CN101817761B - Benzoic acid ester derivatives and preparation method and application - Google Patents

Abstract

The invention provides a benzoate derivative, wherein a series of benzoate derivatives are synthesized by a chemical method, and comprise ester compounds, (thio) ether compounds and amide compounds, most of the synthesized compounds have new chemical structures, in-vitro cell activity experiments prove that the synthesized benzoate derivatives have very obvious activities similar to nerve growth factor NGF, in-vivo animal experiments prove that the synthesized new compounds 2, 3-dihydroxy-benzoic acid tetradecyl ester have the effect of enhancing memory of aged mice, so the benzoate derivatives can be applied to the preparation of medicaments for preventing and treating senile dementia neurodegenerative diseases, particularly the application of medicaments for treating neurodegenerative diseases such as Alzheimer's Disease (AD) and the like. The invention develops the new medicinal application of the benzoate derivatives, and has reasonable preparation method and simple and convenient operation. Provides a new therapeutic drug for preventing and treating neurodegenerative diseases such as senile dementia and the like.

Description

Benzoic acid ester derivatives and preparation method and application

technical field

The invention belongs to the preparation method and application of compounds, and relates to the preparation method of benzoate derivatives and the application of such compounds in the prevention and treatment of neurodegenerative diseases such as senile dementia.

Background technique

Alzheimer's disease can be roughly divided into three types: Alzheimer's disease (AD for short), vascular dementia and other types of dementia. With the increase of the aging population, the prevalence of Alzheimer's disease has increased significantly, and it has become the fourth leading cause of death in adults, second only to heart disease, cancer, and stroke. It is estimated that there are more than 5 million senile dementia patients in my country, accounting for about 1/4 of the total number of cases in the world; moreover, with the acceleration of the aging process of my country's population, this number will become even larger, which will have a significant impact on social stability and development . According to statistics, the incidence rate of Alzheimer's disease in China is 5% over the age of 65, 10% over the age of 70, 30% over the age of 80, and as high as 40% over the age of 85. In another 20 years, today's middle-aged people will enter the ranks of the elderly, the number of dementia patients will increase sharply, and the health of the elderly will also be related to the stability and development of the entire society. Therefore, the research and development of effective drugs for the prevention and treatment of senile dementia has become an urgent medical problem in the world.

Among the three classifications of Alzheimer's disease, AD is the most common and most important dementia disease. AD is a neurodegenerative disease, with memory and cognitive impairment as the main clinical symptoms, which can lead to inability to take care of oneself in severe cases. The exact pathological mechanism of AD is still unclear. At present, the main academic viewpoints are as follows: 1. Beta amyloid polypeptide (Aβ) toxicity and deposition; 2. Cholinergic deficiency theory; 3. Neurodegeneration (Neurodegeneration); 4. . Various other factors, such as gene mutation theory, oxidative stress theory.

Aβ deposition and toxicity is one of the main factors in the pathogenesis of Alzheimer's disease. The abnormal regulation of APP gene in neurons leads to the accumulation of toxic Aβ in nerve cells, causing a cascade reaction of pathological changes, which in turn leads to the degeneration of nerve cells. The focus of research at home and abroad is to reduce the production of Aβ, inhibit the aggregation of Aβ, and change the configuration of Aβ to reduce its neurotoxicity. At present, several drugs have entered clinical trials.

At present, there are many kinds of drugs for the treatment of AD, mainly cholinergic drugs, among which acetylcholinesterase (AChE) inhibitors, the main marketed drugs are tacrine (tacrine), rivastigmine tartrate (rivastigmine), stone Huperzine A (huperzine A), donepezil (donepezil), etc.; β and γ secretase inhibitors; brain metabolism regulators, such as vincamine, nimodipine, and brain beneficial zine; drugs that affect free radical metabolism, such as vitamin C binding vitamin E etc. However, these AD treatment drugs are mainly symptomatic treatment, which cannot delay the progression of AD, and the efficacy of the drug gradually decreases with the progression of the disease, and serious side effects occur at the same time, so people turn their attention to the research and development of new anti-senile dementia drugs. Finding therapeutic drugs and methods for the etiology of AD has become a hot and difficult point in current research.

Studies have shown that neurotrophic factors have important effects on both neurodevelopment and disease processes in the adult nervous system. In animal models of neurodegeneration, it was found that nerve growth factor (nerve growth factor, NGF) can prevent or reduce the degeneration of neurons. NGF is the first neurotrophic factor discovered by humans, and it is also the most important neurotrophic factor; it is a biologically active polypeptide that plays an important role in regulating the growth, development, differentiation and function maintenance of nerve cells; The treatment of neurological diseases such as neurodegeneration and trauma repair has a significant effect. Studies have found that NGF can prevent the progression of AD to a certain extent, and its role in promoting nerve growth and neuroprotection has been a long-term research hotspot. However, it is a polypeptide composed of more than 100 amino acids; due to reasons such as large molecular weight and strong polarity, it cannot pass through the blood brain barrier (Blood Brain Barrier), and it is difficult to prepare on a large scale, which limits its practical clinical application. , NGF has not yet found a better treatment method except direct administration of intracerebral surgery. Therefore, finding low-molecular-weight compounds that have NGF-like activity (NGF mimics) or can enhance its activity (NGFenhancer) and can pass through the blood-brain barrier has naturally become a research hotspot. Because PC12 cells (Pheochromocytoma cells, cloned from rat adrenal chromaffin cells) have the general characteristics of nerve cells and can be passaged, under the action of NGF, the cells will stop dividing, grow protrusions, and transform into neuron-like cells. Therefore, PC12 cells are a good model to study the function of NGF at the molecular level. Currently, there are NGF mimics in Phase III clinical trials.

Recently, our research group isolated and purified a new class of 2,3-dihydroxybenzoic acid esters from Gentiana, a traditional Chinese medicine, and found that it has good NGF mimics biological activity against senile dementia. So far, no researchers have discovered such substances from natural products, let alone reports that such compounds have NGF-like activity against senile dementia. There are only chemically synthesized compounds with similar structures (fatty chain carbon number less than 11) reported in the literature, and European patent (EP 1 930 002 A1) describes the efficacy of benzoate compounds (1) in the treatment and prevention of viral infections. Application, the benzoic acid compound described in Chinese patent (CN1411339A) is mainly used for antibacterial, as food additive etc.

In the formula, R is a C _1-11 alkyl group; R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are independently hydroxyl or hydrogen, and R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are at least one of them One is a hydroxyl group, and two or more are hydroxyl groups, except for salicylic acid; it is optimal when the number of carbon atoms is 1-3.

Aspirin (Aspirin, also known as acetylsalicylic acid), has a similar core nucleus to naturally obtained 2,3-dihydroxybenzoic acid ester compounds, and is a classic small molecule non-steroidal anti-inflammatory drug (NSAIDs). Strong antipyretic, analgesic, anti-inflammatory, anti-rheumatic effects. Aspirin has a unique effect on inhibiting platelet aggregation and can prevent thrombus formation. It can be used to prevent stroke, coronary heart disease, etc., and can receive certain effects. In recent years, with the in-depth research on the pharmacological effects of NSAIDs, their new clinical applications have also been continuously discovered. Epidemiological studies have shown that the risk of AD and cognitive impairment in the elderly who regularly take aspirin is significantly lower, suggesting that NSAIDs have potential application value in the treatment of AD. Studies suggest that the possible mechanism is that aspirin can prevent the inflammatory process of AD and directly regulate the metabolism of Aβ.

The activity test of Aspirin in the in vitro screening model PC 12 cell system found that it had no obvious NGF-like activity. Although the structure is similar, it can cause a high proportion of PC12 cells to elongate neurites, indicating that natural 2,3-dihydroxybenzoate has a good NGF-like activity and has the value of developing anti-senile dementia prevention and treatment drugs . Using 2,3-dihydroxybenzoate compounds as precursors, a series of benzoate derivatives were designed and synthesized, and their in vitro activity research was extensively carried out to find the structure-activity relationship of such substances. If compounds with potentially better activity and/or lower toxicity can be found, and can be used to prevent and treat neurodegenerative diseases such as Alzheimer's disease, it will have important practical significance.

Contents of the invention

The object of the present invention is to provide benzoate derivatives, including ester compounds, (thio) ether compounds and amide compounds, with the following general structural formula:

In the formula:

R is a straight chain or branched chain alkyl group with carbon atoms from 1 to 30, especially C ₁₂ to C ₂₂ ;

_R is hydrogen, hydroxy, carboxy, ester, fluorine, chlorine, bromine, iodine, mercapto, amino, cyano, nitro, sulfonate, trifluoromethyl, propenyl, alkyl, alkoxy or substituted One of the phenyl groups;

_R is hydrogen, hydroxyl, carboxyl, ester, fluorine, chlorine, bromine, iodine, mercapto, amino, cyano, nitro, sulfonate, trifluoromethyl, propenyl, alkyl or alkoxy A sort of;

_R3 is hydrogen, hydroxyl, carboxyl, ester, fluorine, chlorine, bromine, iodine, mercapto, amino, cyano, nitro, sulfonate, trifluoromethyl, propenyl, alkyl, alkoxy or substituted One of the phenyl groups;

_R4 is hydrogen, hydroxyl, carboxyl, ester, fluorine, chlorine, bromine, iodine, mercapto, amino, cyano, nitro, sulfonic acid, trifluoromethyl, propenyl, alkyl or alkoxy A sort of;

_R is hydrogen, hydroxyl, carboxyl, ester, fluorine, chlorine, bromine, iodine, mercapto, amino, cyano, nitro, sulfonic acid, trifluoromethyl, propenyl, alkyl or alkoxy A sort of;

X is one of O, N or _CH2 ;

Y is one of O, S or _CH2 ;

Another object of the present invention is to provide the preparation method of benzoic acid ester derivative, realize through the following steps:

(1) The preparation method of ester compound (formula I, II, IV, V, X=O), first dissolves acid and alcohol or phenol with an appropriate amount of solvent, cools to 0°C, adds dehydrating agent dropwise under stirring, and then rises React at room temperature or under reflux for 1 to 2 days, and track the reaction with thin-layer chromatography. After the reaction, evaporate the solvent, and then purify by silica gel column chromatography to obtain ester compounds. The acids used are (substituted) benzoic acids, (substituted) naphthoic acids or straight-chain or branched fatty acids with 1 to 30 carbon atoms; the alcohols used are straight-chain or branched fatty alcohols with 1 to 30 carbon atoms The phenol used is (substituted) phenol or (substituted) naphthol; Dehydrating agent selects a kind of in the vitriol oil, diisopropylcarbodiimide or dicyclohexylcarbodiimide for use; Solvent selects protic solvent methanol, Ethanol or tetrahydrofuran, or select aprotic solvent dichloromethane, chloroform, benzene, toluene, xylene, dimethyl sulfoxide or acetonitrile; the molar ratio of acid and alcohol in the reaction is 1:1 to 1:20, acid and dehydration The molar ratio of the agent is 1:0.2 to 1:3.

(2) The preparation method of (thio) ether compounds (formula III, Y=O, S), first dissolves phenol and alkali with an appropriate amount of solvent, then adds the halogenated compound dropwise under stirring, and reacts at room temperature to 80°C for 1-2 After the reaction, the system was poured into a large amount of distilled water, filtered, washed with water and 10% sodium hydroxide several times, and post-treated to obtain (thio)ether compounds. The phenols used are thiophenols, (substituted) phenols or (substituted) naphthols; the halides used are linear or branched alkyl chlorides, bromides or iodides with carbon atoms from 1 to 30; the solvent is selected from protons solvent methanol, ethanol or tetrahydrofuran, or select aprotic solvent dichloromethane, chloroform, benzene, toluene, xylene, dimethyl sulfoxide or acetonitrile; the base used is sodium hydroxide, potassium hydroxide, potassium carbonate or hydrogenation Sodium; the molar ratio of phenol to halide in the reaction is 1:1 to 1:10, and the molar ratio of phenol to base is 1:1 to 1:5.

(3) The preparation method of amide compounds (formula I, II, IV, V, X=N), under the protection of inert gas, the acid is dissolved in an appropriate amount of dry dichloromethane, and the dry chlorinated chlorinated acid is added dropwise under stirring. Sulfone or oxalyl chloride, react at room temperature for 1 day. After the reaction, excess thionyl chloride or oxalyl chloride was distilled off under reduced pressure, and washed with dry dichloromethane several times to obtain the acid chloride. Then dissolve the acid chloride with an appropriate amount of dry dichloromethane, add the dichloromethane solution of amine and triethylamine dropwise under stirring, and react at room temperature for 2 to 5 hours. After the reaction, wash with deionized water, 1 mole per liter of sodium hydroxide solution, 1 mole per liter of hydrochloric acid solution, dry over anhydrous magnesium sulfate, concentrate, and finally wash with n-hexane to obtain amides; the inert gas used is nitrogen or argon; the acid used is (substituted) benzoic acid, (substituted) naphthoic acid, or a straight-chain or branched fatty acid with a carbon number from 1 to 30; the amine used is (substituted) aniline, (substituted) naphthylamine Or straight-chain or branched fatty amines with carbon atoms from 1 to 30; the molar ratio of acid to thionyl chloride or oxalyl chloride is 1:2 to 1:10, and the molar ratio of acid chloride to amine is 1:1 to 1:5.

Another object of the present invention is to provide the application of the benzoic acid ester derivative formula (I-V) in the preparation of drugs for the prevention and treatment of neurodegenerative diseases of Alzheimer's disease. It is mainly used in the preparation of drugs for treating neurodegenerative diseases such as Alzheimer's disease (AD).

The present invention further provides a pharmaceutical composition for preventing neurodegenerative diseases such as senile dementia. acceptable carrier or diluent.

The pharmaceutically acceptable carrier described here refers to the conventional drug carrier in the field of pharmacy, such as diluent, excipient, etc., fillers such as starch, sucrose, microcrystalline cellulose, etc.; binders such as starch slurry, hydroxyl Propylene cellulose, gelatin, polyethylene glycol, etc.; wetting agents such as magnesium stearate, micronized silica gel, polyethylene glycols, etc.; absorption enhancers polysorbate, lecithin, etc., surfactants boloxamer, fatty acid Sorbitan, polysorbate, etc., and other adjuvants such as flavoring agents, sweetening agents, etc. can also be added to the composition.

The benzoic acid ester compound and its derivatives described in the present invention can be administered in the form of unit dosage, and the route of administration can be enteral or parenteral, including oral, intramuscular, subcutaneous and nasal cavity.

The route of administration of the compounds of the present invention may be intravenous administration. Injections include intravenous, intramuscular, subcutaneous, and point injections.

Various dosage forms of the pharmaceutical composition of the present invention can be prepared according to conventional production methods in the field of pharmacy, such as mixing the active ingredient with one or more carriers, and then making it into the desired dosage form.

The dosage form can be tablets, capsules, dispersible tablets, oral liquids, large infusions, small needles, freeze-dried powder injections, ointments, liniments or suppositories.

The preparation method of the present invention is reasonable in design, easy to operate, and most of the synthesized compounds have new chemical structures, and it is confirmed by in vitro cell activity experiments that the synthesized benzoate derivatives have significant activity similar to nerve growth factor NGF, especially It is confirmed by in vivo animal experiments that the synthesized new compound 2,3-dihydroxybenzoic acid tetradecyl ester has the effect of enhancing the memory of aged mice, so benzoate derivatives can be used in the preparation of drugs for the prevention and treatment of Alzheimer's neurodegenerative diseases It is used in medical treatment, especially in the preparation of drugs for the treatment of neurodegenerative diseases such as Alzheimer's disease (AD). The invention opens up new medical applications of the benzoate derivatives. Provide new therapeutic drugs for the prevention and treatment of neurodegenerative diseases such as Alzheimer's disease.

Description of drawings

Fig. 1 adds the obvious change of PC 12 cell neurite after 48 hours by adding compound I-6.

Fig. 2 changes the neurite differentiation rate of PC12 cells with dose increase after adding compound I-6 for 48 hours.

Fig. 3 adds compound I-8, I-12, I-14, I-15, I-16 and I-18 after 48 hours the neurite differentiation rate of PC 12 cells changes with dose increase.

Fig. 4 adds compound II-1, III-1, IV-2 and V-1 after 48 hours the change of neurite differentiation rate of PC12 cell with dose increase.

Figure 5 Changes in the total number of arms and alternating action rate of mice after injection of compound I-6.

Detailed ways

The above-mentioned content of the present invention will be described in further detail below through the embodiment and the accompanying drawings of the preparation examples of some specific compounds of this class, but this should not be interpreted as that the scope of the above-mentioned subject of the present invention is limited to the following examples. The technologies realized in the above contents of the present invention all belong to the scope of the present invention.

Example 1

Compound I-1: Ethyl 2,3-dihydroxybenzoate

Put (154mg, 1mmol) 2,3-dihydroxybenzoic acid and 10ml ethanol in a 25ml round bottom flask, cool to 0°C, add 2-3 drops of concentrated sulfuric acid dropwise, and stir at reflux for 24h. Track the reaction with thin layer chromatography (developing agent: n-hexane/ethyl acetate, 5/1, V/V). After the reaction stops, ethanol is evaporated to obtain 390 mg of crude product. Silica gel column chromatography (developing agent: n-hexane/ethyl acetate Ethyl acetate, 5/1, V/V), to obtain 180 mg of white solid, yield: 99%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.00(s, 1H, benzene 2-OH), 7.38(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.12(dd, 1H, J= 1.0, 7.5Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.66(s, 1H, Benzene 3-OH), 4.41(q, 2H, J=7.0Hz ), 1.42(t, 3H, J=7.0Hz); MS(m/z): 182[M] ⁺ .

Compound I-2: Amyl 2,3-dihydroxybenzoate

The synthesis method was the same as that of compound I-1, and the reaction materials were: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, 10ml amyl alcohol, and 170mg of white solid was obtained, with a yield of 76%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.00(s, 1H, benzene 2-OH), 7.38(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.12(dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.65(s, 1H, Benzene 3-OH), 4.41(t, 2H, J=7.0Hz ), 1.78(m, 2H), 1.33～1.38(m, 4H), 0.90(t, 3H, J=7.0Hz); MS(m/z): 224[M] ⁺ .

Compound I-3: Octyl 2,3-dihydroxybenzoate

The synthesis method is the same as that of compound I-1, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, 10ml octanol to obtain 128mg of white solid, yield: 48%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.01(s, 1H, benzene 2-OH), 7.38(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.10(dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.64(s, 1H, Benzene 3-OH), 4.35(t, 2H, J=7.0Hz ), 1.78(m, 2H), 1.44(m, 2H), 1.26～1.38(m, 8H), 0.89(t, 3H, J=7.0Hz); MS(m/z): 266[M] ⁺ .

Compound I-4: Decyl 2,3-dihydroxybenzoate

Put (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (316mg, 2mmol) n-decyl alcohol, and 10ml tetrahydrofuran in a 25ml round bottom flask, cool to 0°C, add (145mg, 0.7mmol) dicyclohexyl carbon Diimine, stirred at room temperature for 24h. The reaction was followed by thin layer chromatography (developer: n-hexane/ethyl acetate, 2/1, V/V). After the reaction stopped, the solvent was evaporated, the residue was dissolved in ethyl acetate, filtered, the filtrate was washed with 5% citric acid solution, saturated sodium bicarbonate solution, and water, the ester layer was dried over anhydrous sodium sulfate, filtered, and concentrated by rotary evaporation to obtain the initial 440 mg of the product was subjected to silica gel column chromatography (developing solvent: n-hexane/ethyl acetate, 2/1, V/V) to obtain 41 mg of a white solid, yield: 14%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.01(s, 1H, benzene 2-OH), 7.37(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.09(dd, 1H, J= 1.5, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.65(s, 1H, Benzene3-OH), 4.35(t, 2H, J=7.0Hz) , 1.78(m, 2H), 1.44(m, 2H), 1.27～1.35(m, 12H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 294[M] ⁺ .

Compound I-5: Dodecyl 2,3-dihydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (372mg, 2mmol) dodecanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, 180mg white solid was obtained, yield: 56%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.01(s, 1H, benzene 2-OH), 7.38(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.10(dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.64(s, 1H, Benzene 3-OH), 4.35(t, 2H, J=6.5Hz ), 1.78(m, 2H), 1.44(m, 2H), 1.26～1.35(m, 16H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 322[M] ⁺ .

Compound I-6: Myristyl 2,3-Dihydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (428mg, 2mmol) tetradecanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml of tetrahydrofuran, 150mg of white solid was obtained, yield: 43%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.01(s, 1H, benzene 2-OH), 7.37(dd, 1H, J=1.5, 8.5Hz, benzene H-6), 7.10(dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.63(s, 1H, Benzene 3-OH), 4.35(t, 2H, J=6.5Hz ), 1.78(m, 2H), 1.44(m, 2H), 1.26～1.35(m, 20H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 350[M] ⁺ .

Compound I-7: Hexadecyl 2,3-dihydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (484mg, 2mmol) hexadecanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, 178mg white solid was obtained, yield: 47%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.01(s, 1H, benzene 2-OH), 7.37(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.10(dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.65(s, 1H, Benzene 3-OH), 4.35(t, 2H, J=6.5Hz ), 1.78(m, 2H), 1.44(m, 2H), 1.25～1.35(m, 24H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 378[M] ⁺ .

Compound I-8: Octadecyl 2,3-dihydroxybenzoate

The synthesis method is the same as compound I-4, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (540mg, 2mmol) stearyl alcohol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, 170mg white solid was obtained, yield: 42%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.01(s, 1H, benzene 2-OH), 7.37(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.10(dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.63(s, 1H, Benzene 3-OH), 4.35(t, 2H, J=6.5Hz ), 1.78(m, 2H), 1.44(m, 2H), 1.25～1.35(m, 28H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 406[M] ⁺ .

Compound I-9: Eicosyl 2,3-dihydroxybenzoate

The synthesis method is the same as compound I-4, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (896mg, 3mmol) eicosanol, (206mg, 1mmol) dicyclohexylcarbodiimide, 15ml Tetrahydrofuran, 104 mg of white solid was obtained, yield: 24%. ¹ H NMR (500 MHz, CDCl ₃ ) δ: 11.00 (s, 1H, benzene 2-OH), 7.37 (dd, 1H, J=1.5, 8.0 Hz, benzene H-6), 7.10 (dd, 1H, J= 0.5, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.63(s, 1H, Benzene 3-OH), 4.34(t, 2H, J=6.5Hz ), 1.78(m, 2H), 1.43(m, 2H), 1.25～1.35(m, 32H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 434[M] ⁺ .

Compound I-10: Behenyl 2,3-Dihydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (653mg, 2mmol) docosanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide , 15ml tetrahydrofuran, 102mg white solid was obtained, yield: 22%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.01(s, 1H, benzene 2-OH), 7.37(dd, 1H, J=1.5, 8.0Hz, benzene H-6), 7.10(dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.63(s, 1H, Benzene 3-OH), 4.34(t, 2H, J=6.5Hz ), 1.78(m, 2H), 1.43(m, 2H), 1.25～1.35(m, 36H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 462[M] ⁺ .

Compound I-11: Triadecyl 2,3-dihydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (154mg, 1mmol) 2,3-dihydroxybenzoic acid, (1.32g, 3mmol) triacontanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide , 20ml tetrahydrofuran, 75mg white solid was obtained, yield: 13%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 11.00 (s, 1H, benzene 2-OH), 7.37 (dd, 1H, J=1.5, 8.5Hz, benzene H-6), 7.10 (dd, 1H, J= 1.0, 8.0Hz, Benzene H-4), 6.80(t, 1H, J=8.0Hz, Benzene H-5), 5.63(s, 1H, Benzene 3-OH), 4.34(t, 2H, J=6.5Hz ), 1.77(m, 2H), 1.45(m, 2H), 1.25～1.35(m, 52H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 575[M] ⁺ .

Compound I-12: Myristyl 2,6-dihydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (154mg, 1mmol) 2,6-dihydroxybenzoic acid, (428mg, 2mmol) tetradecanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, 66mg white solid was obtained, yield: 19%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 9.79(s, 2H), 7.32(t, 1H, J=8.5Hz), 6.48(d, 2H, J=8.5Hz), 4.35(t, 2H, J=8.5Hz) 6.5Hz), 1.78(m, 2H), 1.44(m, 2H), 1.26～1.35(m, 20H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 350[M] ⁺ .

Compound I-13: Eicosyl 2,6-dihydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (154mg, 1mmol) 2,6-dihydroxybenzoic acid, (597mg, 2mmol) eicosanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, 104mg white solid was obtained, yield: 24%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 9.79(s, 2H), 7.31(t, 1H, J=8.5Hz), 6.48(d, 2H, J=8.5Hz), 4.50(t, 2H, J=8.5Hz) 6.5Hz), 1.83(m, 2H), 1.43(m, 2H), 1.25～1.35(m, 32H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 434[M] ⁺ .

Compound I-14: Myristyl 2-Hydroxybenzoate

The synthesis method is the same as compound I-4, and the reaction materials are: (138mg, 1mmol) 2-hydroxybenzoic acid, (428mg, 2mmol) tetradecanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, Obtained white solid 164 mg, yield: 49%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 10.88(s, 1H), 7.37(m, 1H), 7.10(m, 1H), 6.91(m, 1H), 6.80(t, 1H, J=8.0Hz) , 4.35(t, 2H, J=6.5Hz), 1.78(m, 2H), 1.44(m, 2H), 1.26～1.35(m, 20H), 0.88(t, 3H, J=7.0Hz); MS( m/z): 334[M] ⁺ .

Compound I-15: Myristyl 3-Hydroxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (138mg, 1mmol) 3-hydroxybenzoic acid, (428mg, 2mmol) tetradecanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, Obtained white solid 174 mg, yield: 52%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 9.76(s, 1H), 7.57(m, 1H), 7.37(m, 1H), 7.25(m, 1H), 7.01(m, 1H), 4.35(t, 2H, J=6.5Hz), 1.78(m, 2H), 1.44(m, 2H), 1.26～1.35(m, 20H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 334[M] ⁺ .

Compound I-16: Myristyl 2,3-dimethoxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (182mg, 1mmol) 2,3-dimethoxybenzoic acid, (428mg, 2mmol) tetradecanol, (250mg, 1.2mmol) dicyclohexylcarbodiethylene Amine, 15ml tetrahydrofuran, 162mg white solid was obtained, yield: 43%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 7.08 (t, 1H, J=7.5Hz), 6.95 (dd, 1H, J=1.5, 8.0Hz), 6.79 (dd, 1H, J=1.0, 7.0Hz) , 4.35(t, 2H, J=6.5Hz), 3.92(s, 3H), 3.88(s, 3H), 1.78(m, 2H), 1.44(m, 2H), 1.26～1.35(m, 20H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 378[M] ⁺ .

Compound I-17: Octadecyl 2,3-Dimethoxybenzoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (182mg, 1mmol) 2,3-dimethoxybenzoic acid, (540mg, 2mmol) stearyl alcohol, (250mg, 1.2mmol) dicyclohexylcarbodiethylene Amine, 15ml tetrahydrofuran, 170mg white solid was obtained, yield: 39%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 7.06 (t, 1H, J=8.0Hz), 6.93 (dd, 1H, J=1.5, 8.0Hz), 6.77 (dd, 1H, J=1.5, 8.0Hz) , 4.35(t, 2H, J=6.5Hz), 3.92(s, 3H), 3.88(s, 3H), 1.78(m, 2H), 1.44(m, 2H), 1.25～1.35(m, 28H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 434[M] ⁺ .

Compound I-18: 2,3-Dimethoxy-N-tetradecylbenzamide

(1.1g, 6mmol) 2,3-dimethoxybenzoic acid, (7ml, 0.09mol) thionyl chloride were placed in a 25ml round bottom flask, and stirred at room temperature for 24h under nitrogen protection. After the reaction stopped, excess thionyl chloride was distilled off under reduced pressure, and washed with dry dichloromethane several times to obtain acid chloride. Under the protection of nitrogen, (0.5g, 2.5mmol) acid chloride was dissolved with a small amount of dry dichloromethane, and then (640mg, 3mmol) tetradecylamine, (0.9ml, 9mmol) triethylamine were dissolved in 10ml of dry Dichloromethane was added dropwise. Stir at room temperature for 2 hours. After the reaction stops, wash with deionized water, 1 mole per liter of sodium hydroxide solution, deionized water, 1 mole per liter of hydrochloric acid solution, and deionized water. Dry over anhydrous magnesium sulfate, concentrate, and wash with n-hexane to obtain 219 mg of white solid, yield: 58%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 7.94(bt, 1H), 7.57(dd, 1H, J=1.5, 8.0Hz), 7.09(dd, 1H, J=1.5, 8.0Hz), 6.85(t, 1H, J=8.0Hz), 3.82(bs, 6H), 3.37(q, 2H, J=5.8Hz), 1.58(m, 2H), 1.17～1.35(m, 22H), 0.86(t, 3H, J =7.0Hz); MS(m/z): 377[M] ⁺ .

Compound I-19: 2,3-Dihydroxy-N-tetradecylbenzamide

Under nitrogen protection, compound I-19 (188 mg, 0.5 mmol) was dissolved in 30 ml of dry dichloromethane, and (2 ml) boron tribromide was added dropwise, and the resulting bromide was absorbed with 1 mole per liter of sodium hydroxide solution. hydrogen, stirred at room temperature for three days. After the reaction was completed, ice water was slowly added dropwise to quench, the solvent was distilled off, and then washed with methanol several times to obtain 140 mg of gray solid, yield: 40%. ¹ H NMR (500 MHz, DMSO-d ₆ ) δ: 12.71 (s, 1H), 8.58 (s, 1H), 8.05 (bt, 1H), 7.35 (dd, 1H, J=1.5, 8.5Hz), 6.98 ( dd, 1H, J=1.0, 8.0Hz), 6.75(t, 1H, J=8.0Hz), 3.25~3.38(m, 2H), 1.71(m, 2H), 1.18~1.35(m, 22H), 0.86 (t, 3H, J=7.0Hz); MS(m/z): 349[M] ⁺ .

Compound I-20: Myristyl 2-chlorobenzoate

The synthesis method is the same as compound I-4, and the reaction materials are: (156mg, 1mmol) 2-chlorobenzoic acid, (428mg, 2mmol) tetradecanol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, Obtained white solid 150 mg, yield: 43%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 7.65(m, 1H), 7.30(m, 2H), 7.08(m, 1H), 4.35(t, 2H, J=6.5Hz), 1.78(m, 2H) , 1.44(m, 2H), 1.26～1.35(m, 20H), 0.88(t, 3H, J=7.0Hz); MS(m/z): 352[M] ⁺ .

Example 2

Compound II-1: 1,2-phenylene eicosate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (110mg, 1mmol) o-diphenol, (310mg, 1mmol) eicosanoic acid, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, and a white Solid 391 mg, yield: 56%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 7.13～7.16(t, 1H, J=7.5Hz), 7.09～7.11(d, 1H, J=7.5Hz), 7.02～7.04(d, 1H, J=7.5 Hz), 6.92~6.95(t, 1H, J=7.5Hz), 2.63(t, 2H, J=6.5Hz), 2.42(t, 2H, J=6.5Hz), 1.96~1.99(m, 12H), 1.17～1.42(m, 60H), 0.89(bs, 6H); MS(m/z): 699[M] ⁺ .

Example 3

Compound III-1: 1,4-bis(tetradecyloxy)benzene

Under nitrogen protection, (110mg, 1mmol) hydroquinone, (280mg, 5mmol) potassium hydroxide, 10ml N,N-dimethylformamide were placed in a 25ml round bottom flask, and (830mg, 3mmol) was added dropwise Bromotetradecane. Stir overnight at room temperature. After the reaction stops, pour the system into a large amount of distilled water. A yellow solid precipitates in the upper layer, which is filtered, washed with water and 10% sodium hydroxide to obtain 111 mg of the product, yield: 22%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 6.76 (bs, 4H), 3.75 ~ 3.80 (t, 4H, J = 6.5Hz), 1.82 (m, 4H), 1.25 ~ 1.33 (m, 44H), 0.85 ( t, 6H, J=7.0Hz); MS (m/z): 502[M] ⁺ .

Example 4

Compound IV-1: Tetradecyl 1-Hydroxy-2-naphthoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (188mg, 1mmol) 1-hydroxyl-2-naphthoic acid, (428mg, 2mmol) tetradecyl alcohol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, 184mg white solid was obtained, yield: 48%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 12.09(s, 1H), 8.41(d, 1H, J=8.5Hz), 7.76～7.79(m, 2H), 7.59～7.62(m, 1H), 7.51～ 7.54(m, 1H), 7.28(d, 1H, J=9.0Hz), 4.39(t, 2H, J=6.5Hz), 1.82(m, 2H), 1.47(m, 2H), 1.25～1.38(m , 20H), 0.88 (t, 3H, J=7.0Hz); MS (m/z): 384[M] ⁺ .

Compound IV-2: Octadecyl 1-Hydroxy-2-naphthoate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (188mg, 1mmol) 1-hydroxyl-2-naphthoic acid, (270mg, 1mmol) stearyl alcohol, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml of tetrahydrofuran, 198mg of white solid was obtained, yield: 45%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 12.09(s, 1H), 8.41(d, 1H, J=8.5Hz), 7.75～7.79(m, 2H), 7.59～7.63(m, 1H), 7.51～ 7.54(m, 1H), 7.28(d, 1H, J=9.0Hz), 4.39(t, 2H, J=6.5Hz), 1.82(m, 2H), 1.47(m, 2H), 1.25～1.38(m , 28H), 0.88 (t, 3H, J=7.0Hz); MS (m/z): 440[M] ⁺ .

Example 5

Compound V-1: 1-Naphthyl Myristate

The synthesis method is the same as that of compound I-4, and the reaction materials are: (144mg, 1mmol) naphthol, (228mg, 1mmol) tetradecanoic acid, (250mg, 1.2mmol) dicyclohexylcarbodiimide, 15ml tetrahydrofuran, and a white solid is obtained 258 mg, yield: 70%. ¹ H NMR (500MHz, CDCl ₃ ) δ: 8.39 (d, 1H, J=8.5Hz), 7.77-7.82 (m, 2H), 7.59-7.62 (m, 2H), 7.49-7.51 (m, 1H), 7.28(m, 1H), 2.32(t, 2H, J=6.5Hz), 1.76～1.88(m, 6H), 1.14～1.32(m, 18H), 0.88(s, 3H); MS(m/z) : 368[M] ⁺ .

Example 6

Identification of biological activity: In animal models of neurodegeneration, studies have found that NGF can prevent or reduce the degeneration of neurons, prevent the progression of AD to a certain extent, and have the effects of promoting nerve growth and neuroprotection. Because PC12 cells have the general characteristics of nerve cells, PC12 cells will stop dividing under the action of NGF, grow protrusions, and transform into neuron-like cells. Therefore, the compound that can cause PC12 cells to transform into neuron-like cells has application value in the prevention and treatment of neurodegenerative diseases such as senile dementia.

experimental method:

1) Cultivation of PC 12 cells: Place 20×10 ⁴ PC 12 cells in a 100 mm culture dish, containing 10 ml of DMEM medium (containing 10% horse serum and 5% fetal bovine serum), and replace the medium after two days , another three days later. First wash the cells twice with PBS, then add 10ml PBS to the culture dish, incubate at 37°C, 5% CO ₂ incubator for 10 minutes, rinse, transfer to a 15ml disposable centrifuge tube, centrifuge and count blood cells count on the board. Add 1ml of serum-containing DMEM medium to each well of a 24-well cell culture plate. After counting the cells, inoculate 2×10 ⁴ cells in each well, and add the sample after culturing in a CO ₂ incubator for 24 hours.

2) Activity test: DMSO was used as a negative control, and NGF 40ng was used as a positive control. Compound I-6 was formulated into DMSO solutions with different concentrations. Replace the original medium in each well of the 24-well cell plate with 1 ml of DMEM solution containing 1% DMSO and the sample (without serum), and then culture in an incubator at 37° C. with 5% CO ₂ . Observe the cell morphology changes every 24 hours and 6 consecutive days under an inverted microscope, and record the cell differentiation rate NA (the ratio of the number of cells with neurites longer than twice the diameter of the cell body to the total number of cells in the field of view), about 100 cells in each field of view , randomly select 3 locations, and draw statistical graphs.

Figure 1: The obvious changes of neurite in PC 12 cells after adding compound I-6 for 48 hours, A: 1% DMSO is negative control; B: NGF 40ng/ml is positive control; C: Compound I-6, concentration , 1 μM ;)

Figure 2: The neurite differentiation rate of PC 12 cells changes with dose after 48 hours after adding compound I-6, C: negative control 1% DMSO, the concentration unit of I-6: μM;

Figure 3: Changes in neurite differentiation rate of PC12 cells with increasing doses after adding compounds I-8, I-12, I-14, I-15, I-16 and I-18 for 48 hours, C: negative control 1 %DMSO, the concentration unit of the compound: μM;

Figure 4: Adding compound II-1, III-1, IV-2 and V-1 after 48 hours, the neurite differentiation rate of PC 12 cells changes with dose increase, C: negative control 1% DMSO, the concentration unit of the compound : μM).

3) Experimental results: It was found that at a concentration of 0.03-10 μM, all the tested compounds showed NGF-mimics activity after 48 hours. Under the condition of compound I-6 at an optimal concentration of 1 μM, the neurites induced by the compound in PC 12 cells can exceed the neurites induced by NGF.

Example 7

Animal Experiment: Investigation of Compound I-6 (Tetradecyl 2,3-Dihydroxybenzoate) on Improving Short-term Memory in Aged Rats

1) Acute poisoning test: 20 4-week-old ICR male mice were randomly divided into a control group and a 100mg/kg treatment group. The compound I-6 dissolved in 1% Tween-80 was intraperitoneally injected into the animals at one time according to the dose, and observed continuously for one week, and the mental state of the animals was observed every day, and the body weight and food intake were measured. Ten minutes after the compound was administered, the limbs of the mice curled up, and the amount of exercise decreased. After 1 hour, everything is back to normal. There was no death of the mice within a week, and no significant change in food intake, but the change in body weight was significantly reduced. Heart, liver, spleen, kidney and white adipose tissue weight and visual appearance had no significant difference.

2) Drug efficacy test: 18 12-month-old ICR male mice were randomly divided into a control group, a 1 mg/kg treatment group and a 10 mg/kg treatment group. At the same time, 4-week-old young ICR mice were used as the control group, and the corresponding dose of compound I-6 dissolved in Tween-80 was injected every day. After 11 days of drug administration, the changes in food intake and body weight were measured every day, and the Y-maze was used to test the improvement of the short-term memory effect of the compound on 12 days. The test results showed that there was no significant difference in the body weight change and food intake of the mice treated with 1 mg/kg compared with the aged mice control group. The total number of arms entered and the rate of alternate actions increased (Figure 5, the changes in the total number of arms entered and the rate of alternate actions of mice after injection of compound I-6, P<0.05). In the 10mg/kg treatment group, there was no significant change in food intake, total number of arms and alternating action rate, but the body weight decreased significantly. The results suggest that the compound has an improving effect on short-term memory in aged mice. 10mg/kg dose has some side effects.

Claims (5)

1. A benzoic acid ester derivative has the following general structural formula:

In the formula: R is a straight chain or branched chain alkyl group with 14 carbon atoms; R ₁ , R ₂ are hydroxyl, R ₃ , R ₄ , R ₅ are hydrogen; X is O. 2. A benzoic acid ester derivative has the following general structural formula:    

In the formula: R is a straight chain or branched chain alkyl group with 18 carbon atoms; R ₁ , R ₂ are hydroxyl, R ₃ , R ₄ , R ₅ are hydrogen; X is O. 3. Use of the benzoate derivatives according to any one of claims 1-2 in the preparation of neurodegenerative disease medicines for the prevention and treatment of Alzheimer's disease. 4. Use of the benzoate derivatives according to any one of claims 1-2 in the preparation of neurodegenerative disease medicines for treating Alzheimer's disease. 5. the preparation method of the benzoate derivatives of any one of claims 1-2, is characterized in that, realizes by the following steps: Dissolve the acid and alcohol in a solvent, cool to 0°C, add a dehydrating agent dropwise under stirring, then rise to room temperature or reflux to react for 1-2 days, follow the reaction with thin-layer chromatography, after the reaction, distill off the solvent, and then Purify through silica gel column chromatography to obtain benzoate compounds; used acid is 2,3-dihydroxybenzoic acid; used alcohol is selected from straight chain or branched chain fatty alcohols with 14 and 18 carbon atoms; dehydrating agent is selected for use One of concentrated sulfuric acid, diisopropylcarbodiimide or dicyclohexylcarbodiimide; the solvent is selected from protic solvent tetrahydrofuran, and the molar ratio of acid to alcohol in the reaction is 1:1 to 1:20, acid and The molar ratio of the dehydrating agent is 1:0.2 to 1:3. 6. the application of a kind of benzoic acid ester derivative in the neurodegenerative disease medicine of preparation prevention and treatment senile dementia, it is characterized in that, described benzoic acid ester derivative has following general structural formula:    

In the formula: R is a straight chain or branched chain alkyl group with carbon atoms from 12 to 22; R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are respectively selected from hydrogen and hydroxyl, and among R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ there are at least two adjacent hydroxyl groups; X is O. 7. the application of a kind of benzoic acid ester derivative in the neurodegenerative disease medicine of preparation prevention and treatment senile dementia, it is characterized in that, described benzoic acid ester derivative has following general structural formula:    

In the formula: R is a straight chain or branched chain alkyl group with carbon atoms from 12 to 22; R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are respectively selected from hydrogen and hydroxyl, and R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ have and only two adjacent hydroxyl groups; X is O. 8. Use according to any one of claims 6-7, characterized in that the neurodegenerative disease of senile dementia is Alzheimer's disease. the

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