Deuterated tetrahydrofuran NaV1.8 inhibitor and application thereof

Abstract

The invention belongs to the field of medicine, and particularly discloses a deuterated tetrahydrofuran NaV1.8 inhibitor and application thereof, and the NaV1.8 inhibitor comprises a compound shown as a formula I or pharmaceutically acceptable salt and solvate thereof; wherein R1 and R2 are respectively and independently selected from H and deuterated C1-3 alkyl groups. The NaV1.8 inhibitor adopts a deuterated tetrahydrofuran medicine, the pharmacokinetic property of the NaV1.8 inhibitor can be remarkably improved, the administration dosage and toxic and side effects can be reduced, specifically, the channel activity IC50 of the NaV1.8 is lower than 0.1 nmol / L, the inhibitory activity IC50 of the NaV1.8 is lower than 43 nmol / L, the oral pharmacokinetic parameter t1 / 2 is 5.2 + / -1.2 h, and the NaV1.8 inhibitor is remarkably superior to a commercially available VX-548 preparation. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of medicine, and in particular relates to deuterated tetrahydrofuran NaV1.8 inhibitors and uses thereof. Background Art

[0002] Electrical signals are the control basis of a series of physiological processes such as pain signal transmission, and sodium ion channels are the main factors that initiate electrical signals. Voltage-gated sodium channels are multi-subunit transmembrane glycoproteins expressed on the cell membrane, composed of α and β subunits. The α subunit is a functional unit composed of 4 homologous transmembrane domains, each of which contains 6 transmembrane hydrophobic α helices (S1-S6). S1-S4 constitute a voltage receptor that can regulate the hydrophilicity of the sodium ion channel between S5 and S6, causing cell depolarization or hyperpolarization, and completing signal transmembrane transmission.

[0003] There are 9 different subtypes of α subunits in the human body, named NaV1.1 to 1.9. Their abnormal inactivation or activation is associated with a variety of neurological, cardiovascular and muscular diseases, among which the subtypes related to pain are mainly NaV1.3, NaV1.7, NaV1.8 and NaV1.9. NaV1.7 is present in sympathetic ganglion neurons and peripheral sensory neurons. NaV1.8 and NaV1.9 are only expressed in peripheral sensory neurons. Abnormal activation of these channels can cause loss of pain or abnormal pain, which also provides a possible target for non-addictive analgesic mechanisms. NaV1.8 is a tetrodotoxin-insensitive sodium channel mainly expressed on nociceptive neurons. It plays a key role in pain signal transduction in the peripheral nervous system and is the main selective target for pain treatment. Since NaV1.8 is mainly distributed in pain-sensing neurons, the use of selective NaV1.8 inhibitors is unlikely to cause the common adverse reactions of non-selective NaV inhibitors. More importantly, NaV1.8 is not involved in central nervous system-related activities, so NaV1.8 inhibitors will not have addiction problems similar to opioids, nor will they affect motor function. VX-548 is an oral selective NaV1.8 inhibitor. Compared with other NaV ion channels, it is highly selective for NaV1.8 (about 30,000 times more than other subtypes) and selectively produces an inhibitory effect. Compared with opioids, VX-548 can avoid side effects such as addiction while providing better analgesic effects, but VX-548 has a shorter half-life in the body, lower bioavailability, and possible toxic side effects. Summary of the invention

[0004] In order to overcome at least one technical problem existing in the above-mentioned prior art, one of the objectives of the present invention is to provide a NaV1.8 inhibitor.

[0005] A second object of the present invention is to provide a pharmaceutical composition.

[0006] The third object of the present invention is to provide the use of the above-mentioned NaV1.8 inhibitor in the preparation of analgesic drugs.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] The first aspect of the present invention provides a NaV1.8 inhibitor, comprising a compound represented by Formula I or a pharmaceutically acceptable salt or solvate thereof;

[0009]

[0010] Among them, R 1 , R 2 Each independently selected from H, deuterated C 1～3 alkyl.

[0011] Preferably, R 1 , R 2 Each independently selected from H, deuterated C 1～2 alkyl.

[0012] Preferably, R 1 , R 2 Each independently selected from H, -CD 3 、-CHD 2 、-CH 2 D. -CD 2 CD 3 、-CH 2 CD 3 or -CD 2 CHD 2 , D stands for deuterium.

[0013] Preferably, R 1 , R 2 Each independently selected from H, -CD 3 、-CHD 2 、-CH 2 D or -CD 2 CD 3 , D stands for deuterium.

[0014] Preferably, the compound represented by formula I is selected from:

[0015] Preferably, the pharmaceutically acceptable salt is selected from methanesulfonate, maleate, hydrochloride or phosphate.

[0016] The second aspect of the present invention provides a pharmaceutical composition comprising the NaV1.8 inhibitor described in the first aspect of the present invention and a pharmaceutically acceptable excipient.

[0017] Preferably, the dosage form of the pharmaceutical composition is selected from capsules, powders, tablets, granules, pills, injections, syrups, oral solutions, inhalants, ointments, suppositories or patches.

[0018] Preferably, the amount of the NaV1.8 inhibitor is a therapeutically effective amount.

[0019] Preferably, the pharmaceutically acceptable excipients include but are not limited to ion exchangers, alumina, aluminum stearate, lecithin, serum proteins (such as human serum albumin), buffer substances (such as phosphates, glycine, sorbic acid or potassium sorbate), saturated vegetable fatty acid partial glyceride mixtures, water, salts or electrolytes (such as protamine sulfate, disodium hydrogen phosphate, potassium hydrogen phosphate, sodium chloride, zinc salts), colloidal silicon dioxide, magnesium trisilicate, polyvinyl pyrrolidone, polyacrylates, waxes, polyethylene-polyoxypropylene block polymers, lanolin, sugars such as lactose, Glucose and sucrose; starches such as corn starch and potato starch; cellulose and its derivatives such as sodium carboxymethylcellulose, ethylcellulose and cellulose acetate; powdered tragacanth; malt; gelatin; talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; glycols such as propylene glycol or polyethylene glycol; esters such as ethyl oleate and ethyl laurate; agar; buffers such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethanol and phosphate buffer solutions and other non-toxic compatible lubricants such as sodium lauryl sulfate and magnesium stearate as well as colorants, release agents, coating agents, sweeteners, flavoring agents and aroma bases, preservatives and antioxidants, etc.

[0020] The third aspect of the present invention provides the use of the NaV1.8 inhibitor described in the first aspect of the present invention in the preparation of analgesic drugs.

[0021] Preferably, the analgesic is used to treat chronic pain, intestinal pain, neuropathic pain, musculoskeletal pain, acute pain, inflammatory pain, cancer pain, idiopathic pain, postoperative pain, visceral pain, multiple sclerosis, Charcot-Marie-Tooth syndrome, incontinence, pathological cough or arrhythmia.

[0022] Preferably, the intestinal pain includes inflammatory bowel disease pain, Crohn's disease pain or interstitial cystitis pain.

[0023] Preferably, the neuropathic pain comprises post-herpetic neuralgia, diabetic neuropathy, painful HIV-associated sensory neuropathy, trigeminal neuralgia, burning mouth syndrome, post-amputation pain, phantom limb pain, painful neuroma, traumatic neuroma, Morton's neuroma, nerve entrapment injury, spinal stenosis, carpal tunnel syndrome, radicular pain, sciatica, nerve avulsion injury, brachial plexus avulsion injury, complex regional pain syndrome, drug therapy-induced neuralgia, cancer chemotherapy-induced neuralgia, antiretroviral therapy-induced neuralgia, pain after spinal cord injury, small fiber neuropathy, idiopathic small fiber neuropathy, idiopathic sensory neuropathy or trigeminal autonomic cephalus.

[0024] Preferably, the musculoskeletal pain comprises osteoarthritis pain, back pain, cold pain, burn pain or dental pain.

[0025] Preferably, the postoperative pain comprises joint replacement pain, soft tissue surgery pain, hernia repair pain, bunionectomy pain or abdominoplasty pain.

[0026] The beneficial effects of the present invention are: the NaV1.8 inhibitor of the present invention adopts deuterated tetrahydrofuran drugs, which can significantly improve the pharmacokinetic properties of the NaV1.8 inhibitor, reduce the dosage and toxic side effects, specifically: the channel activity IC of NaV1.8 50 The inhibitory activity IC of NaV1.8 is lower than 0.1nmol / L 50 Below 43nmol / L, oral pharmacokinetic parameters t 1 / 2 It is 5.2±1.2h, which is significantly better than the commercially available VX-548 preparation. DETAILED DESCRIPTION

[0027] The specific implementation of the present invention is further described in detail below in conjunction with examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. The reagents or instruments used that do not indicate the manufacturer are all conventional products that can be purchased commercially.

[0028] Example 1

[0029] This example provides a NaV1.8 inhibitor, the structural formula of which is as follows:

[0030]

[0031] The synthetic route of the NaV1.8 inhibitor in this example is as follows:

[0032]

[0033] The specific synthesis steps of the NaV1.8 inhibitor in this example are as follows:

[0034] (1) Synthesis of intermediate 2

[0035] The intermediate 1 (5 mmol) and triethylamine (7.5 mmol) were dissolved in dichloromethane, trimethylsilyl trifluoromethanesulfonate (TMSOTf, 7.5 mmol) was added dropwise, and then placed in an ice bath. After continuing the reaction for 0.5 hours, dichloromethane was added, and the mixture was washed with saturated sodium bicarbonate solution and brine. The organic phase was collected, dried with anhydrous sodium carbonate, and concentrated to remove dichloromethane to obtain the intermediate to be used. 1,1,1-trifluoropropane-2-one-3,3,3-d3 (5 mmol) was dissolved in dichloromethane at -78°C, and TiCl 4 The above intermediate was dissolved in dichloromethane and added dropwise to continue the reaction for two hours. After TLC detection, water was added to quench the reaction. After the temperature of the reaction mixture was raised to room temperature, dichloromethane was added for extraction. The organic phase was collected, dried, concentrated, and purified by column chromatography to obtain intermediate 2.

[0036] (2) Synthesis of Intermediate 3

[0037] Intermediate 2 (5 mmol) was dissolved in toluene, rhodium acetate (0.05 mmol) was added, and the mixture was stirred at 100°C for 2 hours. The reaction was complete after TLC detection. The mixture was filtered through celite and the filtrate was concentrated to obtain Intermediate 3.

[0038] (3) Synthesis of intermediate 4

[0039] Referring to the synthesis method of Example 3 in CN114945566A, the intermediate (4R, 5R)-4,5-dimethyl-3-oxo-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid ethyl ester in the synthesis route of Example 3 in CN114945566A is replaced by the intermediate 3 in the present invention, and the intermediate 4, i.e. (4S, 5R)-3-(3,4-difluoro-2-methoxyphenyl)-4,5-bis(methyl-d3)-5-(trifluoromethyl)tetrahydrofuran-2-carboxylic acid, can be obtained through multi-step reaction.

[0040] (4) Synthesis of NaV1.8 inhibitors

[0041] The intermediate 4 (5mmol) was dissolved in dichloromethane, 0.5mL of DMF was added, oxalyl chloride (8mmol) was added dropwise under ice bath conditions, and the mixture was stirred for half an hour and then moved to room temperature, and the reaction was continued for one hour. The solvent was spin-dried, dissolved in dichloromethane, and a dichloromethane solution of 4-aminopyridine-2-carboxylic acid methyl ester (5mmol) and triethylamine (12mmol) was added dropwise. After one hour of reaction, water was added for extraction, and the organic phase was collected. After drying and concentration, it was dissolved in methanol, and a 5mol / L methanol solution of ammonia (10mmol) was added. The reaction was reacted at room temperature for 5 hours, and the reaction was concentrated after TLC detection was complete, and separated by a chiral column to obtain the NaV1.8 inhibitor in this example. The nuclear magnetic resonance data of the NaV1.8 inhibitor in this example are as follows:

[0042] 1 H NMR (400 MHz, chloroform-d) δ 8.46 (d, J = 5.4 Hz, 1H), 8.32 (d, J = 2.1 Hz, 1H), 8.02–7.99 (m, 1H), 7.18 (d, J = 4.4 Hz, 1H), 7.00 (ddd, J = 8.3, 5.4, 2.1 Hz, 1H), 5.42 (d, J = 8.3 Hz, 1H), 4.78 (d, J = 5.7 Hz, 1H), 4.22 (d, J = 2.0 Hz, 1H), 3.97 (s, 3H), 2.98 (d, J = 2.0 Hz, 1H).

[0043] Example 2

[0044] This example provides a NaV1.8 inhibitor, the structural formula of which is as follows:

[0045]

[0046] The NaV1.8 inhibitor in this example can be synthesized by referring to the synthesis method in Example 1. In this example, 2-diazo-3-oxo-pentanoic acid ethyl ester is used as intermediate 1. The NMR data of the NaV1.8 inhibitor in this example are as follows:

[0047] 1 H NMR (400MHz, Chloroform-d) δ8.51(d,J=5.5Hz,1H),8.30(d,J=2.0Hz,1H),7.98(d,J=3.2Hz,1H),7.22(d,J=5.1Hz,1H),7.00–6.97( m,1H),5.45(d,J=7.6Hz,1H),4.74(d,J=5.2Hz,1H),4.21(d,J=2.0Hz,1H),3.96(s,3H),2.94(d,J=2.0Hz,1H),1.01(d,J=1.5Hz,3H).

[0048] Example 3

[0049] This example provides a NaV1.8 inhibitor, the structural formula of which is as follows:

[0050]

[0051] The NaV1.8 inhibitor in this example can be synthesized by referring to the synthesis method in Example 1. In this example, 1,1,1-trifluoropropan-2-one is used to replace 1,1,1-trifluoropropan-2-one-3,3,3-d3 in Example 1. The NMR data of the NaV1.8 inhibitor in this example are as follows:

[0052] 1 H NMR(400MHz,Chloroform-d)δ8.62(d,J=5.2Hz,1H),8.35(d,J=2.2Hz,1H),8.01–7.98(m,1H),7.21(d,J=5.0Hz,1H),7.00–6.98(m, 1H), 5.36 (d, J = 8.0Hz, 1H), 4.72 (d, J = 5.3Hz, 1H), 4.24 (d, J = 2.1Hz, 1H), 3.95 (s, 3H), 2.91 (d, J = 2.0Hz, 1H), 1.70 (d, J = 1.2Hz, 3H).

[0053] Performance Test:

[0054] (1) Nav1.8 channel activity test

[0055] The NaV1.8 inhibitors in Examples 1 to 3 were dissolved in DMSO to prepare a stock solution at a concentration of 30 mmol / L. An 11-point half-log dilution series was made in DMSO with a maximum concentration of 600 μmol / L. The test compound plate also contained a positive control well of VX-548 (commercially available). The compound plate was diluted 1 to 60 so that the maximum concentration of the final assay compound was 10 μmol / L and the DMSO content was 2%. The test article and the assay control were added to a 384-well plate.

[0056] HEK293 cells that stably express human Nav1.8 sodium channels were used for testing. Nav1.8 sodium channel currents were recorded using whole-cell voltage clamp technology at room temperature. The whole-cell voltage clamp recording experiment used an Axon patch 700B patch clamp amplifier (Molecular Devices), a Digidata 1440A (Molecular Devices) digital-to-analog converter, and a glass microelectrode made of glass electrode blanks (World Precision Instrunents) and pulled by a puller (P97, Sutter). The tip resistance after perfusion of the electrode fluid was about 1.5-2.5MΩ. The glass microelectrode was inserted into the amplifier probe to connect to the patch clamp amplifier. Electrophysiological stimulation protocol: After obtaining the whole-cell recording, wait for 4-5 minutes at a clamping voltage of -60mV until the electrode fluid and the intracellular fluid are balanced, and then start electrophysiological recording. Current stimulation and compound activity detection scheme: cells were clamped at -60mV, and a depolarizing voltage stimulus of +10mV was given for 20ms, and then repolarized to -60mV, with a stimulation frequency of 0.5Hz. The drug administration process was started after the Nav1.8 sodium channel current was confirmed to be stable (about 1 minute), until the cell current no longer changed (compound inhibition reached steady state), and then the inhibition rate was calculated according to the following formula:

[0057] Inhibition rate (%) = [1-current size after drug addition / current size before drug addition] × 100%

[0058] The IC values ​​of the NaV1.8 inhibitors and VX-548 in Examples 1 to 3 calculated according to the above calculation method are 50 The data are shown in Table 1 below.

[0059] Table 1 IC values ​​of NaV1.8 inhibitors and VX-548 in Examples 1 to 3 50 data

[0060] Compound No. <![CDATA[Nav1.8 IC 50 (nmol / L)]]> Example 1 0.1 Example 2 0.09 Example 3 0.1 VX-548 0.4

[0061] As shown in Table 1, the IC values ​​of the NaV1.8 inhibitors prepared in Examples 1 to 3 are 50 The concentration is significantly lower than that of VX-548, and it has better Nav1.8 channel inhibition activity than VX-548 reagent.

[0062] (2) E-VIPR detection of Nav1.8 inhibitory activity

[0063] HEK293 cells stably expressing human Nav1.8 sodium channels were washed three times with 80 μL of buffer and added to each well, and 25 μL of hexyl dye solution was added to each well. The cells were incubated in the dark at room temperature for 20 minutes. 45 μL of the stock solution (containing the compounds in Examples 1 to 3 or VX-548) was added to the compound plate in each well. Incubate for 30 minutes at room temperature. The cell plate containing the compound was read on the E-VIPR using a current-controlled amplifier to deliver stimulation wave pulses using a symmetrical biphasic waveform. The electrical stimulation protocol was 1.25-4 amperes, and a 4 millisecond pulse width (depending on the electrode composition) was delivered at 10 Hz for 10 seconds. A 0.5 second pre-stimulation recording was performed on each well to obtain an unstimulated intensity baseline. All E-VIPR responses were measured at a 200 Hz acquisition rate, and then the dose response curve of the compound was plotted to obtain the Navl.8IC 50 The specific values ​​are shown in Table 2 below.

[0064] Table 2 NaV1.8 IC of NaV1.8 inhibitors and VX-548 in Examples 1 to 3 50 Value Data

[0065] Compound No. <![CDATA[E-VIPR Nav1.8 IC 50 (nM)]]> Example 1 19 Example 2 23 Example 3 43 VX-548 56

[0066] As shown in Table 2, the NaV1.8 inhibitors in Examples 1 to 3 of the present invention have a NaV1.8 IC lower than that of VX-548. 50 The values ​​indicate that the NaV1.8 inhibitors in Examples 1 to 3 have higher NaV1.8 inhibitory activity.

[0067] (3) Pharmacokinetic studies of compounds

[0068] Experimental instruments and materials:

[0069] High-speed refrigerated centrifuge, vortex oscillator (Vortex Genius3), high-speed centrifuge (Eppendorf5415D), disposable syringes, pipettes (Eppendorf), SD male rats used in the experiment were purchased from Yangzhou University, EDTA-K2 vacuum blood collection tubes, and normal saline. All rats in the oral group fasted for 12 hours before administration, had free access to water, and had free access to water and food during administration.

[0070] Experimental procedures

[0071] The NaV1.8 inhibitor and VX-548 in Example 1 were dissolved in a mixed solvent of DMSO, polyethylene glycol, and water (volume ratio of 10:10:80) to prepare a clear solution. The compound was administered orally at a dose of 10 mg / kg, and the compound was administered by tail vein at a dose of 2 mg / kg. 0.5 mL of blood was continuously collected from the venous plexus of the fundus into a heparin tube at 2 min, 10 min, 30 min, 1 h, 2 h, 3 h, 5 h, 8 h, 12 h, 16 h, and 24 h after tail vein administration. 0.5 mL of blood was continuously collected from the venous plexus of the fundus into a heparin tube at 5 min, 15 min, 30 min, 1 h, 2 h, 3 h, 5 h, 8 h, 12 h, 16 h, and 24 h after intranasal administration. After the sample was centrifuged at 8000 rpm and 4 ° C for 10 min, 0.15 mL of the upper plasma was collected and stored at -20 ° C, and then analyzed by LC-MS / MS. The data were analyzed by WinNolin non-compartmental model to obtain key pharmacokinetic parameters. The pharmacokinetic data of the NaV1.8 inhibitor and VX-548 in Example 1 measured by the above test method are shown in Table 3 below.

[0072] Table 3 Pharmacokinetic data

[0073]

[0074] As shown in Table 3, compared with VX-548, the half-life of the oral administration of the NaV1.8 inhibitor in Example 1 is significantly improved, which can effectively reduce the dosage and thus reduce the toxic side effects of high-dose administration, indicating that the NaV1.8 inhibitor in Example 1 has higher bioavailability.

[0075] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A NaV1.8 inhibitor, characterized in that: Including the compound represented by formula I or its pharmaceutically acceptable salt or solvate; Wherein, R1 and R2 are each independently selected from H, deuterated C 1～3 alkyl.

2. The NaV1.8 inhibitor according to claim 1, characterized in that: R1 and R2 are each independently selected from H, deuterated C 1～2 alkyl.

3. The NaV1.8 inhibitor according to claim 2, characterized in that: R1 and R2 are each independently selected from H, -CD3, -CHD2, -CH2D, -CD2CD3, -CH2CD3 or -CD2CHD2, and D is deuterium.

4. The NaV1.8 inhibitor according to claim 3, characterized in that: R1 and R2 are each independently selected from H, -CD3, -CHD2, -CH2D or -CD2CD3, and D is deuterium.

5. The NaV1.8 inhibitor according to claim 4, characterized in that: The compound represented by formula I is selected from:

6. The NaV1.8 inhibitor according to any one of claims 1 to 5, characterized in that: The pharmaceutically acceptable salt is selected from methanesulfonate, maleate, hydrochloride or phosphate.

7. A pharmaceutical composition, characterized in that: It comprises the NaV1.8 inhibitor according to any one of claims 1 to 6 and pharmaceutically acceptable excipients.

8. The pharmaceutical composition according to claim 7, characterized in that: The dosage form of the pharmaceutical composition is selected from capsules, powders, tablets, granules, pills, injections, syrups, oral solutions, inhalants, ointments, suppositories or patches.

9. Use of the NaV1.8 inhibitor according to any one of claims 1 to 6 in the preparation of analgesic drugs.

10. The use according to claim 9, characterized in that: The analgesic is used to treat chronic pain, intestinal pain, neuropathic pain, musculoskeletal pain, acute pain, inflammatory pain, cancer pain, idiopathic pain, postoperative pain, visceral pain, multiple sclerosis, Charcot-Marie-Tooth syndrome, incontinence, pathological cough or arrhythmia.

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