Method for preparing 1,2,3,5,6,7-hexahydro-s-indacene derivatives

Abstract

The present invention relates to intermediates and processes useful for preparing 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide and its salts.The present invention further relates to 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide and its salts when prepared by such processes, and related pharmaceutical compositions and uses for the treatment and prevention of medical disorders and diseases, particularly by NLRP3 inhibition.

Description

[Technical field]

[0001] The present invention relates to intermediates and processes useful for preparing 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide and its salts.The present invention further relates to 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide and its salts when prepared by such processes, and related pharmaceutical compositions and uses for the treatment and prevention of medical disorders and diseases, particularly by NLRP3 inhibition. [Background technology]

[0002] 1-Ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide has been disclosed in WO 2019 / 008025 as an NLRP3 inhibitor (see Example 6). However, there is a need to provide an improved method for preparing 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide and its salts. In particular, there is a need to provide an efficient method that is suitable for large-scale synthesis and avoids, for example, multiple complex and partially low-yield chemical steps and overall atom inefficient synthesis.

[0003] There is also a need to provide 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide and its salts in higher yields, especially on a large scale, as compared to the prior art processes. Furthermore, for large-scale industrialization, more environmentally friendly synthetic routes, reduced solvent waste, and improved safety are also of concern. The present invention solves the above problems. Moreover, the present invention can be carried out in both batch and continuous processes. Summary of the Invention

[0004] The present invention provides a process for preparing compound (C) or a salt thereof, comprising the step of contacting compound (A) with compound (B) in the presence of a solvent and a base to obtain compound (C) or a salt thereof. [ka]

[0005] Unless otherwise specified, any reference to an element should be considered as a reference to all isotopes of that element. Thus, for example, unless otherwise specified, a reference to hydrogen is considered to encompass all isotopes of hydrogen, including deuterium and tritium.

[0006] Unless otherwise stated, any reference to a compound or group should be considered as a reference to all tautomers of that compound or group.

[0007] In one embodiment of the present invention, the solvent for contacting compound (A) with compound (B) is selected from toluene, anisole, cyclopentyl methyl ether, ethylbenzene, isopropyl acetate, isobutyl acetate, 2-methyltetrahydrofuran, water, t-butanol, ethyl acetate, methyl acetate, xylene, tetrahydrofuran, dimethylsulfoxide, acetonitrile, t-butyl methyl ether, N-methylpyrrolidine, N-ethylpyrrolidone, heptane, cyclohexane, acetone, or any combination thereof.

[0008] In a further embodiment of the invention the solvent for contacting compound (A) with compound (B) is selected from toluene, anisole, ethylbenzene and xylene.

[0009] In a further embodiment of the invention the solvent for contacting compound (A) with compound (B) is selected from 2-methyltetrahydrofuran and tetrahydrofuran.

[0010] In a further embodiment of the invention the solvent for contacting compound (A) with compound (B) is dimethylsulfoxide.

[0011] In a further embodiment of the invention, the solvent for contacting compound (A) with compound (B) is toluene or toluene in combination with water, t-butanol, tetrahydrofuran, dimethylsulfoxide or acetonitrile.

[0012] In a further embodiment of the invention, the solvents for contacting compound (A) with compound (B) are toluene and tetrahydrofuran.

[0013] In a further embodiment of the invention, the base for contacting compound (A) with compound (B) is selected from potassium tert-butoxide, potassium hydroxide or any other basic potassium salt.

[0014] In a further embodiment of the invention the base for contacting compound (A) with compound (B) is selected from potassium tert-butoxide or potassium hydroxide.

[0015] In a further embodiment of the invention the base for contacting compound (A) with compound (B) is potassium tert-butoxide.

[0016] An embodiment of the present invention provides a method for preparing a salt of compound (C), such as a cationic salt. Typically, the salt is pharma- ceutically acceptable.

[0017] For purposes of the present invention, a "cationic salt" of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide is a salt formed between a protonic acid functional group of the compound (such as a urea proton) and a suitable cation by loss of a proton. Suitable cations include, but are not limited to, lithium, sodium, potassium, magnesium, calcium and ammonium. The salt may be a mono- or di-sodium salt. Preferably, the salt is a mono- or di-lithium, sodium, potassium, magnesium, calcium or ammonium salt. More preferably, the salt is a mono- or di-sodium salt or a mono- or di-potassium salt. More preferably, the salt is a mono- or di-potassium salt, and even more preferably, the salt is a mono-potassium salt.

[0018] Advantageously, when a cationic salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (compound (C)) is desired, the cation of the salt is provided by the conjugate acid of the base. For example, one embodiment of the first aspect of the present invention provides a method for preparing an alkali metal or alkaline earth metal salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (C), comprising contacting 1-ethyl-4-piperidinesulfonamide (A) with a 1,2,3,5,6,7-hexahydro-s-indacene derivative (B) or (B') in the presence of a solvent and an alkali metal or alkaline earth metal alkoxide to obtain the alkali metal or alkaline earth metal salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)-carbamoyl)-piperidine-4-sulfonamide, wherein the alkali metal or alkaline earth metal of the salt is the same as the alkali metal or alkaline earth metal of the alkoxide. Typically, in such embodiments, the alkali metal or alkaline earth metal alkoxide is an alkali metal or alkaline earth metal tert-butoxide.

[0019] In one embodiment of the present invention, the salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (C) is purified by recrystallization or reprecipitation. For example, the crude salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (C) may be dissolved in a first solvent to obtain a first mixture, the mixture may be optionally filtered, and the salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (C) may be precipitated by adding a second solvent, optionally with cooling. Typically, the first solvent is a polar protic solvent, such as methanol. Typically, the second solvent is a polar aprotic solvent, such as acetonitrile.

[0020] A further aspect of the present invention comprises the step of contacting compound (A) with compound (B) in the presence of a solvent and a base to obtain compound (C) or a salt thereof, wherein compound (B) is a compound (D): [ka] The present invention provides a method for preparing compound (C) or a salt thereof, which is obtained from

[0021] In one embodiment of the present invention, compound (C) is isolated using an anti-solvent.

[0022] In a further embodiment of the invention, compound (C) is isolated using an anti-solvent, said anti-solvent being selected from acetonitrile, any alcohol or water.

[0023] In one embodiment of the present invention, compound (C) is isolated using a wash solvent.

[0024] In a further embodiment of the invention, compound (C) is isolated using a wash solvent, said wash solvent being selected from tetrahydrofuran, toluene, dimethylsulfoxide or acetonitrile.

[0025] A second aspect of the present invention provides 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (compound (C)), or a salt thereof, prepared by the method of the first aspect of the present invention.

[0026] In one embodiment, the second aspect of the invention provides an alkali metal or alkaline earth metal salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)-piperidine-4-sulfonamide. Typically, the second aspect of the invention provides a potassium salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)-piperidine-4-sulfonamide. Most typically, the second aspect of the invention provides a monopotassium salt of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)-piperidine-4-sulfonamide.

[0027] In one embodiment of the invention, compound (B) is prepared by the process according to the third aspect of the invention.

[0028] A third aspect of the present invention is a method for preparing compound (B), comprising reacting compound (D) with compound (B): [ka] The method includes converting the

[0029] Thus, in one embodiment of the third aspect of the invention there is provided a method for preparing compound (B), comprising converting compound (D) to compound (B) using a reaction mixture of compound (D) with phosgene, triphosgene, carbonyldiimidazole or di-tert-butyl dicarbonate in the presence of a base and a solvent.

[0030] In a further embodiment of the third aspect of the invention, the solvent is selected from toluene, anisole, cyclopentyl methyl ether, ethylbenzene, isopropyl acetate, isobutyl acetate, 2-methyltetrahydrofuran, water, ethyl acetate, methyl acetate, xylene, tetrahydrofuran or dimethylsulfoxide, acetonitrile, t-butyl methyl ether, diethyl ether, dichloromethane, 1,2-dichloroethane, chloroform, N-methylpyrrolidine, N-ethylpyrrolidone, heptane, cyclohexane or any combination thereof, and the base is a tertiary amine such as N,N-diisopropylethylamine, triethylamine or tributylamine, or the base is an inorganic base such as potassium carbonate, potassium hydroxide or sodium carbonate.

[0031] In a further embodiment of the third aspect of the invention, the solvent is selected from toluene or toluene in combination with water, acetonitrile or tetrahydrofuran and the base is selected from N,N-diisopropylethylamine, trimethylamine, tributylamine, potassium carbonate, potassium hydroxide, or sodium carbonate.

[0032] In a further embodiment of the third aspect of the invention, the solvent is toluene and / or water and the base is N,N-diisopropylethylamine, trimethylamine or potassium carbonate.

[0033] In a further embodiment of the third aspect of the invention, the solvent is toluene and the base is N,N-diisopropylethylamine or potassium carbonate.

[0034] In a further embodiment of the third aspect of the invention, the solvent is toluene and the base is potassium carbonate.

[0035] In a further embodiment of the third aspect of the invention, the solvent is toluene and the base is N,N-diisopropylethylamine.

[0036] Toluene and potassium carbonate, or toluene and N,N-diisopropylethylamine, offer advantages over the previously used THF (tetrahydrofuran) and TEA (triethylamine) (EGGLER JF ET AL: Journal of Labelled Compounds and Radiopharmaceuticals, vol. 45, no. 9, 2002, pages 785-794, XP002264662). This is because the proposed method requires less time and energy for workup, since there is no need for evaporation or silica gel filtration runs. Thus, the method here is less intensive than previously reported.

[0037] In another embodiment of the third aspect of the present invention, there is provided a method for preparing compound (B), comprising converting compound (D) to compound (B), and washing the reaction mixture with an aqueous solution to obtain compound (B) in an organic solvent.

[0038] An embodiment of the present invention provides a method for obtaining compound (C), wherein compound (B) is obtained according to the third aspect of the present invention.

[0039] An embodiment of the present invention provides a method for obtaining compound (C) according to the first aspect of the present invention, wherein compound (B) is obtained according to the third aspect of the present invention.

[0040] In one embodiment of the present invention, compound (B) is prepared by a batch process or a continuous mode.

[0041] In one embodiment of the present invention, compound (B) is prepared in a continuous mode.

[0042] In one embodiment of the present invention, the methods for obtaining compound (B) and compound (C) are nested.

[0043] A fourth aspect of the invention relates to compound (B): [ka] to provide.

[0044] In one embodiment of the third aspect of the present invention, compound (D) is prepared by the following process: [ka] It is prepared by a method comprising:

[0045] The preparation method of compound (D) may be as described in WO 2020 / 079207, the contents of which are incorporated herein by reference in their entirety.

[0046] In one embodiment, the process of the fifth aspect of the invention is a process for preparing compound (A) or a salt thereof. [ka]

[0047] A fifth aspect of the present invention is a method for producing a pharmaceutical composition comprising the steps of: [ka] where Cbz is carboxybenzyl / benzyloxycarbonyl, OM is methanesulfonate, and SAc is acetylthio. The present invention provides a method for preparing compound (A), which is prepared by a process comprising:

[0048] In an exemplary embodiment of the fifth aspect of the present invention, reacting step (a) comprises contacting compound (1) with benzyl chloroformate to produce N-carboxybenzyl-4-hydroxypiperidine compound (2): [ka] This includes obtaining

[0049] Typically, in such embodiments, compound (1) is contacted with benzyl chloroformate in the presence of a base and a solvent.

[0050] In an exemplary embodiment of the fifth aspect of the present invention, reacting step (b) comprises contacting compound (2) with mesyl chloride to produce compound (3): [ka] This includes obtaining

[0051] Typically, in such embodiments, compound (2) is contacted with mesyl chloride in the presence of a tertiary amine base, such as triethylamine, and a polar aprotic solvent, such as dichloromethane.

[0052] In an exemplary embodiment of the fifth aspect of the present invention, reacting step (c) comprises reacting compound (3) with MeCOS in a solvent. - to obtain a compound (4): [ka] This includes obtaining

[0053] Typically, in such embodiments, MeCOS - is generated in situ by reaction of MeCOSH with a base such as cesium carbonate. Typically, in such embodiments, the solvent is N,N-dimethylformamide.

[0054] In an exemplary embodiment of the fifth aspect of the present invention, reacting step (d) comprises contacting compound (4) with a chlorinating agent to produce compound (5): [ka] This includes obtaining

[0055] Typically, in such embodiments, the chlorinating agent is N-chlorosuccinimide. Typically, in such embodiments, compound (4) is contacted with the chlorinating agent in the presence of acetic acid and water.

[0056] In an exemplary embodiment of the fifth aspect of the present invention, reacting step (e) comprises contacting compound (5) with ammonia to produce compound (6): [ka] This includes obtaining

[0057] Typically, in such embodiments, compound (5) is contacted with ammonia in the presence of a polar aprotic solvent, such as dichloromethane.

[0058] In an exemplary embodiment of the fifth aspect of the invention, reacting step (f) comprises contacting compound (6) with acetonitrile or acetaldehyde in the presence of a catalyst and hydrogen gas to produce compound (A): [ka] This includes obtaining

[0059] Typically, in such embodiments, compound (6) is contacted with acetonitrile in the presence of a catalyst and hydrogen gas. Typically, the catalyst is a palladium catalyst, such as palladium hydroxide on carbon.

[0060] In one specific embodiment of the fifth aspect of the present invention, there is provided a method for preparing compound (A) or a salt thereof, comprising: [ka] The process is as follows: (a) converting compound (1) into compound (2): [ka] (b) converting compound (2) into compound (3): [ka] (c) converting compound (3) into compound (4): [ka] (d) converting compound (4) into compound (5): [ka] (e) converting compound (5) into compound (6): [ka] (f) converting compound (6) into compound (A): [ka] A method is provided, comprising:

[0061] In one particular embodiment of the fifth aspect of the present invention, a method for producing a medicament comprising the steps of: [ka] where Cbz is carboxybenzyl / benzyloxycarbonyl, OM is methanesulfonate, and SAc is acetylthio. A process for preparing compound (A) or a salt thereof is provided via:

[0062] An embodiment of the present invention provides a method for obtaining compound (C), wherein compound (A) is obtained according to the fifth aspect of the present invention.

[0063] The compounds used in and provided by the present invention may be used both in their free base form and in their acid addition salt form. For the purposes of the present invention, the "salt" of the compound of the present invention includes acid addition salts. Acid addition salts are preferably salts of an acid selected from the group consisting of inorganic acids, such as hydrohalic acids (e.g., hydrofluoric acid, hydrochloric acid, hydrobromic acid or hydroiodic acid) or other inorganic acids (e.g., nitric acid, perchloric acid, sulfuric acid or phosphoric acid); or organic acids, such as organic carboxylic acids (e.g., propionic acid, butyric acid, glycolic acid, lactic acid, mandelic acid, citric acid, acetic acid, benzoic acid, salicylic acid, succinic acid, malic acid or hydroxysuccinic acid, tartaric acid, fumaric acid, maleic acid, hydroxymaleic acid, mucic acid or galacic acid). The acid addition salts are pharma- ceutically acceptable non-toxic addition salts with suitable acids, including, but not limited to, organic sulfonic acids (e.g., methanesulfonic acid, trifluoromethanesulfonic acid, ethanesulfonic acid, 2-hydroxyethanesulfonic acid, benzenesulfonic acid, toluene-p-sulfonic acid, naphthalene-2-sulfonic acid or camphorsulfonic acid) or amino acids (e.g., ornithine acid, glutamic acid or aspartic acid). The acid addition salts may be mono-, di-, tri- or multi-acid addition salts. Preferred salts are hydrogen halide, sulfuric acid, phosphoric acid or organic acid addition salts. Preferred salts are hydrochloric acid addition salts.

[0064] When the compound of the present invention comprises quaternary ammonium group, the compound is typically used in its salt form.The counterion for quaternary ammonium group can be any pharma-ceutically acceptable non-toxic counterion.The example of suitable counterion includes the conjugate base of protonic acid mentioned above for acid addition salt.

[0065] The compounds used in the present invention and provided by the present invention can be used in both their free acid form and their salt form. For the purposes of the present invention, the "salt" of the compound of the present invention includes those formed between the protonic acid functional group of the compound of the present invention (such as a carboxylic acid group or a urea group) and a suitable cation. Suitable cations include, but are not limited to, lithium, sodium, potassium, magnesium, calcium and ammonium. The salt may be a mono-salt, di-salt, tri-salt or multi-salt. Preferably, the salt is a mono- or di-lithium, sodium, potassium, magnesium, calcium or ammonium salt. More preferably, the salt is a mono- or di-sodium salt or a mono- or di-potassium salt.

[0066] Preferably, any salts are pharma- ceutically acceptable, non-toxic salts, but other salts are included in the invention because, in addition to pharma- ceutically acceptable salts, they may serve, for example, as intermediates in the purification or preparation of pharma- ceutically acceptable salts, or are useful in the identification, characterization, or purification of free acids or free bases.

[0067] The compounds and / or salts used in and provided by the present invention may be anhydrous or in the form of a hydrate (e.g., hemihydrate, monohydrate, dihydrate or trihydrate) or other solvate. Such other solvates may be formed with common organic solvents, including, but not limited to, alcoholic solvents such as methanol, ethanol or isopropanol.

[0068] The compounds, salts and solvates used in and provided by the present invention are 12 C. 13 C. 1 H, 2 H(D), 14 N, 15 N, 16 O. 17 O. 18 O. 19 F and 127any stable isotope, including but not limited to I, and 11 C. 14 C. 3 H(T), 13 N, 15 O. 18 F, 123 I, 124 I, 125 I and 131 It may contain any radioisotope, including but not limited to I.

[0069] Unless otherwise specified, the compounds, salts and solvates used in and provided by the present invention may be in any polymorphic or amorphous form.

[0070] A sixth aspect of the present invention provides a pharmaceutical composition comprising a compound (C) according to the second aspect of the present invention, or a salt thereof, and a pharma- ceutically acceptable excipient.

[0071] Conventional procedures for the selection and preparation of suitable pharmaceutical formulations are described, for example, in "Aulton's Pharmaceutics-The Design and Manufacture of Medicines", MEAulton and KMG Taylor, Churchill Livingstone Elsevier, 4th Edition, 2013. Pharmaceutically acceptable excipients, including adjuvants, diluents or carriers, that may be used in the pharmaceutical composition of the present invention are those conventionally used in the field of pharmaceutical formulations.

[0072] A seventh aspect of the invention provides a compound (C) or a salt thereof of the second aspect of the invention, or a pharmaceutical composition of the sixth aspect of the invention, for use in medicine and / or for use in the treatment or prophylaxis of a disease, disorder or condition.

[0073] Most specifically, when compound (C) is used to treat or prevent diseases, disorders and conditions, compound (C) acts as an NLRP3 inhibitor.

[0074] In one embodiment, the disease, disorder or condition to be treated or prevented is one of the following: (i) Inflammation; (ii) autoimmune diseases; (iii) cancer; (iv) infectious diseases; (v) central nervous system disorders; (vi) metabolic diseases; (vii) cardiovascular disease; (viii) respiratory diseases; (ix) liver disease; (x) Kidney disease; (xi) eye diseases; (xii) skin diseases; (xiii) Lymphatic symptoms; (xiv) psychological disorders; (xv) pain; and (xvi) Any disease in which an individual is determined to have a germline or somatic non-silent mutation in NLRP3. is selected from.

[0075] Typically, the treatment or prevention of a disease, disorder or condition involves the administration of compound (C) or a salt thereof of the second aspect of the invention, or a pharmaceutical composition of the sixth aspect of the invention to a subject.

[0076] Any of the medicaments used in the present invention may be administered by oral, parenteral (including intravenous, subcutaneous, intramuscular, intradermal, intratracheal, intraperitoneal, intraarticular, intracranial and epidural), respiratory (aerosol), rectal, vaginal or topical (including transdermal, buccal, mucosal and sublingual) administration.

[0077] Typically, the mode of administration selected will be that most suitable for the disorder, disease, or condition being treated or prevented.

[0078] An eighth aspect of the present invention provides a method of inhibiting NLRP3, the method comprising use of compound (C) or a salt thereof of the second aspect of the present invention, or the pharmaceutical composition of the sixth aspect of the present invention, to inhibit NLRP3.

[0079] For the avoidance of doubt, it is to be understood that, wherever practicable, any embodiment of a given aspect of the invention may be implemented in combination with any other embodiment of the same aspect of the invention. Further, wherever practicable, a preferred, exemplary or optional embodiment of any aspect of the invention is also to be considered as a preferred, exemplary or optional embodiment of the other aspects of the invention. EXAMPLES

[0080] All solvents, reagents and compounds were purchased and used without further purification unless otherwise noted.

[0081] Abbreviation Cbz: carboxybenzyl / benzyloxycarbonyl SAc: Acetylthio [ka] GC: Gas chromatography HPLC: High-performance liquid chromatography THF: tetrahydrofuran MTBE: Methyl tertiary butyl ether DCM: dichloromethane DMF: Dimethylformamide TEA: Triethylamine HDPE: High density polyethylene NMT: Below Vol: Volume AKX Reagent: AQUAMICRON® AKX % a / a: (area under the peak of compound (a) / total area under the peaks of compound (a) and all other components) x 100

[0082] Experimental Method NMR method: NMR spectra were obtained on a Bruker AV 400 MHz spectrometer (model: Advance IIID) operated at room temperature (25° C.).

[0083] GC method: GC analyses were performed on one of the following instruments: Agilent 7890, 6890 or Agilent 6890N equipped with an ALS injector.

[0084] KF method: Coulometric KF (Karl Fischer) titrations were performed on a Mitsubishi CA-20 or Predicta OM1000 using AKX reagent.

[0085] Synthesis of Examples 1-Ethyl-4-piperidinesulfonamide (7) 1-Ethyl-4-piperidinesulfonamide (7) was prepared according to the reaction sequence shown in Reaction Scheme 1. [ka]

[0086] Reaction Scheme 1 - Steps (a) and (b) [ka] 4-Hydroxypiperidine (1) (46.0 Kg) was charged to the reactor at 25-30°C. 1,4-Dioxane (226.0 L) was charged to the reactor at 25-30°C. The reaction mixture was stirred for 5-10 minutes and then cooled to 15-20°C. 2N NaOH solution (prepared in a separate reactor by mixing NaOH (18.4 Kg) with cold purified water (230.0 L) at 25-30°C) was slowly charged to the reaction mixture at 15-25°C. The reaction mixture was stirred for 5-10 minutes. 50% benzyl chloroformate in toluene solution (147.2 L) was slowly added to the reaction mixture over 1-2 hours. The temperature was raised to 25-30°C and stirred for 1-2 hours.

[0087] Purified water (230.0 L) was added to the reaction mixture and the reaction mixture was stirred at 25-30 °C for 10-15 min. MTBE (230.0 L) was charged into the reactor at 30-35 °C. The reaction mixture was stirred at 25-30 °C for 15-20 min and then allowed to settle for 20-30 min. The organic layer (OL-1) and aqueous layer (AL-1) were separated into different vessels and AL-1 was recharged into the reactor. MTBE (230.0 L) was charged into the reactor at 25-30 °C. The reaction mixture was stirred at 25-30 °C for 15-20 min and then allowed to settle for 20-30 min. The organic layer (OL-2) and aqueous layer (AL-2) were separated into different vessels. OL-1 and OL-2 were combined and charged into the reactor at 25-30 °C. Purified water (138.0 L) was charged into the reactor at 25-30° C. The reaction mixture was stirred at 25-30° C. for 15-20 min and then allowed to settle for 20-30 min. The aqueous layer (AL-3) was separated from the organic layer (OL-3).

[0088] 10% NaCl solution (prepared by adding NaCl (13.80 Kg) to purified water (138.0 L) in a reactor at 25-30 °C with stirring) was charged to OL-3 at 25-30 °C. The reaction mixture was stirred at 25-30 °C for 15-20 min and then allowed to settle for 20-30 min. The organic layer (OL-4) and aqueous layer (AL-4) were separated into different vessels. OL-4 was dried over sodium sulfate (23.0 Kg). OL-4 was filtered through a Buchner funnel and washed with MTBE (46.0 L). OL-4 was distilled under reduced pressure (650 mmHg) at 40-45 °C to 46-92 L. The vacuum was released and DCM (138.0 L) was charged to the mixture and the mixture was co-distilled under reduced pressure at 35-40 °C to 46-92 L. The mixture was cooled to 25-30°C and the vacuum was released. DCM (552.0 L) was charged to the mixture at 25-30°C and the mixture was stirred for 5-10 min. The reaction mixture was cooled to 20-25°C. TEA (127.8 L) was added at 20-25°C. The reaction mixture was cooled to -5-5°C.

[0089] Methanesulfonyl chloride (67.62 kg) was slowly added over 1 to 2 hours at −5 to 5° C. The reaction mixture was warmed to 25 to 30° C. and stirred at 25 to 30° C. for 1 to 2 hours.

[0090] The undesired salts were filtered, washed with DCM (92.0 L) at 25-30°C and sucked dry completely under reduced pressure at 25-30°C. The filtrate was charged into the reactor at 25-30°C. 10% sodium bicarbonate solution (prepared by adding sodium bicarbonate (23.0 Kg) to purified water (230.0 L) at 25-30°C) was charged into the filtrate at 25-30°C. The reaction mixture was stirred at 25-30°C for 15-20 minutes and then allowed to settle for 20-30 minutes. The organic layer (OL-5) and aqueous layer (AL-5) were separated into different vessels and OL-5 was recharged into the reactor at 25-30°C.

[0091] Purified water (230.0 L) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 15-20 minutes and then allowed to settle for 20-30 minutes. The organic layer (OL-6) and aqueous layer (AL-6) were separated into different vessels and OL-6 was recharged into the reactor at 25-30°C. 10% sodium chloride solution (prepared by adding sodium chloride (11.50 Kg) to purified water (230.0 L) at 25-30°C) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 15-20 minutes and then allowed to settle for 20-30 minutes.

[0092] The organic layer (OL-7) and aqueous layer (AL-7) were separated into different vessels. OL-7 was dried over sodium sulfate (23.0 Kg). OL-7 was filtered through a Buchner funnel and washed with DCM (46.0 L). OL-7 was distilled under reduced pressure (650 mmHg) at 40-45°C to 46-92 L. The vacuum was released and ethyl acetate (92.0 L) was charged to the mixture and the mixture was co-distilled under reduced pressure at 40-45°C to 46-92 L. The mixture was cooled to 30-40°C and the vacuum was released. Ethyl acetate (115.0 L) was charged to the mixture at 30-40°C and the mixture was stirred at 30-35°C for 10-15 minutes. Hexane (1150.0 L) was slowly charged to the mixture at 30-35°C and the mixture was stirred at 25-30°C for 2-3 hours. The solid was filtered through a Nutsche filter under reduced pressure, washed with hexane (92.0 L) at 25-30° C., and sucked dry completely under reduced pressure at 25-30° C. The solid material was dried in a vacuum oven at 30-35° C. for 6-8 h, scraping the material every 3-4 h.

[0093] Final product: benzyl 4-((methylsulfonyl)oxy)piperidine-1-carboxylate Grayish white (solid) Output: 121.87Kg Yield: 85.5% HPLC purity: 94.7% 1 H NMR:(CDCl3400MHz):δ 1.82-1.86(m,2H),δ 1.96-1.97(m,2H),δ 3.03(s,3H),δ 3.41-3.45(m,2H)δ 3.72-3.78(m,2H),δ 4.88-4.92(m,1H)δ 5.13(s,2H),δ 7.26-7.37(m,5H)

[0094] Reaction Scheme 1 - Steps (c, d, e) [ka] DMF was charged to a clean, dry, four-neck reactor (equipped with a mechanical stirrer, nitrogen inlet, thermopocket, and reflux condenser) under a nitrogen atmosphere and heated to reflux at 60-65° C. for 20-30 minutes. The temperature was lowered to 25-30° C., the refluxed DMF was removed, and the reactor was dried under nitrogen and reduced pressure.

[0095] Benzyl 4-((methylsulfonyl)oxy)piperidine-1-carboxylate (3) (29.0 Kg) was charged to the reactor at 25-30° C. DMF (145.0 L) was charged to the reactor at 25-30° C. The reaction mixture was stirred for 5-10 minutes, cooled to 15-20° C., and then allowed to settle for 20-30 minutes.

[0096] 44.95 Kg of cesium carbonate was charged into the reactor at 15-25° C. The reaction mixture was stirred for 5-10 minutes. 10.56 Kg of thioacetic acid was charged at 15-25° C. The reaction mixture was brought to 45-50° C. and stirred for 24 hours.

[0097] The reaction mixture was cooled to 25-30°C. The undesired salts were filtered through a Büchner funnel under reduced pressure at 25-30°C, washed with ethyl acetate (145.0 L) and sucked dry completely under reduced pressure at 25-30°C. The filtrate was recharged to the reactor at 25-30°C and cooled to 15-20°C. Purified water (145.0 L) was charged to the reactor at 15-25°C and the reaction mixture was stirred for 5-10 minutes. Ethyl acetate (145.0 L) was charged to the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 15-20 minutes and allowed to settle for 20-30 minutes.

[0098] The organic layer (OL-1) and aqueous layer (AL-1) were separated into separate vessels. AL-1 was charged into the reactor at 25-30°C. Ethyl acetate (145.0 L) was charged at 25-30°C. The reaction mixture was stirred at 25-30°C for 15-20 min and allowed to settle for 20-30 min.

[0099] The organic layer (OL-2) and the aqueous layer (AL-2) were separated into separate vessels. OL-1 and OL-2 were combined and charged into a reactor at 25-30°C.

[0100] 10% NaHCO3 solution (prepared by adding sodium bicarbonate (14.50 Kg) to purified water (145.0 L) at 25-30°C and mixing well) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 15-20 minutes and allowed to settle for 20-30 minutes.

[0101] The organic layer (OL-3) and aqueous layer (AL-3) were separated into separate vessels. OL-3 was charged into the reactor at 25-30°C. 10% NaCl solution (prepared by adding NaCl (14.50 Kg) to purified water (145 L) at 25-30°C and mixing with sufficient stirring) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 15-20 minutes and allowed to settle for 20-30 minutes.

[0102] The organic layer (OL-4) and aqueous layer (AL-4) were separated into different vessels. OL-4 was dried over sodium sulfate (14.50 Kg), filtered through a Buchner funnel and washed with ethyl acetate (29.0 L). The filtrate was distilled completely in the reactor under reduced pressure (650 mmHg) at 45-50 °C until no droplets remained. The vacuum was released and the mixture was cooled to 25-30 °C.

[0103] Acetic acid (377.0 L) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 5-10 minutes. Purified water (37.7 L) was charged at 25-30°C. The reaction mixture was stirred at 25-30°C for 5-10 minutes and then cooled to 17-25°C. N-chlorosuccinimide (33.64 Kg) was added slowly in portions at 18-25°C for 1-2 hours. The reaction mixture was stirred at 25-30°C for 1 hour.

[0104] The reaction mixture was cooled to 15-20°C. Purified water (377.0 L) was added to the reaction mixture at 15-20°C and the reaction mixture was stirred at 25-30°C for 5-10 min. DCM (145.0 L) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 10-15 min and allowed to settle for 20-30 min. The organic layer (OL-5) and aqueous layer (AL-5) were separated into different vessels. AL-5 was charged into the reactor. DCM (145.0 L) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 10-15 min and allowed to settle for 20-30 min.

[0105] The organic layer (OL-6) and aqueous layer (AL-6) were separated into different vessels. OL-5 and OL-6 were combined and charged into the reactor at 25-30°C. Purified water (145.0 L) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 5-10 minutes and allowed to settle for 25-30 minutes.

[0106] The organic layer (OL-7) and aqueous layer (AL-7) were separated into different vessels. OL-7 was charged into the reactor. A portion of 2% sodium bicarbonate solution (prepared by adding sodium bicarbonate (8.70 Kg) along with purified water (435.0 L) and divided into three equal volume parts) was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 5-10 minutes and allowed to settle for 25-30 minutes.

[0107] The organic layer (OL-8) and aqueous layer (AL-8) were separated into different vessels. OL-8 was charged into the reactor. The second portion of the above 2% sodium bicarbonate solution was charged into the reactor at 25-30°C. The reaction mixture was stirred at 25-30°C for 5-10 minutes and allowed to settle for 25-30 minutes.

[0108] The organic layer (OL-9) and aqueous layer (AL-9) were separated into different vessels. OL-9 was charged into the reactor. Three parts of the above 2% sodium bicarbonate solution were charged into the RBF at 25-30°C. The reaction mixture was stirred at 25-30°C for 5-10 minutes and allowed to settle for 25-30 minutes.

[0109] The organic layer (OL-10) and aqueous layer (AL-10) were separated into separate vessels. OL-10 was dried over sodium sulfate (14.50 Kg), filtered at 25-30°C, and washed with DCM (29.0 L). The filtrate was charged into a RBF at 25-30°C.

[0110] The reaction mixture was cooled to -40 to -30°C and purged with ammonia gas for 2 to 3 hours. The temperature was raised to 25 to 30°C and stirred at 25 to 30°C for 10 to 12 hours.

[0111] The undesired salts were filtered under reduced pressure at 25-30°C, washed with DCM (14.50 L) and sucked dry thoroughly. The filtrate was charged into a clean, dry reactor at 25-30°C and dried over sodium sulfate (14.50 Kg). The mixture was filtered at 25-30°C and the sodium sulfate was washed with DCM (14.50 L). The mixture was charged through a 0.2 micron filter cartridge into a clean, dry reactor and distilled under reduced pressure at 35-40°C to a volume of 29-58 L).

[0112] The vacuum was released and the reaction mixture was cooled to 25-30°C. Ethyl acetate (58.0 L) was charged to the reactor at 25-30°C and the mixture was distilled under reduced pressure at 35-40°C to 29-58 L). The vacuum was released and the reaction mixture was cooled to 25-30°C. Ethyl acetate (72.5 L) was charged to the reactor at 25-30°C and the mixture was stirred at 25-30°C for 30 minutes. Hexane (36.25 L) was charged to the reactor at 25-30°C and the mixture was stirred at 25-30°C for 1-2 hours. The solid was filtered under reduced pressure at 25-30°C, washed with hexane (58.0 L) and sucked dry completely. Output: 11.0Kg Yield: 39.85% HPLC purity: 90.5%

[0113] purification Wet material (6) (53.95 Kg) was charged into a clean dry reactor at 25-30°C. DCM (580 L) was charged at 25-30°C and the mixture was stirred at 25-30°C for 5-10 minutes. Methanol (25.0 L) was charged at 25-30°C and the mixture was stirred at 25-30°C for 5-10 minutes. Neutral alumina (174.0 Kg) was charged at 25-30°C and the mixture was stirred at 25-30°C for 1 hour. Neutral alumina was filtered at 25-30°C. The salts were washed with DCM (150.0 L). The filtrate was charged into a clean dry reactor at 25-30°C. Hexane (1050 L) was charged at 25-30°C and the mixture was stirred at 25-30°C for 1 to 2 hours. The precipitate was filtered under reduced pressure at 25-30 °C, washed with hexane (116.0 L) and sucked dry completely. The wet material was dried under reduced pressure at 30 °C-35 °C for 6-8 h, stripping every 3 h.

[0114] Final product: 1-(benzyloxycarbonyl)-4-piperidinesulfonamide White (solid powder) Output: 41.60Kg Yield: 41.80% HPLC purity: 96.1% 1 H NMR:(DMSO 400MHz):δ 1.41-1.51(m,2H),δ 1.99-2.01(m,2H),δ 2.50-286(m,2H),δ 3.022-3.05(m,1H)δ 4.08-4.11(m,2H),δ 5.75(s,2H)δ 6.78(s,2H),δ 7.40-7.30(m,5H)

[0115] Reaction Scheme 1-Step (f) [ka] 1-(Benzyloxycarbonyl)-4-piperidinesulfonamide (6) (21.85 Kg) was charged to the vessel which was then purged with nitrogen. Acetonitrile (propionitrile free) (109.8 Kg) and purified water (65.0 L) were charged to the vessel and the temperature was adjusted to 15-25°C. The vessel was vacuum / nitrogen purged three times at 15-25°C and then charged with palladium hydroxide on carbon (20% by weight; 50% water) (0.455 Kg). The vessel was vacuum / nitrogen purged three times at 15-25°C. The vessel was vacuum / hydrogen purged three times at 15-25°C and maintained under a hydrogen atmosphere (approximately 1 bar absolute). The reaction mixture was stirred until completion.

[0116] The vessel was vacuum / purged with nitrogen three times at 15-25° C. and then charged with palladium hydroxide on carbon (20% by weight; 50% water) (2.265 Kg) at 15-25° C. The vessel was vacuum / purged with nitrogen three times at 15-25° C. The vessel was vacuum / purged with hydrogen three times at 15-25° C. and maintained under a hydrogen atmosphere (approximately 1 bar absolute). The reaction mixture was stirred at 15-25° C. until completion.

[0117] The reaction mixture was stirred at 15-25° C. until completion.

[0118] Once the reaction was deemed complete by GC, the vessel was purged with nitrogen and the reaction mixture was filtered through a 1 μm filter at 15-25 °C to remove the catalyst. The filter cake was washed twice with premixed purified water and acetonitrile at 15-25 °C.

[0119] The filtrate was charged with charcoal (activated carbon) (4.40 Kg) and stirred at 15-25°C for at least 60 minutes (target 60-120 minutes). The mixture was filtered through a 1 μm filter at 15-25°C to remove the charcoal. The filter cake was washed twice with premixed purified water and acetonitrile at 15-25°C. The filtrate was charged with SiliaMetS Thiol 40-63 μm 60 Å (4.515 Kg) and stirred at 15-25°C for at least 60 minutes (target 60-120 minutes). The mixture was filtered through a 0.6 μm filter at 15-25°C to remove the SiliaMetS Thiol. The filter cake was washed twice with premixed purified water and acetonitrile at 15-25°C.

[0120] The filtrate was placed in a vessel, adjusted to 50-60°C, and concentrated under reduced pressure at 50-60°C to approximately 110 L. n-Butanol (89.8 Kg) was added at 50-60°C, and the mixture was concentrated under reduced pressure at 50-60°C to approximately 110 L. n-Butanol (86.9 Kg) was added at 50-60°C, and the mixture was concentrated under reduced pressure at 50-60°C to approximately 110 L. n-Butanol (88.4 Kg) was added at 50-60°C, and the mixture was concentrated under reduced pressure at 50-60°C to approximately 90 L.

[0121] The temperature was adjusted to 15-25°C and ethyl acetate (98.6 Kg) was charged at 15-25°C. The reaction mixture was cooled to -2 to +2°C over at least 60 minutes (target 60-120 minutes). The mixture was stirred at -2 to 2°C for at least 4 hours (target 4-6 hours). The solids were filtered through a 20 μm filter cloth at -2 to 2°C and washed twice with ethyl acetate (38.1 Kg and 39.9 Kg) at -2 to 2°C.

[0122] Until the n-butanol content is 0.5% by weight or less and the ethyl acetate content is 0.5% by weight or less ( 1 The dry weight of the solid 1-ethyl-4-piperidinesulfonamide (7) was determined and assayed using 1H NMR spectroscopy.

[0123] Final product: 1-ethyl-4-piperidinesulfonamide Output: 12.00Kg Yield: 85% GC purity: 99.7% NMR purity: 98.7% 1 H NMR:(DMSO)0.95(t),1.55(dq),1.80(app t),1.95(app d),2.30(q),2.75(m),2.90(app d)

[0124] 1,2,3,5,6,7-Hexahydro-s-indacen-4-amine (12) 1,2,3,5,6,7-Hexahydro-s-indacen-4-amine (12) was prepared according to the reaction sequence shown in Reaction Scheme 2. [ka]

[0125] Reaction Scheme 2-Step (a) [ka] DCM (385 L) and AlCl3 (99.86 Kg) were charged to a clean, dry glass-lined reactor under nitrogen atmosphere at 25-30° C. The reaction mixture was cooled to −10° C.

[0126] 3-Chloropropanoyl chloride (90.99 Kg) was added slowly at -10 to -5°C under nitrogen atmosphere. The reaction mixture was maintained at 10°C for 30 minutes under nitrogen atmosphere. Then, 2,3-dihydro-1H-indene (8) (77.00 Kg) was added slowly to the reaction mixture at -10 to -5°C under nitrogen atmosphere.

[0127] The reaction mixture was maintained at 10-15° C. for 2 h.

[0128] After completion of the reaction, the reaction mixture was slowly added to 6 N hydrochloric acid solution (water (308 L) and concentrated hydrochloric acid (308 L)) at 0-10 °C. DCM (231 L) was added and the temperature of the reaction mixture was increased to 30-35 °C. The reaction mixture was stirred at 30-35 °C for 30 min and allowed to settle at 30-35 °C for 30 min. The layers were separated and the organic layer (OL-1) was set aside. DCM (231 L) was charged to the aqueous layer at 25-30 °C. The reaction mixture was stirred at 25-30 °C for 30 min and allowed to settle at 25-30 °C for 30 min. The layers were separated (aqueous layer (AL-1) and organic layer (OL-2)) and AL-1 was set aside. OL-1 and OL-2 were combined at 25-30 °C. Demineralized water (385 L) was added to the combined organic layer. The reaction mixture was stirred for 30 min at 25-30° C. and allowed to settle for 30 min at 25-30° C. The layers were separated (aqueous layer (AL-2) and organic layer (OL-3)) and AL-2 was set aside.

[0129] 10% saturated sodium bicarbonate solution (prepared from demineralized water (385 L) and sodium bicarbonate (38.5 Kg)) was charged to OL-3 at 25-30°C. The reaction mixture was stirred for 30 min at 25-30°C and allowed to settle for 30 min at 25-30°C. The layers were separated (aqueous layer (AL-3) and organic layer (OL-4)) and AL-3 was set aside. OL-4 was dried over anhydrous Na2SO4 (38.5 Kg) and the anhydrous Na2SO4 was washed with DCM (150 L) at 25-30°C.

[0130] The solvent was distilled under reduced pressure below 35-40°C until 5% remained. n-Hexane (308 L) was charged to the reaction mixture at 35-40°C, and the solvent was completely distilled at 35-40°C until no condensation droplets were formed. N-hexane (150 L) was charged to the reaction mixture at 35-40°C, and the reaction mixture was cooled to 5-10°C and held at 5-10°C for 30 minutes.

[0131] The solid product was filtered, washed with chilled hexane (77 L) and dried in a hot air oven at 40-45°C for 6 h to obtain the product.

[0132] Final product: 3-chloro-1-(2,3-dihydro-1H-inden-5-yl)propan-1-one (9) Output: 120.5Kg Yield: 88.63% HPLC purity: 99.3% Moisture content: 0.09% 1 H NMR:(500 MHz,CDCl3):δ 7.81(S,1H),7.76(d,1H),7.31(d,1H),3.93(t,2H),3.45(t,2H),2.97(t,4H),2.15(q,2H)

[0133] Reaction Scheme 2-Step (b) and Step (c) [ka] Sulfuric acid (300.0 L) was charged into a 2.0 KL clean, dry glass lined reactor at 25-30° C. 3-Chloro-1-(2,3-dihydro-1H-inden-5-yl)propan-1-one (9) (60.0 Kg) was charged in lots at 25-30° C. and the reaction mixture was maintained at 25-30° C. for 30 minutes. The reaction mixture was slowly heated to 65-70° C. and maintained at 65-70° C. for 24 hours. Absence of 3-chloro-1-(2,3-dihydro-1H-inden-5-yl)propan-1-one (9) was confirmed by HPLC (limit: ≦1.0%).

[0134] The reaction mixture was then cooled to 0-5° C. Nitration mixture *1 was added slowly at 0-5°C and the reaction mixture was maintained at 0-5°C for 1 hour. The reaction mixture was maintained at 0-5°C.

[0135] Demineralized water (900.0 L) was charged to a 2.0 KL clean dry glass lined reactor at 25-30°C. The water was cooled to 0-5°C. The reaction mixture was slowly added to the reactor at 0-5°C. Toluene (480.0 L) was added and the temperature was raised to 30-35°C. The reaction mixture was maintained at 30-35°C for 30 minutes and allowed to settle at 30-35°C for 30 minutes. The reaction mixture was filtered through a Celite® bed (prepared using Celite® (6.0 Kg) and toluene (30.0 L)). The Celite® bed was washed with toluene (60.0 L). The solid was filtered and sucked dry for 30 minutes.

[0136] The reaction mixture was charged into a 2.0 KL clean, dry glass-lined reactor. The reaction mixture was allowed to settle for 30 minutes at 30-35° C. The layers were separated (aqueous layer (AL-1) and organic layer (OL-1)) and OL-1 was set aside.

[0137] Toluene (60.0 L) was charged to AL-1. The reaction mixture was stirred at 35-40° C. for 30 min and allowed to settle at 35-40° C. for 30 min. The layers were separated (aqueous layer (AL-2) and organic layer (OL-2)) and OL-2 was set aside. OL-1 and OL-2 were combined to form OL-3.

[0138] 5% saturated sodium bicarbonate solution (prepared from demineralized water (300.0 L) and sodium bicarbonate (15.0 Kg)) was charged slowly into OL-3 at 30-35°C. The reaction mixture was stirred for 30 min at 35-40°C and allowed to settle for 30 min at 35-40°C. The reaction mixture was filtered through a Celite® bed (prepared using Celite® (6.0 Kg) and demineralized water (60.0 L)). The Celite® bed was washed with toluene (60.0 L).

[0139] The reaction mixture was charged into a 3.0 KL clean, dry glass-lined reactor. The reaction mixture was allowed to settle for 30 minutes at 30-35° C. The layers were separated (aqueous layer (AL-3) and organic layer (OL-4)) and OL-4 was set aside.

[0140] Toluene (60.0 L) was charged to AL-3. The layers were separated (aqueous layer (AL-4) and organic layer (OL-5)) and OL-5 was set aside. OL-4 and OL-5 were combined to form OL-6. Brine solution (prepared from demineralized water (300.0 L) and sodium chloride (12.0 Kg)) was added at 25-30°C. The reaction mixture was stirred at 30-35°C for 30 minutes and allowed to settle at 30-35°C for 30 minutes. The layers were separated (aqueous layer (AL-5) and organic layer (OL-7)) and OL-7 was set aside. OL-7 was dried with anhydrous Na2SO4 (9.0 Kg) and the anhydrous Na2SO4 was washed with toluene (30.0 L) at 25-30°C. The solvent was distilled under reduced pressure below 40°C-45°C until 5% remained. Methanol (60.0 L) was charged into the reaction mixture at 40-45°C to a reaction mass of 60 L.

[0141] Methanol (120.0 L) was charged to the reaction mixture at 40-45° C., the reaction mixture was cooled to 5-10° C. and held at 5-10° C. for 30 min. The solid product was filtered, washed with chilled methanol (30.0 L) and dried in a hot air oven at 40-45° C. for 6 h to obtain the product.

[0142] *1: To prepare the nitration mixture, sulfuric acid (27.0 L) was charged into a 160 L clean, dry glass-lined reactor at 25-30°C. The reaction mixture was cooled to 0-5°C. Nitric acid (27.0 L) at 0-5°C was slowly added and the reaction mixture was maintained at 0-5°C for 30 minutes to obtain the nitration mixture.

[0143] Final products: 8-nitro-1,2,3,5,6,7-hexahydro-s-indacen-1-one (11a) and 4-nitro-1,2,3,5,6,7-hexahydro-s-indacen-1-one (11b) Combined output (11a+11b): 38.87Kg Composite yield (11a+11b): 62.24% Weight ratio (11a:11b):9:1 HPLC purity: 95.9% Moisture content: 0.19% 1H NMR:(500 MHz,CDCl3):δ7.44(S,1H),2.21(m,2H),2.78(t,2H),3.02(m,4H),3.13(t,2H)

[0144] Reaction Scheme 2-Step (d) [ka] A mixture of 8-nitro-1,2,3,5,6,7-hexahydro-s-indacen-1-one (11a) and 4-nitro-1,2,3,5,6,7-hexahydro-s-indacen-1-one (11b) (9:1 ratio; 27.0 Kg) was charged into a 600 L clean, dry pressure reactor at 25-30 °C.

[0145] Methanol (270 L) was charged at 25-30° C. Methanesulfonic acid (14.3 Kg) was charged slowly at 25-30° C. and the reaction mixture was maintained for 30 minutes. 15% Pd(OH)2 slurry (60% wet) *2 was added.

[0146] The reaction mixture was degassed under reduced pressure and filled with argon atmosphere (0.5 Kg) three times. The reaction mixture was degassed under reduced pressure and filled with hydrogen atmosphere (0.5 Kg) three times. The reaction mixture was then stirred under hydrogen pressure (100 Psi) at room temperature for 32 hours. After completion of the reaction, the reaction mixture was cooled to 25-30°C. The reaction mixture was degassed under reduced pressure and filled with nitrogen atmosphere (0.5 Kg) three times.

[0147] The reaction mixture was filtered through a candy filter to remove Pd(OH)2, followed by microfiltration and washing the bed with methanol (54 L). 95% of the solvent was distilled off under reduced pressure below 45-50°C. Demineralized water (135 L) was charged into the reaction mixture at 25-30°C and maintained for 30 minutes. The reaction mixture was cooled to 5-10°C. The pH was adjusted to about 9-10 with 2N aqueous NaOH solution (prepared from NaOH (6.48 Kg) and demineralized water (81 L)) and the reaction mixture was stirred for 30 minutes. Toluene (135 L) was then charged into the reaction mixture and the reaction mixture was stirred for 30 minutes. The reaction mixture was stirred for another 30 minutes while the temperature was increased to 25-30°C. The reaction mixture was allowed to settle for 30 minutes while maintaining the temperature at 25-30°C.

[0148] The reaction mixture was filtered through a Celite® bed (prepared with Celite® (5.4 Kg) and toluene (13.5 L). The Celite® bed was washed with toluene (54 L).

[0149] The layers were separated (aqueous layer (AL-1) and organic layer (OL-1)) and OL-1 was set aside. Toluene (54 L) was added to AL-1 at 25-30°C. The reaction mixture was stirred at 25-30°C for 30 minutes and allowed to settle at 25-30°C for 30 minutes. The layers were separated (aqueous layer (AL-2) and organic layer (OL-2)) and AL-2 was set aside. Toluene (54 L) was added to AL-1 at 25-30°C. Brine solution (prepared with demineralized water (135 L) and sodium chloride (54 Kg)) was charged to the combined organic layers (OL-1 and OL-2) at 25-30°C. The reaction mixture was stirred at 25-30°C for 30 minutes and allowed to settle at 25-30°C for 30 minutes.

[0150] The layers were separated (aqueous layer (AL-3) and organic layer (OL-3)) and AL-3 was kept aside. Charcoal (1.3 Kg) was added to OL-3 and the temperature was raised to 35-40°C and maintained at 35-40°C for 30 minutes. The reaction mixture was filtered through a Celite® bed (prepared using Celite® (5.4 Kg) and toluene (54 L)) at 35-40°C. The Celite® bed was washed with toluene (54 L). The organic layer was dried over anhydrous Na2SO4 (13.5 Kg). The Na2SO4 was washed with toluene (27 L).

[0151] The solvent was distilled under reduced pressure below 35-40°C until 5% remained. Methanol (40.5 L) was charged to the reaction mixture at 35-40°C and distilled until 5% remained. Methanol (97.2 L) and water (10.8 L) were charged to the reaction mixture at 35-40°C. The reaction mixture was heated to 50-55°C, stirred at 50-55°C for 1 h, cooled slowly to 0-5°C and maintained at 0-5°C for 30 min.

[0152] The solid product was filtered, washed with cold methanol (13.5 L) and dried in a hot air oven at 40-45°C for 6 h to obtain the product.

[0153] *2: To prepare 15% Pd(OH)2 slurry, 20% Pd(OH)2 on carbon (60% wet; 4.05 Kg) was added to methanol (27 L).

[0154] Final product: 1,2,3,5,6,7-hexahydro-s-indacen-4-amine (12) Output: 11.3Kg Yield: 41.85% HPLC purity: 98.1% Moisture content: 0.10 1 H NMR:(400 MHz,DMSO-d6):δ 6.38(S,1H),4.45(S,2H),2.75(t,4H),2.58(t,4H),1.98(t,4H).

[0155] Purification of 1,2,3,5,6,7-hexahydro-s-indacen-4-amine (12) (A) 1,2,3,5,6,7-Hexahydro-s-indacen-4-amine (12) (54.5 Kg) was charged into a 250 L clean dry reactor at 25-30 °C. Toluene (27.2 L) was charged at 25-30 °C and the reaction mixture was stirred at 25-30 °C for 30 minutes. Methanol (163 L) was charged into the reaction mixture at 25-30 °C. The reaction mixture was stirred at 25-30 °C for 30 minutes, cooled to -5-0 °C and stirred at -5-0 °C for 30 minutes. The solid product was filtered, washed with cold methanol (54.5 L) and dried at 40-45 °C for 6 hours.

[0156] Final product: 1,2,3,5,6,7-hexahydro-s-indacen-4-amine (12) Output: 40.5Kg Yield: 74.31% HPLC purity: 99.5% Moisture content: 0.3% 1 H NMR:(400 MHz,DMSO-d6):δ 6.33(s,1H),4.53(s,2H),2.72(t,4H),2.57(t,4H),1.98(t,4H).

[0157] 1-Ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (potassium salt) (14) [ka]

[0158] Preparation of 1,2,3,5,6,7-hexahydro-s-indacen-4-amine-isocyanate (13) in batch mode: 1,2,3,5,6,7-Hexahydro-s-indacen-4-amine (12) (1.00 g, 1.00 equiv.) was dissolved in toluene (9.60 g) in a 50 mL reactor at 10-20 °C. N,N-Diisopropylethylamine (2.25 g, 3.00 equiv.) was added followed by 20 wt. % phosgene solution (4.28 g, 1.50 equiv.) over 3 min and the formed suspension was further stirred for 30 min at 10-20 °C. The reaction mixture was washed with saturated NaHCO3 solution (5.0 mL) and water (5.0 mL). The layers are separated to give 1,2,3,5,6,7-hexahydro-s-indacen-4-amine-isocyanate in toluene (OL-1, approximately 20 mL, containing 1,2,3,5,6,7-hexahydro-s-indacen-4-amine (12) (5.77 mmol). The resulting solution OL-1 is used in the next step (coupling of indacenamine-isocyanate (12) with 1-ethyl-4-piperidinesulfonamide (7)) to give (14) in approximately 80% overall yield.

[0159] Preparation of 1,2,3,5,6,7-hexahydro-s-indacen-4-amine-isocyanate (13) in flow mode: Preparation of feeding solution: Feed Solution A: 1,2,3,5,6,7-Hexahydro-s-indacen-4-amine (12) (43.31 g) was dissolved in toluene (206.69 g) to give a 0.90 M solution. Feed Solution B: Potassium carbonate (103.5 g) was dissolved in water (950 g) to give a 0.75 M solution.

[0160] Feed A (0.70 mL / min, 1.10 equiv.), 20% w / w phosgene solution in toluene (0.45 mL / min, 1.50 equiv.) and Feed B solution (2.35 mL / min, 3.10 equiv.) were simultaneously charged in reactor 1 (approximately 25 mL) at 0-10 °C (internal temperature). The residence time in reactor 1 is 5-10 min. The biphasic solution from reactor 1 is continuously pumped and the layers are continuously separated to obtain an organic layer (OL-1) containing 1,2,3,5,6,7-hexahydro-s-indacene-4-amine isocyanate (13) and an aqueous layer (AL-1) directed to waste. The organic layer OL-1 is collected at steady state for 81 min to obtain approximately 90 mL (51 mmol) of 1,2,3,5,6,7-hexahydro-s-indacene-4-amine (12). The resulting solution OL-1 was used in the next step.

[0161] Coupling of indacenamin-isocyanate (12) with 1-ethyl-4-piperidinesulfonamide (7): 1-Ethyl-4-piperidinesulfonamide (7) (8.88 g, 46 mmol, 1.0 equiv.) was charged to the vessel. Tetrahydrofuran (62.52 g) was charged to the vessel and the mixture was adjusted to 20-25 °C. The mixture was stirred at 20-25 °C for at least 20 min until lumps disappeared and a homogenous suspension was formed. Potassium tert-butoxide (1.05 M, 43.98 mL, 46 mmol) was charged to the vessel over 90-120 min, the temperature was maintained at 20-25 °C, and the mixture was stirred at 20-25 °C for 2-4 h to give a thick white suspension.

[0162] The organic layer OL-1 containing 1,2,3,5,6,7-hexahydro-s-indacene-4-amine-isocyanate (13) (51 mmol of 1,2,3,5,6,7-hexahydro-s-indacene-4-amine (12), ca. 90 mL) prepared in batch or flow mode was added to the formed white suspension in toluene over 2 h by keeping at 20-25 °C. The reaction mixture quickly became a well-stirrable suspension and at the end of the addition a slightly turbid brown solution was obtained. The reaction mixture was stirred at 20-25 °C for another 1-2 h. The water content was analyzed by KF and the conversion of 1,2,3,5,6,7-hexahydro-s-indacene-4-amine was confirmed by LC / MS or HPLC analysis (typically >95%). Optionally, a clarification filtration through a layer of Celite (G3 filter) is performed. Water (4.44 g, 0.5 V) was added dropwise to the reaction mixture over 2 h at 25-40 °C. The solid started to crystallize at a water content of approximately 0.5-1 wt%. A suspension formed at the end of dosing. The reaction mixture was cooled to 0-5 °C (IT) over 1 h and stirred at 0-5 °C for an additional 16 h. The solid was filtered through a G3 filter and washed with a toluene / THF (1 / 1 by volume, 44.4 mL) mixture.

[0163] The solid was dried under nitrogen flow at 50°C max. and 10-20 mbar for 12 hours. The dry weight of the crude solid was measured and identified. 1 Analyses were performed using 1 H NMR spectroscopy and HPLC.

[0164] Final product: 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)-carbamoyl)piperidine-4-sulfonamide (potassium salt) (14) Output: Approx. 16.0g Yield: about 80% NMR purity:>97% HPLC purity:>99%

[0165] Recrystallization of 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)-carbamoyl)piperidine-4-sulfonamide (potassium salt) (14) Crude 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)carbamoyl)piperidine-4-sulfonamide (potassium salt) (14) (15.00 g) was charged to a reaction vessel. Methanol (33.55 g) was charged to the vessel followed by acetonitrile (33.55 g) and stirred for 10-20 min (until a homogeneous cloudy solution with no solid chunks was formed) while adjusting the temperature to 15-25 °C as needed. The solution was filtered through a 1 μm filter at 15-25 °C. The filter was washed with a methanol / acetonitrile mixture (7.59 g) at 15-25 °C and more acetonitrile (64.0 g) was added followed by seed crystals of (14) (0.138 g) in acetonitrile (ca. 1 g). A solution was formed.

[0166] The solution was concentrated to approximately 122 mL at 25-35°C. Acetonitrile (54.32 g) was charged to the mixture and the solution was concentrated to approximately 122 mL at 25-35°C. Acetonitrile (52.53 g) was charged to the mixture and the mixture was concentrated to approximately 122 mL at below 35°C. The mixture was analyzed for residual methanol content. Acceptance criteria ≦0.3% w / w methanol. Acetonitrile (53.45 g) was charged to the vessel and the temperature was adjusted to 15-25°C. The slurry was aged at 15-25°C for at least 1 hour (target 1-2 hours) and then filtered through a 20 μm cloth at 15-25°C. The filter cake was washed twice with acetonitrile (43.39 g) at 15-25°C. The solid was dried under nitrogen flow up to 50°C to give 13.75 g (92%) of a white solid.

[0167] Final product: 1-ethyl-N-((1,2,3,5,6,7-hexahydro-s-indacen-4-yl)-carbamoyl)piperidine-4-sulfonamide (potassium salt) (14) Output: 13.75g Yield: 92% HPLC purity: 99.7%

Claims

1. A method for preparing compound (C) or a salt thereof, comprising the step of contacting compound (A) with compound (B) in the presence of a solvent and a base to obtain compound (C) or a salt thereof. 【Chemistry 1】

2. 2. The method of claim 1, wherein the solvent for contacting compound (A) with compound (B) is selected from toluene, anisole, cyclopentyl methyl ether, ethylbenzene, isopropyl acetate, isobutyl acetate, 2-methyltetrahydrofuran, water, t-butanol, ethyl acetate, methyl acetate, xylene, tetrahydrofuran, dimethyl sulfoxide, acetonitrile, t-butyl methyl ether, N-methylpyrrolidine, N-ethylpyrrolidone, heptane, cyclohexane, acetone, or any combination thereof.

3. 2. The method of claim 1, wherein the solvent for contacting compound (A) with compound (B) is toluene or toluene in combination with water, tert-butanol, tetrahydrofuran, dimethyl sulfoxide, or acetonitrile.

4. 10. The method of claim 1, wherein the solvent for contacting compound (A) with compound (B) is toluene and tetrahydrofuran.

5. 2. The process of claim 1, wherein the base for contacting compound (A) with compound (B) is selected from potassium tert-butoxide, potassium hydroxide or any other basic potassium salt.

6. 2. The process of claim 1, wherein the base for contacting compound (A) with compound (B) is selected from potassium tert-butoxide or potassium hydroxide.

7. 2. The method of claim 1, wherein the base for contacting compound (A) with compound (B) is potassium tert-butoxide.

8. Compound (D) is compound (B): 【Chemistry 2】 A method for preparing compound (B), wherein

9. The method according to claim 8, wherein compound (D) is converted to compound B using a reaction mixture of compound (D) with phosgene, triphosgene, carbonyldiimidazole or di-tert-butyl dicarbonate in the presence of a base and a solvent.

10. the solvent is selected from toluene, anisole, cyclopentyl methyl ether, ethylbenzene, isopropyl acetate, isobutyl acetate, 2-methyltetrahydrofuran, water, ethyl acetate, methyl acetate, xylene, tetrahydrofuran or dimethyl sulfoxide, acetonitrile, t-butyl methyl ether, diethyl ether, dichloromethane, 1,2-dichloroethane, chloroform, N-methylpyrrolidine, N-ethylpyrrolidone, heptane, cyclohexane, or any combination thereof; the base is a tertiary amine such as N,N-diisopropylethylamine, triethylamine, or tributylamine, or the base is an inorganic base such as potassium carbonate, potassium hydroxide, or sodium carbonate; 10. The method of claim 9.

11. the solvent is selected from toluene or toluene in combination with water, acetonitrile or tetrahydrofuran; the base is selected from N,N-diisopropylethylamine, trimethylamine, tributylamine, potassium carbonate, potassium hydroxide or sodium carbonate; 10. The method of claim 9.

12. 10. The method of claim 9, wherein the solvent is toluene and / or water, and the base is N,N-diisopropylethylamine, trimethylamine, or potassium carbonate.

13. 10. The method of claim 9, wherein the solvent is toluene and the base is N,N-diisopropylethylamine or potassium carbonate.

14. 9. The method of claim 8, wherein the reaction mixture is washed with an aqueous solution to obtain compound (B) in an organic solvent.

15. 9. The method of claim 1, wherein compound (B) is prepared by the method of claim 8.

16. 9. The method of claim 8, wherein compound (B) is prepared in a batch process or in a continuous mode.

17. The method of claim 8 , wherein the method is performed in a continuous mode.

18. 10. The method of claim 1, wherein compound (C) is isolated using an anti-solvent.

19. 19. The method of claim 18, wherein the anti-solvent is selected from acetonitrile, any alcohol or water.

20. 10. The method of claim 1, wherein compound (C) is isolated using a washing solvent.

21. 21. The method of claim 20, wherein the washing solvent is selected from tetrahydrofuran, toluene, dimethyl sulfoxide, or acetonitrile.

22. 16. The method of claim 15, wherein the methods for obtaining compound (B) and compound (C) are nested.

23. 20. Compound (C) or a salt thereof prepared by the method of claim 1 or 18.

24. Compound (D) can be prepared by the following process: 【Transformation 3】 The method of claim 8, wherein the compound is prepared via:

25. Compound (A) is prepared by the following steps: 【Chemistry 4】 wherein Cbz is carboxybenzyl / benzyloxycarbonyl, OM is methanesulfonate, and SAc is acetylthio. prepared via 25. The method of claim 1, 18 or 24.

26. 24. A pharmaceutical composition comprising the compound (C) of claim 23 or a salt thereof and a pharmaceutically acceptable excipient.

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