or carrier.

A further aspect of the invention is a method of using a compound N-(2,5-difluoro-4- (morpholinomethyl)phenyl)-5 -fluoro-4-(2 -methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H- imidazol-5-yl)pyrimidin-2-amine or a pharmaceutically acceptable salt thereof to administer a metabolite thereof, 2-(2,5-difluoro-4-(5-fluoro-4-(2-methyl-l-(tetrahydro pyran-4-yl)-lH-imidazol-5-yl)pyrimidin-2-ylamino)benzylamino)ethanol.

The present invention also provides a compound 2-(4-bromo-2,5- difluorobenzylamino)ethanol, which is useful as an intermediate in the process of preparing a compound according to formula (I).

The definition of compound of formula (I) also includes solvates or solvates of salts thereof.

The present invention further includes isotopically-labeled compounds of the invention. An "isotopically" or "radio-labeled" compound is a compound of the invention where one or more atoms are replaced or substituted with an atom having an atomic mass or mass number different from the atomic mass or mass number typically found in nature (i.e., naturally occurring). Suitable stable or radioactive nuclides that may be incorporated in compounds of the present invention include but are not limited to ²H (also written as D for deuterium), ³H (also written as T for tritium), ⁿC, ¹³C, ¹⁴C, ¹³N, ¹⁵N, ¹⁵0, ¹⁷0, ¹⁸0, ¹⁸F, ³⁵S, ³⁶C1, ⁸²Br, ⁷⁵Br, ⁷⁶Br, ⁷⁷Br, ¹²³I, ¹²⁴I, ¹²⁵I and ¹³ T. The radionuclide that is incorporated in the instant radio-labeled compounds will depend on the specific application of that radiolabeled compound. For example, for in vitro receptor labeling and competition assays,

3 14 82 125 131 35

compounds that incorporate H, C, Br, I , I, S or will generally be most useful. For radio-imaging applications ^UC, ¹⁸F, ¹²⁵I, ¹²³I, ¹²⁴I, ¹³¹I, ⁷⁵Br, ⁷⁶Br or ⁷⁷Br will generally be most useful. It is understood that a "radio-labeled compound" is a compound that has incorporated at least one radionuclide. In some embodiments the radionuclide is selected from the group consisting of ³H, ¹⁴C, ¹²⁵1, ³⁵S and ⁸²Br.

The present invention also relates to the use of a compound of formula (I) as hereinbefore defined.

Salts for use in pharmaceutical formulations will be pharmaceutically acceptable salts, but other salts may be useful in the production of the compounds of formula (I).

PHARMACEUTICAL FORMULATIONS

According to one aspect of the present invention there is provided a pharmaceutical formulation comprising the compound of formula (I) or a pharmaceutically acceptable salt thereof, for use in the treatment of conditions associated with glycogen synthase kinase-3.

The formulation used in accordance with the present invention may be in a form suitable for oral administration, for example as a tablet, pill, syrup, powder, granule or capsule, for parenteral injection (including intravenous, subcutaneous, intramuscular, intravascular or infusion) as a sterile solution, suspension or emulsion, for topical administration as an ointment, patch or cream, for rectal administration as a suppository and for local administration in a body cavity or in a bone cavity.

The formulation may be in a form suitable for oral administration, for example as a tablet, for parenteral injection as a sterile solution or suspension. In general the above formulation may be prepared in a conventional manner using pharmaceutically carriers or diluents.

A formulation of the invention can be in a unit dosage form such as a tablet or an injectable solution. The tablet may additionally comprise a disintegrant and/or may be coated (for example with an enteric coating or coated with a coating agent such as hydroxypropyl methylcellulose). Suitable daily doses of the compound of formula (I) or pharmaceutically acceptable salts thereof in the treatment of a mammal, including human, are approximately 0.01 to 250 mg/kg bodyweight at per oral administration and about 0.001 to 250 mg/kg bodyweight at parenteral administration. The typical daily dose of the active ingredients varies within a wide range and will depend on various factors such as the relevant indication, the route of administration, the age, weight and sex of the patient and may be determined by a physician.

The compound of formula (I) or a pharmaceutically acceptable salt thereof, may be used on its own but will usually be administered in the form of a pharmaceutical formulation in which the active ingredient is in association with pharmaceutically acceptable diluents, excipients or inert carrier. Dependent on the mode of administration, the pharmaceutical formulation may comprise from 0.05 to 99 %w (per cent by weight), for example from 0.10 to 50 %w, of active ingredient, all percentages by weight being based on total composition.

An example of a diluent or carrier may include one or more, but not limited to, of the following ingredients water, aqueous poly(ethylene glycol), magnesium carbonate, magnesium stearate, talc, a sugar (such as lactose), pectin, dextrin, starch, tragacanth, microcrystalline cellulose, methyl cellulose, sodium carboxymethyl cellulose or cocoa butter.

The invention further provides a process for the preparation of a pharmaceutical formulation of the invention which comprises mixing of the compound of formula (I) or a pharmaceutically acceptable salt thereof, a hereinbefore defined, with pharmaceutically acceptable diluents, excipients or inert carriers.

An example of a pharmaceutical formulations of the invention is an injectable solution comprising the compound of formula (I) or a pharmaceutically acceptable salt thereof, as hereinbefore defined, and sterile water, and, if necessary, either a base or an acid to bring the pH of the final formulation to a pH in the range of about 4 to 9, particularly about 5, and optionally a surfactant to aid dissolution. A suitable base is sodium hydroxide. A suitable acid is hydrochloric acid.

A suitable pharmaceutically acceptable salt of the compound of formula (I) useful in accordance to the invention is, for example, an acid-addition salt, which is sufficiently basic, for example an inorganic acid such as hydrochloric acid, hydrobromic acid or sulfuric acid, or an organic acid such as succinic acid, citric acid, fumaric acid, benzoic acid, cinnamic acid, methane sulfonic acid, l-hydroxy-2-naphtoic acid and 2-naphtalene sulfonic acid (for further example see Berge et al, J. Pharm. Sci. 1977, 66, 1-19, and/or Handbook of Pharmaceutical salts: Properties, Selection and Use by Stahl and

Wermuth(Wiley-VCH, 2002.)

It will be understood that certain compounds of the formula (I) may exist in solvated, for example hydrated, as well as unsolvated forms. It is to be understood that the present invention encompasses all such solvated forms that possess GSK3 inhibitory activity.

MEDICAL USES

It has been found that the compound of formula (I) defined in the present invention, are well suited for inhibiting glycogen synthase kinase-3 (GSK3). Accordingly, said compound of the present invention is expected to be useful in the prevention and/or treatment of conditions associated with glycogen synthase kinase-3 activity, i.e. the compounds may be used to produce an inhibitory effect of GSK3 in mammals, including human, in need of such prevention and/or treatment.

GSK3 is highly expressed in the central and peripheral nervous system and in other tissues. Thus, it is expected that the compound of the invention is well suited for the prevention and/or treatment of conditions associated with glycogen synthase kinase-3 in the central and peripheral nervous system. In particular, the compound of the invention is expected to be suitable for prevention and/or treatment of conditions associated with cognitive disorder(s) or indications with deficit(s) in cognition such as: dementia; incl. pre-senile dementia (early onset Alzheimer's Disease); senile dementia (dementia of the Alzheimer's type); Alzheimer's Disease (AD); Familial Alzheimer's disease; Early Alzheimer's disease; mild to moderate dementia of the Alzheimer's type; delay of disease progression of Alzheimer's Disease; neurodegeneration associated with Alzheimer's disease, Mild Cognitive Impairment (MCI); Amnestic Mild Cognitive Impairment (aMCI); Age- associated Memory Impairment (AAMI); Lewy body dementia; vascular dementia (VD); HIV-dementia; AIDS dementia complex; AIDS - Neurological Complications;

Frontotemporal dementia (FTD); Frontotemporal dementia Parkinson's Type (FTDP); dementia pugilistica; dementia due to infectious agents or metabolic disturbances;

dementia of degenerative origin; dementia - Multi-Infarct; memory loss; cognition in Parkinson's Disease; cognition in multiple sclerosis; cognition deficits associated with chemotherapy; Cognitive Deficit in Schizophrenia (CDS); Schizoaffective disorders including schizophrenia; Age-Related Cognitive Decline (ARCD); Cognitive Impairment No Dementia (CIND); Cognitive Deficit arising from stroke or brain ischemia; Congenital and/or development disorders; progressive supranuclear palsy (PSP); amyotrophic lateral sclerosis (ALS); corticobasal degeneration(CBD); traumatic brain injury (TBI);

postencephalatic parkinsonism; Pick's Disease; Niemann-Pick's Disease; Down's syndrome; Huntington's Disease; Creuztfeld-Jacob's disease; prion diseases; multiple sclerosis (MS); motor neuron diseases (MND); Parkinson's Disease (PD); β-amyloid angiopathy; cerebral amyloid angiopathy; Trinucleotide Repeat Disorders; Spinal Muscular Atrophy; Friedreich's Ataxia; Neuromyelitis Optica; Multiple System Atrophy;

Transmissible Spongiform Encephalopathies; Attention Deficit Disorder (ADD); Attention Deficit Hyperactivity Disorder (ADHD); Bipolar Disorder (BD) including acute mania, bipolar depression, bipolar maintenance; Major Depressive Disorders (MDD) including depression, major depression, mood stabilization, dysthymia; agnosia; aphasia; apraxia; apathy.

One embodiment of the invention relates to the prevention and/or treatment of Alzheimer's Disease, especially the use in the delay of the disease progression of Alzheimer's Disease.

Other embodiments of the invention relate to the prevention and/or treatment of disorders selected from the group consisting of attention deficit disorder (ADD), attention deficit hyperactivity disorder (ADHD) and affective disorders, wherein the affective disorders are Bipolar Disorder including acute mania, bipolar depression, bipolar maintenance, major depressive disorders (MDD) including depression, major depression, mood stabilization, schizoaffective disorders including schizophrenia, and dysthymia.

Other aspects of the compound of the invention is its use for treatment of Type I diabetes, Type II diabetes, diabetic neuropathy; pain incl. neuropathic pain, nociceptive pain, chronic pain, pain associated with cancer, pain associated with rheumatic disease; alopecia; glaucoma; inflammatory diseases; incl. inclusion body myositis (IBM); pemphigus vulgaris.

Another aspect of the compound of the invention is its use for treatment of benign or malignant tumours incl. non-solid tumours such as leukaemia including MLL leukemia; myeloma including multiple myeloma; or lymphoma; and solid tumours, for example bile duct, bone, bladder, brain/CNS, breast, colorectal, endometrial, gastric, head, neck, hepatic, lung particularly, non-small-cell lung, neuronal, oesophageal, ovarian, pancreatic, prostate, renal, skin, testicular, thyroid, uterine and vulval cancers.

Yet another aspect of the compound of the invention is its use for treatment of bone related effects of specific cancers for example breast, prostate, lung cancer, multiple myeloma, osteosarcoma, Ewing's sarcoma, chondrosarcoma, chordoma, malignant fibrous histiocytoma of bone, fibrosarcoma of bone, cancer induced bone disease and iatrogenic bone disease.

A further aspect of the compound of the invention is its use for treatment of osteoporosis (genetic, iatrogenic or generated through aging/hormone imbalance), fracture repair as a result of injury or surgery, chronic-inflammatory diseases that result in bone loss such as for example rheumatoid arthritis, cancers that lead to bone lesions, such as for example cancers of the breast, prostate and lung, multiple myeloma, osteosarcoma, Ewing's sarcoma, chondrosarcoma, chordoma, malignant fibrous histiocytoma of the bone, fibrosarcoma of the bone, cancer induced bone disease, iatrogenic bone disease, benign bone disease and Paget's disease, for promoting bone formation, increasing bone mineral density, reducing the rate of fracture and/or increasing the rate of fracture healing, increasing cancellous bone formation and/or new bone formation. The present invention relates also to the use of the compound of formula (I) as defined in the present invention in the manufacture of a medicament for the prevention and/or treatment of conditions associated with glycogen synthase kinase-3.

The invention also provides for a method of treatment and/or prevention of conditions associated with glycogen synthase kinase-3 comprising administering to a mammal, including human in need of such treatment and/or prevention a therapeutically effective amount of the compound of formula (I) as as defined in the present invention.

The dose required for the therapeutic or preventive treatment of a particular disease will necessarily be varied depending on the host treated, the route of administration and the severity of the illness being treated.

For veterinary use the amounts of different components, the dosage form and the dose of the medicament may vary and will depend on various factors such as, for example the individual requirement of the animal treated.

In the context of the present specification, the term "therapy" or "treatment" includes "prevention" unless there are specific indications to the contrary. The terms "therapeutic" and "therapeutically" should be construed accordingly.

In the context of the present specification, the term "disorder" also includes "condition" unless there are specific indications to the contrary.

Another aspect of the invention is wherein a compound of formula (I) or a

pharmaceutically acceptable salt thereof as defined herein, or a pharmaceutical composition or formulation comprising a combination comprising such a compound of formula (I) is administered, concurrently, simultaneously, sequentially, separately or adjunct with another pharmaceutically active compound or compounds selected from the following:

(i) antidepressants such as agomelatine, amitriptyline, amoxapine, bupropion, citalopram, clomipramine, desipramine, doxepin duloxetine, elzasonan, escitalopram, fluvoxamine, fluoxetine, gepirone, imipramine, ipsapirone, maprotiline, nortriptyline, nefazodone, paroxetine, phenelzine, protriptyline, ramelteon, reboxetine, robalzotan, sertraline, sibutramine, thionisoxetine, tranylcypromaine, trazodone, trimipramine, venlafaxine; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(ii) atypical antipsychotics including for example quetiapine; and pharmaceutically active isomer(s) and metabolite(s) thereof.

(iii) antipsychotics including for example amisulpride, aripiprazole, asenapine,

benzisoxidil, bifeprunox, carbamazepine, clozapine, chlorpromazine, debenzapine, divalproex, duloxetine, eszopiclone, haloperidol, iloperidone, lamotrigine, loxapine, mesoridazine, olanzapine, paliperidone, perlapine, perphenazine, phenothiazine, phenylbutylpiperidine, pimozide, prochlorperazine, risperidone, sertindole, sulpiride, suproclone, suriclone, thioridazine, trifluoperazine, trimetozine, valproate, valproic acid, zopiclone, zotepine, ziprasidone; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(iv) anxiolytics including for example alnespirone, azapirones,benzodiazepines, barbiturates such as adinazolam, alprazolam, balezepam, bentazepam, bromazepam, brotizolam, buspirone, clonazepam, clorazepate, chlordiazepoxide, cyprazepam, diazepam, diphenhydramine, estazolam, fenobam, flunitrazepam, flurazepam, fosazepam, lorazepam, lormetazepam, meprobamate, midazolam, nitrazepam, oxazepam, prazepam, quazepam, reclazepam, tracazolate, trepipam, temazepam, triazolam, uldazepam, zolazepam; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(v) anticonvulsants including for example carbamazepine, clonazepam, ethosuximide, felbamate, fosphenytoin, gabapentin, lacosamide, lamotrogine, levetiracetam,

oxcarbazepine, phenobarbital, phenytoin, pregabaline, rufinamide, topiramate, valproate, vigabatrine, zonisamide; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof. (vi) Alzheimer's therapies including for example donepezil, rivastigmine, galantamine, memantine; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(vii) Parkinson's therapies including for example levodopa, dopamine agonists such as apomorphine, bromocriptine, cabergoline, pramipexol, ropinirole, and rotigotine, MAO-B inhibitors such as selegeline and rasagiline, and other dopaminergics such as tolcapone and entacapone, A-2 inhibitors, dopamine reuptake inhibitors, NMDA antagonists, Nicotine agonists, and inhibitors of neuronal nitric oxide synthase; and equivalents and

pharmaceutically active isomer(s) and metabolite(s) thereof.

(viii) migraine therapies including for example almotriptan, amantadine, bromocriptine, butalbital, cabergoline, dichloralphenazone, dihydroergotamine, eletriptan, frovatriptan, lisuride, naratriptan, pergolide, pizotiphen, pramipexole, rizatriptan, ropinirole,

sumatriptan, zolmitriptan; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(ix) stroke therapies including for example thrombolytic therapy with eg activase and desmoteplase, abciximab, citicoline, clopidogrel, eptifibatide, minocycline; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(x) urinary incontinence therapies including for example darafenacin, falvoxate, oxybutynin, propiverine, robalzotan, solifenacin, tolterodine; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(xi) neuropathic pain therapies including lidocain, capsaicin, and anticonvulsants such as gabapentin, pregabalin, and antidepressants such as duloxetine, venlafaxine, amitriptyline, klomipramine; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(xii) nociceptive pain therapies including paracetamol, NSAIDS and coxibs, such as celecoxib, etoricoxib, lumiracoxib, valdecoxib, parecoxib, diclofenac, loxoprofen, naproxen, ketoprofen, ibuprofen, nabumeton, meloxicam, piroxicam and opioids such as morphine, oxycodone, buprenorfin, tramadol; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

(xiii) insomnia therapies including for example agomelatine, allobarbital, alonimid, amobarbital, benzoctamine, butabarbital, capuride, chloral, cloperidone, clorethate, dexclamol, ethchlorvynol, etomidate, glutethimide, halazepam, hydroxyzine,

mecloqualone, melatonin, mephobarbital, methaqualone, midaflur, nisobamate, pentobarbital, phenobarbital, propofol, ramelteon, roletamide, triclofos, secobarbital, zaleplon, Zolpidem; and equivalents and pharmaceutically active isomer(s) and

metabolite(s) thereof.

(xiv) mood stabilizers including for example carbamazepine, divalproex, gabapentin, lamotrigine, lithium, olanzapine, quetiapine, valproate, valproic acid, verapamil; and equivalents and pharmaceutically active isomer(s) and metabolite(s) thereof.

Such combination products employ the compound of this invention within the dosage range described herein and the other pharmaceutically active compound or compounds within approved dosage ranges and/or the dosage described in the publication references.

In one embodiment of the invention the combination comprises the group of compounds (a) and (b) as defined below:

(a) a first therapeutic agent, which is a GSK3 inhibitor and (b) a second therapeutic agent, which is an antipsychotic selected from:

(a) 2-(2,5-difluoro-4-(5-fluoro-4-(2 -methyl- l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5- yl)pyrimidin-2-ylamino)benzylamino)ethanol, in a pure and isolated form and (b) quetiapine.

(a) a first therapeutic agent, which is a GSK3 inhibitor and (b) a second therapeutic agent, which is an a7 -nicotinic agonist selected from:

(a) 2-(2, 5-difluoro-4-(5-fluoro-4-(2 -methyl- l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5- yl)pyrimidin-2-ylamino)benzylamino)ethanol, in a pure and isolated form and (b) (R)-5-(5- (morpholinomethyl)furan-3 -yl)-3H- Γ-azaspiro [furo [2,3 -b]pyridine-2,3 '- bicyclo[2.2.2]octane].

(a) 2-(2,5-difluoro-4-(5-fluoro-4-(2 -methyl- l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5- yl)pyrimidin-2-ylamino)benzylamino)ethanol, in a pure and isolated form and (b) ((-)- spiro[l-azabicyclo[2.2.2]octane-3,2'-(2',3'-dihydrofuro[2,3-B]pyridine)];

The combination may employ any alpha-7 agonist, including but not limited to those disclosed in US Patent Nos. 6,1 10,914 and 6,569,865; and pending US Application 2008-

0139600 (Al), WO96/06098, WO99/03859, WOOO/42044, WOOl/060821 , WO02/096912,

WO03/087103, WO2005/030777, WO2005/030778 and WO2007/133155.

(a) a first therapeutic agent, which is a GSK3 inhibitor and (b) a second therapeutic agent, which is a an α4β2 -neuronal nicotinic agonist selected from:

(a) 2-(2,5-difluoro-4-(5-fluoro-4-(2 -methyl- l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5- yl)pyrimidin-2-ylamino)benzylamino)ethanol, in a pure and isolated form and (b) (2S)- (4E)-N-methyl-5-[3-(5-isopropoxypyridin)yl]-4-penten-2-amine;

(a) 2-(2,5-difluoro-4-(5-fluoro-4-(2 -methyl- l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5- yl)pyrimidin-2-ylamino)benzylamino)ethanol, in a pure and isolated form and (b) 3-(5- chloro-2-furoyl)-3,7-diazabicyclo[3.3.0]octane. α4β2 -neuronal nicotinic agonist useful in the combination of the present invention are those described in US 6,603,01 1 , US 6,958,399 and WO/2008/057938, which are hereby incorporated by reference. Particular nicotinic agonists are compounds N-methyl-5-[3-(5- isopropoxypyridin)yl]-4-penten-2-amine, (4E)-N-methyl-5 - [3 -(5 -isopropoxypyridin)yl] -4- penten-2-amine and (2S)-(4E)-N-methyl-5-[3-(5-isopropoxypyridin)yl]-4-penten-2-amine, 3-(5-chloro-2-furoyl)-3,7-diazabicyclo[3.3.0]octane, metabolites or prodrugs and pharmaceutically-acceptable salts, solvates or solvated salts of any of the foregoing. The preparation of these compounds is described in said US patents.

(a) a first therapeutic agent, which is a GSK3 inhibitor and (b) a second therapeutic agent, which is a BACE inhibitor.

(a) a first therapeutic agent, which is the GSK3 inhibitor 2-(2,5-difluoro-4-(5-fluoro-4-(2- methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2- ylamino)benzylamino)ethanol, in a pure and isolated form and (b) a second therapeutic agent, which is a BACE inhibitor.

Drugs useful in the combination of the present invention are those that reduce or block BACE activity should therefore reduce Αβ levels and levels of fragments of Αβ in the brain, and thus slow the formation of amyloid plaques and the progression of AD or other maladies involving deposition of Αβ or fragments thereof.

(a) a first therapeutic agent, which is a GSK3 inhibitor and (b) a second therapeutic agent, which is a H3 antagonist.

(a) a first therapeutic agent, which is the GSK3 inhibitor 2-(2,5-difluoro-4-(5-fluoro-4-(2- methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2- ylamino)benzylamino)ethanol, in a pure and isolated form and (b) a second therapeutic agent, which is a H3 antagonist.

The histamine H3 receptor has been shown to regulate the release of pro-cognitive neurotransmitters, such as, for example, histamine and acetylcholine. Some histamine H3 ligands, such as, for example, a histamine H3 receptor antagonist or inverse agonist may increase the release of these neurotransmitters in the brain. This suggests that histamine H3 receptor inverse agonists and antagonists could be used to improve cognitive deficits associated with neurodegenerative disorders such as AD.

(a) a first therapeutic agent, which is a GSK3 inhibitor and (b) a second therapeutic agent, which is a Αβ42 inhibitor.

(a) a first therapeutic agent, which is the GSK3 inhibitor 2-(2,5-difluoro-4-(5-fluoro-4-(2- methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2- ylamino)benzylamino)ethanol, in a pure and isolated form and (b) a second therapeutic agent, which is a Αβ42 inhibitor.

Αβ42 inhibitors useful in the combination of the present invention are those affecting the γ- secretase mediated processing of APP (Αβ amyloid precursor protein) and thereby lowering the Αβ42 and Αβ40 peptides. (a) a first therapeutic agent, which is a GSK3 inhibitor and (b) a second therapeutic agent, which is a partial agonist or antagonist of the 5-HT_IA and/or 5-HT_IB receptors,

(a) a first therapeutic agent, which is the GSK3 inhibitor 2-(2,5-difluoro-4-(5-fluoro-4-(2- methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2- ylamino)benzylamino)ethanol, in a pure and isolated form and (b) a second therapeutic agent, which is a partial agonist or antagonist of the 5-HT_IA and/or 5-HT_IB receptors.

A partial agonist or antagonist of the 5-HTi_A and/or 5-HTi_B receptors is expected to be useful in the prevention and/or treatment of conditions associated with disturbances in 5- HT signaling mediated by 5-HT_IA and/or 5-HTi_B receptors, i.e. such compounds may be used to produce an increased levels of acetylcholine, glutamate, serotonin in mammals, including human, in need of such prevention and/or treatment. In particular a partial agonist or antagonist of the 5-HT_IA and/or 5-HTi_B receptors is expected to be suitable for prevention and/or treatment of conditions associated with cognitive disorders and predemented states, especially dementia, Alzheimer^'s Disease (AD),

The first therapeutic agent (a) as well as the second therapeutic agent (b) may be in the form of the free base or a pharmaceutically acceptable salt thereof.

METHODS OF PREPARATION

Another aspect of the present invention provides a process for preparing a compound of formula (I), or a pharmaceutically acceptable salt thereof, by

reacting a pyrimidine of formula (III):

with a com ound of formula (II):

wherein Y is a displaceable group;

Y is a displaceable group, suitable values for Y are for example, a halogeno or

sulphonyloxy group, for example a chloro, bromo, iodo or trifluoromethanesulphonyloxy group. Preferably Y is bromo or chloro.

Specific reaction conditions for the above reactions are as follows:

Pyrimidines of formula (III) and compounds of formula (II) may be reacted together under standard Buchwald-Hartwig conditions (for example see J. Am. Chem. Soc, 118, 7215; J. Am. Chem. Soc, 119, 8451; J. Am. Chem. Soc, 125, 6653; J. Org. Chem., 62, 1568 and 6066) for example in the presence of palladium acetate or Ι,Γ- bis(diphenylphosphino)ferrocene)-dichloropalladium(II), in a suitable solvent for example an aromatic solvent such as toluene, benzene or xylene or an aprotic organic solvent such as 1,4-dioxane or THF, with a suitable base for example an inorganic base such as caesium carbonate or an organic base such as potassium-t-butoxide, in the presence of a suitable ligand such as 2,2'-bis(diphenylphosphino)-l, -binaphthyl or 2-dicyclohexylphosphino- 2',4',6'-triiso-propyl-l, -biphenyl and at a temperature in the range of about +25 to about +120°C.

The starting materials are either commercially available, prepared by standard methods from known materials or as described below.

A synthesis of pyrimidines of formula (III) is described in WO 2007/040440.

5 -Fluoro-4-(2 -methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2-amine may be prepared as described in WO2007/040440; Example 7(e). difluorobenzylamino)ethanol was prepared as described below:

4-Bromo-2,5-difluorobenzaldehyde (1.0 g, 4.52 mmol) was dissolved in degassed DCE (25 mL) and stirred under nitrogen. 2-Aminoethanol (0.238 mL, 4.52 mmol) was added followed by sodium triacetoxyborohydride (2.398 g, 11.31 mmol) portionwise. The mixture was stirred at room temperature for 3 hours. Sodium carbonate (aq) was added. The phases were separated and the organic phase was extracted with HC1 (2M, aq). The aquous phase was neutralized with KOH (s) and was extracted with dichloromethane (x3). The combined organic phases were dried and evaporated to give the title compound (1.2 g, 90%) that was used without further purification.

MS (APCI⁺) m/z 266 [M+H]⁺.

WORKING EXAMPLE

The following working example will describe, but not limit, the invention. Example 1

2-(2,5-Difluoro-4-(5-fluoro-4-(2-methyl-l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5- yl)pyrimidin-2-ylamino)benzylamino)ethanol

5 -Fluoro-4-(2 -methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2-amine (0.104 g, 0.38 mmol), 2-(4-bromo-2,5-difluorobenzylamino)ethanol (0.1 g, 0.38 mmol), (l, -bis(diphenylphosphino)ferrocene)-dichloropalladium(II) (0.015 g, 0.02 mmol), 4,5- Bis(diphenylphosphino)-9,9-dimethylxanthene (10.87 mg, 0.02 mmol) and sodium tert- pentoxide (83 mg, 0.75 mmol) were mixed in toluene (15 mL). The mixture was heated at 110 °C under argon atmosphere over night. The reaction mixture was filtered through diatomeous earth. The filter plug was washed with dichloromethane and the filtrate was concentrated. The residue was purified by preparative HPLC. The fractions containing product were pooled and extracted with dichloromethane. The organic phase was dried and evaporated to give the title compound (14 mg, 8%).

1H NMR (500 MHz, CHLOROFORM-;/) δ ppm 1.92 (m, 2 H) 2.45 (m, 2 H) 2.67 (s, 3 H) 2.85 (m, 3 H) 3.30 (m, 2 H) 3.71 (m, 2 H) 3.83 (s, 2 H) 3.90 (t, 1 H) 4.08 (dd, 2 H) 5.26 (ddt, 1 H) 7.16 (m, 1 H) 7.33 (m, 1 H) 7.63 (m, 1 H) 8.13 (m, 1 H) 8.35 (d, 1 H).

MS (APCI⁺) m/z 463[M+H]⁺.

GENERAL METHODS

1H NMR spectra were recorded in the indicated deuterated solvent at 500MHz using Bruker 500MHz ultrashield spectrometer equipped with a 4-nucleus probehead with Z- gradients. Chemical shifts are given in ppm down- and up field from TMS. Resonance multiplicities are denoted s, d, t, q, m and br for singlet, doublet, triplet, quartet, multiplet, and broad respectively.

Preparative chromatography was run on a Waters FractionLynx system with a

Autosampler combined Automated Fraction Collector (Waters 2767), Gradient Pump (Waters 2525), Column Switch (Waters CFO) and PDA (Waters 2996). Column;

XBridge® Prep C18 ΙΟμιη OBD™ 19 x 250mm, with guard column; XTerra® Prep MS C8 ΙΟμιη 19 x 10mm Cartridge. A gradient of 30-70% B (100% MeOH) in A (95% 0.1M NH₄OAc in MilliQ water and 5% MeOH) was applied for LC-separation at flow rate 20 mL/min. The PDA was scanned from 210-350 nm. UV triggering determined the fraction collection.

Purity analyses were performed on an Agilent HP 1100 system consisting of a G1322A Micro Vacuum Degasser, a G1312A Binary Pump, a G1367 A Well-Plate Autosampler, a G1316A Thermostatted Column Compartment, a G1315C Diode Array Detector and a 6120, G1978B mass spectrometer. The mass spectrometer was configured with an atmospheric pressure chemical ionisation (APCI) ion source operated in positive and negative ion mode. The APCI corona was set to 5.0 μΑ. The capillary voltage was set to 2.0 kV. The desolvation temperature was 350°C and desolvation gas (5 L/min). The mass spectrometer was scanned between m/z 100-1000. The column used was a X-Bridge C-18 3.0 x 100mm, 3.5 um run at a flow rate of 1.0 mL/min. The column oven temperature was set to 40 °C. The diode array detector scanned from 200-400 nm. A linear gradient was starting at 100 % A (A: 10 mM NH₄OAc in 5 % CH₃CN) and ending at 100 % B (B:

CH₃CN) after 6.3 minutes, then 100 % B stop at 9.0 min. LC-MS analyses were performed on a LC-MS system consisting of a Waters Alliance 2795 HPLC, a Waters PDA 2996 diode array detector, a Sedex 85 ELS detector and a ZQ single quadrupole mass spectrometer. The mass spectrometer was equipped with an electrospray ion source (ES) operated in positive and negative ion mode. The capillary voltage was set to 3.3 kV and the cone voltage to 28 V, respectively. The mass spectrometer scanned between m/z 100-800 with a scan time of 0.3s. The diode array detector scanned from 200-400 nm. The temperature of the ELS detector was adjusted to 40 °C and the pressure was set to 1.9 bar. Separation was performed on an Gemini CI 8, 3.0 mm x 50 mm, 3 μιη, (Phenomenex) run at a flow rate of 1 mL/min. A linear gradient was applied starting at 100% A (A: lOmM NH₄OAc in 5% CH₃CN) ending at 100% B (B: CH₃CN) in 4.0 min followed by 100 % B until 5.5 min. The column oven temperature was set to 40 °C.

The compound has been named using CambridgeSoft MedChem ELN v2.1

PHARMACOLOGY

Determination of ATP competition in Scintillation Proximity GSK3 Assay.

The inhibition experiments were carried out in duplicate with 10 concentrations of the inhibitor in 384 well clear-bottom microtitre plates. A biotinylated peptide substrate (Biotin-Ala-Ala-Glu-Glu-Leu-Asp-Ser-Arg-Ala-Gly-Ser(P03H2)-Pro-Gln-Leu

(AstraZeneca, Lund)), was added at a final concentration of 1 mmol/L in an assay buffer (pH 7.0) containing 0.1 mU recombinant human GSK3 (Dundee University, UK), (1 nmol/L active enzyme), 10 mmol/L morpholinepropanesulfonic acid (MOPS), 0.3 mmol/L EDTA, 0.01% (v/v) β-mercaptoethanol, 0.003% (w/v) polyethylene 23 lauryl ether (Brij 35), 0.4%) glycerol and 0.02 mg bovine serum albumine (BSA) and preincubated for 10 minutes. The reaction was initiated by the addition of 0.06 mCi [γ-33Ρ]ΑΤΡ (Amersham, UK) and unlabelled ATP in 30 mmol/L Mg(Ac)₂ to a final concentration of 1 mmol/L ATP. The final assay volume was 15 mL. Blank controls without peptide substrate were used. After incubation for 15 min at room temperature, the reaction was terminated by the addition of stop solution containing 1.3 mmol/L EDTA, 13 mmol/L ATP, 0.02%

Triton™X-100 and 0.15 mg streptavidin coated SPA beads. After a 5 minutes

centrifugation at 2000 rpm, the radioactivity was measured in a liquid scintillation counter (1450 MicroBeta Trilux, Perkin Elmer, Finland). The Km value of ATP for GSK3 , used to calculate the inhibition constants (K) of the various compounds, was 20 μΜ.

Determination of ATP competition in Scintillation Proximity CDK2 Assay.

The competiton experiments were carried out in duplicate with 10 concentrations of the inhibitor in 96 well clear-bottom microtiter plates. Cdk2/cyclin E enzyme was added at a concentration corresponding to a 80 times dilution of the partially purified baculovial infected insect cell lysate in a buffer containing 50 mmol/L HEPES, 10 mmol/L MnCl₂, 1 mmol/L dithiothreitol (DTT), 100 μιηοΙ/L NaF, 100 μιηοΙ/L sodium vanadate, 10 mmol/L sodium glycerophosphate, 5 μg/mL aprotinin, 2.5 μg/mL leupeptin and 100 μιηοΙ/L PMSF, pH 7.5. Blank controls without enzyme were used. The reaction was initiated by the addition of 1.25 μg GST-Rb, 0.15 μθ [γ-33Ρ]ΑΤΡ and unlabelled ATP at a final concentration of 0.1 μιηοΙ/L. The final assay volume was 50 ί. After incubation for 60 min at room temperature, each reaction was terminated by the addition of 150 stop solution containing 45 μΐ_^ protein A coated SPA beads in 50 mmol/L HEPES, 3.28 mg antiglutathione-S-transferase, and 5.5 mmol/L EDTA and 35 μιηοΙ/L ATP. The plate was centrifuged at 2000 rpm for 5 min and the radioactivity was determined in a liquid scintillation counter (1450 MicroBeta Trilux, Perkin Elmer, Finland). The Km value of ATP for Cdk2 used to calculate the inhibition constants (Ki) of the various compounds, was 0.5 μΜ. CaCo-2 cell permeability assay

CaCo-2 cells were seeded onto filter membrane at a density of 340500 cells/cm² for 24 well plates (0.33 cm²/well). The cells were grown in culture medium consisting of Dulbecco's modified Eagle's medium with glucose and L-glutamine supplemented with 10% fetal bovine serum, 100 U/mL penicillin-G, and 100 μg/mL streptomycin and 1% (v/v) 100X non-essential amino acids. The culture medium was replaced every second day and the cells were maintained at 37 °C, 95% relative humidity, and 5% C0₂. Permeability studies were conducted with the monolayers cultured for 21-28 days with the cell passage numbers between 25 and 50.

The CaCo-2 A to B assay was performed in the apical to basolateral direction (each in duplicates) at pH 7.4. HBSS containing 25 mM HEPES (pH 7.4) was used as transport medium. The drug solutions, typically 10 μΜ, were prepared in transport medium (1% DMSO). Studies of six compounds can be performed in one 24 well plate that generates one 96 deepwell analysis plate (maximum capacity 6 plates = 36 compounds and 6 deep well plates). The CaCo-2 cell monolayers were washed once with HBSS for 10 minutes prior to start. Transport buffer, 800 μί, (HBSS, pH 7.4) is first dispensed to the basal side of the monolayer. The assay is then initiated by addition of 225 μΐ_^ of each compound (10 μΜ) to the apical side. Samples are withdrawn directly (Donor 0) and at 60 min (Donor end and Receiver 60) post addition of test compound. 25 μΐ, and 150 μί are withdrawn from the donor compartment and the receiver compartment, respectively. During washing- step and incubation with compounds the transwell plates are placed in a shaking incubator at 480 rpm and 37°C. The integrity of the epithelial cell monolayer is monitored by measuring the amount of radiolabeled [¹⁴C]mannitol (low passive paracellular diffusion) in the donor compartment at time 0 min to 60 min. Luma Plate 96-well is used for analysis of [¹⁴C]mannitol. Compound recovery was assessed by calculating the sum of the cumulatively transported amount and the amount left in the donor side against the initial amount of drug. The samples were analysed online using liquid chromatography tandem mass spectrometry (LC/MS/MS). The apparent permeability coefficient is calculated as follows:

AQ/At

P app =

A * C,

where AQ/At is the total amount of substance transported into the receiver chamber per unit time, A is the surface area (cm²), and Co the starting donor concentration.

The apparent permeability P_app is expressed in xlO ⁶ cm/sec.

Results

The GSK ¾ value, CDK2 K_; value, the selectivity GSK3 versus CDK2 for the compound of formula (I) of the present invention are shown in Table 1. All the values given are mean values.

The CaCo-2 P_app/CaCo-2 A to B P_app for the compound of formula (I), 2-(2,5-difluoro-4- (5 -fluoro-4-(2 -methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2- ylamino)benzylamino)ethanol, in essentially pure and isolated form is 5.6xl0^~6 (mean values .

The following abbreviations have been used:

APCI Atmospheric Presssure Chemical Ionization

ATP Adenosine Triphosphate

BSA Bovin Serum Albumin

CaCo-2 Human Epithelia Colorectal Adenocarcinoma Cells CDK2 Cyklin dependent kinase 2

CH₃CN methylnitrile

CI Chemical Ionization

C0₂ Carbondioxide

DCE 1 ,2-Dichloroethane

DMSO Dimethyl sulfoxide

DTT Dithiothreitol

EDTA Ethylenediaminetetraacetic acid

ESI Electrospray ionization

GSK3 Glycogen synthase kinase 3

HBSS Hank's Balanced Salt solution

HC1 Hydrochloride

HEPES 4-(2-Hydroxyethyl)-l-piperazine ethane sulfonic acid

HPLC High Pressure Liquid Chromatography

KOH Potasium hydroxide

LC-MS Liquid Chromatography Mass Spectrometry

MeOH Methanol

MES 2-(N-Morpholino)ethanesulfonic acid

Mg(Ac)₂ Magnesium Acetate

MnCl₂ Mangandichloride

MOPS Morpholinepropanesulfonic acid

NaF Sodiumfluoride

NH₄CI Ammonium chloride

NH₄OAc Ammonium acetate

Pd₂dba₃ Tris-(dibenzylideneacetone)dipalladium(0)

PBS Phosphate Buffered Saline

PMSF Phenylmethylsulphonyl fluoride

RT Room temperature

SPA Scintillation Proximity Assay

UV Ultra Violet

UV-DAD Ultra Violet-Diode Array Detector

Claims

1. A compound of the formula (I) as a free base or a pharmaceutically acceptable salt thereof,

in a pure and isolated form.

2. A compound according to claim 1, which is 2-(2,5-difluoro-4-(5-fluoro-4-(2-methyl-l- (tetrahydro-2H-pyran-4-y 1)- 1 H-imidazol-5 -yl)pyrimidin-2-ylamino)benzylamino)ethanol as a free base.

3. A pharmaceutical composition comprising a compound of formula (I) or a

harmaceutically acceptable salt thereof,

4. An oral pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof as described in claim 3.

5. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 2, for use in therapy.

6. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to any one of claims 1 to 2, or a pharmaceutical composition according to any one of claims 3 to 4, for use in treating of cognitive disorder(s) or indications with deficit(s) in cognition such as: dementia; incl. pre-senile dementia (early onset Alzheimer's Disease); senile dementia (dementia of the Alzheimer's type); Alzheimer's Disease (AD); Familial Alzheimer's disease; Early Alzheimer's disease; mild to moderate dementia of the Alzheimer's type; delay of disease progression of Alzheimer's Disease; neurodegeneration associated with Alzheimer's disease, Mild Cognitive Impairment (MCI); Amnestic Mild Cognitive Impairment (aMCI); Age-associated Memory Impairment (AAMI); Lewy body dementia; vascular dementia (VD); HIV-dementia; AIDS dementia complex; AIDS - Neurological Complications; Frontotemporal dementia (FTD); Frontotemporal dementia Parkinson's Type (FTDP); dementia pugilistica; dementia due to infectious agents or metabolic disturbances; dementia of degenerative origin; dementia - Multi-Infarct; memory loss; cognition in Parkinson's Disease; cognition in multiple sclerosis; cognition deficits associated with chemotherapy; Cognitive Deficit in Schizophrenia (CDS); Schizoaffective disorders including schizophrenia; Age-Related Cognitive Decline (ARCD); Cognitive Impairment No Dementia (CIND); Cognitive Deficit arising frome stroke or brain ischemia; Congenital and/or development disorders; progressive supranuclear palsy (PSP); amyotrophic lateral sclerosis (ALS); corticobasal degeneration(CBD); traumatic brain injury (TBI); postencephelatic parkinsonism; Pick's Disease; Niemann-Pick's Disease; Down's syndrome; Huntington's Disease; Creuztfeld-Jacob's disease; prion diseases; multiple sclerosis (MS); motor neuron diseases (MND); Parkinson's Disease (PD); β- amyloid angiopathy; cerebral amyloid angiopathy; Trinucleotide Repeat Disorders; Spinal Muscular Atrophy; Friedreich's Ataxia; Neuromyelitis Optica; Multiple System Atrophy; Transmissible Spongiform Encephalopathies; Attention Deficit Disorder (ADD); Attention Deficit Hyperactivity Disorder (ADHD); Bipolar Disorder (BD) including acute mania, bipolar depression, bipolar maintenance; Major Depressive Disorders (MDD) including depression, major depression, mood stabilization; dysthymia; agnosia; aphasia; apraxia and apathy.

7. A compound of formula (I) or a pharmaceutically acceptable salt thereof according to claim 6 for use in treating of Alzheimer^'s Disease.

8. A method of the treatment of cognitive disorder(s) or indications with deficit(s) in cognition such as: dementia; incl. pre-senile dementia (early onset Alzheimer's Disease); senile dementia (dementia of the Alzheimer's type); Alzheimer's Disease (AD); Familial Alzheimer's disease; Early Alzheimer's disease; mild to moderate dementia of the Alzheimer's type; delay of disease progression of Alzheimer's Disease; neurodegeneration associated with Alzheimer's disease, Mild Cognitive Impairment (MCI); Amnestic Mild Cognitive Impairment (aMCI); Age-associated Memory Impairment (AAMI); Lewy body dementia; vascular dementia (VD); HIV-dementia; AIDS dementia complex; AIDS - Neurological Complications; Frontotemporal dementia (FTD); Frontotemporal dementia Parkinson's Type (FTDP); dementia pugilistica; dementia due to infectious agents or metabolic disturbances; dementia of degenerative origin; dementia - Multi-Infarct; memory loss; cognition in Parkinson's Disease; cognition in multiple sclerosis; cognition deficits associated with chemotherapy; Cognitive Deficit in Schizophrenia (CDS); Schizoaffective disorders including schizophrenia; Age-Related Cognitive Decline (ARCD); Cognitive Impairment No Dementia (CIND); Cognitive Deficit arising frome stroke or brain ischemia; Congenital and/or development disorders; progressive supranuclear palsy (PSP); amyotrophic lateral sclerosis (ALS); corticobasal degeneration(CBD); traumatic brain injury (TBI); postencephelatic parkinsonism; Pick's Disease; Niemann-Pick's Disease; Down's syndrome; Huntington's Disease; Creuztfeld-Jacob's disease; prion diseases; multiple sclerosis (MS); motor neuron diseases (MND); Parkinson's Disease (PD); β- amyloid angiopathy; cerebral amyloid angiopathy; Trinucleotide Repeat Disorders; Spinal Muscular Atrophy; Friedreich's Ataxia; Neuromyelitis Optica; Multiple System Atrophy; Transmissible Spongiform Encephalopathies; Attention Deficit Disorder (ADD); Attention Deficit Hyperactivity Disorder (ADHD); Bipolar Disorder (BD) including acute mania, bipolar depression, bipolar maintenance; Major Depressive Disorders (MDD) including depression, major depression, mood stabilization; dysthymia; agnosia; aphasia; apraxia and apathy, comprising administering to a mammal, including human in need of such treatment, a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof as defined in any one of claims 1 to 2, or a pharmaceutical composition as defined in any one of claims 3 to 4.

9. The method according to claim 8, wherein the disease is Alzheimer^'s Disease.

10. A method of using a compound N-(2,5-difluoro-4-(morpholinomethyl)phenyl)-5- fluoro-4-(2-methyl-l-(tetrahydro-2H-pyran-4-yl)-lH-imidazol-5-yl)pyrimidin-2-amine or a pharmaceutically acceptable salt thereof to administer a metabolite 2-(2,5-difluoro-4-(5- fluoro-4-(2 -methyl- 1 -(tetrahydro-2H-pyran-4-yl)- 1 H-imidazol-5 -yl)pyrimidin-2- ylamino)benzylamino)ethanol.