Methods of the synthesis of 3-(aminomethyl)-4-chloro-7-(2- hydroxyethoxy)benzo[c1[1,2]oxaborol-1(3H)-ol and compound prepared by said methods

Description

1 / 22 “METHODS OF SYNTHESIS OF 3-(AMINOMETIL)-4-CHLORO-7-(2-HYDROXYETHOXY)BENZO[C1[1,2]OXABOROL-1(3H)-OL AND COMPOUND PREPARED BY SAID METHODS” FIELD OF THE INVENTION

[001] The present invention relates to improved synthetic methods for 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H))-ol, which is a useful compound as an antimycobacterial, for example, in the treatment of tuberculosis. BACKGROUND OF THE INVENTION

[002] Mycobacterium is a genus of the class of bacteria called Actinobacteria, with its own distinct family, known as Mycobacteriaceae. Mycobacterium contains several obligate and opportunistic pathogens of animals, which can also be transmitted to humans and cause disease in humans, thus exhibiting considerable zoonotic potential. In recent decades, members of the Mycobacterium avium-intracellulare (MAIC) complex have emerged as pathogens of human diseases, including lymphadenitis in children, tuberculosis-like lung disease, and disseminated infections (occurring predominantly in immunocompromised individuals, particularly AIDS patients). Similarly, important animal diseases result from infections in an animal by members of this group, for example, avian tuberculosis and paratuberculosis in ruminants. MAIC includes M. intracellulare and 4 subspecies of M. avium, namely, M. avium subsp. avium, M. avium subsp. hominissuis, M. avium subsp. silvaticum and M.avium subsp. paratuberculosis. While members of the M. tuberculosis complex are transmitted through direct contact with the host, MAIC species are acquired predominantly from environmental sources, including soil, water, dust, and food.

[003] Mycobacterium tuberculosis (MTB) is a small, aerobic, non-motile bacillus with a high GC content and an abnormally thick outer membrane, Petition 870250086121, dated 09 / 23 / 2025, page 38 / 74 2 / 22 waxy, hydrophobic, rich in mycolic acids, and extremely impermeable, which makes mycobacterial infections difficult to treat. It is believed that one-third of the world's population is infected (including latent MTB), but this number rises to over 80% of the population in many Asian and African countries. If left untreated, the mortality rate from active MTB infections exceeds 50%. Furthermore, the combination of HIV and MTB is deadly, and a growing number of MTB strains are becoming resistant to standard medications; approximately 300,000 new cases of multidrug-resistant (MDR) M. tuberculosis are reported each year. Multidrug-resistant (MDR) M. tuberculosis is resistant to isoniazid and rifampicin, and extensively drug-resistant (XDR) M. tuberculosis is also resistant to at least one quinolone and one aminoglycoside.

[004] Synthetic drugs to treat tuberculosis (TB) have been available for more than half a century, but the incidence of the disease continues to increase worldwide. More than 2 billion people are currently infected with M. tuberculosis, most of them latent cases, and it is estimated that more than 9 million new cases occur each year worldwide, resulting in 1.7 to almost 2 million deaths per year. In 2004 alone, approximately 24,500 new infections and nearly 5,500 deaths were recorded per day. See Zignol, M. et al., M. Surveillance of anti-tuberculosis drug resistance in the world: an updated analysis, 2007-2010. Bull. World Health Organ 2012, 90 (2), 1 1 1 -1 19D) Co-infection with HIV is driving the increase in incidence (Williams, BG; Dye, C. Science, 2003, 301, 1535) and the cause of death in 31 % of AIDS patients in Africa can be attributed to TB. See Corbett, El and others. Arch. Inti. Med., 2003, 163, 1009, Septkowitz, A. et al., Clin.Microbiol. Rev. 1995, 8, 180).

[005] The limitations of tuberculosis treatment and prevention are well known. The currently available vaccine, BCG, was introduced in 1921 and does not Petition 870250086121, dated 09 / 23 / 2025, p. 39 / 74 3 / 22 protects most people after childhood. According to a 2006 report – International Standards for Tuberculosis Care, a document developed by the Tuberculosis Technical Assistance Coalition (TBCTA), whose partners include the Centers for Disease Control, the American Thoracic Society, the Tuberculosis Foundation, the KNCV, the World Health Organization, and the International Union Against Tuberculosis and Lung Disease – patients who are currently infected with active disease undergo two months of combination therapy with drugs introduced between 50 and 60 years ago – isoniazid (1952), rifampicin (1963), pyrazinamide (1954), and ethambutol (1961) – followed by another 4 months of isoniazid and rifampicin (also known as rifampicin).Alternatively, the continuation phase may include isoniazid and ethambutol for six months when adherence cannot be assessed, but according to this report, a longer continuation phase is associated with a higher failure and relapse rate, especially in patients with HIV infection. Furthermore, as detailed in this report, the doses of antituberculosis drugs used should be in accordance with international recommendations, and fixed-dose combinations of two (isoniazid and rifampicin), three drugs (isoniazid, rifampicin, and pyrazinamide), and four (isoniazid, rifampicin, pyrazinamide, and ethambutol) are highly recommended, especially when it is not possible to monitor the patient to ensure treatment is being taken.

[006] Daily dosing is necessary in these phases of treatment, and poor adherence leads to the emergence and spread of multidrug-resistant strains, which are difficult to treat. Shorter treatments with more active agents that can be taken less frequently and that represent a high barrier to the emergence of resistance are urgently needed, i.e., agents that are effective against multidrug-resistant TB strains (MDR-TB). A March 2013 report Petition 870250086121, dated 09 / 23 / 2025, page 40 / 74 A study published on 4 / 22 (http: / / www.aidsmap.com / Once-weekly-continuation-phase-TB-treatment-equalsstandard-of-care / page / 2589498 / ) suggests that a combination of two drugs, rifapentine (a long-acting derivative of rifampicin) with moxifloxacin (a fluoroquinolone antibiotic not previously used in TB treatment), could allow tuberculosis (TB) treatment to be given once a week during the four-month continuation phase and achieve the same standard of care as the traditional daily continuation treatment with isoniazid and rifampicin. This treatment phase would allow treatment supervision to extend throughout the continuation phase, increasing adherence. However, moxifloxacin has not yet been approved for TB treatment, and the weekly treatment protocol has not yet been endorsed or approved as an alternative standard of care.National and international guideline panels will need to review the published evidence to determine whether this alternative continuous treatment protocol should be recommended and adopted. Furthermore, rifapentine is expensive, and interactions between rifapentine and antiretroviral drugs from the non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor classes may preclude its use in TB patients who are also HIV-positive and using antiretroviral medications. Therefore, currently, the cost / benefit analysis of a continuation treatment with weekly rifapentine versus daily rifampicin has not yet been fully evaluated.

[007] Document WO2015021396A2 describes benzoxaborole compounds that show unexpected selectivity for inhibiting Mycobacterium tuberculosis (M. tuberculosis) replication versus inhibition (toxicity) of human cells compared to other benzoxaborole compounds, and exhibit submicromolar MIC values ​​against mycobacterial species, particularly Mycobacterium tuberculosis and Mycobacterium tuberculosis complex (MTC), Mycobacterium avium and Petition 870250086121, dated 09 / 23 / 2025, page 41 / 74 5 / 22 Mycobacterium avium complex (MAC) and Mycobacterium avium intracellulare complex (MAIC).

[008] In particular, WO2015021396A2 reveals (S)-3-(aminomethyl)-4-chloro-7(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H))-ol (in a tricyclic closed-ring configuration): h2o

[009] A synthetic route is described. The synthesis of the sulfate salt is described in Example 4-II SUMMARY OF THE INVENTION

[0010] A method for preparing 3(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol is disclosed in this document: or its salt, the method comprising the preparation of ((3-chloro-7,8-dihydro-2H1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl)methyl) tert-butyl carbamate: Petition 870250086121, dated 09 / 23 / 2025, p. 42 / 74 6 / 22 followed by conversion of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl) tert-butyl carbamate to 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3 / - / )-ol or its salt.

[0011] The following compounds are also disclosed in this document:

[0012] Tert-butyl ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl) carbamate;

[0013] 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt;

[0014] 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt;

[0015] 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol; and

[0016] 2-bromo-3-(2-hydroxyethoxy) benzaldehyde.

[0017] Also disclosed in this document is a method for preparing 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol or its salt, comprising:

[0018] a) convert 2-bromo-3-(2-hydroxyethoxy)benzaldehyde to 1-(2-bromo-3(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol;

[0019] b) convert 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol into 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt;

[0020] c) convert 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt into 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt; Petition 870250086121, dated 09 / 23 / 2025, p. 43 / 74 7 / 22

[0021] d) convert 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan1-ol or its salt into ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2yl)methyl)carbamate;

[0022] e) convert ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl)carbamate into 3-(aminomethyl)-4-chloro-7-(2hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol or its salt. DETAILED DESCRIPTION

[0023] The synthetic route described here may offer any of the following advantages over that revealed in WO'396:

[0024] · Improvement in overall performance.

[0025] · Cost reduction; cheaper reagents can be used.

[0026] · Greater reliability - does not use cryogenic lithification chemistry (unlike the WO'396 route);

[0027] · The current route has a larger number of isolable intermediates (for purity control) - the WO'396 route has several oils that needed to be telescoped through the synthesis.

[0028] In some examples, a method is provided for preparing 3(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol:

[0029] the method comprising preparing a compound selected from: Petition 870250086121, dated 09 / 23 / 2025, page 44 / 74 8 / 22 or 3-bromo-3-(2-hydroxyethoxy)benzaldehyde; followed by conversion of the selected compound into 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3 / - / )-ol or its salt.

[0030] In some examples, the method includes: your salt, and / or Petition 870250086121, dated 09 / 23 / 2025, page 45 / 74 9 / 22

[0033] (iii) preparation of HO. ^0 IL / 0HNHz or its salt and / or

[0034] (iv) preparation of HO. X) lí ^OH N°2 and / or

[0035] (v) preparation of hydroxyethoxy)benzaldehyde. / °hci L í NH2 or its salt, of HO. 11 s NHí or its salt, of HO. ^O / Br CC- NO< of 2-bromo-3-(2- Petition 870250086121, dated 09 / 23 / 2025, p. 46 / 74 10 / 22

[0036] In some examples, 2-bromo-3-(2-hydroxyethoxy)benzaldehyde can be synthesized from 2-bromo-3-hydroxybenzaldehyde, which in turn can, in some examples, be synthesized from 3-hydroxybenzaldehyde.

[0037] The preparation of 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H))-ol or its salt from carbamate of ((3chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl)methyl) may comprise the deprotection of Boc using sulfuric acid, and the reaction product is the sulfate salt of 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)ol.

[0038] In some of these examples, the method may comprise mixing a solution of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl carbamate) in solvent (e.g., isopropyl alcohol) with sulfuric acid at a temperature below 25°C. It may even comprise heating (e.g., to 45-55°C). It may further comprise subsequent cooling (e.g., to 20-30°C), filtration, and solvent cake (e.g., isopropyl alcohol). In some cases, it may comprise one or more additional cycles of heating, cooling, filtration, and washing. In some cases, the wet cake may be vacuum dried. In some cases, the solid may be dissolved in a solvent (e.g., methanol) and recrystallized to improve purity.

[0039] The preparation of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl)carbamate from 2-amino-1-(2-bromo-6-chloro-3(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt may, in some cases, involve a Pd-catalyzed borylation. In some cases, the reaction may comprise a Miyaura borylation. In some cases, the borylation may be preceded by a Boc protection reaction.

[0040] In some of these examples, the method includes: Petition 870250086121, dated 09 / 23 / 2025, p. 47 / 74 11 / 22

[0041] (i) mixture of 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan1-ol with BOC2O, base (e.g., KHCO3) and solvent (e.g., MTBE(aq))

[0042] (ii) add base (e.g., potassium pivalate), Pd catalyst (e.g., palladium(II) acetate) and a phosphine ligand (e.g., tri-t-butylphosphine tetrafluoroborate);

[0043] (iii) add a borylation agent (e.g. B2pin2, HBpin and B2(OH)4);

[0044] (iv) washing; and

[0045] (v) crystallization of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa9a-borabenzo[cd]azulen-2-yl)methyl) carbamate).

[0046] The preparation of 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt from 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt may, in some cases, involve chlorination by electrophilic aromatic substitution. In some cases, the chlorinating agent may comprise N-chlorosuccinimide. In some cases, a crystalline salt of the chlorination product may be formed, such as a mesylate salt, to allow isolation of the reaction product.

[0047] The preparation of 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt from 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol may comprise a nitro reduction reaction. In some cases, this may be metal-catalyzed, for example, Raney nickel-catalyzed hydrogenation to reduce the nitro group. (In other examples, the reduction may be catalyzed by Pt, Pd, Rh, Ru, or Ir-based catalysts). In some cases, a crystalline salt of the reaction product may be formed, such as a tartrate salt, to allow isolation of the reaction product.

[0048] The preparation of 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol from 2-bromo-3-(2-hydroxyethoxy)benzaldehyde may, in some cases, involve a Petition 870250086121, dated 09 / 23 / 2025, p. 48 / 74 12 / 22 Asymmetric nitroaldol reaction (e.g., an asymmetric Henry reaction). This may include the use of a copper catalyst, such as a copper(II) catalyst, such as Cu(OAC)2, Cu(OTf)2, CuCl2 and the like. In some examples, a ligand used in the reaction may be a diamine ligand, such as a diaminocyclohexane, a chiral oxazoline, a Schiff base ligand or a chiral Salen base ligand. In some examples, the ligand comprises (1R,2R,4R)-1,7,7-trimethylN-(pyridin-2-ylmethyl)bicyclo[2.2.1]heptan-2-amine dihydrochloride. In some examples, the asymmetric nitroaldol reaction comprises:

[0049] (i) mixing a ligand and 2-bromo-3-(2-hydroxyethoxy)benzaldehyde in the presence of a copper catalyst, optionally in the presence of a solvent (e.g., ethanol and MeTHF cosolvent) and a base (e.g., DIPEA);

[0050] (ii) addition of nitromethane, optionally in the presence of a solvent

[0051] (iii) acid quenching;

[0052] (iv) washing (e.g., with Na2SO4(aq), EDTA.2Na.2H2O(aq))) to isolate 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol; and

[0053] (v) crystallization of 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol.

[0054] Throughout this descriptive report, in some examples, the method may refer to a stereoisomer of the listed compound. Thus, in some cases, the method may be related to the synthesis of (S)-3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3A7))-ol: or your salt. Petition 870250086121, dated 09 / 23 / 2025, p. 49 / 74 13 / 22

[0055] In some examples, tert-butyl ((3-chloro-7,8-dihydro-2H-1,6,9trioxa-9a-borabenzo[cd]azulen-2yl)methyl) carbamate can be carbamate of (S)-((3chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl) methyl):

[0056] In some examples, 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or its salt may be (S)-2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol: or your salt.

[0057] In some examples, 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan -ol or its salt may be (S)-2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol: or your salt. Petition 870250086121, dated 09 / 23 / 2025, pp. 50 / 74 14 / 22

[0058] In some examples, (S)-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol can be (S)-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol: ABBREVIATIONS

[0059] In the description of the invention, the chemical elements are identified according to the Periodic Table of Elements. The abbreviations and symbols used herein are in accordance with the common usage of such abbreviations and symbols by those skilled in the art. The following abbreviations are used herein:

[0060] AcOH - Acetic acid

[0061] AIBN - 2-2'-Azoisobutyronitrile

[0062] BOC - N-tert-butoxycarbonyl

[0063] B2pyrÍ2 - Bis(pinacolate)diboron, also known as 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi-1,3,2-dioxaborolan

[0064] DCM - Dichloromethane

[0065] DIPEA- A / ,A / -Diisopropylmethylamine

[0066] DMSO-d6 - Deuterated dimethyl sulfoxide

[0067] DMSO - Dimethyl sulfoxide

[0068] EtOH - Ethanol

[0069] EtOAc - Ethyl acetate

[0070] h - hours

[0071] HPLC - High-performance liquid chromatography

[0072] IPA - Isopropyl alcohol Petition 870250086121, dated 09 / 23 / 2025, page 51 / 74 15 / 22

[0073] MCH - Methylcyclohexane

[0074] MeOH - Methanol

[0075] MeCN - Methyl cyanide

[0076] MsOH - Methanesulfonic acid

[0077] ] MTBE - Methyl tertiary butyl ether

[0078] N-Ac-Cys - N-acetyl cysteine

[0079] NBS - N-bromosuccinimide

[0080] NCS - N-chlorosuccinimide

[0081] NMR - Nuclear magnetic resonance spectroscopy

[0082] THF - tetrahydrofuran

[0083] 2-MeTHF - 2-methyl tetrahydrofuran EXAMPLES

[0084] The following examples illustrate the invention. These examples are not intended to limit the scope of the invention, but rather to provide guidance to those skilled in the art regarding the implementation of the methods of the invention. Although embodiments of the invention are described, those skilled in the art will understand that various alterations and modifications can be made.

[0085] Proton nuclear magnetic resonance (1H NMR) spectra were recorded and chemical shifts are reported in parts per million (δ) from the internal standard tetramethylsilane (TMS). Abbreviations for the NMR data are as follows: s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet, dd = doublet of doublets, dt = doublet of triplets, app = apparent, br = wide. All temperatures are reported in degrees Celsius.

[0086] An example of a synthetic route is shown below in Scheme 1. Petition 870250086121, dated 09 / 23 / 2025, page 52 / 74 16 / 22 LU ω LU \p <O CO □) s ω LU Petition 870250086121, dated 09 / 23 / 2025, pp. 53 / 74 17 / 22 Stage A - Synthesis of GW415775X

[0087] To a solution of GR44399X (116 kg) in DCM (1160 L), MsOH (9.3 kg, 0.1 eq.) was added followed by NBS (185 kg, 1.1 eq.) at 20-30°C. The reaction was stirred at 20-30°C and then the reaction mixture was quenched with aqueous Na2S2O2 / KHCO2 (25% w / w, 70 kg). The mixture was concentrated and exchanged with EtOAc (348 L, 3 vol.). After dilution with ETOAc (580 L, 5 vol.), the mixture was washed with aqueous Na2SO4 solution (15% w / w, 3 x 812 kg) at 30-40°C. The organic layer was filtered through diatomaceous earth, rinsing with more EtOAc (77 L). The combined filtrates were washed with aqueous Na2SO4 solution (15% w / w, 812 kg) at 30-40°C, then the organic layer was concentrated under vacuum to ~6 vol. and cooled to -5°C. Methylcyclohexane (MCH) (460 L, 4 vol.) was then added and, after stirring, the mixture was filtered and the cake washed with MCH (120 L, 1 vol.). The wet cake was dried under vacuum at 50°C to yield GW415775X (99 kg, 52%) as a solid.

[0088] 1H NMR (400 MHz; DMSO-d6): 10.8 (1H, s), 10.3 (1H, s), 7.28 (3H, m). Stage B - Synthesis of GSK4026152A

[0084] A solution of GW415775X (68 kg) in 1,4-dioxane (476 L) at 20°C was added to a solution of LiOH.H2O (20 kg) in water (408 L) followed by GI148705X (52.7 kg). The reaction mixture was pumped through a tubular HCl reactor heated to 130°C for a residence time of 30 minutes. The reactor outlet flow was cooled and collected. The mixture was concentrated under vacuum, then the solution was heated and the seed GSK4026152A (0.01 wt) was added. Water (680 L) was added slowly and the resulting paste was cooled, aged and then filtered. The cake was washed with water (68 L) and then vacuum dried at 50°C to generate GSK4026152A (72.6 kg, 86%) as a white solid.

[0089] 1H NMR (400 MHz; CDCI3): 7.57 (1H, dd), 7.38 (1H, t), 7.16 (1H, dd), 4.21 (2H, m), 4.06 (2H, m), 2.27 (1H, t). Stage 1 - Synthesis of GSK4364445A Petition 870250086121, dated 09 / 23 / 2025, pp. 54 / 74 18 / 22

[0090] To a solution of (1R,2R,4R)-1,7,7-trimethyl-N-(pyridin-2-ylmethyl)bicyclo[2.2.1]heptan-2-amine dihydrochloride (GSK2412905A) (3.65 kg) in EtOH (286 L) was added DIPEA (3.75 kg) followed by 2-MeTHF (83 L). The mixture was stirred and Cu(OAc)2.H2O (2.90 kg) was added. After stirring, 2-bromo-3-(2-hydroxyethoxy)benzaldehyde (GSK4026152A, 72.3 kg) followed by DIPEA (3.75 kg) were added rinsing with 2-MeTHF (11 L). The reaction mixture was cooled to -18°C and a nitromethane solution (175 kg) in 2-MeTHF (351 L) was slowly added. The reaction mixture was stirred until HPLC showed that the reaction was complete. The reaction was quenched by the addition of aqueous HCl solution (1 M, 142 kg) and heated to 25°C. Aqueous Na2SO4 solution (15% w / w, 213 kg) followed by water (444 L) were then added and the layers separated. Aqueous HCl solution (1 M, 142 kg) and aqueous EDTA.2Na.2H2O solution (5% w / w, 214 kg) were added to the organic phase.After agitation, the layers were separated and more aqueous HCl solution (1 M, 142 kg) and aqueous EDTA.2Na.2H2O solution (5% w / w, 213 kg) were added to the organic layer. The layers were separated and the organic phase filtered. More aqueous HCl solution (1 M, 141 kg) and aqueous EDTA solution were added to the organic phase.2Na.2H2O (5% w / w, 207 kg). The mixture was filtered and rinsed with 2-MeTHF (29 kg) and the layers separated. The organic phase was concentrated under vacuum to a volume of 220 L and the solvent was converted to IPA below 40°C with a put-and-take distillation (3 x 124 L of IPA). The solution was concentrated under vacuum to a final volume of 150 L, cooled to 25°C and water (721 L) was added slowly. The resulting paste was cooled to 0°C, aged, and then the product was collected by filtration, washing the cake with water (34 L). The wet cake was dried under vacuum at 50°C to yield GSK4364445A as a white solid (71.7 kg, 76%). Petition 870250086121, dated 09 / 23 / 2025, pp. 55 / 74 19 / 22

[0091] 1H NMR (400 MHz; DMSO-d6): 7.40 (1H, t), 7.22 (1H, d), 7.09 (1H, d), 6.31 (1H, d), 5.60 (1H, m), 4.88 (1H, t), 4.78 (1H, dd), 4.40 (1H, dd), 4.07 (2H, m), 3.75 (2H, m). Stage 2 - Synthesis of GSK4023557B

[0092] The reactor was charged with Raney Nickel (15.0 kg) followed by EtOH (598 L), GSK4364445A (71.7 kg) and acetic acid (67.6 kg), rinsing with EtOH (13 L). The reaction mixture was then stirred under a H2 atmosphere at 25°C until HPLC showed that the reaction was complete. The mixture was then filtered through a diatomite pad, washing the cake with EtOH (248 L). The filtered solution was heated to 50°C and L-tartaric acid (34.0 kg) was added. The resulting paste was stirred, cooled to 20°C and aged. The product was collected by filtration, washing the cake with EtOH (87 L). The wet cake was dried under vacuum at 50°C to yield GSK4023557B as a white solid (88.1 kg, 90%).

[0093] 1H NMR (400 MHz; D2O): 7.46 (1H, t), 7.26 (H, d), 7.12 (1H, d), 5.42 (H, dd), 4.50 (2H, s), 4.22 (2H, m), 3.97 (2H, m), 3.30 (1H, dd), 3.16 (1H, dd). Stage 3 - Synthesis of GSK4023558B

[0093] To a suspension of GSK4023557B (63.8 kg) in MeCN (325 L) and MeOH (93 L) was added MsOH (43.8 kg). A solution of NCS (22.0 kg) in MeCN (249 L) was then added, rinsing with more MeCN (17 L). The mixture was stirred at 20°C until HPLC showed that the reaction was complete. The seed GSK4023557B (0.40 kg) was added, the mixture was stirred, and then MeCN (762 L) was added slowly. The mixture was cooled to -18°C, stirred, and the paste filtered. The cake was washed with MeCN (48 L) and then dried under vacuum at 40°C to yield GSK4023558B as a white solid (50.9 kg, 82%).

[0094] 1H NMR (400 MHz; MeOD): 7.40 (1H, d), 7.06 (H, d), 5.79 (1H, dd), 4.14 (2H, m), 3.92 (2H, m), 3.69 (1H, t), 3.08 (1H, dd), 2.70 (3H, s). Stage 4 - Preparation of GSK3177484A Petition 870250086121, dated 09 / 23 / 2025, pp. 56 / 74 20 / 22

[0095] To a solution of GSK4023558B (50.9 kg) in MTBE (147 L) and water (153 L) was added KHCO3 (14.0 kg) followed by BOC2O (28.9 kg), rinsing with MTBE (7 L). The mixture was stirred at 20°C until HPLC showed that the reaction was complete. The reaction mixture was left to stand and separated, then the organic phase was washed with H2O (2 x 100 L). The organic layer was concentrated and converted to MeCN to obtain a solution of C14111825-GA in MeCN (-290 L).

[0096] To the C14111825-GA solution in MeCN was added more MeCN (319 L) and potassium pivalate (25.9 kg) in water (50 L), and palladium(II) acetate (1.93 kg) and tri-t-butylphosphine tetrafluoroborate (5.0 kg) were added to the MeCN solution, followed by the addition of a B2pin2 solution (63.0 kg) in MeCN (99 L), and the reactor was purged with N2. The reaction mixture was heated to 40°C and stirred until HPLC showed that the reaction was complete. The reaction mixture was filtered, and the cake was washed with MeCN (94 L). The filtrate was concentrated to -100 L and then diluted with EtOAc (445 L), and the layers separated. The organic phase was washed with a mixture of aqueous N-Ac-Cys (5% w / w, 231 kg) and aqueous KHCO3 mixed solution (5% w / w, 226 kg) (three times). The organic phase was then stirred with silica thiol (15 kg), filtered, and the cake was washed with EtOAc (32 L). The filtrate was concentrated and transferred to IPA in a solution volume of -110 L.The residue was diluted with IPA (160 L), cooled to 0°C, and GSK3177484A seed (0.25 kg) was added. The mixture was stirred and then filtered. The wet cake was washed with IPA (33 L) and then dried at 40°C under vacuum to obtain GSK3177484A as a white solid (36.5 kg, 66% in 2 stages).

[0098] 1H NMR (400 MHz; DMSO-d6): 7.42 (1H, d), 6.96 (0.8H, s), 6.89 (1H, d), 6.62 (0.2H, s), 5.32 (1H, m), 4.34-4.19 (4H, m), 3.74 (1H, m), 3.21 (1H, m), 1.33 (9H, s). Stage 5 - Preparation of IG GSK3036656E

[0097] To a solution of GSK3177484A (36.5 kg, assay 75.5% by weight) in IPA (196 L, 7.3 vol.), an aqueous solution of sulfuric acid (50% w / w, Petition 870250086121, dated 09 / 23 / 2025, pp. 57 / 74 21 / 22 25.1 kg, 0.91% by weight), maintaining the internal temperature below 25°C. The reaction mixture was heated to 45-55°C and stirred for 33 h, after which HPLC showed that the reaction was complete. The mixture was cooled to 20-30°C and then filtered, washing the cake with IPA (8 L, 0.3 vol.). The wet cake was transferred back to the reactor and IPA (245 L, 8.9 vol.) was added. The mixture was heated to 45-55°C, stirred at this temperature for 3 h, then cooled to 20-30°C. The product was collected by filtration, washing the cake with IPA (8 L, 0.3 vol.). The moist cake was dried under vacuum at 40-50°C for 24 h to give intermediate grade GSK3036656E (27.5 kg, 93%) as a white solid. Stage 6 - Purification of GSK3036656E

[0102] GSK3036656E (27.4 kg, 1.0 wt.), purified water (19 L, 0.7 vol.) and MeOH (372 L, 13.6 vol.) were loaded into a reactor (R1). The mixture was heated to 64°C and stirred at 60-68°C for 2 h to provide a clear solution. The solution in R1 was transferred through a 0.22 μm in-line filter to another reactor (R2), which was preheated to 62-68°C. Purified water (22 L, 0.8 vol.) was added to R1 and the wash water was transferred to R2 through the in-line filter. The mixture in R2 was adjusted to 50-60°C and stirred for 0.5 h to provide a clear solution. The GSK3036656E seed (71 g, 0.26% by weight) was then added to R2, rinsing with MeOH / purified water (9:1 v / v). The mixture was stirred at 50-60°C for 3 h, then cooled to 5°C over 5.5 h and stirred at 0-10°C for 5 h. The paste was then wet-ground for a total of 3.5 h. The mixture was aged at 0-10°C for 15 h, then heated to 50-60°C over 3 h and stirred at that temperature for 1 h.The mixture was cooled to 0-10°C for 5 hours and stirred at that temperature for 2 hours, then heated to 50-60°C for 2.5 hours and stirred in that range for 1 hour. The mixture was then cooled to 0-10°C for 5 hours and stirred at that temperature for 8 hours before being heated to 50-60°C for 3 hours and maintained in that range for 1.5 hours. The mixture was cooled to 0-10°C for 6 hours and aged at that temperature for 19 hours. The mixture was filtered and the cake... Petition 870250086121, dated 09 / 23 / 2025, pp. 58 / 74 22 / 22 washed with MeOH / purified water (9:1 v / v, 44 kg, 1.6 g by weight). The wet cake was dried under vacuum at 35-45°C for 5 h then at 45-55°C for a further 26 h to give GSK3036656E (20.3 kg, 76%) as a white solid.

[0098] 1H NMR (400 MHz; D2O): 7.40 (1H, d), 6.88 (1H, d), 5.39 (1H, dd), 4.16 (2H, m), 4.03 (2H, m), 3.82 (1H, dd), 3.19 (1H, dd).

[0099] It should be understood that the invention encompasses all combinations of aspects with all other suitable aspects and / or exemplary embodiments described herein. It should also be understood that the invention encompasses all combinations of exemplary embodiments with all other suitable aspects and / or exemplary embodiments described.

[0105] It is understood that the examples and embodiments described in this document are for illustrative purposes only and that various modifications or alterations in light thereof are suggested to those skilled in the art and should be included in the spirit and scope of this application and the scope of the appended claims. All publications, patents and patent applications cited in this document are incorporated by reference in full for all purposes. Petition 870250086121, dated 09 / 23 / 2025, pp. 59 / 74

Claims

1 / 7 CLAIMS 1. Method for preparing ((3-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol: 3-(aminomethyl)-4-chloro-7-(2-NH2) or a salt thereof; the method CHARACTERIZED in that it comprises the preparation of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl)methyl) tert-butyl carbamate: followed by conversion of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl)methyl) tert-butyl carbamate into 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol or a salt thereof.

2. Method according to claim 1, CHARACTERIZED in that the carbamate of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2yl)methyl) tert-butyl is prepared from 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol: Petition 870250086121, dated 09 / 23 / 2025, page 60 / 74 2 / 7 3. Method according to claim 2, CHARACTERIZED in that it further comprises the preparation of 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof from 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol:

4. Method according to claim 3, CHARACTERIZED in that it further comprises the preparation of 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof from 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol: Petition 870250086121, dated 23 / 09 / 2025, p. 61 / 74 3 / 7 5. Method according to claim 4, CHARACTERIZED in that it further comprises the preparation of 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol from 2-bromo-3-(2-hydroxyethoxy)benzaldehyde.

6. Method, according to any one of claims 2 to 4, CHARACTERIZED in that the method of converting 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof into ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl)methyl) tert-butyl carbamate includes a Miyaura Borylation.

7. Compound, CHARACTERIZED by the fact that it is selected from: ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen2-yl)methyl) tert-butyl carbamate; 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof; 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof; and 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol.

8. Method for preparing 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol or a salt thereof, CHARACTERIZED in that it comprises: a) conversion of 2-bromo-3-(2-hydroxyethoxy)benzaldehyde into 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol; Petition 870250086121, dated 23 / 09 / 2025, p.62 / 74 4 / 7 b) conversion of 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol to 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof; c) conversion of 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof to 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof; d) conversion of 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof into ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl carbamate); and ee) conversion of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl carbamate into 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol or a salt thereof.

9. Method according to claim 8, CHARACTERIZED in that the method prepares (S)-3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol and comprises: a) converting 2-bromo-3-(2-hydroxyethoxy)benzaldehyde into (S)-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol; b) converting (S)-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol into (S)-2amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol. Petition 870250086121, dated 23 / 09 / 2025, p.63 / 74 5 / 7 c) convert (S)-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol or a salt thereof into (S)-2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol: d) convert (S)-2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof into (S)-((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl carbamate): NHBoc; (ee) convert (S)-((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9aborabenzo[cd]azulen-2-yl)methyl carbamate into (S)-3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol: Petition 870250086121, dated 09 / 23 / 2025, p. 64 / 74 6 / 7 Cl nh2 or salt thereof.

10. Method, according to any one of claims 5, 8 and 9, CHARACTERIZED in that the conversion of 2-bromo-3-(2-hydroxyethoxy)benzaldehyde to 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol comprises an asymmetric nitroaldol reaction.

11. Method, according to any one of claims 4, 5, 8 and 9, CHARACTERIZED in that the conversion of 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol to 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof comprises a nitro reduction reaction.

12. Method according to claim 11, CHARACTERIZED in that L-tartaric acid is added to the reaction and the reaction product is the tartrate salt of 2-amino-1-(2-bromo-3-(2-hydroxyethoxy)phenyl)ethan-1-ol.

13. Method, according to any one of claims 3, 4, 5, 8 and 9, CHARACTERIZED in that the conversion of 1-(2-bromo-3-(2-hydroxyethoxy)phenyl)-2-nitroethan-1-ol or a salt thereof into 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof comprises chlorination by electrophilic aromatic substitution; wherein methylsulfonic acid is added to the reaction and the reaction product is the mesylate salt of 2-amino-1-(2-bromo-6-chloro-3-(2-hydroxyethoxy)phenyl)ethan-1-ol. Petition 870250086121, dated 23 / 09 / 2025, p. 65 / 74 7 / 7 14. Method, according to any one of claims 2 to 5, 8 and 9, CHARACTERIZED in that the conversion of 2-amino-1-(2-bromo-6-chloro-3(2-hydroxyethoxy)phenyl)ethan-1-ol or a salt thereof to ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl)methyl) carbamate comprises a Boc protection reaction and then a Pd-catalyzed borylation.

15. Method, according to any one of claims 1 to 6, 8 and 9, CHARACTERIZED in that the conversion of carbamate of ((3-chloro-7,8-dihydro-2H-1,6,9-trioxa-9a-borabenzo[cd]azulen-2-yl)methyl) to 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol or a salt thereof comprises the deprotection of Boc using sulfuric acid, and the reaction product is the sulfate salt of 3-(aminomethyl)-4-chloro-7-(2-hydroxyethoxy)benzo[c][1,2]oxaborol-1(3H)-ol. Petition 870250086121, dated 23 / 09 / 2025, p. 66 / 74