Tegeprotafib

Tegeprotafib

CAS 2407610-46-0

Molecular Weight	326.30
Formula	C13H11FN2O5S

PTPN2/1-IN-1, YGY4WEM0NZ

5-(1-fluoro-3-hydroxy-7-methoxynaphthalen-2-yl)-1,1-dioxo-1,2,5-thiadiazolidin-3-one

Tegeprotafib (PTPN2/1-IN-1) (Compound 124) is an orally active PTPN1 and PTPN2 inhibitor with IC₅₀s of 4.4 nM and 1-10 nM against PTPN2 and PTP1B, respectively.

Cancer immunotherapy regimens targeting immune evasion mechanisms including checkpoint blockade (e.g., PD-1/PD-L1 and CTLA-4 blocking antibodies) have been shown to be effective in treating in a variety of cancers, dramatically improving outcomes in some populations refractory to conventional therapies. However, incomplete clinical responses and the development of intrinsic or acquired resistance will continue to limit the patient populations who could benefit from checkpoint blockade.

Protein tyrosine phosphatase non-receptor type 2 (PTPN2), also known as T cell protein tyrosine phosphatase (TC-PTP), is an intracellular member of the class 1 subfamily of phospho-tyrosine specific phosphatases that control multiple cellular regulatory processes by removing phosphate groups from tyrosine substrates. PTPN2 is ubiquitously expressed, but expression is highest in hematopoietic and placental cells (Mosinger, B. Jr. et al., Proc NatlAcad Sci USA 89:499-503; 1992). In humans, PTPN2 expression is controlled post-transcriptionally by the existence of two splice variants: a 45 kDa form that contains a nuclear localization signal at the C-terminus upstream of the splice junction, and a 48 kDa canonical form which has a C-terminal ER retention motif (Tillmann U. et al., Mol Cell Biol 14:3030-3040; 1994). The 45 kDa isoform can passively transfuse into the cytosol under certain cellular stress conditions. Both isoforms share an N-terminal phospho-tyrosine phosphatase catalytic domain. PTPN2 negatively regulates signaling of non-receptor tyrosine kinases (e.g., JAK1, JAK3), receptor tyrosine kinases (e.g., INSR, EGFR, CSF1R, PDGFR), transcription factors (e.g., STAT1, STAT3, STAT5a/b), and Src family kinases (e.g., Fyn, Lck). As a critical negative regulator of the JAK-STAT pathway, PTPN2 functions to directly regulate signaling through cytokine receptors, including IFNγ. The PTPN2 catalytic domain shares 74% sequence homology with PTPN1 (also called PTP1B), and shares similar enzymatic kinetics (Romsicki Y. et al., Arch Biochem Biophys 414:40-50; 2003).

Data from a loss of function in vivo genetic screen using CRISPR/Cas9 genome editing in a mouse B16F10 transplantable tumor model show that deletion of Ptpn2 gene in tumor cells improved response to the immunotherapy regimen of a GM-CSF secreting vaccine (GVAX) plus PD-1 checkpoint blockade (Manguso R. T. et al., Nature 547:413-418; 2017). Loss of Ptpn2 sensitized tumors to immunotherapy by enhancing IFNγ-mediated effects on antigen presentation and growth suppression. The same screen also revealed that genes known to be involved in immune evasion, including PD-L1 and CD47, were also depleted under immunotherapy selective pressure, while genes involved in the IFNγ signaling pathway, including IFNGR, JAK1, and STAT1, were enriched. These observations point to a putative role for therapeutic strategies that enhance IFNγ sensing and signaling in enhancing the efficacy of cancer immunotherapy regimens.

Protein tyrosine phosphatase non-receptor type 1 (PTPN1), also known as protein tyrosine phosphatase-1B (PTPiB), has been shown to play a key role in insulin and leptin signaling and is a primary mechanism for down-regulating both the insulin and leptin receptor signaling pathways (Kenner K. A. et al., J Biol Chem 271: 19810-19816, 1996). Animals deficient in PTP1B have improved glucose regulation and lipid profiles and are resistant to weight gain when treated with a high fat diet (Elchebly M. et al., Science 283: 1544-1548, 1999). Thus, PTP1B inhibitors are expected to be useful for the treatment of type 2 diabetes, obesity, and metabolic syndrome.

SCHEME

PATENT

Calico Life Sciences LLC; AbbVie Inc. , WO2021127499

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2021127499&_cid=P21-M9UYU6-17583-1

Example 25: 5-(1-fluoro-3-hydroxy-7-methoxynaphthalen-2-yl)-1λ⁶,2,5-thiadiazolidine-1,1,3-trione (Compound 124)

Example 25A: benzyl 3-(benzyloxy)-7-methoxynaphthalene-2-carboxylate

A mixture of 3-hydroxy-7-methoxy-2-naphthoic acid (75 g, 344 mmol) and cesium carbonate (336 g, 1031 mmol) in N,N-dimethylformamide (687 mL) was rapidly stirred for 5 minutes at 23 °C. Thereafter, benzyl bromide (84 mL, 705 mmol) was added. After 90 minutes, the mixture was poured into H₂O (1 L) and extracted with ethyl acetate (4 × 300 mL). The combined organic layers were washed with saturated aqueous ammonium chloride (3 × 100 mL), dried over sodium sulfate, filtered, and concentrated in vacuo to afford a brown solid. The crude solid was collected by filtration, slurried with tert-butyl methyl ether/heptanes (1:2, 3 × 100 mL), then dried in vacuo (12 mbar) at 40 °C to afford the title compound (122.5 g, 307 mmol, 89% yield) as a beige solid. MS (APCI⁺) m/z 399 [M+H]⁺.

Example 25B: 3-(benzyloxy)-7-methoxynaphthalene-2-carboxylic acid

To a suspension of the product of Example 25A (122.5 g, 307 mmol) in methanol (780 mL) was added 6 M aqueous sodium hydroxide (154 mL, 922 mmol). The heterogeneous, brown slurry was agitated with an overhead mechanical stirrer and heated to an internal temperature of 68 °C. After 15 minutes, the mixture was cooled to room temperature in an ice bath, and 6 M HCl (250 mL) was added over 5 minutes. The off-white solid was collected by filtration, washed with H2O (3 × 500 mL), and dried to constant weight in vacuo at 65 °C to afford the title compound (84.1 g, 273 mmol, 89% yield) as a white solid. MS (APCI⁺) m/z 309 [M+H]⁺.

Example 25C: 3-(benzyloxy)-7-methoxynaphthalen-2-amine

To a suspension of the product of Example 25B (84.1 g, 273 mmol), in toluene (766 mL) and tert-butanol (766 mL) was added triethylamine (40.3 mL, 289 mmol). The homogeneous black solution was heated to an internal temperature of 80 °C under nitrogen, and diphenyl phosphorazidate (62.2 mL, 289 mmol) was added dropwise over 90 minutes with the entire

reaction behind a blast shield. After 5 hours, the reaction was cooled to room temperature, diluted with H₂O (1.5 L), and extracted with ethyl acetate (3 × 150 mL). The combined organic layers were washed with brine (2 × 100 mL), dried over sodium sulfate, filtered and concentrated to give 180.1 g of a dark brown solid. The solid was carried forward to hydrolysis without further purification.

To the crude intermediate was added diethylenetriamine (475 mL, 4.40 mol). The heterogeneous suspension was heated to an internal temperature of 130 °C under nitrogen, at which time a homogeneous dark orange solution formed. After 16 hours, the mixture was cooled to room temperature in an ice bath, and H₂O (1.5 L) was added slowly over 3 minutes, resulting in precipitation of a yellow solid and a concomitant exotherm to an internal temperature of 62 °C. Once the heterogeneous suspension had cooled to room temperature, the crude solid was dissolved in CH₂Cl₂ (1.5 L), and the layers were separated. The aqueous layer was back-extracted with CH₂Cl2 (3 × 150 mL), and the combined organic layers were washed with brine (3 × 100 mL), dried over sodium sulfate, filtered, and concentrated in vacuo to afford 78.8 g of an orange solid. The solid was slurried with isopropanol (50 mL), collected via filtration, re-slurried with isopropanol (1 × 50 mL), and dried in vacuo (15 mbar) at 35 °C to afford the title compound (60.12 g, 215 mmol, 79% yield over two steps) as a yellow solid. MS (APCI⁺) m/z 280 [M+H]⁺.

Example 25D: methyl {[3-(benzyloxy)-7-methoxynaphthalen-2-yl]amino}acetate

To a mixture of the product of Example 25C (59.2 g, 212 mmol) and potassium carbonate (58.6 g, 424 mmol) in dimethylformamide (363 mL) and H₂O (1.91 mL, 106 mmol) was added methyl 2-bromoacetate (30.1 mL, 318 mmol). The suspension was vigorously stirred at room temperature for 5 minutes and then heated to an internal temperature of 60 °C. After 70 minutes, the suspension was cooled to room temperature and diluted with H2O (600 mL) and ethyl acetate (500 mL). The aqueous layer was extracted with ethyl acetate (2 × 300 mL), and the combined organic layers were washed with saturated aqueous ammonium chloride (3 × 60 mL), dried over sodium sulfate, filtered, and concentrated to afford 104.3 g of a pale beige solid. The solid was triturated with heptanes (200 mL). The resulting beige solid was collected via filtration, washed with additional heptanes (2 × 30 mL), and dried in vacuo (15 mbar) at 35 °C to afford the title compound (72.27 g, 206 mmol, 97% yield) as an off-white solid. MS (APCI+) m/z 352 [M+H]⁺.

Example 25E: methyl {[3-(benzyloxy)-1-fluoro-7-methoxynaphthalen-2-yl]amino}acetate To a mixture of the product of Example 25D (30.0 g, 85 mmol) and N-fluorobenzenesulfonimide (26.9 g, 85 mmol) was added tetrahydrofuran (THF) (854 mL), and

the resulting homogeneous yellow solution was stirred at room temperature. After 90 minutes, residual oxidant was quenched by adding a solution of sodium thiosulfate pentahydrate (10.59 g, 42.7 mmol) in water (150 mL), and the mixture was stirred at room temperature for 30 minutes. Thereafter, ethyl acetate (600 mL) was added, the aqueous layer was separated, and the organic layer was washed with a solution of sodium carbonate (18.10 g, 171 mmol) in water (30 mL), followed by water:brine (1:1, 1 × 20 mL). The organic fraction was dried over sodium sulfate, filtered, and the concentrated in vacuo to afford a bright yellow/orange solid. The solids were triturated with tert-butyl methyl ether (300 mL), collected via filtration, and the filter cake (N-(phenylsulfonyl)benzenesulfonamide) was washed with tert-butyl methyl ether (2 × 100 mL). The filtrate was concentrated to afford 34.6 g of a dark red oil that was purified by flash chromatography (750 g SiO2, heptanes to 20% ethyl acetate/heptanes) to afford the title compound (16.07 g, 43.5 mmol, 51% yield) as a yellow solid. MS (APCI⁺) m/z 370 [M+H]⁺. Example 25F: methyl {[3-(benzyloxy)-1-fluoro-7-methoxynaphthalen-2-yl](sulfamoyl)amino}acetate

To a solution of chlorosulfonyl isocyanate (5.13 mL, 59.1 mmol) in dichloromethane (83 mL) at 0 °C was added tert-butanol (5.65 mL, 59.1 mmol) slowly so that the internal temperature remained less than 10 °C. After stirring for 30 minutes at 0 °C, a preformed solution of the product of Example 25E (14.55 g, 39.4 mmol) and triethylamine (10.98 mL, 79 mmol) in dichloromethane (68.9 mL) was added slowly via addition funnel so that the internal temperature remained below 10 °C. Upon complete addition, the addition funnel was rinsed with dichloromethane (23 mL). The resulting solution was stirred for 30 minutes at 0 °C, and then the reaction mixture was quenched with H₂O (20 mL). The layers were separated, and the aqueous layer was extracted with dichloromethane (2 × 30 mL). The combined organic layers were washed with brine (1 × 30 mL), dried over sodium sulfate, filtered and concentrated in vacuo to give an orange oil. The residue was dissolved in ethyl acetate (200 mL) and washed with water:brine (1:1, 2 × 50 mL) to remove residual triethylamine hydrochloride. The organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo to give methyl {[3-(benzyloxy)-1-fluoro-7-methoxynaphthalen-2-yl][(tert-butoxycarbonyl)sulfamoyl]amino}acetate which was used without purification.

To a solution of methyl {[3-(benzyloxy)-1-fluoro-7-methoxynaphthalen-2-yl][(tert-butoxycarbonyl)sulfamoyl]amino}acetate in dichloromethane (98 mL) was added trifluoroacetic acid (45.5 mL, 591 mmol), and the resulting dark solution was stirred at room temperature. After 20 minutes, the reaction was quenched by slow addition of saturated aqueous sodium bicarbonate (691 mL) via an addition funnel. The layers were separated, and the aqueous layer was extracted with dichloromethane (2 × 50 mL). The combined organic layers were concentrated to give a dark red oil; upon addition of tert-butyl methyl ether (60 mL), a yellow solid precipitated that was collected via filtration, washed with tert-butyl methyl ether (2 × 30 mL) and dried in vacuo (15 mbar) at 35 °C to give the title compound (13.23 g, 29.5 mmol, 75% yield over two steps) as a light yellow solid. MS (ESI⁺) m/z 449 [M+H]⁺.

Example 25G: 5-(1-fluoro-3-hydroxy-7-methoxynaphthalen-2-yl)-1λ⁶,2,5-thiadiazolidine-1,1,3-trione

To a solution of the product of Example 25F (13.23 g, 29.5 mmol) in tetrahydrofuran (THF) (355 mL) at room temperature was added solid potassium tert-butoxide (3.31 g, 29.5 mmol), and the resulting solution was stirred at room temperature. After 10 minutes, the reaction was quenched with 1 M hydrochloric acid (90 mL) and diluted with ethyl acetate (400 mL). The layers were separated, and the aqueous layer was extracted with ethyl acetate (2 × 120 mL). The combined organic layers were washed with brine (3 × 50 mL), then dried over sodium sulfate, filtered and concentrated. The crude 5-[3-(benzyloxy)-1-fluoro-7-methoxynaphthalen-2-yl]-1λ⁶,2,5-thiadiazolidine-1,1,3-trione was used in the subsequent reaction without further purification.

A mixture of crude intermediate, 5-[3-(benzyloxy)-1-fluoro-7-methoxynaphthalen-2-yl]-1λ⁶,2,5-thiadiazolidine-1,1,3-trione (12.28 g, 29.5 mmol) and pentamethylbenzene (13.11 g, 88 mmol) in dichloromethane (147 mL) was cooled to an internal temperature of –76 °C under an atmosphere of dry nitrogen. Subsequently, a 1 M solution of boron trichloride (59.0 mL, 59.0 mmol) in CH₂Cl₂ was added dropwise over 15 minutes, so as not to raise the internal temperature past –72 °C. Over the course of the addition, the reaction turned dark brown and became homogeneous. Incomplete conversion was observed, and additional boron trichloride (2 × 5.90 mL, 2 × 5.90 mmol) was added, resulting in full conversion. The reaction was quenched at –75 °C with CH₂Cl₂/methanol (10:1, 140 mL) via cannula transfer under nitrogen over 15 minutes, then slowly warmed to room temperature over 20 minutes under nitrogen. The volatiles were removed in vacuo to afford a brown/tan solid, which was collected by filtration, and slurried with heptanes (5 × 40 mL) and CH₂Cl₂ (3 × 40 mL). The crude solid was suspended in isopropanol (75 mL), warmed until the material dissolved, then allowed to cool slowly to room temperature over 1 hour. The solid was collected by filtration, washed with heptanes (2 × 30 mL), and dried in vacuo (15 mbar) at 60 °C to afford 5.11 g of a white solid. The mother liquor was concentrated, and the process was repeated to give an additional 1.96 g of a white solid. The batches were combined to obtain the title compound (7.07 g, 21.67 mmol, 73.5% yield over two steps). ¹H NMR (CD3OD) δ ppm 7.60 (dd, J = 9.1, 1.5 Hz, 1H), 7.25 (d, J = 2.6, 1H), 7.16 (dd, J = 9.1, 2.6 Hz, 1H), 7.04 (s, 1 H), 4.56 (s, 2H), 3.89 (s, 3 H); MS (ESI^–) m/z 325 [M–H]^–.

PATENT

WO2020186199 

WO2019246513 

PATENT

compound 124 [US20230019236A1]

https://patentscope.wipo.int/search/en/detail.jsf?docId=US389737555&_cid=P21-M9UYQD-14144-1

[1]. Elliot FARNEY, et al. Protein tyrosine phosphatase inhibitors and methods of use thereof. Patent WO2019246513A1.

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