Salicylic acid derivative compounds and use thereof

Abstract

Disclosed in the present invention are salicylic acid derivative compounds and the use thereof. The compounds can significantly relieve ischemic symptoms of cerebral ischemia-reperfusion model rats. The compounds have broad application prospects in the preparation of drugs for preventing and treating cerebral stroke.

Description

A class of salicylic acid derivatives and their uses

[0001] This application claims priority to Chinese Patent Application No. 2024118990777, filed on December 23, 2024, entitled "A Class of Salicylic Acid Derivative Compounds and Their Uses", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of pharmaceutical technology, specifically relating to a class of salicylic acid derivative compounds and their uses. Background Technology

[0003] Acute ischemic stroke is an ischemic injury caused by thrombosis induced by various factors. This type of disease causes great suffering and even life-threatening risks to patients. Currently, research on drugs for this condition remains a hot topic and a frontier in drug research and development. Acute ischemic stroke is a rapidly developing brain dysfunction caused by the obstruction of blood supply to the brain due to ischemia. With the rapid aging of the population, the incidence of cerebral ischemia is showing a continuous upward trend, becoming the leading cause of disability and the second leading cause of death worldwide, further exacerbating the burden on society and families. The pathogenesis of cerebral ischemia is very complex, a malignant cascade process involving multiple factors, mechanisms, and stages. Over the years, research on the related mechanisms of cerebral ischemia and reperfusion injury has included excitotoxicity, ion imbalance, oxidative stress, diffusive cortical depolarization, and inflammatory responses.

[0004] Currently, commonly used anti-cerebral ischemia drugs mainly include antiplatelet aggregation drugs, thrombolytics, neuroprotective agents, and free radical scavengers. Although these drugs exert their effects through different mechanisms, their use alone is unlikely to achieve satisfactory results. Domestic and international experts and scholars have conducted extensive research on the pathogenesis and prevention of cerebral ischemia and have made significant progress, but truly effective clinical prevention and treatment measures are still lacking. Therefore, how to adopt new strategies to research and develop novel, highly effective drugs for the prevention and treatment of cerebral ischemia with multiple functions is an important issue of global concern. Summary of the Invention

[0005] Technical problem solved: This invention provides a class of salicylic acid derivatives, which can significantly improve ischemic symptoms in rats with a cerebral ischemia-reperfusion model and can be used to prepare drugs for the prevention and treatment of stroke.

[0006] Technical solution: A class of compounds as shown in Formula I or pharmaceutically acceptable salts thereof,

[0007] in,

[0008] R1 and R2 are each independently selected from hydrogen, Furthermore, R1 and R2 are not both hydrogen.

[0009] Preferably, the compound is selected from:

[0010] Compound 1, as shown in S1;

[0011] Compound 2, as shown in S2;

[0012] Compound 3, as shown in S3;

[0013] Compound 4, as shown in S4.

[0014] Compound 5, as shown in S5.

[0015] This invention provides the use of the compound of Formula I or a pharmaceutically acceptable salt thereof in the preparation of a medicament for the prevention and treatment of stroke.

[0016] The present invention provides a pharmaceutical composition comprising a compound of formula I or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier. Beneficial effects:

[0017] This invention provides a class of salicylic acid derivatives, which are characterized by significantly improving ischemic symptoms in rats with a cerebral ischemia-reperfusion model and can be used to prepare drugs for the prevention and treatment of stroke. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Synthesis of intermediate A

[0020] first step:

[0021] 10.00 g (1 eq 54.6 mmol) of 4-nitrosalicylic acid and 10.10 g (1.0 eq 54.6 mmol) of dextroborneol were dissolved in 200 mL of THF. 660 mg (0.1 eq 5.46 mmol) of DMAP was added, and the mixture was stirred at room temperature for 5 min. Then, 16.80 g of DCC (1.5 eq 81.9 mmol) was added, and the mixture was stirred at room temperature for 4 h. TLC analysis was performed. After the reaction was complete, the mixture was washed three times with saturated NaHCO3, and the organic phase was dried and concentrated to give 12.4 g of a pale yellow solid, with a yield of 71.2%.

[0022] Step Two:

[0023] The product was dissolved in 100 mL of MeOH, and 1.70 g (0.1 eq 3.9 mmol) of 10% Pd / C was added. The reaction was carried out overnight at room temperature under hydrogen protection. After the reaction was completed, Pt / C was filtered off, and the filtrate was concentrated to give 9.67 g of white solid, with a yield of 85.8%.

[0024] Step 3:

[0025] 5.00 g (1 eq 26.4 mmol) of 3,5-dichlorosalicylaldehyde and 7.64 g (1 eq 26.4 mmol) of the second-step product were dissolved separately in 25 mL of anhydrous ethanol. The solution of the second-step product was added dropwise to the 3,5-dichlorosalicylaldehyde solution with stirring. The reaction was allowed to proceed at room temperature for 1 h. After the reaction was complete, a large amount of red solid precipitated. The filter cake was collected by suction filtration. The filter cake was placed in a 250 mL beaker, and 5 mL of ethanol was added and stirred until homogeneous. 1.50 g (1.5 eq 39.6 mmol) of NaHB4 was added with stirring until the reaction solution became clear. Then, 20 mL of water was added to quench the reaction, and the pH was adjusted to 5–6 with 1 mM HCl. Gradually, a white solid precipitated. The filter cake was collected by suction filtration, yielding 10.89 g of white solid, with a yield of 89.1%. ESI-MS: 464.1 [M+H] + .

[0026] Example 1: Synthesis of compound S1

[0027] Synthesis of intermediate B1 in step 1

[0028] Boc₂O (281 mg, 1.29 mmol) was added to a DCM solution of compound A (500 mg, 1.08 mmol) and TEA (23.4 mg, 215 μmol). The solution was then stirred at 25 °C for 2 h. TLC analysis showed the reaction was complete. The reaction solution was concentrated to obtain the residue. Purification by column chromatography (petroleum ether / ethyl acetate = 20 / 1) gave 600 mg of a white solid, 98.7% yield. ESI-MS: 564.2 [M+H]+

[0029] Synthesis of intermediate C1 in step 2

[0030] B1 (1.22 g, 2.16 mmol) was dissolved in 30 mL of tetrahydrofuran, and tetrabenzyl pyrophosphate (1.38 g, 2.37 mmol) was added. NaHMDS (515 mg, 2.81 mmol) was added at 0 °C, and the reaction was carried out at room temperature for 3 h. TLC analysis showed the reaction was complete. The sample was washed with 20 mL of water and saturated NaCl, dried over anhydrous Na₂SO₄, filtered, and rotary evaporated. The crude product was subjected to silica gel column chromatography (PE:EA = 10:1) to give 1226 mg of a white solid, yield 69%. ESI-MS: 724.2 [M+H] + .

[0031] Synthesis of intermediate D1 in step 3

[0032] TFA (3.08 g, 27.0 mmol) was added to a DCM solution (8.00 mL) of compound C1 (1.00 g, 1.21 mmol), and the reaction mixture was stirred at 25 °C for 0.5 h. TLC analysis showed the reaction was complete. The crude product was concentrated to obtain a yellow oil, which was then purified by pre-HPLC to give 263 mg of a white solid, yielding 30.1%. ESI-MS: 574.1 [M+H] +

[0033] Step 4: Synthesis of final product S1.

[0034] D1 (600 mg, 0.83 mmol) was dissolved in 40 mL of dichloromethane, and TMSBr (760 mg, 4.97 mmol) was added. The mixture was stirred at 40 °C for 10 h, and then 10 mL of methanol was added. The mixture was concentrated to obtain a pale yellow oily crude product. The crude product was subjected to C18 column chromatography (from methanol:water = 1:9 to methanol:water = 7:3) to give 75 mg of a white solid, with a yield of 17%. ESI-MS: m / z = 544.1 [M+H] + ].

[0035] 1H NMR(500MHz, Methanol-d4)δ7.60(d,J=8.8Hz,1H),7.32(d,J=2.1Hz,1H),7.19(d, J=1.9Hz,1H),6.25(dd,J=8.8,1.9Hz,1H),6.05(d,J=1.7Hz,1H),5.08(d,J=9.6Hz, 1H),4.65(s,2H),2.45(d,J=3.5Hz,1H),2.14(dt,J=9.4,4.0Hz,1H),1.79(dt,J=57 .3,4.0Hz,2H),1.58–1.26(m,2H),1.12(dd,J=13.8,3.2Hz,1H),1.05–0.79(m,8H).

[0036] Example 2: Synthesis of compound S2

[0037] Synthesis of intermediate B2 in step 1

[0038] Dissolve A (1.00 g, 2.16 mmol) in 30 mL of tetrahydrofuran, add tetrabenzyl pyrophosphate (1.38 g, 2.37 mmol), and add NaHMDS (515 mg, 2.81 mmol) dropwise at 0 °C. React at room temperature for 3 h. TLC analysis showed the reaction was complete. Wash with 20 mL of water, then with saturated NaCl, dry under anhydrous Na₂SO₄, filter, rotary evaporate, and perform crude silica gel column chromatography (PE:EA = 10:1) to give 1077 mg of a white solid, yield 69%. ESI-MS: 724.2 [M+H] + .

[0039] Step 2: Synthesis of the final product S2.

[0040] B2 (600 mg, 0.83 mmol) was dissolved in 40 mL of dichloromethane, and TMSBr (760 mg, 4.97 mmol) was added. The mixture was stirred at 40 °C for 10 h, and then 10 mL of methanol was added. The mixture was concentrated to obtain a pale yellow oily crude product. The crude product was subjected to C18 column chromatography (from methanol:water = 1:9 to methanol:water = 7:3) to give 75 mg of a white solid, with a yield of 17%. ESI-MS: m / z = 544.1 [M+H] + ].

[0041] 1H NMR(500MHz, Methanol-d4)δ7.60(d,J=8.8Hz,1H),7.32(d,J=2.1Hz,1H),7.19(d, J=1.9Hz,1H),6.25(dd,J=8.8,1.9Hz,1H),6.05(d,J=1.7Hz,1H),5.08(d,J=9.6Hz, 1H),4.65(s,2H),2.45(d,J=3.5Hz,1H),2.14(dt,J=9.4,4.0Hz,1H),1.79(dt,J=57 .3,4.0Hz,2H),1.58–1.26(m,2H),1.12(dd,J=13.8,3.2Hz,1H),1.05–0.79(m,8H).

[0042] Example 3: Synthesis of compound S3

[0043] Synthesis of intermediate B3 in step 1

[0044] Boc₂O (281 mg, 1.29 mmol) was added to a DCM solution of compound A (500 mg, 1.08 mmol) and DMAP (26.3 mg, 215 μmol) (5.00 mL). The solution was then stirred at 25 °C for 2 h. TLC analysis showed the reaction was complete. The reaction solution was concentrated to obtain the residue. Purification by column chromatography (petroleum ether / ethyl acetate = 1 / 0 to 20 / 1) gave 600 mg of a white solid, 98.7% yield. ESI-MS: 564.2 [M+H] +

[0045] Synthesis of intermediate C3 in step 2

[0046] TEA (319 mg, 3.19 mmol) was added to a 12.0 mL solution of compound B3 (1.20 g, 2.13 mmol) and compound 1A (659 mg, 2.55 mmol) in THF. The reaction mixture was then stirred at 25 °C for 12 h. TLC analysis showed the reaction was complete. The reaction mixture was concentrated to obtain crude butter. The crude product was purified by preparative HPLC to give 200 mg of a white solid, yield 11.9%. ESI-MS: 786.3 [M+H] +

[0047] Step 3: Synthesis of compound S3

[0048] TFA (3.08 g, 27.0 mmol) was added to an 8.00 mL DCM solution of compound C3 (1.00 g, 1.27 mmol), and the reaction mixture was stirred at 25 °C for 0.5 h. TLC analysis showed the reaction was complete. The crude product was concentrated to obtain a yellow oil, which was then purified by pre-HPLC to give 220 mg of a white solid, with a yield of 30.1%. ESI-MS: 574.1 [M+H] + ;

[0049] 1 H NMR (400MHz, D2O) δ = 7.64 (d, J = 8.8Hz, 1H), 7.39 (d, J = 2.3Hz, 1H), 7.28 (d, J = 2.3Hz, 1H), 6.24 (br d,J=6.8Hz,1H),6.12(d,J=2.0Hz,1H),5.44(d,J=9.6Hz,2H),4.93(br d,J=10.8Hz,1H),4.60(s,2H),2.39-2.28(m,1H),1.93(br t,J=8.9Hz,1H),1.76-1.62(m,2H),1.32(br t,J=13.1Hz,1H),1.22-1.11(m,1H),1.06-0.97(m,1H),0.89-0.78(m,9H).

[0050] Example 4: Synthesis of compound S4

[0051] Synthesis of intermediate B4 in step 1

[0052] Compound 1A (306 mg, 1.18 mmol) was added to a DMF (5.00 mL) solution of compound A (500 mg, 1.08 mmol) and K₂CO₃ (297 mg, 2.15 mmol), and the mixture was stirred at 25 °C for 12 h. TLC analysis showed the reaction was complete. The reaction mixture was poured into water (20.0 mL), filtered, and dried to give a white crude product of compound B3 (360 mg, crude product), with a yield of 100%, for use in the next step without further purification.

[0053] Step 2: Synthesis of compound S4

[0054] Compound B4 (360 mg, 524 μmol) was added to a DCM (4.00 mL) solution with TFA (1.54 g, 13.5 mmol), and the mixture was stirred at 25 °C for 0.5 h. TLC analysis showed the reaction was complete. The crude product was concentrated to a yellow oil, which was purified by preparative high-performance liquid chromatography to give 200 mg of a white solid compound, with a yield of 76%. ESI-MS: m / z = 572.2 [MH] - .

[0055] 1 H NMR (400MHz, D2O) δ=7.60(br d,J=8.7Hz,1H),7.35(br s,1H),7.23(s,1H),6.21(br d,J=9.2Hz,1H),6.06(s,1H),5.38(br d,J=8.8Hz,2H),4.89(br d,J=8.4Hz,1H),4.55(br s,2H),2.38-2.21(m,1H),1.97-1.82(m,1H),1.72-1.58(m,2H),1.34-1.23(m,1H),1.19-1.07(m,1H),0.98(br d,J=13.9Hz,1H),0.84-0.73(m,9H).

[0056] Example 5: Synthesis of compound S5

[0057] Synthesis of intermediate B5 in step 1

[0058] Compound 1A (612 mg, 2.36 mmol) was added to a DMF (5.00 mL) solution of compound A (500 mg, 1.08 mmol) and K₂CO₃ (297 mg, 2.15 mmol), and the mixture was stirred at 25 °C for 12 h. TLC analysis showed the reaction was complete. The reaction mixture was poured into water (20.0 mL), filtered, and dried to give a white crude product of compound B3 (360 mg, crude product), with a yield of 100%, for use in the next step without further purification.

[0059] Step 2: Synthesis of compound S5

[0060] Compound B4 (360 mg, 524 μmol) was added to a DCM (4.00 mL) solution with TFA (1.54 g, 13.5 mmol), and the mixture was stirred at 25 °C for 0.5 h. TLC analysis showed the reaction was complete. The crude product was concentrated to a yellow oil, which was then purified by preparative high-performance liquid chromatography to give 200 mg of a white solid compound, with a yield of 76%. ESI-MS: m / z = 684.05 [M+1]+

[0061] 1 H NMR (400MHz, Methanol-d4) δ7.67(d,J=8.7Hz,1H),7.36(d,J=2.5Hz,1H),7.28(d,J=2.6Hz,1H),6.64(d,J=2 .2Hz,1H),6.31(dd,J=8.8,2.2Hz,1H),5.54(dd,J=9.9,7.0Hz,4H),5.01–4.96(m,1H),4.64(s,2H),2.40(td ,J=9.5,4.8Hz,1H),2.16(ddd,J=13.1,9.4,4.3Hz,1H),1.79(dq,J=8.1,4.0Hz,1H),1.68(t,J=4.5Hz,1H),1 .38(d,J=14.2Hz,1H),1.33–1.26(m,1H),1.07(dd,J=13.7,3.5Hz,1H),0.96(s,3H),0.91(d,J=11.7Hz,6H).

[0062] Example 6S4 Effect on Focal Cerebral Ischemia-Reperfusion Injury

[0063] 1. Materials and Methods

[0064] 1.1 Laboratory Animals

[0065] Sprague-Dawley (SD) rats, male, weight: 250-280g, SPF grade.

[0066] 1.2 Experimental Methods

[0067] 1.2.1 Preparation of a focal cerebral ischemia-reperfusion model. Main steps: Rats were anesthetized by intraperitoneal injection of 10% chloral hydrate (350 mg / kg). The right external carotid artery was isolated, ligated, and severed. A nylon suture, approximately 18 mm long and enlarged at the cerebellar end, was slowly inserted through the stump of the external carotid artery along the common carotid and internal carotid arteries to obstruct the entrance of the middle cerebral artery, causing ischemia. After 2 hours of ischemia, the suture was removed, and reperfusion was performed for 24 hours. The model was considered successfully established when the animal exhibited Homer's sign and contralateral motor dysfunction upon awakening.

[0068] 1.2.2 Animal Grouping and Administration Experimental animals were randomly divided into four groups: the model group, the positive control edaravone group (6 mg / kg), the compound S4 (8 mg / kg) group, and the S4 (24 mg / kg) group, with 10-12 animals in each group. All test substance groups and the positive control group received a single tail vein injection immediately after reperfusion, for a total of one administration.

[0069] The dosage volume for each group was 0.5 mL / 100 g.

[0070] 1.3.3 Neurological deficit score and determination of cerebral infarction volume

[0071] The modified Bederson 5-point scale was used to evaluate neurological deficit symptoms.

[0072] For the determination of cerebral infarction volume, after the animal underwent a final neurological deficit assessment, the brain was removed by decapitation. The olfactory brain, lower brainstem, and cerebellum were removed, and the remaining portion was immediately weighed wet. The brain was then sliced ​​into five pieces of approximately equal thickness along the coronal plane on ice and incubated in red tetrazolium dye at 37°C for 30 minutes. Normal brain tissue appeared deep red, while the infarcted area appeared pale white. The brain slices were then fixed in 10% formaldehyde, and the white tissue was carefully removed and weighed. The percentage of infarcted tissue weight to total brain weight was used as the infarct volume indicator.

[0073] 2 Results

[0074] 2.1 Effects on cerebral infarction volume and neurological deficit scores after ischemia-reperfusion

[0075] Compared with the model group, the drug groups significantly reduced the infarct volume in rats with cerebral ischemia-reperfusion injury (P<0.05); and improved the neurological deficit symptoms in rats. The results are shown in Table 1.

[0076] Table 1. Effects of infarct volume and neurological deficit score after ischemia-reperfusion. *P<0.05, **P<0.01, compared with the model group.

[0077] Example 7: Effect of S2 on focal cerebral ischemia-reperfusion injury

[0078] 1. Materials and Methods

[0079] 1.1 Laboratory Animals

[0080] Sprague-Dawley (SD) rats, male, weight: 250-280g, SPF grade.

[0081] 1.2 Experimental Methods

[0082] 1.2.1 Preparation of a focal cerebral ischemia-reperfusion model. Main steps: Rats were anesthetized by intraperitoneal injection of 10% chloral hydrate (350 mg / kg). The right external carotid artery was isolated, ligated, and severed. A nylon suture, approximately 18 mm long and enlarged at the cerebellar end, was slowly inserted through the stump of the external carotid artery along the common carotid and internal carotid arteries to obstruct the entrance of the middle cerebral artery, causing ischemia. After 2 hours of ischemia, the suture was removed, and reperfusion was performed for 24 hours. The model was considered successfully established when the animal exhibited Homer's sign and contralateral motor dysfunction upon awakening.

[0083] 1.2.2 Animal Grouping and Administration Experimental animals were randomly divided into four groups: the model group, the positive control edaravone group (6 mg / kg), the compound S2 (8 mg / kg) group, and the S2 (24 mg / kg) group, with 10-12 animals in each group. All test substance groups and the positive control group received a single tail vein injection immediately after reperfusion, for a total of one administration.

[0084] The dosage volume for each group was 0.5 mL / 100 g.

[0085] 1.3.3 Neurological deficit score and determination of cerebral infarction volume

[0086] The modified Bederson 5-point scale was used to evaluate neurological deficit symptoms.

[0087] For the determination of cerebral infarction volume, after the animal underwent a final neurological deficit assessment, the brain was removed by decapitation. The olfactory brain, lower brainstem, and cerebellum were removed, and the remaining portion was immediately weighed wet. The brain was then sliced ​​into five pieces of approximately equal thickness along the coronal plane on ice and incubated in red tetrazolium dye at 37°C for 30 minutes. Normal brain tissue appeared deep red, while the infarcted area appeared pale white. The brain slices were then fixed in 10% formaldehyde, and the white tissue was carefully removed and weighed. The percentage of infarcted tissue weight to total brain weight was used as the infarct volume indicator.

[0088] 2 Results

[0089] 2.1 Effects on cerebral infarction volume and neurological deficit scores after ischemia-reperfusion

[0090] Compared with the model group, the drug groups significantly reduced the infarct volume in rats with cerebral ischemia-reperfusion injury (P<0.05); and improved the neurological deficit symptoms in rats. The results are shown in Table 2.

[0091] Table 2. Effects of infarct volume and neurological deficit score after ischemia-reperfusion. *P<0.05, **P<0.01, compared with the model group.

Claims

1. A class of compounds as shown in Formula I or pharmaceutically acceptable salts thereof, characterized in that, As shown in the following formula I: wherein R1, R2are each independently selected from hydrogen, and R1and R2are not both hydrogen.

2. The compound of claim 1, or a pharmaceutically acceptable salt thereof, wherein, The compound is selected from: Compound 1, as shown in S1; Compound 2, as shown in S2; Compound 3, as shown in S3; Compound 4, as shown in S4; Compound 5, as shown in S5.

3. Use of a compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-2 in the manufacture of a medicament for preventing and treating stroke.

4. A pharmaceutical composition, characterized by, A pharmaceutical composition comprising a compound or a pharmaceutically acceptable salt thereof according to any one of claims 1-2 and a pharmaceutically acceptable carrier.

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