A process for preparing tetrahydroisoquinoline derivative

Abstract

This invention relates to a method for preparing a compound of formula (I), comprising reacting an intermediate of formula (II) with an intermediate of formula (III) in the presence of a base using a coupling agent.

Description

Technical Field

[0001] This invention relates to a tetrahydroisoquinoline derivative and its therapeutic use, and more particularly, to a pharmacologically active substituted tetrahydroisoquinoline derivative.

[0002] This compound is used as a D1 positive ectopic regulator, and is therefore beneficial as a drug for treating diseases caused by D1 receptors. Prior Technology

[0003] Monoamine dopamine regulates motor function, reward mechanisms, cognitive processes, and other physiological functions through two families of GPCRs. Specifically, dopamine acts on neurons by stimulating cAMP production through D1-like receptors (including dopamine D1 and D5) that primarily couple to Gs G proteins, and by attenuating cAMP production through D2-like receptors (including D2, D3, and D4) that couple to Gi / q G proteins. These receptors are widely distributed across various brain regions. In particular, D1 receptors are involved in many physiological functions and behavioral processes. D1 receptors are involved in synaptic plasticity, cognitive function, and goal-oriented motor function, but are also involved in reward processes. Due to their roles in several physiological / neurological processes, D1 receptors are involved in a variety of disorders, including cognitive and negative symptoms in schizophrenia, cognitive impairment associated with tranquilizer therapy, mild cognitive impairment (MCI), impulsivity, attention-deficit hyperactivity disorder (ADHD), Parkinson's disease and related motor disorders, hypotonia, Parkinson's dementia, Huntington's disease, Lewy body dementia, Alzheimer's disease, drug addiction sleep disorders, apathy, traumatic spinal cord injury, or neuropathic pain.

[0004] Developing orally bioavailable small molecules targeting the D1 receptor has proven difficult. To date, most D1 agonists are characterized by their catechol moiety, limiting their clinical application to invasive therapies. Achieving sufficient selectivity is also a challenge due to the high homology of ligand-binding sites between dopamine receptor subtypes (e.g., dopamine D1 and D5). Furthermore, D1 agonists are associated with potential limiting side effects, including but not limited to dyskinesia and hypotension.

[0005] Therefore, there is a need to design new drugs that can regulate the D1 receptor.

[0006] There is considerable interest in identifying ectopic modulators of GPCRs, which can serve as tools for understanding receptor mechanisms and as potential therapeutic agents. GPCRs represent the largest family of cell surface receptors, and many commercially available drugs directly activate or block signaling pathways mediated by these receptors. However, for some GPCRs (e.g., peptide receptors), the high homology of ligand-binding sites between subtypes (e.g., dopamine D1 and D5 or D2 and D3) has proven challenging to develop small molecules or achieve sufficient selectivity. Therefore, much drug research has shifted to identifying small molecules that target different sites than orthosteric natural agonists. Ligands binding to these sites induce conformational changes in GPCRs, thus ectopically modulating receptor function. Ectopic ligands possess different activity ranges, including the ability to enhance (positive allosteric modulators (PAMs)) or attenuate (negative allosteric modulators (NAMs)) the effects of endogenous ligands by influencing affinity and / or efficacy. In addition to subtype selectivity, ectopic modulators may offer other potential advantages from a drug discovery perspective, such as lack of direct action or intrinsic efficacy; enhancing the effects of natural delivery substances only at the site of release and during release; reducing the tendency for desensitization induced by continuous exposure to agonists; and reducing the tendency to induce target-related side effects.

[0007] The compound according to the present invention enhances the effect of D1 agonists or endogenous ligands on D1 receptors through an ectopic mechanism, and is therefore a D1 positive ectopic modulator (D1 PAM).

[0008] Therefore, the compounds according to the present invention (D1 PAM) are beneficial for the treatment and / or prevention of diseases and disorders caused by D1 receptors therein. Such diseases include cognitive and negative symptoms in schizophrenia, cognitive impairment associated with tranquilizer therapy, mild cognitive impairment (MCI), impulsivity, attention deficit hyperactivity disorder (ADHD), Parkinson's disease and related motor disorders, hypotonia, Huntington's disease, Lewy body dementia, Alzheimer's disease, drug addiction, sleep disorders, apathy, traumatic spinal cord injury, or neuropathic pain.

[0009] International Patent Application No. WO 2013 / 051869 A1 discloses certain 3,4-dihydro-1H-isoquinoline-2-yl derivatives, which are NK2 antagonists.

[0010] International patent application number WO 2008 / 109336 A1 discloses certain tetrahydroisoquinoline compounds, which are histamine H3 receptor modulators.

[0011] International Patent Application No. WO 2014 / 193781 A1 discloses certain 3,4-dihydroisoquinoline-2(1H)-yl derivatives for the treatment of cognitive impairment associated with Parkinson's disease or schizophrenia.

[0012] International patent application number WO2016 / 055479 discloses substituted 3,4-dihydroisoquinoline-2(1H)-yl derivatives and their analogues, which can be used to treat diseases caused by the D1 receptor.

[0013] International patent application number WO2019 / 204418 discloses certain pyrazole-tetrahydroisoquinoline derivatives, which are D1 positive ectopic modulators and can be used to treat Parkinson's disease, Alzheimer's disease, schizophrenia and attention deficit hyperactivity disorder (ADHD).

[0014] However, there is still a need to develop effective D1 positive ectopic modulators that combine favorable pharmacokinetic and pharmacodynamic properties while reducing the side effects traditionally associated with selective D1 agonist therapy, such as hypotension or difficulty exercising. Summary of the Invention

[0015] This invention provides 2-(3,5-dichloro-1-methyl-indazol-4-yl)-1-[(1S,3R)-3-(hydroxymethyl)-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-yl] ethyl ketone of formula (I). Or a medicinally acceptable salt.

[0016] The present invention also provides a compound of formula (I) as defined above for therapeutic purposes, or a pharmaceutically acceptable salt thereof.

[0017] On the other hand, the present invention also provides a compound of formula (I) as defined above, or a pharmaceutically acceptable salt thereof, for the treatment of diseases and / or disorders caused by D1 receptors.

[0018] On the other hand, the present invention provides compounds of formula (I) as defined above, or pharmaceutically acceptable salts thereof, for the treatment and / or prevention of cognitive and negative symptoms in schizophrenia, cognitive impairment associated with tranquilizer therapy, mild cognitive impairment (MCI), impulsivity, attention deficit hyperactivity disorder (ADHD), Parkinson's disease and other movement disorders, hypotonia, Parkinson's dementia, Huntington's disease, Lewy body dementia, Alzheimer's disease, drug addiction, sleep disorders, apathy, traumatic spinal cord injury, or neuropathic pain.

[0019] In a particular embodiment of this invention, the present invention provides a compound of formula (I) as defined above, or a pharmaceutically acceptable salt thereof, for the treatment of cognitive and negative symptoms in Parkinson's disease and other movement disorders, Alzheimer's disease, or schizophrenia.

[0020] Therefore, in one particular aspect, the present invention provides a compound of formula (I) as defined above, or a pharmaceutically acceptable salt thereof, for the treatment of Parkinson's disease and other movement disorders.

[0021] On the other hand, the present invention provides the use of a compound of formula (I) as defined above or a pharmaceutically acceptable salt thereof for the manufacture of a medicine for the treatment and / or prevention of diseases and / or disorders caused by D1 receptors.

[0022] In another aspect, the present invention provides the use of a compound of formula (I) as defined above, or a pharmaceutically acceptable salt thereof, for the manufacture of a pharmaceutical product for the treatment and / or prevention of cognitive and negative symptoms in schizophrenia, cognitive impairment associated with tranquilizer therapy, mild cognitive impairment (MCI), impulsivity, attention deficit hyperactivity disorder (ADHD), Parkinson's disease and other movement disorders, hypotonia, Parkinson's dementia, Huntington's disease, Lewy body dementia, Alzheimer's disease, drug addiction, sleep disorders, apathy, traumatic spinal cord injury, or neuropathic pain.

[0023] In a particular embodiment of this invention, the present invention provides the use of a compound of formula (I) as defined above, or a pharmaceutically acceptable salt thereof, in the manufacture of a pharmaceutical product for the treatment of cognitive and negative symptoms in Parkinson's disease and other movement disorders, Alzheimer's disease, or schizophrenia.

[0024] In one particular aspect, the present invention provides the use of a compound of formula (I) as defined above, or a pharmaceutically acceptable salt thereof, for the manufacture of a pharmaceutical product for the treatment of Parkinson's disease and other movement disorders.

[0025] The present invention also provides a method for treating and / or preventing dysregulation requiring administration of a D1 positive ectopic regulator, comprising administering an effective amount of a compound of formula (I) as defined above or a pharmaceutically acceptable salt thereof to a patient requiring such treatment.

[0026] On the other hand, the present invention provides a method for treating and / or preventing cognitive and negative symptoms in schizophrenia, cognitive impairment associated with tranquilizer therapy, mild cognitive impairment (MCI), impulsivity, attention deficit hyperactivity disorder (ADHD), Parkinson's disease and other movement disorders, hypotonia, Parkinson's dementia, Huntington's disease, Lewy body dementia, Alzheimer's disease, drug addiction, sleep disorders, apathy, traumatic spinal cord injury or neuropathic pain, comprising administering an effective amount of a compound of formula (I) as defined above or a pharmaceutically acceptable salt thereof to the patient requiring such treatment.

[0027] In a particular embodiment of this invention, the present invention provides a method for treating cognitive and negative symptoms in Parkinson's disease and other movement disorders, Alzheimer's disease or schizophrenia, comprising administering an effective amount of a compound of formula (I) as defined above or a pharmaceutically acceptable salt thereof to a patient requiring such treatment.

[0028] In one particular aspect, the present invention provides a method for treating Parkinson's disease and other movement disorders, comprising administering an effective amount of a compound of formula (I) as defined above or a pharmaceutically acceptable salt thereof to a patient requiring such treatment.

[0029] For use in pharmaceuticals, salts of compounds of formula (I) shall be pharmaceutically acceptable salts. However, other salts may be used to prepare compounds of formula (I) or pharmaceutically acceptable salts thereof. Standard principles for the selection and preparation of pharmaceutically acceptable salts are described, for example, in Handbook of Pharmaceutical Salts: Properties, Selection and Use, ed. PH Stahl & CG Wermuth, Wiley-VCH, 2002. Suitable pharmaceutically acceptable salts of compounds of formula (I) include acid addition salts, which may be formed, for example, by mixing a solution of a compound of formula (I) with a solution of a pharmaceutically acceptable acid.

[0030] It should be understood that each individual atom present in formula (I) or the formula described below may, in fact, exist in the form of any naturally occurring isotope, with the most abundant isotope being preferred. Thus, for example, each individual hydrogen atom present in formula (I) or the formula described below may exist as a 1H, 2H (deuterium), or 3H (tritium) atom, with 1H being preferred. Similarly, for example, each individual carbon atom present in formula (I) or the formula described below may exist as a 12C, 13C, or 14C atom, with 12C being preferred.

[0031] The present invention includes solvates of compounds of formula (I) above, which can be formed by common organic solvents or water.

[0032] This invention also includes, within its scope, co-crystals of compounds of formula (I) above. The technical term "co-crystal" is used to describe the presence of neutral molecular components in a stoichiometric proportion within a crystalline compound. The preparation of pharmaceutical co-crystals allows for alteration of the crystal form of active pharmaceutical ingredients, thereby changing their physicochemical properties without impairing their desired biological activity (see Pharmaceutical Salts and Co-crystals, ed. J. Wouters & L. Quere, RSC Publishing, 2012).

[0033] The compounds according to the present invention may exist in different polymorphic forms. Although not explicitly indicated in the above formula, such forms are intended to be included within the scope of the present invention.

[0034] In a particular aspect of the invention, as further described in the examples, the compound of formula (I) is isolated as a monohydrate.

[0035] The present invention also includes (I) prodrug forms of compounds and their various subscopes and subgroups within its scope.

[0036] The activity in any of the above-mentioned therapeutic indications or disorders can of course be determined by conducting appropriate clinical trials for the specific indication and / or by designing general clinical trials in a manner known to those skilled in the art.

[0037] For the treatment of disease, the compound of formula (I) or its pharmaceutically acceptable salt may be administered in an effective daily dose as a pharmaceutical composition.

[0038] Therefore, the present invention provides a pharmaceutical composition comprising a compound of formula (I) as described above or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.

[0039] In order to prepare the pharmaceutical composition according to the present invention, one or more of the formula (I) compounds or their pharmaceutically acceptable salts are tightly mixed with a pharmaceutical diluent or carrier according to conventional pharmaceutical formulation techniques known to a skilled practitioner.

[0040] Appropriate diluents and carriers can be used in various forms, depending on the desired route of administration, such as oral, rectal, parenteral, or intranasal.

[0041] The pharmaceutical composition according to the present invention can be administered, for example, orally, parenterally (i.e., intravenously, intramuscularly, or subcutaneously), intrathecally, by inhalation, or intranasally.

[0042] Pharmaceutical ingredients suitable for oral administration can be solid or liquid, and can be in the form of tablets, pills, sugar-coated tablets, gelatin capsules, solutions, syrups, chewing gum, etc.

[0043] For this purpose, the active ingredient may be mixed with an inert diluent or a non-toxic, pharmaceutically acceptable carrier (e.g., starch or lactose). Alternatively, these pharmaceutical compositions may also contain binders such as microcrystalline cellulose, tragacanth gum, or gelatin; disintegrants such as alginate; lubricants such as magnesium stearate; slip agents such as colloidal silica; sweeteners such as sucrose or saccharin; or colorants or flavorings such as menthol or methyl salicylate.

[0044] The present invention also considers compositions that can release active substances in a controlled manner. Pharmaceutical compositions that can be administered parenterally are in known forms, such as aqueous or oily solutions or suspensions typically contained in ampoules, disposable syringes, glass or plastic vials or infusion containers.

[0045] In addition to the active ingredient, these solutions or suspensions may optionally contain sterile diluents, such as water for injection, physiological saline, oil, polyethylene glycol, glycerin, propylene glycol or other synthetic solvents; antimicrobial agents, such as benzyl alcohol; antioxidants, such as ascorbic acid or sodium bisulfite; chelating agents, such as ethylenediaminetetraacetic acid; buffers, such as acetates, citrates or phosphates; and agents for adjusting osmotic pressure, such as sodium chloride or dextrose.

[0046] These pharmaceutical forms are prepared using methods routinely employed by pharmacists.

[0047] The dosage of the compounds of the present invention used for the prevention or treatment of specific symptoms will vary depending on the compound selected and the symptoms of the patient to be treated. However, generally, for parenteral components, the daily dose range can be 0.05 to 3000 mg, typically 0.5 mg to 1000 mg.

[0048] The compounds of the present invention or their pharmaceutically acceptable salts may be administered alone (monotherapy) or in combination with levodopa (combination therapy). The compounds of formula (I) of the present invention or their pharmaceutically acceptable salts may be used to treat motor difficulties associated with levodopa administration, either alone or in combination with a portion of the levodopa dose necessary to improve motor disability. For example, if the compounds of formula (I) of the present invention are used with a portion of the patient's levodopa dose or alone to replace levodopa, it is believed that the compounds of formula (I) of the present invention will effectively prevent motor disability without causing troublesome motor difficulties. Therefore, it is believed that the compounds of the present invention may be used to treat motor deficits and levodopa-induced dyskinesia (LID).

[0049] Therefore, in one particular aspect, the present invention also provides a compound of formula (I) for treating levodopa-induced dyskinesia (LID).

[0050] Compound (I) can be prepared by a method involving the reaction of intermediate (II) with intermediate (III).

[0051] In the presence of (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethylurea hexafluorophosphate (HBTU) or another coupling agent known to those skilled in the art, the intermediate of formula (III) can be readily reacted with the intermediate of formula (II) in a suitable solvent (e.g., dimethylformamide) and an excess of base (e.g., N,N-diisopropylethylamine).

[0052] Intermediate (III) can be prepared by a reaction involving intermediate (IV). in Z represents halogen or 1-hydroxy-1-methylethyl; Ra represents tert-butyldimethylsilyl; and Rc represents hydrogen or tert-butoxycarbonyl.

[0053] In the first step, the intermediate of formula (IV) (where Z represents bromine and Rc represents hydrogen, hereinafter referred to as intermediate (IVa)) may be protected with a suitable protecting group according to methods known to those skilled in the art to provide the compound of formula (IV) (where Z represents bromine and Rc represents tertiary butoxycarbonyl, hereinafter referred to as intermediate (IVb)).

[0054] In the second step, for example in the presence of n-BuLi, in a suitable solvent (e.g., tetrahydrofuran), at low temperature, in the presence of continuously flowing anhydrous acetone, according to the method described in the appended examples, a metal-halogen exchange reaction is carried out to provide the corresponding intermediate (IV) (where Z represents 1-hydroxy-1-methylethyl, hereinafter referred to as intermediate (IVc)).

[0055] Then, the tertiary butoxycarbonyl (Boc) group (Rc) can be deprotected first, according to methods known to those skilled in the art or as further described in the appended examples, and then the trimethylsilyl group and the tertiary butyldimethylsilyl group (Ra) formed during the deprotection of the Boc group can be deprotected to provide intermediate (III).

[0056] The intermediate of formula (IVa) can be prepared by a reaction involving the intermediate of formula (V) (where Y is a halogen, such as bromine, and Ra is as defined in the intermediate of formula (IV)).

[0057] The reaction occurs readily at low temperatures in the presence of methylmagnesium chloride in a suitable solvent (e.g., tetrahydrofuran).

[0058] Intermediate (V) can be prepared by a two-step method involving the reaction of intermediate (VI). Where Y is as defined in the intermediate of formula (V) above, and Ra represents hydrogen or tert-butyl-dimethylsilyl.

[0059] In the first step, intermediate (VI) (where Ra represents hydrogen) is reacted with tributyldimethylsilyl chloride at room temperature in the presence of a suitable base (e.g., 4-dimethylaminopyridine) to provide intermediate (VI) (where Ra represents tributyl-dimethylsilyl).

[0060] In the second step, intermediate (VI) (where Ra represents tert-butyl-dimethylsilyl) is reacted with N-chlorosuccinimide (NCS) in a suitable solvent (e.g., THF) to provide intermediate (V).

[0061] Intermediate (VI) (where Ra represents hydrogen) can be prepared by a method involving intermediate (VII) (where Y is as defined in intermediate (V) above).

[0062] The reaction occurs readily in the presence of a strong base (e.g., sodium hydroxide) in a suitable solvent (e.g., a mixture of ethanol and water) at high temperatures.

[0063] The intermediate of formula (VII) can be prepared by a reaction involving intermediate (VIII). Where Y is defined as in the intermediate of the above formula (V).

[0064] The reaction occurs readily in a suitable solvent (e.g., dichloromethane) in the presence of trimethylsilane trifluoromethanesulfonate and polyoxymethylene.

[0065] Intermediate (VIII) can be prepared by a two-step method involving commercially available intermediate (IX). Y is defined as described in the intermediate (V) above.

[0066] The reaction can be conveniently carried out according to the methods described in the appended examples or according to methods known to those skilled in the art.

[0067] Intermediate (II) can be prepared by a multi-step method involving the reaction of intermediate (X). in R1 represents chlorine, amino, or nitro; and Rb represents hydrogen or tert-butyl.

[0068] In the first step, intermediate (X) (where R1 represents nitro and Rb represents tert-butyl, hereinafter referred to as intermediate (Xa)) is reduced to the corresponding intermediate (X) (where R1 represents amino and Rb represents tert-butyl, hereinafter referred to as intermediate (Xb)), and the reaction is conveniently carried out under high pressure in a suitable solvent (e.g., methanol) by Pd / C catalytic hydrogenation.

[0069] By adding concentrated hydrochloric acid and sodium nitrite, followed by further addition of hydrochloric acid and copper(II) chloride, intermediate (Xb) is converted into the corresponding intermediate (X) (where R1 represents chlorine and Rb represents hydrogen, hereinafter referred to as intermediate (Xc)). This reaction readily occurs at low temperatures.

[0070] Then, intermediate (II) is obtained directly from intermediate (Xc) by reacting with N-chlorosuccinimide, according to the method described in the appended examples or according to methods known to those skilled in the art.

[0071] The intermediate of formula (Xa) can be prepared by a method involving the intermediate of formula (XI). R2 represents hydrogen or methyl.

[0072] In the first step, a commercially available intermediate of formula (XI) (where R2 represents hydrogen, hereinafter referred to as intermediate (XIa)) is reacted with methyl iodine in the presence of a strong base (e.g., potassium hydroxide) and in a suitable solvent (e.g., dimethylformamide). Then, the resulting intermediate (XI) (where R2 represents methyl, hereinafter referred to as intermediate (XIb)) is reacted with tert-butyl 2-chloroacetate in the presence of potassium tert-butoxide and in a suitable solvent (e.g., tetrahydrofuran) at low temperature to provide intermediate (Xa).

[0073] In cases where the product mixture is prepared by any of the methods described above for preparing compounds according to the invention, the desired product may be separated at an appropriate stage by conventional methods, such as preparative HPLC; or column chromatography using, for example, silicon dioxide and / or alumina combined with a suitable solvent system.

[0074] In cases where the method described above for preparing compounds according to the invention produces a mixture of stereoisomers, these isomers can be separated using conventional techniques. In particular, in cases where a specific mirror-image isomer of the compound of formula (I) is desired, this can be produced from the mixture of mirror-image isomers using any conventional procedure suitable for resolving mirror-image isomers. Thus, for example, by reacting a mixture of mirror-image isomers of formula (I) (e.g., a racemic mixture) with a suitable chiral compound (e.g., a chiral base), a non-mirror-image derivative (e.g., a salt) can be produced. The non-mirror-image isomer can then be separated by any suitable method, such as by crystallization, and if the non-mirror-image isomer is a salt, the desired mirror-image isomer can be recovered, for example, by acid treatment. In another analytical method, chiral HPLC can be used to separate the racemic mixture of formula (I). Furthermore, if desired, a specific mirror-image isomer can be obtained using a suitable chiral intermediate in one of the above methods. Alternatively, a specific mirror-isomer can be obtained by performing mirror-isomer-specific enzymatic biotransformation, such as ester hydrolysis using esterases, followed by purification of the hydrolyzed acid, which is only mirror-isomerically pure, from the unreacted ester mirror-isomer. In cases where a specific geometric isomer of the invention is desired, chromatography, recrystallization, and other known separation procedures can also be used with intermediates or the final product. Alternatively, according to methods known to those skilled in the art, or according to the methods described in the accompanying examples, a non-desired mirror-isomer can be racemicized to the desired mirror-isomer in the presence of an acid or base.

[0075] During any of the above synthetic sequences, it may be necessary and / or necessary to protect any sensitive or reactive groups on the relevant molecules. This can be achieved using known protecting groups, such as those described in the following literature: Protective Groups in Organic Chemistry, ed. JFW McOmie, Plenum Press, 1973; and TW Greene & PGM Wuts, Protective Groups in Organic Synthesis, John Wiley & Sons, 3rd edition, 1999. Protecting groups can be removed at any suitable subsequent stage using methods known in the art.

[0076] The compound of formula (I) according to the present invention does not directly activate the dopamine D1 receptor, but enhances the effect of D1 agonists or endogenous ligands on the dopamine D1 receptor through an ectopic mechanism, and is therefore a D1 positive ectopic regulator (D1 PAM).

[0077] Dopamine and other D1 agonists directly activate dopamine D1 receptors.

[0078] The analysis has been designed to measure the effects of the compounds according to the invention in the absence of dopamine ("activation assay") and in the presence of dopamine ("enhancement assay").

[0079] The activation assay measures the stimulation of cyclic adenosine monophosphate (cAMP) production in homogeneous time-resolved fluorescence (HTRF) assays. The maximum increase in cAMP achieved by increasing the concentration of the endogenous agonist dopamine is defined as 100% activation.

[0080] When tested, the compound of formula (I) according to the invention lacks a significant direct agonist-like effect because it produces less than 20% activation (compared to the maximum response of dopamine) when present at a concentration of 10 μM.

[0081] The enhancement assay measures the ability of a compound to increase cAMP levels produced by low-threshold concentrations of dopamine. The dopamine concentration used ([EC20]) was designed to produce a 20% increase in stimulation compared to the maximum response (100%) observed with increased dopamine concentration. To measure this enhancement, the compound at increased concentrations was incubated with dopamine at [EC20], and the enhancement was measured as cAMP production increased, with the concentration of the compound producing a 50% increase in cAMP levels being measured.

[0082] When tested in a cAMP HTRF assay, the compound of formula (I) according to the invention exhibits a pEC50 value greater than about 6.5, indicating that it is a D1 positive ectopic regulator.

[0083] GABAA receptor inhibition is known to be closely associated with epileptic seizures and epilepsy. Therefore, there is a need to develop compounds that act as positive ectopic regulators of D1 while minimizing such effects.

[0084] When tested in the GABA-A receptor inhibition assay described herein, when measured at a concentration of 10 μM of compound (I), it is therefore expected that compound (I) will show an inhibition percentage of GABAA receptor less than or equal to about 20%, ideally less than about 10%, and appropriately less than about 5%.

[0085] A potential challenge in developing therapeutic compounds is the ability of some compounds to induce CYP450 enzymes. Induction of these enzymes can affect patient exposure to these compounds or other compounds that may be co-administered with them, potentially altering their safety or efficacy. Therefore, there is a need to develop compounds that minimize this induction potential.

[0086] The CYP450 induction potential of the compound of formula (I) according to the present invention has been tested by measuring the potential increase in CYP450 activity in human hepatocytes tested at increased concentrations of the compound of the present invention.

[0087] When tested in a CYP3A4 induction assay according to the scheme described in this patent application, it is expected that the compound of formula (I) of the present invention will exhibit a fold-induction value that is at least about 2 times lower than that of the positive control compound (rifampicin), ideally at least about 3 times lower, and appropriately about 4 times lower.

[0088] When developing compounds for therapeutic purposes, it is important to have the concept of excretion once they are introduced into the body.

[0089] Clearance is the parameter that provides this information because it represents the volume of plasma (or blood) that completely removes the target compound per unit of time, typically expressed in ml / min / kg or L / h. It can then be compared to any physiological blood flow (e.g., hepatic blood flow) to assess whether the clearance is low, medium, or high.

[0090] When clearance is low, depending on the volume of distribution, a low dose may be expected to achieve a relatively long duration of action. When clearance is high, again depending on the volume of distribution, a high dose may be expected to achieve a relatively short duration of action.

[0091] According to the protocol described in this paper, assuming that the main excretion route is metabolism, the clearance rate is usually assessed by using hepatocyte culture and scale calculation. The intrinsic clearance rate assessed by hepatocytes is expressed in µl / min / 106 cells.

[0092] When tested in the clearance analysis described herein, the compound of formula (I) according to the invention advantageously exhibited clearance of less than about 10 μl / min / 106 cells.

[0093] [cAMP HTRF] [Measurement] [, , ] The following describes the specific conditions under which the compounds were tested.

[0094] [a. Method D1 Cell Culture] Cells were cultured at 37°C in a humid environment with 5% CO2. Cells were grown in DMEM-F12+GlutaMAX™-I medium (GIBCO®, Invitrogen, Merelbeke, Belgium) containing 10% fetal bovine serum (BioWhittaker®, Lonza, Verviers, Belgium), 400 µg / mL Geneticin (GIBCO®), 100 IU / mL Penicillin, and 100 IU / mL Streptomycin (Pen-Strep solution, BioWhittaker®). LMtk (Ltk-) mouse fibroblasts expressing the dopamine D1 receptor (BioSignal Inc, Montreal, Canada, now Perkin Elmer) were used because they have been shown to effectively couple and provide robust functional responses (Wattset et al., 1995).

[0095] [b. cAMP assay] Intracellular cyclic adenosine monophosphate (cAMP) changes were measured using the HTRF cAMP dynamics assay kit from CisBio (Codolet, France). Homogenized time-resolved fluorescence spectroscopy was employed; the assay was based on competition between naturally produced cAMP and cAMP labeled with dye d2. Tracer binding was determined using an anti-cAMP antibody labeled with a cryptate compound. The individual effects (promoting effects) of compounds were determined by assays in the absence of dopamine, while the effects of compounds acting as positive ectopic modulators (PAMs) were determined in the presence of EC20 concentrations of dopamine. Cells (20,000 cells per well) were cultured at room temperature in 384 pans for 1 hour in a final volume of 20 µL HBSS (Lonza, with calcium, magnesium, and HEPES buffer 20 mM, pH 7.4). The HBSS contained isobutylmethylxanthine (Sigma, final 0.1 mM), with the concentration of the test compound varying in the presence and absence of dopamine (final 1.1 nM) (typically from 10⁻⁹.5 M to 10⁻⁴.5 M). The reaction was then terminated, and cells were lysed according to the manufacturer's instructions by adding the d2 assay reagent to lysis buffer (10 μL) and the crypt compound reagent to lysis buffer (10 μL). Cells were then further cultured at room temperature for 60 minutes, and changes in HTRF fluorescence emissivity were determined using a laser-excited Envision pan reader (Perkin Elmer, Zaventem, Belgium) according to the manufacturer's instructions. All cultures were repeated twice, and the results were compared with concentration-effect curves of dopamine (10⁻¹¹ M to 10⁻⁶ M).

[0096] [c. Data Analysis] Data were analyzed using Excel and PRISM (GraphPad software), and pEC50 and Erel were obtained using a 4-parameter logarithmic equation (DeLean et al, 1978), where Erel is the fitted maximum response of the test compound minus the basis, expressed as a percentage relative to the one obtained with dopamine, defined as 100%. The pEC50 of the compound is -log10 of the concentration of the compound that produces a 50% increase in cAMP levels. Erel is the measured relative efficacy, defined as the maximum enhancement effect produced by the compound relative to the maximum response produced by increasing dopamine concentration (Erel = 1 = maximum dopamine response). When tested in the above analysis, the compound of formula (I) exhibited a pEC50 value of approximately 8.1 and an Erel value of approximately 68%.

[0097] GABA, A , ] [Fully Automated Patch Clamping of Recipient Cells] [(Automated Patch Clamp)] [Research] [, , ] CHO-K1 cells stably expressing human GABAA receptor α1, β2, and γ2 subunits were harvested using trypsin and stored in serum-free medium at room temperature. Prior to testing, the cells were washed and resuspended in extracellular solution.

[0098] [Diaphragm clamping study]

[0099] Experiments were performed on human GABAA (α1β2γ2) channels using a fully automated patch-clamp assay (IonFlux™ HT). Compounds were tested in 3 to 4 cells at three concentrations (0.1, 1, and 10 µM). The external solution for recording GABAA currents consisted of 137 mM sodium chloride, 4 mM potassium chloride, 1.8 mM calcium chloride, 1 mM magnesium chloride, 10 mM HEPES, and 10 mM glucose. Both the external and internal solutions were titrated with NaOH or KOH to obtain pH 7.35 or 7.3, respectively. The internal pipette solution contained 70 mM potassium fluoride, 60 mM potassium chloride, 70 mM sodium chloride, 5 mM HEPES, 5 mM EGTA, and 4 mM magnesium ATP. The final concentration of the diluent used to dilute the compounds in each well was 0.33% DMSO. Bicuculline (0.032 to 100 µM) was used as a positive control inhibitor. GABA (15 µM) was used as the agonist. All records were obtained from a holding potential of -60 mV.

[0100] The compounds were added in the following order: GABA at an EC80 concentration was added once to establish a baseline reaction. Each concentration of compound was applied for 30 seconds, followed by the addition of 15 μM GABA for 2 seconds in the presence of that compound. This process was repeated for the next concentration of compound. The peak inward current induced by the addition of GABA was measured in the presence of a single compound concentration. All compound data were normalized to the baseline peak current induced by the addition of 15 μM GABA for 2 seconds.

[0101] When tested in the above analysis, at a concentration of 10 μM, the compound represented by formula (I) showed an inhibition percentage of less than about 0.1% against the GABAA receptor at a concentration of 10 μM of the compound represented by formula (I).

[0102] [Induced Analysis] The following analysis is aimed at determining the potential of the compounds according to the present invention to induce CYP3A4 enzymes.

[0103] [A. In vitro evaluation of CYP3A4 induction potential using cryopreserved human hepatocytes]

[0104] The purpose of human hepatocyte analysis is to characterize the induction potential of compound (I) by measuring CYP3A4 activity after treating hepatocytes with a single culture medium or a culture medium containing an increased concentration of NCE for 3 days.

[0105] For this purpose, cryopreserved human hepatocytes from a single donor were seeded onto 48-well collagen-coated discs to achieve a final seeding density of 0.2 x 10⁶ cells / well (final volume per well 0.25 mL). Cells were then cultured in seeding medium at 37°C, 95% humidity, and 5% CO₂ to allow cell attachment. After 4 hours, the seeding medium was replaced with 0.25 mL of pre-warmed serum-free Williams E medium containing 100 IU / mL penicillin, 100 µg / mL streptomycin, 10 µg / mL insulin, 2 mM glutamic acid, and 0.1 µM dihydrocortisone.

[0106] The following day, cells were given analytical medium containing the test compound at 1 µM (final DMSO concentration 0.1%), and positive control inducer, rifampicin (10 μM), were cultured together with the test compound. Three aliquots of each test compound were administered, with the test compound replaced by analytical medium containing 0.1% DMSO in the negative control wells. Cells were exposed to the medium for 72 hours, with the medium changed every 24 hours.

[0107] To determine catalytic activity, a CYP3A4 probe matrix solution (midazolam, final concentration 2.5 µM) was prepared in pre-warmed analytical medium. At the end of the 72-hour exposure period, the medium was replaced with the CYP3A4 probe matrix, hepatocytes were cultured for 30 minutes, aliquots were transferred and placed in an equal volume of methanol containing an internal standard, and the samples were centrifuged at 2500 rpm for 20 minutes at 4°C. The supernatant aliquots were diluted with deionized water, and the level of 1-hydroxymidazolam was quantified using a general LC MS / MS method.

[0108] Hepatocytes were dissolved in 0.1M sodium hydroxide at room temperature, and the protein content in each well was measured using a Pierce™ BCA protein analysis kit (Thermo Scientific) with bovine serum albumin as the standard.

[0109] [Data Analysis] []

[0110] Fold-induction (increased CYP activity) was obtained by comparing the enzyme activity measured in hepatocytes treated with compound (I) with that measured in control hepatocytes treated with the methylating agent. Fold-induction was calculated in the same manner for the positive control (rifampin). The induction potential of compound (I) was then compared with that of rifampin by calculating the ratio of fold-induction observed with rifampin to fold-induction observed with compound (I).

[0111] When tested at a concentration of 1 µM in CYP3A4 induction assay according to the above scheme, the compound of formula (I) according to the present invention exhibits a fold induction value that is at least about 7 times lower than that of the positive control compound (rifampin) at a concentration of 10 µM.

[0112] Using the same protocol described above, cells were given analytical medium (final DMSO concentration of 0.1%) containing test compounds at concentrations ranging from 0.03 to 10 µM, and the positive control inducer rifampin was cultured together with test compounds at concentrations ranging from 0.1 to 30 µM.

[0113] When comparing the highest fold induction values ​​from the above schemes, i.e. those obtained at the highest soluble concentration (3 µM) of the compound of formula (I) of the present invention and the 10 µM positive control (rifampin), the induction potential of the compound of formula (I) was about 4 times lower than that of the positive control compound (rifampin).

[0114] [Azamorin] [(Azamulin)] [Measurement] [, , ]

[0115] According to the supplier's information, thawed cryopreserved human hepatocytes (from 20 donors' stockpiles, BSU batches from Celsis / IVT / Bioreclamation) were used. Viability (trypan blue excluded) was higher than 75%. Pre-cultured in Williams' medium (containing 2 mM glutamic acid and 15 mM Hepes) in 48-well plates at +37°C in an incubator (5% CO2) with gentle stirring (Titramax 100, CA 300 rpm) for 30 minutes (250 µL of 2 x 10⁶ hepatocytes / mL hepatocyte suspension). After pre-culture, hepatocytes were cultured by adding 250 µL of medium (see above composition) containing either a UCB compound (1 µM) or midazolam (positive control) and azamoline (6 µM – a specific CYP3A4 / 5 inhibitor) with or without azamoline (see above composition). The final concentrations of UCB compound and azamoline in the culture were 0.5 µM and 3 µM, respectively. The cell suspension was rapidly rehomogenized by two pipetting operations. After culturing for 0, 30, 60, 120, 180, and 240 minutes, the reaction was terminated by transferring 50 µL of culture to appropriate wells in a 96-well dish containing 50 µL of ice-cold acetonitrile (with 1 µM ketoconazole as an internal standard). Before each sampling, the cell culture was rehomogenized by two pipetting operations.

[0116] When cultured with human hepatocyte suspensions of different concentrations, the inherent clearance (Clint) of the compound of formula (I) according to the invention is equal to 2.1 ± 0.6 µl / min / 10⁶ cells. Implementation

[0117] The following examples illustrate the preparation of compounds of formula (I) according to the present invention.

[0118] [Example]

[0119] [abbreviation] [ / ] [Reagents that appear repeatedly] ACN: Acetonitrile Salt water: saturated sodium chloride aqueous solution nBu: n-Butyl tBu: Tertiary Butyl DCM: Dichloromethane DMAP: 4-Dimethylaminopyridine DMF: N,N-Dimethylformamide DMSO: Dimethyl sulfoxide EC20 / 50: Concentrations that produce 20% / 50% of the maximum response. Erel: Relative efficacy ES+: Electro-injection positive ionization Et: Ethyl EtOH: Ethanol Et2O: Diethyl ether EtOAc: Ethyl acetate h: hours HPLC: High-performance liquid chromatography HTRF: Homogeneous Time-Resolved Fluorescence LCMS: Liquid Chromatography-Mass Spectrometry MeOH: Methanol min.: minutes NCS: N-chlorosuccinimide NMR: Nuclear Magnetic Resonance iPrOH: Isopropanol rt: room temperature SFC: Supercritical Fluid Chromatography TEA: Triethylamine THF: Tetrahydrofuran TLC: Thin-layer chromatography cAMP: Cyclic Adenosine Monophosphate

[0120] The name IUPAC has been determined using Biovia Draw 16.1.

[0121] [Analysis Methods]

[0122] All reactions involving air- or moisture-sensitive reagents are carried out in a nitrogen or argon atmosphere using dry solvents and glassware. Commercial solvents and reagents are typically used without further purification, including anhydrous solvents where appropriate (usually Sure-Seal™ products from Aldrich Chemicals or AcroSeal™ from ACROS Organics). Generally, thin-layer chromatography, HPLC, or mass spectrometry analysis is performed after the reaction.

[0123] Crude substances can be purified by normal phase chromatography, (acidic or basic) reverse phase chromatography, chiral separation, or recrystallization.

[0124] The product is usually dried under vacuum before final analysis and delivery to biological experiments.

[0125] All NMR spectra were obtained at 250 MHz, 300 MHz, 400 MHz, or 500 MHz.

[0126] Compounds were studied in DMSO-d6, CDCl3, or MeOH-d4 solutions at a probe temperature of 300 K and a concentration of 10 mg / mL, with the instrument locked to the deuterium signal of DMSO-d6, CDCl3, or CD3OD. Chemical shifts are given in ppm in the downfield region relative to TMS (tetramethylsilane) as an internal standard.

[0127] [1.] [Preparative Formula] [(II)] [Intermediate]-2-(3,5-dichloro-1-methyl-indazol-4-yl)acetic acid

[0128] 1.1. [Preparation of intermediates] [(XIb)]-1-methyl-5-nitro-indazole 5-nitro-1H-indazole [(XIa)] (3.00 kg, 18.4 mol) and DMF (30.0 L) were packed into a 50 L three-necked round-bottom flask at 15–30°C. One part KOH (2.06 kg, 36.7 mol) was added to the reactor at 0–5°C. The mixture was stirred at 0–50°C for 1 hour. Then, methyl iodine (2.87 kg, 20.2 mol) was added at 0–5°C, and the mixture was stirred at 15–30°C for 3 hours. The reaction mixture was added to water (30 L) at 0–10°C, and the mixture was stirred for 10 minutes, then filtered. The filter cake was washed with water (5 L) and dried. This entire procedure was performed in parallel on four batches of the same size. The solids obtained from the four batches were combined to obtain 1-methyl-5-nitro-indazole as a brown solid. [(XIb)](10.0 kg, 42.3 mol, 75% purity (LC / MS), 57.5% yield) requires no further purification for the next step. 1H NMR (400 MHz, CDCl3) δ 8.65 (s, 1H), 8.21 (d, J = 9.17 Hz, 1 H), 8.13 (s, 1 H), 7.39 (d, J = 9.17 Hz, 1 H), 4.08 (s, 3 H).

[0129] 1.2. [Preparation of intermediates] [(Xa)]-2-(1-methyl-5-nitro-indazol-4-yl)acetic acid tributyl ester t-BuOK (4.43 kg, 39.5 mol) and THF (30 L) were packed into a 50 L three-necked round-bottom flask, and the mixture was cooled to -45 / -35°C under nitrogen and stirred. Then, 1-methyl-5-nitro-indazole was added in portions at -45 / -35°C. [(XIb)] (3.50 kg, 19.7 mol), 2-chloroacetic acid tributyl ester (3.57 kg, 23.7 mol) was added dropwise at the same temperature, and the mixture was stirred for 1 hour. The mixture was heated to 15-30°C and stirred for 5 hours. The reaction was terminated by adding saturated ammonium chloride solution (9 L) and water (2 L). The organic layer was separated and the aqueous layer was extracted with ethyl acetate (2 x 5 L). The organic phases were combined, washed with brine (2 L), dried on Na2SO4, filtered, and concentrated under vacuum. The crude product was purified by recrystallization with ethyl acetate (5 L). This whole process was carried out in parallel in two batches of the same size. The solids obtained from the two batches were combined and dried together to obtain 2-(1-methyl-5-nitro-indazole-4-yl)acetic acid tributyl ester as a yellow solid. [Xa)](5.30 kg, 17.7 mol, 97.6% purity (LC / MS), 44.9% yield). 1H NMR (400 MHz, CDCl3) δ 8.18-8.20 (m, 2H), 7.37 (d, J = 9.21 Hz, 1 H), 4.27 (s, 2 H), 4.14 (s, 3 H), 1.44 (s, 9 H).

[0130] 1.3. [Preparation of intermediates] [(Xb)]-2-(5-amino-1-methyl-indazol-4-yl)acetic acid tributyl ester Tributyl 2-(1-methyl-5-nitro-indazole-4-yl)acetate [(Xa)] (7.30 kg, 25.0 mol) and MeOH (76 L) were packed into the reactor. The reactor was purged with argon and Pd / C (50%, 760 g) was added. Hydrogen was added three times, and the mixture was stirred at 50°C in a hydrogen atmosphere (50 psi) for 3 hours. The reaction mixture was filtered, and the solids were washed with MeOH (5 L). The mixture was concentrated to obtain a brown oily tributyl 2-(5-amino-1-methyl-indazole-4-yl)acetic acid. [(Xb)](6.50 kg, 23.9 mol, 96.2% purity (LC / MS), 95.4% yield), which does not require further purification for the next step. 1H NMR (400 MHz, CDCl3) δ 7.72 (s, 1H), 7.27 (d,J= 8.80 Hz, 1 H), 6.91 (d,J= 8.80 Hz, 1 H), 4.60 (s, 2 H), 3.93 (s, 3 H), 3.68 (s, 2H), 1.38 (s, 9 H).

[0131] 1.4. [Preparation of intermediates] [(Xc)]-2-(5-chloro-1-methyl-indazol-4-yl)acetic acid Tributyl 2-(5-amino-1-methyl-indazole-4-yl)acetate [(Xb)] (2.00 kg, 7.65 mol) and concentrated HCl (10.0 L, 12M) were added to a 50 L three-necked round-bottom flask, and the mixture was cooled to -10 / -5°C and stirred. Sodium nitrite (686 g, 9.95 mol) aqueous solution (5 L) was added dropwise at -10 / -5°C and stirred for 30 minutes. CuCl (833 g, 8.42 mol) and concentrated HCl (10.0 L, 12M) were added to a 20 L three-necked round-bottom flask, and the mixture was stirred at -10 / -5°C for 30 minutes, then added to other reactors. The mixture was stirred at -10 / -5°C for 1 hour, then at 10–30°C for 16 hours. The reaction mixture was filtered, and the solids were washed with water. This overall procedure was performed in three batches of the same size in parallel. The solids obtained from the three batches were combined and dried together to obtain 2-(5-chloro-1-methyl-indazol-4-yl)acetic acid as a yellow solid. [(Xc)](4.00 kg, 16.3 mol, 92% purity (LC / MS), 71.3% yield), which does not require further purification for the next step.

[0132] 1.5. Preparation of 2-(3,5-dichloro-1-methyl-indazol-4-yl)acetic acid [(II)] 2-(5-chloro-1-methyl-indazol-4-yl)acetic acid [(Xc)] (1.30 kg, 5.79 mol) and DMF (6.5 L) were packed into a 50 L three-necked round-bottom flask at 20°C. N-chlorosuccinimide (772 g, 5.79 mol) was added in a batch at 20°C, and the mixture was stirred at 20°C for 2 hours. The reaction mixture was poured into water (25 L) and filtered. The crude product was ground at 20°C with isopropyl ether:ethyl acetate (3:1) (7.0 L) for 2 hours, then filtered and dried. This overall procedure was performed in three parallel batches of the same size. The solids obtained from the three batches were combined to give 2-(3,5-dichloro-1-methyl-indazol-4-yl)acetic acid. [(II)](2.1 kg, 7.9 mol, 97.5% purity (LC / MS), 46% yield). 1H NMR (400 MHz, CDCl3) δ 12.67 (s, 1 H), 7.68 (d,J= 9.05 Hz, 1 H), 7.53 (d,J= 9.05 Hz, 1 H), 4.20 (s, 2 H), 4.02 (s, 3 H).

[0133] [2.] [Preparative Formula] [(I)] [Compound] 2-(3,5-Dichloro-1-methyl-indazol-4-yl)-1-[(1S,3R)-3-(hydroxymethyl)-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-yl] ethyl ketone

[0134] 2.1. [Preparation of intermediates] [(IX)] (2R)-2-amino-3-(2-bromophenyl)prop-1-ol- [a6] (2R)-2-amino-3-(2-bromophenyl)propionic acid [a5] (34.0 kg, 139 mol) and THF (238 L) were packed into the reactor. Sodium borohydride (15.6 kg, 413 mol) was slowly added at 20–30°C. Iodine (35.3 kg, 139 mol) in dry THF (20.0 L) was slowly added at 0–10°C, and the reaction mixture was stirred at 70°C for 12 hours. The reaction was terminated at 0°C with methanol (70.0 L) and heated to 80°C for 30 minutes. The mixture was cooled, concentrated under vacuum, and the residue was suspended in NaOH (30.0 L, 2N) and then filtered. The filter cake was dried under vacuum to obtain (2R)-2-amino-3-(2-bromophenyl)prop-1-ol as a white solid. [a6] (31.0 kg, 135 mol, 96.7% yield) does not require further purification for the next step. 1H NMR (400 MHz, CDCl3) δ 7.57 (d,J= 7.7 Hz, 1H), 7.21 - 7.29 (m, 2H), 7.07 - 7.15 (m, 1H), 3.66 (dd,J= 10.5, 3.6 Hz, 1H), 3.41 (dd,J= 10.5, 7.2 Hz, 1H), 3.18 - 3.29 (m, 1H), 2.95 (dd,J= 13.5, 5.5 Hz, 1H), 2.70 (dd,J= 13.5, 8.2 Hz, 1H), 1.51 - 1.91 (m, 3H).

[0135] 2.2. [Preparative Formula] [(VIII)] [Intermediate] (4R)-4-[(2-bromophenyl)methyl]azolidin-2-one- [a7] (2R)-2-amino-3-(2-bromophenyl)prop-1-ol [a6] (31.0 kg, 135 mol) and dichloromethane (220 L) were packed into the reactor. Triphosgene (13.9 kg, 47.1 mol) was added at room temperature, followed by the slow addition of N,N-diisopropylethylamine (39.1 kg, 303 mol) at 0–10°C. The reaction mixture was stirred at 0–10°C for 1 hour, then washed twice with water (50.0 L), dried over anhydrous sodium sulfate, and filtered to obtain (4R)-4-[(2-bromophenyl)methyl]azolidin-2-one as a solution in dichloromethane. [a7], which is used directly in the next step.

[0136] 2.3. [Preparation of intermediates] [(VII)] (10aR)-9-bromo-1,5,10,10a-tetrahydrozozo[3,4-b]isoquinoline-3-one [a8] The (4R)-4-[(2-bromophenyl)methyl]azolidin-2-one A solution of [a7](135 mol) of dichloromethane (220 L) was packed into the reactor and cooled to 0–5°C. Trimethylsilane trifluoromethanesulfonate (35.9 kg, 162 mol) and polyoxymethylene (13.3 kg, 148 mol) were added at 0–5°C, followed by stirring at 15–20°C for 2 hours. Water (170 L) was added to the mixture, which was then extracted twice with dichloromethane (50.0 L). The organic layer was dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. A mixture of petroleum ether:ethyl acetate (1:1, 45.0 L) was added, and the mixture was stirred at room temperature for 6 hours and filtered. The solid was dried to obtain a grayish-white solid of (10aR)-9-bromo-1,5,10,10a-tetrahydrozozazo[3,4-b]isoquinoline-3-one. [a8](29.0 kg, 80.2% yield). 1H NMR (400 MHz, CDCl3) δ 7.45 - 7.52 (m, 1H), 7.08 - 7.14 (m, 2H), 4.83 (d,J= 17.0 Hz, 1H), 4.62 (t,J= 8.4 Hz, 1H), 4.36 (d,J= 17.0 Hz, 1H), 4.21 (dd,J= 8.6, 4.9 Hz, 1H), 3.91 - 3.99 (m, 1H), 3.25 (dd,J= 16.3, 4.2 Hz, 1H), 2.67 (dd,J= 16.1, 11.0 Hz, 1H).

[0137] 2.4. [Preparation of intermediates] [(VI)]

[0138] 2.4.1. [(3R)-5-bromo-1,2,3,4-tetrahydroisoquinoline-3-yl]methanol [a9] Ethanol (120 L) and water (60.0 L) were mixed in the reactor. (10aR)-9-bromo-1,5,10,10a-tetrahydrozozazo[3,4-b]isoquinoline-3-one was then added. [a8] (29.7 kg, 111 mol), followed by slow addition of sodium hydroxide (13.3 kg, 332 mol) at 15–20°C. The reaction mixture was stirred at 90°C for 2 hours and then cooled to room temperature. Water (300 L) was added to the mixture and centrifuged. The centrifuged filter cake was dried in a circulating oven to obtain [(3R)-5-bromo-1,2,3,4-tetrahydroisoquinoline-3-yl]methanol as a white solid. [a9] (23.7 kg, 88.3% yield) does not require further purification for the next step. 1H NMR (400 MHz, CDCl3) δ 7.37 - 7.47 (m, 1H), 6.95 - 7.08 (m, 2H), 4.00 - 4.10 (m, 2H), 3.85 (dd,J= 10.9, 3.7 Hz, 1H), 3.57 (dd,J= 10.9, 7.9 Hz, 1H), 3.06 (ddt,J= 11.3, 7.6, 4.1, 4.1 Hz, 1H), 2.79 (dd,J= 17.1, 4.4 Hz, 1H), 2.40 (dd,J= 17.1, 10.9 Hz, 1H), 1.93 (br s, 2H).

[0139] 2.4.2. [(3R)-5-bromo-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane [a10] [(3R)-5-bromo-1,2,3,4-tetrahydroisoquinoline-3-yl]methanol [a9] (23.7 kg, 97.8 mol) and dichloromethane (240 L) were packed into the reactor. DMAP (120 g, 0.98 mol) and imidazole (13.3 kg, 196 mol) were added. Tributyldimethylsilyl chloride (TBSCl) (17.7 kg, 117 mol) was slowly added at 15-20°C, and the mixture was stirred for 12 hours. Ammonium chloride (100 L) was added to the mixture. The organic phase was separated, washed with water (50.0 L), dried with anhydrous sodium sulfate, filtered, and concentrated under vacuum to obtain a yellow oily substance of [(3R)-5-bromo-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy-tributyl-dimethyl-silane. [a10] (37.6 kg, 86% purity, 93% yield) requires no further purification for the next step. 1H NMR (400 MHz, CDCl3) δ 7.36 - 7.45 (m, 1H), 7.01 (d,J= 4.6 Hz, 1H), 4.01 - 4.13 (m, 2H), 3.84 (dd,J= 9.9, 3.7 Hz, 1H), 3.64 (dd,J= 9.8, 7.2 Hz, 1H), 2.96 - 3.08 (m, 1H), 2.75 (dd,J= 17.0, 4.2 Hz, 1H), 2.44 (dd,J= 17.0, 10.8 Hz, 1H), 1.76 - 2.20 (m, 2H), 0.89 - 0.97 (m, 9H), 0.08 - 0.14 (m, 6H).

[0140] 2.5. [Preparation of intermediates] [(V)] [(3R)-5-bromo-3,4-dihydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane [a11] [(3R)-5-bromo-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane [a10] (3.42 kg, 8.31 mol) and THF (30.0 L) were packed into the reactor. N-chlorosuccinimide (NCS) (1.17 kg, 8.73 mol) was slowly added at room temperature, and the mixture was stirred at 25°C for 30 min. KOH (1.52 kg, 27.1 mol) in a solution of dry methanol (7.00 L) was slowly added at room temperature, and the reaction was stirred at 25°C for 1 h. The reaction was terminated with water (10.0 L) and extracted with petroleum ether:ethyl acetate (1:2, 5.00 L). The organic layer was separated, washed with brine (10.0 L), dried over anhydrous sodium sulfate, and filtered. This overall procedure was performed in parallel on 10 batches of the same size, and the 10 reaction filtrates were combined and concentrated under vacuum to obtain a brown oily substance, [(3R)-5-bromo-3,4-dihydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane. [a11](28.0 kg, crude), which does not require further purification for the next step. 1H NMR (400 MHz, CDCl3) δ 8.24 (d,J= 2.6 Hz, 1H), 7.58 (dd,J= 7.8, 1.2 Hz, 1H), 7.12 - 7.25 (m, 2H), 4.03 (dd,J= 9.5, 4.0 Hz, 1H), 3.67 - 3.77 (m, 2H), 3.07 (dd,J= 17.0, 6.2 Hz, 1H), 2.68 (dd,J= 17.1, 10.9 Hz, 1H), 0.88 - 0.91 (m, 9H), 0.07 (d,J= 1.5 Hz, 6H).

[0141] [2.6.] [Preparative Formula] [(IV)] [Intermediate]

[0142] 2.6.1. [(1S,3R)-5-bromo-1-methyl-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane [(IVa)] [(3R)-5-bromo-3,4-dihydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane [a11] (3.10 kg, 8.75 mol) and THF (20.0 L) were packed into the reactor. The mixture was cooled to 0°C and methyl magnesium chloride (3M, 11.6 L) was added. The mixture was stirred at 20°C for 12 hours. The reaction was terminated with a saturated ammonium chloride solution, the phases were separated, and the aqueous layer was extracted twice with petroleum ether:ethyl acetate (3:1, 5.00 L). The combined organic phases were washed with brine (10.0 L), dried over anhydrous sodium sulfate, and filtered. This whole process was carried out in nine parallel batches of the same size, and the nine reaction filtrates were combined and concentrated under vacuum. The crude mixture was purified by silica gel chromatography with petroleum ether:ethyl acetate (10:1) to give a brown oily substance of [(1S,3R)-5-bromo-1-methyl-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane. [(IVa)](4.60 kg, 99.7% purity, 15.7% yield). 1H NMR (400 MHz, DMSO-d 6) δ 7.41 (dd,J=7.7, 0.9 Hz, 1H), 7.12 - 7.18 (m, 1H), 7.03 - 7.11 (m, 1H), 4.12 (q,J=6.8 Hz, 1H), 3.62 (d,J=5.7 Hz, 2H), 3.07 - 3.17 (m, 1H), 2.67 - 2.76 (m, 1H), 2.26 (dd,J=16.9, 10.0 Hz, 1H), 2.12 (br s, 1H), 1.32 (d,J=6.8 Hz, 3H), 0.84 - 0.93 (m, 9H), 0.07 (d, J = 0.9 Hz, 6H).

[0143] 2.6.2. (1S,3R)-5-bromo-3-[[tert-butyl(dimethyl)silyl]oxymethyl]-1-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester [(IVb)] [(1S,3R)-5-bromo-1-methyl-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy-tert-butyl-dimethyl-silane [(IVa)] (1.85 kg, 4.99 mol) and dichloromethane (13.0 L) were packed into the reactor. N,N-diisopropylethylamine (1.94 kg, 14.9 mol) and dibutyl dicarbonate (1.14 kg, 5.24 mol) were added at room temperature, and the mixture was stirred for 12 hours. The reaction mixture was washed twice with saturated ammonium chloride solution (10.0 L), and the organic layer was dried over anhydrous sodium sulfate and filtered. This entire procedure was performed in two parallel batches of the same size, and the two reaction filtrates were combined and concentrated under vacuum. The crude mixture was purified by silica gel chromatography using petroleum ether:ethyl acetate (30:1) to obtain (1S,3R)-5-bromo-3-[[tributyl(dimethyl)silyl]oxymethyl]-1-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tributyl ester as a yellow oil. [(IVb)](4.00 kg, 99.5% purity, 85.2% yield). 1H NMR (400 MHz, DMSO-d 6) δ 7.50 (d,J= 7.9 Hz, 1H), 7.22 (br d,J= 6.7 Hz, 1H), 7.06 - 7.18 (m, 1H), 4.84 (br s, 1H), 4.12 (br s, 1H), 3.46 (br d,J= 15.4 Hz, 2H), 2.94 (br dd,J= 15.8, 5.2 Hz, 1H), 2.71 (br t,J= 9.5 Hz, 1H), 1.45 (s, 9 H), 1.28 (br s, 3H), 0.81 (s, 9H), -0.08 (s, 6H).

[0144] 2.6.3. (1S,3R)-3-[[tert-butyl(dimethyl)silyl]oxymethyl]-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester [(IVc)] (1S,3R)-5-bromo-3-[[tributyl(dimethyl)silyl]oxymethyl]-1-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tributyl ester A solution of [(IVb)] (42.5 g, 90.3 mmol) in dry THF (0.5 M solution) and a commercially available solution of n-butyllithium in hexane (1.6 M solution) were pumped at 6.0 mL / min (1.0 equivalent) and 2.46 mL / min (1.3 equivalent), respectively, and mixed in a glass microplate cooled to -40 °C. The mixed flow was pumped through reaction zone 1 of the microplate (0.3 mL) and then combined with a solution of dry acetone (13.5 M) pumped at 6.0 mL / min (27 equivalent). The resulting flow was then passed through reaction zone 2 of the microplate (0.7 mL) at -40 °C. Finally, the total flow leaving the reactor was collected, and the reaction was terminated at room temperature in a saturated aqueous solution of ammonium chloride. When all the feed solutions were consumed, a bilayer reaction mixture was obtained. The aqueous layer was separated from the organic layer and then extracted twice with ethyl acetate. The combined organic layer was washed with brine, dried on anhydrous sodium sulfate, and concentrated under vacuum. A yellow oil (46.5 g) was obtained and purified by SFC chromatography on a GreenSep Nitro column (10 µL, 5 x 22.3 μm using 98% CO2 / 2% EtOH eluent). The solvent was removed under vacuum to yield a white solid, (1S,3R)-3-[[tributyl(dimethyl)silyl]oxymethyl]-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tributyl ester. [(IVc)](25 g, 56 mmol, 62% yield). UPLC_MS basic 1 pic @ 3.83 min (ES+): 350 (M-Boc+H)+, 332 (M-Boc-H2O+H)+, 100% purity. 1H NMR (400 MHz, DMSO-d 6) δ 7.44 (d, J = 7.9 Hz, 1H), 7.19 (dt, J = 8.1, 5.2 Hz, 1H), 7.09 (t, J = 9.0 Hz, 1H), 4.99 (s, 1H), 4.87 (dq, J = 13.4, 6.4 Hz, 1H), 4.11 (s, 1H), 3.96 (t, J = 14.9 Hz, 1H), 3.48 (dd, J = 9.4, 4.1 Hz, 1H), 2.98 (dd, J = 16.5, 5.0 Hz, 1H), 2.89 (t, J = 9.6 Hz, 1H), 1.65 (s, 3H), 1.58 (s, 3H), 1.55 (d, J = 2.5 Hz, 9H), 1.34 (dd, J = 20.5, 6.6 Hz, 3H), 0.90 (s, 9H), 0.08 (d, J = 7.2 Hz, 3H), -0.00 (s, 3H).

[0145] 2.7. [Preparation of intermediates] [(III)]2-[(1S,3R)-3-(hydroxymethyl)-1-methyl-1,2,3,4-tetrahydroisoquinoline-2-onthium-5-yl]prop-2-ol chloride

[0146] 2.7.1. Tributyl-dimethyl-[[(1S,3R)-1-methyl-5-(1-methyl-1-trimethylsiloxy-ethyl)-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy]silane- [a15] (1S,3R)-3-[[tributyl(dimethyl)silyl]oxymethyl]-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tributyl ester [(IVc)] (148 g, 87% purity, 287 mmol) was dissolved in 1000 mL of dichloromethane and transferred to a 2 L double-layer reactor. 2,6-Dimethylpyridine (100 mL, 860 mmol) was added and the jacket temperature was set to -2°C. Trimethylsilane trifluoromethanesulfonate (154 g, 129 mL, 692 mmol) was added over an additional funnel over a period of 40 minutes. Two hours after the start of the addition, the reaction was terminated by adding 650 mL of aqueous citric acid (1 M) and the mixture was warmed to 20°C. One hour after the start of the termination of the reaction, the layers were separated. The organic layer was washed twice with 350 mL of aqueous citric acid (1 M). Before separating the layers, the organic layer was stirred for 10 minutes with 750 mL of aqueous sodium carbonate solution (10% w / w). The organic layer was dried on anhydrous sodium sulfate, then filtered, and the filtrate was concentrated under vacuum at 40°C to provide tertiary butyl-dimethyl-[[(1S,3R)-1-methyl-5-(1-methyl-1-trimethylsiloxy-ethyl)-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy]silane. The yellow oily substance of [a15] (128 g) does not require further purification and is used in the next step. 1H NMR (400 MHz, CDCl3) δ 7.19 (d, J = 7.7 Hz, 1H), 7.07 (t, J = 7.7 Hz, 1H), 7.00 (d, J = 7.6 Hz, 1H), 4.24 (q, J = 6.8 Hz, 1H), 3.75 (dd, J = 9.7, 4.4 Hz, 1H), 3.60 (dd, J = 9.7, 7.0 Hz, 1H), 3.54 (dd, J = 16.3, 3.5 Hz, 1H), 3.15 (ddt, J = 10.9, 7.4, 4.0 Hz, 1H), 2.52 (dd, J = 16.3, 10.9 Hz, 1H), 1.66 (d, J = 14.6 Hz, 6H), 1.52 – 1.43 (m, 3H), 0.92 (q, J = 1.2 Hz, 9H), 0.14 (q, J = 1.2 Hz, 2H), 0.09 (d, J = 1.1 Hz, 6H), 0.00 (q, J = 1.2, 0.8 Hz, 9H).

[0147] 2.7.2. 2-[(1S,3R)-3-(hydroxymethyl)-1-methyl-1,2,3,4-tetrahydroisoquinoline-2-onthiol-5-yl]prop-2-ol chloride intermediate [(III)] In a three-necked round-bottom flask equipped with a mechanical stirrer, tert-butyl-dimethyl-[[(1S,3R)-1-methyl-5-(1-methyl-1-trimethylsiloxy-ethyl)-1,2,3,4-tetrahydroisoquinoline-3-yl]methoxy]silane [a15] (20.0 g, 47.4 mmol) was dissolved in 220 mL of isopropanol. 42.3 mL of hydrochloric acid (5–6 M, about 5 eq.) in isopropanol was added to this solution. 45 minutes after the addition of hydrochloric acid, 100 mg of the desired product was introduced as a seed crystal. After 7 hours at room temperature, the reaction mixture was filtered through a sintered glass filter. The filter cake was washed with 40 mL of isopropanol and dried overnight under vacuum at room temperature. 11.1 g of 2-[(1S,3R)-3-(hydroxymethyl)-1-methyl-1,2,3,4-tetrahydroisoquinoline-2-onthiol-5-yl]prop-2-ol chloride was obtained as a pale pink solid. [(III)]. The yield of the two deprotection steps was 91%. 1H NMR (400 MHz, CD3OD) δ 7.46 (dd, J = 7.8, 1.3 Hz, 1H), 7.28 (t, J = 7.8 Hz, 1H), 7.21 (dd, J = 7.8, 1.3 Hz, 1H), 4.63 (q, J = 6.9 Hz, 1H), 3.97 (dd, J = 11.7, 3.8 Hz, 1H), 3.88 (dd, J = 17.2, 4.3 Hz, 1H), 3.78 (dd, J = 11.8, 6.1 Hz, 1H), 3.66 – 3.56 (m, 1H), 3.14 (dd, J = 17.2, 11.4 Hz, 1H), 1.73 (d, J = 6.8 Hz, 3H), 1.64 (d, J = 4.8 Hz, 6H). No OH or NH protons were observed.

[0148] 2.8. [Preparative Formula] [(I)] [Compound] 2-(3,5-Dichloro-1-methyl-indazol-4-yl)-1-[(1S,3R)-3-(hydroxymethyl)-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-yl] ethyl ketone In a 100 mL Easymax reactor equipped with a mechanical stirrer, 2-(3,5-dichloro-1-methyl-indazol-4-yl)acetic acid was filled. [(II)] (4.00 g, 15.4 mmol), 2-[(1S,3R)-3-(hydroxymethyl)-1-methyl-1,2,3,4-tetrahydroisoquinoline-2-onthiol-5-yl]prop-2-ol chloride [(III)] (4.46 g, 16.4 mmol) and 48 mL DMF. The suspension was stirred at 20°C and then cooled by setting the jacket temperature to -2°C. Once the temperature of the mixture was below 3°C, N,N-diisopropylethylamine (9.5 mL, 54 mmol) was added. (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethylurea hexafluorophosphate (6.4 g, 17 mmol)) was added in four fractions over a period of 1 hour. The mixture was stirred for 1 hour and 45 minutes, after which the jacket temperature was set at 15°C, and 16 mL of water was added over several minutes. After 15 minutes, 30 mg of solid product was added as a seed crystal to initiate crystallization. The jacket temperature was set at 20°C. After half an hour, 16 mL of water was added over a period of 17 minutes. The suspension was stirred and stirred at 20°C for 2 hours and 15 minutes before filtration on a sintered glass. The filter cake was washed with 20 mL of water in two fractions and then dried overnight under vacuum at 50°C to produce 6.03 g of 2-(3,5-dichloro-1-methyl-indazol-4-yl)-1-[(1S,3R)-3-(hydroxymethyl)-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-yl] ethyl ketone [(I)](crude material). Recrystallization was performed on 5.00 g of crude material obtained by first suspending it in 50 mL of acetonitrile. The jacket temperature was set at 70°C. Once the solid melted and the agglomerate temperature reached 66°C, 720 µl of water was added. The agglomerate temperature was then cooled to 59°C, and 125 mg of the solid product was added as seed material. The agglomerate temperature was then lowered to 55°C over a period of 25 minutes, during which crystallization occurred. The jacket temperature was then lowered from 58°C to 20°C over a period of two hours. After 50 minutes, the suspension was filtered, and the filter cake was washed with 7.5 mL of acetonitrile. The filter cake was then dried under vacuum at 45°C overnight and at 50°C for 2 hours, yielding 4.04 g of 2-(3,5-dichloro-1-methyl-indazol-4-yl)-1-[(1S,3R)-3-(hydroxymethyl)-5-(1-hydroxy-1-methyl-ethyl)-1-methyl-3,4-dihydro-1H-isoquinoline-2-yl] ethyl ketone as a grayish-white powder. [(I)] (hydrate form), yield = 64%. 1H NMR (400 MHz, DMSO-d 6) δ 7.65 (dd, J = 9.0, 2.2 Hz, 1H), 7.52 (dd, J = 9.0, 2.1 Hz, 1H), 7.37 (ddd, J = 19.6, 7.6, 1.7 Hz, 1H), 7.25 – 7.03 (m, 2H), 5.30 (q, J = 6.5 Hz, 0.3H), 5.16 – 4.99 (m, 1.7H), 4.99 – 4.84 (m, 0.7H), 4.63 – 4.30 (m, 3.3H), 4.17 – 3.93 (m, 4H), 3.28 (dt, J = 10.5, 5.1 Hz, 1.3H), 3.10 – 2.85 (m, 1.7H), 1.56 (dd, J = 13.2, 6.9 Hz, 6.7H), 1.24 (d, J = 6.5 Hz, 2.3H).

Claims

1. A method for preparing a compound of formula (I), comprising reacting an intermediate of formula (II) with an intermediate of formula (III) in the presence of a base using a coupling agent.

2. The method for preparing compound (I) as claimed in claim 1, wherein compound (II) is prepared by a method comprising the following steps: (i) reacting intermediate (XIa) with iodomethane in the presence of a base to provide intermediate (XIb); (ii) reacting intermediate (XIb) obtained in step (i) with tributyl 2-chloroacetate in the presence of a base to provide intermediate (Xa); (iii) reducing intermediate (Xa) by Pd / C catalytic hydrogenation to provide intermediate (Xb); (iv) saponifying intermediate (Xb) and performing a Sandmeyer reaction in the presence of sodium nitrite, a strong acid and copper chloride (II) to provide intermediate (Xc); and (v) chlorinating intermediate (Xc) with N-chlorosuccinimide to provide intermediate (II).

3. The method of claim 1, wherein the coupling agent is 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethylurea hexafluorophosphate, and the base is N,N-diisopropylethylamine.

4. The method of claim 1, which includes an additional recrystallization step to provide a hydrate form of the compound of formula (I).

5. The method of claim 2, wherein the base in step (i) is potassium hydroxide.

6. The method of claim 2, wherein the base in step (ii) is potassium tert-butoxide.

7. The method of claim 2, wherein the strong acid in step (iv) is hydrochloric acid.

8. A compound of formula (II), .

9. A compound of formula (III), .