AMG-319

N-((1S)-1-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine, WO2008118468

(S)-N-(1-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine

 CAS 1608125-21-8

Chemical Formula: C21H16FN7
Exact Mass: 385.14512

Phosphoinositide-3 kinase delta inhibitor

AMGEN, PHASE 2

PI3K delta isoform selective inhibitor that is being investigated in human clinical trials for the treatment of PI3K-mediated conditions or disorders, such as cancers and/or proliferative diseases

Useful for treating PI3K-mediated disorders such as acute myeloid leukemia, myelo-dysplastic syndrome, myelo-proliferative diseases, chronic myeloid leukemia, T-cell acute lymphoblastic leukemia, B-cell acute lymphoblastic leukemia, non-Hodgkins lymphoma, B-cell lymphoma, or breast cancer.

Amgen is developing AMG-319, a small molecule PI3K-δ inhibitor, for treating lymphoid malignancies and solid tumors including, head and neck squamous cell carcinoma.

AMG-319 is a highly selective, potent, and orally bioavailable small molecule inhibitor of the delta isoform of the 110 kDa catalytic subunit of class IA phosphoinositide-3 kinases (PI3K) with potential immunomodulating and antineoplastic activities. PI3K-delta inhibitor AMG 319 prevents the activation of the PI3K signaling pathway through inhibition of the production of the second messenger phosphatidylinositol-3,4,5-trisphosphate (PIP3), thus decreasing proliferation and inducing cell death. Unlike other isoforms of PI3K, PI3K-delta is expressed primarily in hematopoietic lineages. The targeted inhibition of PI3K-delta is designed to preserve PI3K signaling in normal, non-neoplastic cells.

PATENT

http://www.google.com/patents/WO2008118468A1?cl=en

PATENT

WO2013152150

http://www.google.com/patents/WO2013152150A1?cl=en

PATENT

WO-2015171725

Example 4: Method of making N-((lSM-(7-fluoro-2-(2-pyridinyl)- 3-quinolinyl)ethyl)-9H-purin-6-amine

N-((l S)- 1 -(7-Fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine (4) is synthesized in four steps beginning with (S)-l-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethanamine hydrochloride (1). A nucleophilic aromatic substitution between coupling partners 1 and purine 5 affords the penultimate intermediate 2. Cleavage of the p-methoxybenzyl (PMB) group leads to the isolation of the desired butyl acetate solvate 3. A crystalline form change is induced through an aqueous-acetone recrystallization to afford the target hydrate 4.

Synthetic Scheme

Step 1. Preparation of PMB protected pyridylpurinamine tosylate (2)

(S)- 1 -(7-Fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethanamine is prepared similar to that described in US20130267524. The (S)-l-(7-fluoro-2-(pyridin-2-

yl)quinolin-3-yl)ethanamine hydrochloride (1) is coupled to PMB-chloropurine (5, prepared similar to that described in J. Med. Chem. 1988,31, 606-612) in the presence of K₂CO₃ in IPA. Upon reaction completion the K₂CO₃ is removed via filtration and the product is crystallized by the addition of /?-toluenesulfonic acid (pTSA). Isolation of the PMB-protected pyridylpurinamine tosylate (2) is conducted via filtration.

Dry 100 L reactor under nitrogen. Set the temperature to 20 ± 5 °C. Charge (l S)-N-chloro-l-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethanamine HCl salt (1) to the reactor. Then 9-(4-methoxybenzyl)-6-chloro-9H-purine (5) is added. Potassium carbonate is added to the reactor. Isopropyl alcohol is added to the reactor and the mixture is heated to 80 °C and stirred for 24 hours. Additional isopropyl alcohol is added to the reactor and the mixture is cooled to 20 °C. The mixture is filtered through Celite and the solid is washed with isopropyl alcohol and the isopropyl alcohol solutions containing 9-(4-methoxybenzyl)-N-((S)- 1 -(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine are collected.

The 9-(4-methoxybenzyl)-N-((S)- 1 -(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine isopropyl alcohol solution is heated to 50 °C. /^-Toluene sulfonic acid monohydrate is dissolved in isopropyl alcohol and added to the 9-(4-methoxybenzyl)-N-((S)-l-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine in portions. The mixture is slowly cooled to 20 ± 5 °C over 6 ± 2 hrs. The crystalline 9-(4-methoxybenzyl)-N-((S)- 1 -(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)- 9H-purin-6-amine toluene sulfonic acid salt is collected, rinsed with isopropyl alcohol and dried with vacuum.

Example 5: Method of Making the Crystalline Hydrate Form of N-((1S)-1- (7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine Step 1: Isolation of a Butyl Acetate (BuOAc) Solvate of N-((lS)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine (3)

To a 2 L jacketed reactor equipped with a condenser, a mechanical stirrer, and a bubbler, under an atmosphere of N₂, was added N-((l S)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9-(4-methoxybenzyl)-9H-purin-6-amine (2, 100.0 g, 0.148 mol), followed by acetic acid (AcOH; 240 mL) and 1 -dodecanethiol (71.1 mL, 0.295 mol). The vessel was evacuated and back-filled with nitrogen three times. Methanesulfonic acid (MSA; 28.7 mL, 0.443 mol) was added to the vessel over 10 minutes. Then, the reaction was heated to 80 °C and stirred for 20 hrs. The reaction was then cooled to ambient temperature, after which toluene (1000 mL) and water (700 mL) were sequentially added. The solution was then stirred for 30 minutes. The phases were separated by removing the organic phase, adding another charge of toluene (1000 mL) to the aqueous phase, and the mixture was stirred for another 30 minutes. After removing the organic phase again, the aqueous phase was charged to a jacketed 5 L reactor equipped with a mechanical stirrer followed by n-butyl acetate (1500 mL,) and heated to 50 °C. The aqueous phase was neutralized to pH 6.3 with 10 N NaOH (350 mL). The organic (BuOAc) phase was azeotropically dried to 600 ppm water, while keeping a constant volume. The dried organic phase was polish filtered at 50 °C to remove salts, which were subsequently washed with hot BuOAc (285 mL). The BuOAc was charged back into the 2 L jacketed reactor equipped with a mechanical stirred and distillation apparatus, and then concentrated to 54 mg/g of N-((l S)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine in solution. The solution was then seeded with 1 wt% seed of the BuOAc solvate of N-((l S)- 1 -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. The slurry was further concentrated to 300 mL total volume and cooled to ambient temperature over 1 hour. Heptane (460 mL) was added dropwise to the solution, and the solution was aged overnight. The supernatant concentration was checked, and determined to be 5.3 mg/g of N-((l S)-l-(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. The supernatant was filtered and the resulting solid cake was washed with 1 : 1 BuOAc:heptane (280 mL), followed by heptane (280 mL). The washed cake was then

allowed to dry on the filter. The BuOAc solvate of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine was obtained as a white solid (59.5 g, 99.6 LCAP, 86.3 wt%, 90 % corrected yield). ^!H NMR (400 MHz, CDC1₃) δ 13.72 (s, 1H), 8.80 (s, 1H), 8.37 (s, 1H), 8.31 (s, 1H), 8.09 (d, J = 7.8 Hz, 1H), 7.92 (d, J = 18.8 Hz, 2H), 7.76 (t, J = 1 1.6 Hz, 2H), 7.39 (s, 1H), 7.31 (td, J = 8.7, 2.5 Hz, 1H), 6.15 (s, 1H), 4.06 (t, J = 6.7 Hz, 1H), 2.04 (s, 1H), 1.65 – 1.44 (m, 3H), 1.39 (dt, J = 14.9, 7.4 Hz, 1H), 1.33 – 1.20 (m, 2H), 0.93 (t, J = 7.4 Hz, 1H), 0.88 (t, J = 6.8 Hz, 1H); ¹³C NMR (101 MHz, CDC1₃) δ 152.28 (s), 148.46 (s), 138.10 (s), 137.22 (s), 135.58 (s), 129.47 (s), 124.80 (s), 123.53 (s), 1 13.24 – 1 13.09 (m), 1 12.89 (d, J = 20.3 Hz), 64.40 (s), 48.60 (s), 31.91 (s), 30.67 (s), 29.05 (s), 22.72 (s), 19.15 (s), 14.15 (s); IR: 3193, 3087, 2967, 2848, 1738, 1609, 1493, 1267, 1242, 1 143, 933, 874, 763, 677, 646, 627, 606, 581 , 559, 474 cm^“1; exact mass m/z calcd for C₂iH₁₆FN₇, (M + H)⁺386.1451 , found 386.1529; MP = 144 °C.

Step 2: Isolation of the Crystalline Hydrate of N-((lS)-l-(7-fluoro-2-(2-pyridinvn-3-quinolinyl)ethyl)-9H-purin-6-amine 4

To a 100 L reactor with its jacket set to 20 °C, 1.206 kg butyl acetate solvate of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine 3 was charged, followed by 6.8 L of acetone and 6.8 L of water. The resulting mixture was stirred at 90 rpm under nitrogen for 13 minutes to ensure complete dissolution of all solids. During these charges, the reactor contents increased in temperature that maximized at 26 °C. The solution was then transferred to another clean 100 L reactor through a 5 μιη filter, and stirred at 85 rpm under nitrogen. The solution was heated to 45 °C, and water (14.8 L) was added to reach a water content (by Karl Fischer, KF) of 75 wt%. The reactor solution was assayed by HPLC and shown to contain 42 mg/g N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. The solution was seeded with a slurry of 1 13 g of the crystalline hydrate of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine in 1 L water, and the seed slurry was rinsed into the reactor with an additional 1 L water. The reactor contents were cooled to 0 °C over 16 h and held at that temperature for 1 h. The supernatant was then assayed, and found to contain 7.6 mg/g of N-((l S)- l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine. Next, 10 L of water was added to the reactor over 38 min and aged for 1 h. The supernatant was assayed at 4.9 mg/g, and the solids were isolated by filtration. The solids were washed with an acetone/water solution (140 mL acetone in 2.7 L water), then 4 L water, and dried under nitrogen on the filter for 68 h. The crystalline hydrate of N-((l S)-l -(7-fluoro-2-(2-pyridinyl)-3-quinolinyl)ethyl)-9H-purin-6-amine was isolated as an off-

white solid (1.12 kg, 616 ppm acetone, 3.73 wt% water, 99.56 LCAP, 95.88 wt%). This material was co-milled at 3900 rpm using a 0.024″ screen to yield an off-white powder (1.09 kg, 99.7 LCAP, 95.4 wt%, 75% yield). Calculated losses were 212 g (18%) to liquors, 5.5g (0.5%) to washes, and 23 g (2%) to fouling. ¾ NMR (400 MHz, DMSO) δ 12.86 (s, 1H), 8.69 (s, 1H), 8.64 (s, 1H), 8.27 (s, 1H), 8.10 (s, 1H), 8.06 – 7.91 (m, 4H), 7.76 (dd, J = 10.4, 2.4 Hz, 1H), 7.50 (ddd, J = 19.2, 9.5, 3.6 Hz, 2H), 6.03 (s, 1H), 3.38 (s, 2H), 1.63 (d, J = 6.6 Hz, 3H). ¹³C NMR (101 MHz, DMSO) δ 163.58, 161.12, 158.36, 157.94, 151.99, 147.98, 146.49, 146.36, 136.82, 134.07, 130.24, 130.14, 124.69, 124.65, 123.30, 1 17.36, 1 17.1 1, 112.10, 1 1 1.90, 46.02, 22.01. HRMS m/z Calcd. for C₂iH₁₇FN₇ (M + H): 386.15295. Found: 386.15161.

PAPER

1: Cushing TD, Hao X, Shin Y, Andrews K, Brown M, Cardozo M, Chen Y, Duquette J, Fisher B, Gonzalez-Lopez de Turiso F, He X, Henne KR, Hu YL, Hungate R, Johnson MG, Kelly RC, Lucas B, McCarter JD, McGee LR, Medina JC, San Miguel T, Mohn D, Pattaropong V, Pettus LH, Reichelt A, Rzasa RM, Seganish J, Tasker AS, Wahl RC, Wannberg S, Whittington DA, Whoriskey J, Yu G, Zalameda L, Zhang D, Metz DP. Discovery and in vivo evaluation of (S)-N-(1-(7-fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine (AMG319) and related PI3Kδ inhibitors for inflammation and autoimmune disease. J Med Chem. 2015 Jan 8;58(1):480-511. doi: 10.1021/jm501624r. Epub 2014 Dec 3. PubMed PMID: 25469863.

http://pubs.acs.org/doi/abs/10.1021/jm501624r

The development and optimization of a series of quinolinylpurines as potent and selective PI3Kδ kinase inhibitors with excellent physicochemical properties are described. This medicinal chemistry effort led to the identification of 1 (AMG319), a compound with an IC₅₀ of 16 nM in a human whole blood assay (HWB), excellent selectivity over a large panel of protein kinases, and a high level of in vivo efficacy as measured by two rodent disease models of inflammation.

(S)-N-(1-(7-Fluoro-2-(pyridin-2-yl)quinolin-3-yl)ethyl)-9H-purin-6-amine (1)

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