A class of methyl (3-methylaminopropyl) carbamate derivatives of ZL006-05, their pharmaceutically acceptable salts and their pharmaceutical uses

Abstract

The present invention relates to pharmaceutically acceptable salts of a class of methyl (3-methylaminopropyl) carbamate derivatives of ZL006-05 and their pharmaceutical uses. Their structures are shown in formula (1): #imgabs0# After oral administration, higher blood drug concentrations of ZL006-05 can be obtained for these drugs, which can be used to prepare drugs for treating diseases such as stroke and neuropathic pain.

Description

Technical Field

[0001] The present invention relates to the field of biopharmaceuticals, and in particular to a class of methyl (3-methylaminopropyl) carbamate derivatives of ZL006-05, their pharmaceutically acceptable salts, and their pharmaceutical uses. Background Art

[0002] Stroke seriously endangers human health. The nNOS-PSD-95 uncoupler 4-N-(2-hydroxy-3,5-dichlorobenzyl) aminosalicylic acid (ZL006) can reduce the pathological release of NO mediated by NMDAR without affecting the physiological functions of NMDAR and nNOS, and shows obvious neuroprotective effects on nerve cell damage stimulated by glutamate, improving the neurological deficit symptoms of animals after middle cerebral artery occlusion (MCAO) reperfusion and reducing the infarct volume (Nature Medicine 2010, 16, 1439–1443). The invention patent PCT / CN2012 / 083455 discloses the 2-campher ester of ZL006 (ZL006-05), and ZL006-05 has good anti-stroke (Stroke Vasc Neurol. 2023 Apr 25: svn-2022-002156) and neuropathic pain effects (Theranostics 2021; 11(12): 5970-5985). ZL006-05 has currently entered phase II clinical research. Since the recovery administration of neuropathic pain and stroke requires multiple administrations, oral preparations are more suitable for clinical needs.

[0003]

[0004] However, ZL006-05 has poor water solubility and poor oral bioavailability (4.2%), which is not conducive to the preparation of oral preparations. After intragastric administration of ZL006-05, the blood drug concentration at 90 mg / kg is equivalent to that at 30 mg / kg, indicating that increasing the oral dose further cannot obtain better drug efficacy. Chinese invention patent CN110218202A discloses a class of piperazine derivatives of N-benzyl-substituted aminosalicylic acid 2-campher esters and their pharmaceutical uses. This class of drugs can increase the blood drug concentration of the drug after oral administration, but further studies show that it has no significant analgesic effect or anti-stroke drug efficacy. The reason may be that the amount of ZL006-05 produced in vivo is very limited, indicating that its main metabolite is not ZL006-05 (Chinese invention patent CN111233789A).

[0005]

[0006] Chinese Patent Invention CN111233789A discloses a class of phenyl 2-piperazin-1-ylethylcarbamates and their pharmaceutical uses. These drugs can be metabolized into ZL006-05 after injection and have good efficacy in treating stroke. However, the blood drug concentration of ZL006-05 does not increase after oral administration.

[0007] Summary of the Invention

[0008] Therefore, the technical problem to be solved by the present invention is to overcome the problem that high blood drug concentration of ZL006-05 cannot be obtained after oral administration of ZL006-05 and its derivatives in the prior art.

[0009] To solve the above technical problem, the present invention provides a pharmaceutically acceptable salt of a methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 and its pharmaceutical use.

[0010] The first object of the present invention is to provide a pharmaceutically acceptable salt of a methyl (3-methylaminopropyl) carbamate derivative of ZL006-05, and the general structural formula is shown in formula (1):

[0011]

[0012] In the embodiments of the present invention, the pharmaceutically acceptable salt is selected from hydrochloride, sulfate, trifluoroacetate or 4-methylbenzenesulfonate.

[0013] In the embodiments of the present invention, the pharmaceutically acceptable salt is selected from hydrochloride.

[0014] The second object of the present invention is to provide a pharmaceutical composition, which is characterized in that the active ingredient of the pharmaceutical composition is the methyl (3-methylaminopropyl) carbamate derivative or its pharmaceutically acceptable salt.

[0015] The third object of the present invention is to provide the application of the methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 or its pharmaceutically acceptable salt and the pharmaceutical composition in the preparation of drugs for treating stroke or neuropathic pain.

[0016] The above technical solutions of the present invention have the following advantages compared with the prior art:

[0017] The methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 obtained in the present invention can obtain a higher blood drug concentration of ZL006-05 after oral administration and can be used to prepare drugs for treating diseases such as stroke and neuropathic pain.

[0018] The compounds of the examples disclosed in Chinese Invention Patent CN110218202A and Chinese Invention Patent CN111233789A are carbamate derivatives of ZL006-05, which have good stability and are difficult to be rapidly metabolized into ZL006-05 in vivo. The compounds of the examples of the present invention have relatively good stability under acidic conditions. Under neutral conditions, the lone pair electrons on the N atom in the molecule attack the carbonyl group, forming an intramolecular reaction and being able to rapidly release ZL006-05. The mechanism is as Figure 4 shown. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention in conjunction with the drawings, wherein,

[0020] Figure 1 is a schematic diagram of the synthesis of the target compound of the present invention.

[0021] Figure 2 is the blood drug concentration of ZL006-05 (unit: μg / mL) after intragastric administration of the target compound 1 of the present invention.

[0022] Figure 3 is the experimental result diagram of the analgesic effect of the target compound obtained in Example 1 of the present invention on neuropathic pain after oral administration.

[0023] Figure 4 is the reaction mechanism diagram of the target compound obtained in Example 1 of the present invention in vivo. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to solve the technical problems pointed out in the background art, the present invention provides a class of methyl (3-methylaminopropyl) carbamate derivatives of ZL006-05 or pharmaceutically acceptable salts thereof and their applications.

[0025] The present invention is realized through the following specific solutions:

[0026] The present invention provides a class of methyl (3-methylaminopropyl) carbamate derivatives of ZL006-05 or pharmaceutically acceptable salts thereof, and the general structural formula is as shown in formula (1):

[0027]

[0028] In specific embodiments, the pharmaceutically acceptable salts are selected from hydrochloride, sulfate, trifluoroacetate or 4-methylbenzenesulfonate.

[0029] In specific embodiments, the pharmaceutically acceptable salt is selected from hydrochloride.

[0030] In a specific embodiment, the structural formula of the pharmaceutically acceptable salt of the methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 is shown in Formula 2:

[0031]

[0032] Wherein, HX is HCl, H2SO4, CF3COOH, 4-CH3-PhSO3H (4-methylbenzenesulfonic acid).

[0033] The class of methyl (3-methylaminopropyl) carbamate derivatives of ZL006-05 or their pharmaceutically acceptable salts according to the present invention are prepared by the following method:

[0034] (1) Mix p-nitrosalicyl alcohol ester and triethylamine in an organic solvent, add an organic solvent containing triphosgene, and carry out a mixing reaction to obtain Compound 1; mix tert-butyl methyl (2-(methylamino)ethyl)carbamate and triethylamine in an organic solvent, add Compound 1, and carry out a mixing reaction to obtain Intermediate 1-1;

[0035]

[0036] (2) Dissolve Intermediate 1-1 in a reaction solvent, add a catalyst, and carry out a reflux reaction under a hydrogen atmosphere to obtain Intermediate 1-2;

[0037]

[0038] (3) Dissolve Intermediate 1-2 in a reaction solvent, add a 3,5-dichlorosalicylaldehyde solution, carry out a reaction, filter, and dry to obtain Compound 2; add ethanol to the dried Compound 2, and add NaBH4 in several portions for reaction; adjust the reaction solution to acidic to precipitate a solid substance, filter to obtain the filtrate, add water to the filtrate, mix to precipitate a white solid, filter to obtain the solid phase, and obtain Intermediate 1-3;

[0039]

[0040] (4) Dissolve Intermediate 1-3 in an organic solvent, add a hydrochloric acid saturated solution, and carry out a stirring reaction to obtain the hydrochloride salt of the methyl (3-methylaminopropyl) carbamate derivative;

[0041]

[0042] In a specific embodiment, in step (1), at least one or more of the following conditions are satisfied:

[0043] a): The molar ratio of p-nitrosalicyl alcohol ester, triethylamine to triphosgene is 1:1:0.6.

[0044] b): The molar ratio of tert-butyl (2-(methylamino)ethyl)carbamate to triethylamine l is 1:10.

[0045] c): The organic solvent is a conventional organic solvent in the art, preferably dichloromethane.

[0046] In a specific embodiment, in step (2), at least one or more of the following conditions are satisfied:

[0047] I), The catalyst is selected from palladium on carbon;

[0048] II), The reaction solvent is a conventional organic solvent in the art, preferably methanol;

[0049] III), The reflux reaction temperature is 70°C and the reaction time is 3 hours.

[0050] In a specific embodiment, in step (3), at least one or more of the following conditions are satisfied:

[0051] The acidic pH value range of the reaction solution is 5;

[0052] The molar ratio of intermediate 1-2 to 3,5-dichlorosalicylaldehyde is 1:1.

[0053] The present invention also provides a pharmaceutical composition, and the active ingredient of the pharmaceutical composition is the methyl (3-methylaminopropyl)carbamate derivative or a pharmaceutically acceptable salt thereof.

[0054] The present invention further provides the use of the methyl (3-methylaminopropyl)carbamate derivative or a pharmaceutically acceptable salt thereof of ZL006-05 in the preparation of a drug for treating stroke or neuropathic pain.

[0055] The present invention further provides the use of the above-mentioned pharmaceutical composition in the preparation of a drug for treating stroke or neuropathic pain.

[0056] The following further illustrates the present invention with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the exemplified embodiments do not limit the present invention.

[0057] Example 1: Synthesis of dextrorphan hydrochoride (target compound 1) of 4-((3,5-dichloro-2-hydroxybenzyl)amino)-2-(((3-(methylamino)propyl)carbamoyl)oxy)benzoic acid

[0058] Synthesis steps (synthesis schematic diagram is as Figure 1 shown), specifically as follows:

[0059] (1) Add p-nitrosalicylic acid (1.83 g, 10 mmol), camphenilol (3.08 g, 20 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI, 2.9 g, 15 mmol), and 4-dimethylaminopyridine (DMAP, 0.6 g, 5 mmol) into a eggplant-shaped flask in sequence. Add an appropriate amount of dichloromethane and react at room temperature for 24 hours. After monitoring the completion of the reaction by thin-layer chromatography (TLC), add water for extraction, rotary evaporate the organic phase, and separate by column chromatography (petroleum ether: ethyl acetate = 100:1) to obtain camphenilol p-nitrosalicylate, 1.7 g of white solid, yield: 53.3%. 1 H NMR(400MHz,Chloroform-d)δ10.51(s,1H),7.27(d,1H),7.20(d,1H),7.08(d,1H),6.97(dd,1H),6.88(d,1H),5.04(dt,1H),2.43(tt,1H),1.92–1.70(m,3H),1.42(ddd,1H),1.24(ddd,1H),1.07(dd,1H),0.92(d,6H),0.85(s,3H).

[0060] (2) Take camphenilol p-nitrosalicylate (1.2 g, 4 mmol), add triethylamine (0.4 g, 4 mmol), and dissolve with dichloromethane to prepare a mixed solution for standby. Dissolve triphosgene (710 mg, 2.4 mmol) in an appropriate amount of dichloromethane, slowly add the mixed solution, and react at room temperature for 6 hours. After monitoring the completion of the reaction by TLC, rotary evaporate the solvent for standby. Take tert-butyl methyl(2-(methylamino)ethyl)carbamate (752 mg, 4 mmol) and triethylamine (0.4 g, 4 mmol), dissolve with dichloromethane for standby. Dissolve the solid obtained in the previous step with a small amount of dichloromethane, slowly add the prepared solution thereto, react at room temperature for 2 hours. After monitoring the completion of the reaction by TLC, add water for extraction, rotary evaporate the organic phase, and separate by column chromatography (petroleum ether: ethyl acetate = 20:1) to obtain intermediate 1-1, 1.5 g of white oil, yield 70.4%. 1 HNMR(400MHz,Chloroform-d)δ8.20–7.93(m,3H),5.09(ddt,1H),3.70–3.34(m,4H),3.22–2.83(m,6H),2.43(ddt,1H),2.07–1.90(m,1H),1.87–1.69(m,2H),1.46(d,9H),1.41–1.21(m,2H),1.10(dd,1H),0.94(s,3H),0.89(d,6H).ESI-MS m / z:518.3[M+H] + 。

[0061] (3) Dissolve intermediate 1-1 (500 mg, 1 mmol) in 50 mL of methanol, add palladium on carbon, introduce hydrogen gas, reflux the reaction at 70 °C for 3 hours. After monitoring the completion of the reaction by TLC, filter off the palladium on carbon by suction filtration, and rotary evaporate the filtrate to obtain intermediate 1-2, 400 mg of white solid, yield: 80.4%. 1 HNMR (400 MHz, DMSO-d6) δ 7.58 (dd, 1H), 6.41 (dd, 1H), 6.17 (dd, 1H), 6.01 (d, 2H), 4.86 (dd, 1H), 3.54–3.29 (m, 4H), 3.04–2.69 (m, 6H), 2.26 (ddq, 1H), 1.94 (ddd, 1H), 1.75–1.59 (m, 2H), 1.37 (s, 3H), 1.33–1.29 (m, 6H), 1.22–1.13 (m, 2H), 0.91 (dd, 1H), 0.86 (s, 3H), 0.82 (s, 3H), 0.77 (s, 3H). ESI-MS m / z: 592.2 [M+H] + 。

[0062] (4) Add 259 mg (0.5 mmol) of intermediate 1-2 to a dry 100 mL eggplant-shaped flask, and completely dissolve it with 20 mL of absolute ethanol to obtain solution A. Weigh 97 mg (0.5 mmol) of 3,5-dichlorosalicylaldehyde, place it in a 100 mL beaker, and dissolve it with 10 mL of absolute ethanol to obtain solution B. While stirring, add solution B dropwise to solution A, and react at room temperature for 5 h. The color of the solution quickly deepens, and then bright red flocculates are produced. Filter the reaction solution by suction filtration with a Buchner funnel, quickly rinse the filter cake with ethanol twice, and naturally dry the filter cake to obtain a red imine intermediate.

[0063] (5) Place the dried imine intermediate in a 100 mL eggplant-shaped flask, add 20 mL of absolute ethanol, and the solution becomes turbid. While stirring, add solid NaBH4 in small portions several times until the solution becomes colorless and transparent. Detect the completion of the reaction by TLC. Adjust the pH of the solution to 5 with concentrated hydrochloric acid, and inorganic salts insoluble in the solution will precipitate. Filter to obtain the filtrate. Carefully add deionized water dropwise to the filtrate while constantly shaking the eggplant-shaped flask until white solid precipitates in the solution. Let it stand for 12 h, a large amount of white precipitate will form in the solution. Filter with a Buchner funnel to obtain the filter cake, and dry it to obtain 145 mg (0.21 mmol) of white solid, which is intermediate 1-3, yield 42.0%. ESI-MS m / z: 692.3 [M+H] + 。

[0064] (6) Dissolve intermediate 1-3 (138 mg, 0.21 mmol) in 10 mL of ethyl acetate, add an equal volume of 2 M hydrochloric acid saturated ethyl acetate solution, stir and react for 1 h. After monitoring the completion of the reaction by TLC, pour out the liquid in the reaction flask, and wash it with ethyl acetate for several times. After the washing is completed, spin-dry the excess solvent to obtain 112.1 mg of the hydrochloride salt of the target compound, yield: 90.0%.

[0065] 1 HNMR (400 MHz, DMSO-d6) δ 10.88 (s, 1H), 9.76 (s, 1H), 7.56 - 7.54 (d, 1H), 7.40 - 7.39 (d, 1H), 7.14 (s, 1H), 7.11 - 7.10 (d, 1H), 6.25 - 6.23 (dd, 1H), 5.95 (s, 1H), 4.97 (s, 1H), 4.30 (s, 2H), 4.00 (s, 2H), 3.66 (s, 2H), 3.23–3.07 (m, 6H), 2.77 (s, 3H), 2.37 - 0.84 (m, 16H). ESI-MS m / z: 592.2 [M+H] + 。

[0066] Example 2: Synthesis of other pharmaceutically acceptable salts of the target compound

[0067] 2.1: Synthesis of dextrorphan 4-((3,5-dichloro-2-hydroxybenzyl)amino)-2-(((3-(methylamino)propyl)carbamoyl)oxy)benzoate sulfate

[0068] Refer to the synthesis method of target compound 1, and synthesize it with intermediate 1-3 and sulfuric acid saturated ethyl acetate solution.

[0069] 2.2: Synthesis of dextrorphan 4-((3,5-dichloro-2-hydroxybenzyl)amino)-2-(((3-(methylamino)propyl)carbamoyl)oxy)benzoate trifluoroacetate

[0070] Refer to the synthesis method of target compound 1, and synthesize it with intermediate 1-3 and trifluoroacetic acid saturated ethyl acetate solution.

[0071] 2.3: Synthesis of dextrorphan 4-((3,5-dichloro-2-hydroxybenzyl)amino)-2-(((3-(methylamino)propyl)carbamoyl)oxy)benzoate p-toluenesulfonate

[0072] Refer to the synthesis method of target compound 1, and synthesize it with intermediate 1-3 and p-toluenesulfonic acid saturated ethyl acetate solution.

[0073] Other pharmaceutically acceptable salts of the target compound can be obtained by reacting Intermediate 1-3 with the corresponding acids.

[0074] Example 3: Blood Concentration Test of the Target Compound after Oral Administration of ZL006-05

[0075] C57 mice were orally administered the target compound (hydrochloride, the target compound obtained in Example 1). Blood was collected at different times after administration, plasma was separated, and the concentrations of the target compound and ZL006-05 in the plasma were determined by high performance liquid chromatography - mass spectrometry (HPLC-MS).

[0076] Chromatographic conditions: The chromatographic column was an Agilent Eclipse Plus C18 column (50 mm × 2.1 mm, 1.8 μm); the mobile phase was ultrapure water - acetonitrile; the flow rate was 0.4 mL / min -1 ; the column temperature was 40 °C; the injection volume was 5 μL; the temperature of the autosampler was 4 °C. From 0 to 1 min, 10% acetonitrile, from 1 to 3 min, 10% - 90% acetonitrile, from 3 to 7 min, 90% acetonitrile, from 7 to 8 min, 90% - 10% acetonitrile.

[0077] Mass spectrometry conditions: Electrospray ionization source (ESI), detected in positive ion mode; multiple reaction monitoring (MRM); all gases used were high purity nitrogen; the curtain gas was 35 psi; the ion source voltage was 5500 V, the temperature was 500 °C; the pressure of the nebulizing gas (GS1) was 55 psi; the pressure of the auxiliary heating gas (GS2) was 55 psi; the collision gas was Medium; the dwell time was 3.53 min.

[0078] The blood concentrations of the target compound 1, ZL006-05, reference compounds CN110218202A-2, and CN111233789A-2 were determined by HPLC-MS 1 h and 2 h after intragastric administration.

[0079] The experimental results showed that: after intragastric administration, when the dosage of ZL006-05 was 90 mg / kg, the blood concentration of ZL006-05 was equivalent to that after intragastric administration of 30 mg / kg, indicating that further increasing the dosage could not obtain better drug efficacy. However, the blood concentration of ZL006-05 after intragastric administration of the target compound (hydrochloride) of the present invention was significantly higher than that after intragastric administration of ZL006-05, and the blood concentration at 90 mg / kg was significantly higher than that at 30 mg / kg. This indicates that the target compound of the present invention can obtain better drug efficacy than ZL006-05 after intragastric administration. The blood concentrations of ZL006-05 after intragastric administration of reference compounds CN110218202A-2 and CN111233789A-2 were very low, indicating that it was difficult for them to improve oral drug efficacy.

[0080] Example 4 Analgesic effect of orally administered target compound on neuropathic pain

[0081] A neuropathic pain model was prepared by segmental spinal nerve ligation (SNL), and the 50% paw withdrawal threshold (PWT) to mechanical stimulation was measured to preliminarily test the analgesic effect of the target compound (hydrochloride). Mice with a baseline 50% mechanical stimulation paw withdrawal threshold were subjected to SNL surgery. On the 7th day after surgery, they were randomly divided into a drug group and a solvent group (n = 8), and were intragastrically administered equal volumes of the drug or a 1% sodium carboxymethylcellulose suspension. The dose of the drug was 30 mg / kg, and the drug was formulated with a 1% sodium carboxymethylcellulose suspension, administered once. The change in the paw withdrawal threshold to mechanical stimulation was measured 2 hours after administration. The experimental results are shown in Figure 3 . The PWT after intragastric administration of the target compound was significantly higher than that of ZL006-05, while the PWT after intragastric administration of the control compounds CN110218202A-2 and CN111233789A-2 was significantly lower than that of ZL006-05. The above experimental results suggest that the target compound of the present invention has good efficacy when administered orally.

[0082] Obviously, the above examples are only for clear illustration and not a limitation of the implementation manner. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 or a pharmaceutically acceptable salt thereof, characterized in that, The structural general formula is as shown in formula (1): 。 2. The methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 according to claim 1 or a pharmaceutically acceptable salt thereof, characterized in that, The pharmaceutically acceptable salts are selected from hydrochloride, sulfate, trifluoroacetate or 4-methylbenzenesulfonate.

3. The methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 according to claim 2 or a pharmaceutically acceptable salt thereof, characterized in that, The pharmaceutically acceptable salt is selected from hydrochloride.

4. A pharmaceutical composition, characterized in that, The active ingredient of the pharmaceutical composition is the methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 described in any one of claims 1-3 or a pharmaceutically acceptable salt thereof.

5. Use of the methyl (3-methylaminopropyl) carbamate derivative of ZL006-05 described in any one of claims 1-3 or a pharmaceutically acceptable salt thereof, and the pharmaceutical composition described in claim 4, in the preparation of a medicament for treating stroke or neuropathic pain.

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