CN115850270A - Alpha-carboline compound or pharmaceutical composition thereof, and preparation method and application thereof - Google Patents

Abstract

The invention discloses an alpha-carboline compound or a pharmaceutical composition thereof, a preparation method and application thereof, wherein the alpha-carboline compound is N ¹ The-site substituted quaternary ammonium salt can effectively inhibit the activity of cholinesterase AChE and BuChE, has anti-neuritis activity, and can be developed into a medicine for preventing and/or treating related diseases such as neurodegenerative diseases (such as Alzheimer disease), neuroinflammatory diseases and the like.

Description

Alpha-carboline compound or pharmaceutical composition thereof, and preparation method and application thereof

Technical Field

The invention relates to the field of drug synthesis, in particular to an alpha-carboline compound or a pharmaceutical composition thereof, and a preparation method and application thereof.

Background

Alzheimer's Disease (AD) is often referred to as senile dementia, and particularly with the recent aging of the global population, the incidence of AD in countries around the world is increasing. According to World Health Organization (WHO) data, AD has become the most influential neurodegenerative disease in the World. AD patients need long-term comprehensive care, which inevitably brings heavy economic burden to families and society; furthermore, patients are easy to have various complications in the middle and late stages, and dementia such as AD is counted to be the seventh leading cause of death in the world and the third leading cause of death in human beings. Now, the disease is reported for more than one hundred years from the first time, but because the pathogenic factors are complex, the disease course is changed by various physiological and biochemical conditions, although the research and development work of anti-AD drugs is not interrupted, most of the research and development work is failed, so that no drugs can successfully treat the Alzheimer disease at present, and the exact pathogenesis of the drugs is needed to be further researched. It is reported that in addition to the decrease of acetylcholine level, the brain of AD patients also has symptoms such as amyloid aggregation, metal ion metabolic disorder, free radical increase and induced inflammatory reaction, and these factors all have certain influence on the development of AD disease course, and different mechanisms are related and influenced. Therefore, researchers have proposed a series of hypotheses based on which the currently recognized mechanisms of development of AD include cholinergic hypothesis, a β cascade hypothesis, metal ion hypothesis, oxidative stress hypothesis, neuroinflammation hypothesis, tau protein hyperphosphorylation hypothesis, and the like.

The most mature and most accepted hypothesis of the pathological mechanism of AD is the cholinergic hypothesis, so designing cholinesterase inhibitors on the basis of the central cholinergic hypothesis remains the most prevalent clinical strategy in the treatment of AD at present. The hypothesis states that acetylcholine (Ach) is one of the most important transmitters of signal transmission in cholinergic neurons, and is also a neurotransmitter primarily affected by AD, which is synthesized in the cytoplasm, stored in vesicles, released at the neurosynaptic membrane, passes through the synaptic cleft and then acts at the postsynaptic membrane, and then is rapidly decomposed into choline by acetylcholinesterase (AChE) for Ach synthesis again. The degeneration of cholinergic neurons in the cerebral cortex can cause the level of ACh to be reduced, the signal transmission capability between the neurons is greatly reduced, and then pathological manifestations of memory loss, cognitive ability, motor ability and the like of AD patients are caused, so the cholinergic neurons are important causes of the memory decline and the cognitive function degeneration of the AD patients. In the brain, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are the two major types of cholinesterase that hydrolyze acetylcholine. Particularly AChE has received much attention over the past decades, and 4 of the 6 anti-AD drugs currently approved for the market have therapeutic effects on cholinergic system dysfunction.

Due to the complexity and severity of the causes of AD, the development of anti-AD drugs has progressed very slowly, and only 6 drugs approved by the national drug administration for the treatment of AD are on the market: rivastigmine (rivastigmine), donepezil (Donepezil), galantamine (Galanthamine), memantine (Memantine), huperzine a (Huperzine A) and Sodium mannolite (Sodium oligomanate). In addition, besides limited pharmacological effects, most of the currently used drugs are accompanied by other adverse reactions, such as gastrointestinal reactions like vomiting and diarrhea, cardiovascular reactions like bradycardia, conduction block and arrhythmia, nervous system reactions like dizziness, headache and insomnia, and other types of side reactions or malignant syndromes like skin irritation and myolysis, and especially Tacrine (Tacrine) approved by FDA in 1993 has exited the market in 2012 due to its serious hepatotoxicity. The development of new and highly effective anti-AD drugs is still an urgent task.

Currently clinically used anti-AD drug list on the market

Name of drug	Time to market	Mechanism of action
			Donepezil	1994	AChE inhibitors
Huperzine A	1996	AChE inhibitors
			Rivastigmine	2000	AChE inhibitors
Galanthamine	2001	AChE inhibitors
			Memantine	2003	NMDA receptor antagonists
Manmote sodium	2019	Remodeling gut flora balance

Currently, the number of patients with AD is still increasing worldwide, preventing and treating AD is a major challenge and problem faced by contemporary society, and also becomes an important public health problem to be solved urgently, but the existing six drugs can only show limited relief effect on symptoms, and have narrow coverage, and the current drugs have great limitations in actual market promotion and clinical treatment, so that the need of obtaining effective therapeutic drugs is still compelled from the fundamental mechanism of AD pathogenesis. In recent years, more attention has been paid to anti-AD treatment of the a β cascade and tau hyperphosphorylation mechanism, but the result is that various targeted drugs against a β and tau "zephyte" are sequentially in the clinical trial phase. Increasing levels of ACh in the brain to improve cholinergic neurotransmission remains the most effective method for AD treatment based on the cholinergic dysfunction hypothesis, so the success rate of AD drug design based on this mechanism is relatively high. Anticholinesterase inhibitors (ChEI) are currently one of the only two therapies approved by the U.S. food and drug administration for the treatment of mild to moderate AD in the world, is also the mainstream drug approved for clinical application at present. To improve cholinergic neurotransmission, anti-AD drug development has undergone different strategies including increasing ACh synthesis, increasing presynaptic ACh release, stimulating cholinergic postsynaptic muscarinic and nicotinic receptors, and reducing ACh synaptic degradation with cholinesterase inhibitors, among others. However, due to the lack of therapeutic efficacy and unacceptable side effects, current data do not support the use of AChE precursors, presynaptic release agents or muscarinic agonists, and thus increasing ACh levels in patients by inhibiting AChE hydrolysis, which in turn increases the duration of action of cholinergic signaling and potentiates the effect, is the most desirable treatment modality under this hypothesis. In addition, studies have shown that AChE can not only hydrolyze acetylcholine, but also accelerate the formation of amyloid fibrils through its Peripheral Anionic Sites (PAS) near the oral cavity to produce a stable acetylcholine-a β complex, which is more toxic than a single a β peptide, and thus the strategy of inhibiting BuChE has become the focus of treating AD in recent years. At the same time, there is increasing evidence that AChE activity decreases to 10-15% of normal in certain areas of the brain as disease progresses, while BuChE can compensate for the absence of acetylcholinesterase and maintain normal cholinergic pathways. In patients with advanced AD, AChE levels are reduced by nearly 90% due to severe cholinergic neuronal damage. At this time, the level and function of BuChE increased to 105-165% under normal conditions, and became the main metabolic enzyme of ACh. Therefore, the single selective AChE inhibitors donepezil and galantamine etc. have increasingly limited therapeutic effect on severe AD. Particularly in the current development dilemma for anti-AD drugs, more and more researchers are beginning to focus on the development of BuChE inhibitors for the treatment of advanced AD. Thus, designing dual ChE inhibitors that block AChE and BuChE simultaneously may have a dual, collateral effect on the treatment of AD.

The report shows that during 1998-2017, the clinical failure rate of 146 tested drugs including fevered, li lai, mausadon, astrazeneca and the like in the international pharmaceutical huge head is as high as 97.3%. As is well known, drug screening is an important approach for discovering drug lead compounds, and a good compound library is an essential weapon for drug screening.

Based on this, it is necessary to establish a compound library for cholinergic hypothesis to further aid high-throughput screening of AD drugs.

The alpha-carboline contains a pyridine ring fused with an indole skeleton (formula 1), and is a drug chemical scaffold molecule with rich potential. In recent decades, there has been increasing evidence that α -carboline natural products and their derivatives have diverse biological activities, including anti-tumor, anti-bacterial, anti-inflammatory, anti-fungal, anti-plasmodium, anti-trypanosome, anti-atherosclerosis, anti-diabetic, anti-oxidative, anti-anxiety and central nervous system stress modulating activities, among others. However, to date, there has been little research into α -carbolines for the treatment and prevention of AD. In addition, the activity research of the existing alpha-carboline is mostly focused on N ⁹ -and C ⁸ Evaluation of-site derivatives, and research on anti-inflammatory and antioxidant activities have also been focused on N ⁹ -and C ² -、C ³ On-position or on ring-extended derivatives, not visible for N ¹ Activity of-position substituted quaternary ammonium salt is reported. In view of the excellent activities of the compounds in the aspects of anti-inflammation, antioxidation and central nervous system stress activity regulation, on the basis, more alpha-carboline compounds with therapeutic action on AD are found through an effective activity screening model, and the method is obviously an attractive exploration direction. In particular N ¹ The research result of the-site substituted quaternized derivative provides a novel tool compound for the research of AD diseases and the like or provides a brand new lead compound for the research and development of AD medicaments and the like.

Disclosure of Invention

Based on the needs of the prior art, the invention provides an alpha-carboline compound or a pharmaceutical composition thereof, and a preparation method and application thereof.

The invention provides an alpha-carboline compound, the structure of which is shown in the general formula (I):

wherein R is ₁ Selected from the group consisting of hydrogen atoms, alkyl groups, haloalkyl groups and halogens, said R ₁ Is any of positions 2',3',4',5' and 6 ';

is halogen.

Preferably, the alkyl group is C _1-6 Alkyl, said haloalkyl being fluoro C _1-6 Alkyl, chloro C _1-6 Alkyl, bromo C _1-6 An alkyl group.

Preferably, the

Selected from the group consisting of fluorine atoms, chlorine atoms and bromine atoms.

Preferably, the

Is a chlorine atom or a bromine atom.

Preferably, the

When it is a bromine atom, said R ₁ Selected from the group consisting of a hydrogen atom, a methyl group, a trifluoromethyl group, a fluorine atom and a bromine atom.

Preferably, the

When it is a chlorine atom, said R ₁ Is a chlorine atom.

Preferably, the α -carboline compound is selected from:

/>

/>

/>

in a second aspect, the present invention provides a pharmaceutical composition comprising an effective amount of a compound as described above, and optionally a pharmaceutically acceptable excipient or a pharmaceutically acceptable carrier.

The third aspect of the invention provides the application of the alpha-carboline compound in preparing cholinesterase inhibitors.

The fourth aspect of the invention provides the use of the above alpha-carboline compound or the above pharmaceutical composition in the preparation of a medicament for preventing and/or treating alzheimer's disease.

The beneficial effects of the invention at least comprise:

the technical problem to be solved by the invention is to take alpha-carboline as a molecular skeleton and to define a series of N ¹ The preparation means and structural properties of the-site substituted quaternized derivatives are researched, and meanwhile, the anti-neuritis activity of the ChEI is researched, so that a brand new thought is provided for the development and design of medicines for resisting neurodegenerative diseases such as Alzheimer's disease and the like, and an innovative research foundation is laid for the application of the derivatives in the field of neurodegenerative diseases.

The research of the inventor finds that the alpha-carboline compounds have better inhibition effect on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and have anti-neuritic activity, and some alpha-carboline compounds of the invention show very high-efficiency activity on butyrylcholinesterase, wherein the IC of the optimal compound 6i ₅₀ The value reaches 0.77 mu M, is far stronger than that of a positive drug galanthamine (13.7 mu M), the anti-neuritis effect of the compound 6b-6p is stronger than that of a positive control quercetin, a new candidate drug lead for selectively inhibiting cholinesterase and resisting Alzheimer disease can be provided for clinic, and the development of a candidate drug lead for selectively inhibiting cholinesterase and resisting Alzheimer disease can be realizedThe alpha-carboline compound is a medicine for preventing and/or treating related diseases such as neurodegenerative diseases (such as Alzheimer disease), neuroinflammatory diseases and the like, and particularly has good effect of resisting the Alzheimer disease.

The features and advantages of the present invention will be described in detail in the detailed description that follows.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to specific embodiments. It should be understood that the specific examples described in the following description of the embodiments of the present invention are merely illustrative of specific embodiments of the present invention and are intended to be used for the purpose of explanation, not limitation, of the invention.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein. In the description of the present application, the terms "a", "an", "the" and the like mean two or more unless otherwise specified.

[ term description ] to

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

As used herein, the term "about" when used in reference to a specifically recited value means that the value can vary from the recited value to within ± 5%.

As used herein, the term "comprising" or "includes" can be open, semi-closed, and closed.

As used herein, definitions of standardized chemical terms (e.g., radicals) can be found in the literature references in the field.

Unless otherwise indicated, conventional methods within the skill of the art are employed, such as mass spectrometry, NMR, IR and UV/VIS spectroscopy, and pharmacological methods. Unless a specific definition is set forth, the terminology used herein in the pertinent description of analytical chemistry, organic synthetic chemistry, and pharmaceutical and medicinal chemistry is known in the art. Standard techniques can be used in chemical synthesis, chemical analysis, pharmaceutical preparation, formulation and delivery, and treatment of patients. For example, the reaction and purification can be carried out using the instructions of the kit from the manufacturer, or according to the methods known in the art or the instructions of the present invention. The techniques and methods described above can generally be practiced according to conventional methods well known in the art, as described in various general and more specific documents referred to and discussed in this specification. In the present specification, groups and substituents thereof may be selected by one skilled in the art to provide stable moieties and compounds.

When a substituent is described by a general formula written from left to right, the substituent also includes chemically equivalent substituents obtained when the formula is written from right to left.

The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. All documents, or portions of documents, cited in this application, including but not limited to patents, patent applications, articles, books, operating manuals, and treatises, are hereby incorporated by reference in their entirety.

In addition to the foregoing, when used in the specification and claims of this application, the following terms take the meanings indicated below, unless otherwise specifically indicated.

The term "alkyl" refers to a straight or branched chain saturated hydrocarbon group. In some preferred embodiments, the alkyl group contains 1 to 6 carbon atoms (C) _1-6 Alkyl), for example 1, 2,3, 4, 5 or 6 carbon atoms. In other embodiments, the alkyl group contains 1 to 3 carbon atoms, such as 1, 2, or 3 carbon atoms. Some non-limiting examples of alkyl groups include methyl, ethyl, propyl, 2-propyl (isopropyl), n-butyl, isobutyl, sec-butyl, tert-butylA 2, 2-dimethylpropyl group. A particularly preferred but non-limiting example of an alkyl group is methyl.

The term "halogen" or "halo" refers to fluorine (F), chlorine (Cl), bromine (Br), or iodine (I). Preferably, the term "halogen" or "halo" refers to fluorine (F), chlorine (Cl) or bromine (Br). More preferred are chlorine (Cl) and bromine (Br).

The term "haloalkyl" refers to an alkyl group wherein at least one hydrogen atom of the alkyl group has been replaced with a halogen atom. Preferably, "haloalkyl" refers to an alkyl group wherein 1, 2 or 3 hydrogen atoms of the alkyl group have been substituted with halogen atoms, preferably with fluorine, chlorine, bromine, more preferably with chlorine, bromine. A particularly preferred, but non-limiting, example of haloalkyl is trifluoromethyl (CF) ₃ )。

In the present invention, in the case of the present invention,

and in the body of a compound of the general formula (I)>

The connecting bond between them is an ionic bond.

In some of the preferred embodiments, the first and second,

when it is a bromine atom, R ₁ Selected from the group consisting of a hydrogen atom, a methyl group, a trifluoromethyl group, a fluorine atom and a bromine atom.

In yet other preferred embodiments of the present invention,

when it is a chlorine atom, R ₁ Is a chlorine atom. />

As used herein, the terms "compound of the present invention" or "active ingredient of the present invention" are used interchangeably and refer to a stereoisomer, enantiomer, or pharmaceutically acceptable salt of a compound of general formula (la). The term also includes racemates, optical isomers, isotopic compounds (e.g., deuterated compounds), or precursors.

"stereoisomers" refers to compounds that consist of the same atoms, are bonded by the same bonds, but have different three-dimensional structures. The present invention is intended to cover various stereoisomers and mixtures thereof.

When the compounds of the present invention contain an olefinic double bond, the compounds of the present invention are intended to include both E-and Z-geometric isomers unless otherwise specified.

"tautomer" refers to an isomer formed by the transfer of a proton from one atom of a molecule to another atom of the same molecule. All tautomeric forms of the compounds of the invention are also intended to be included within the scope of the invention.

The compounds of the invention or pharmaceutically acceptable salts thereof may contain one or more chiral carbon atoms and may therefore give rise to enantiomers, diastereomers and other stereoisomeric forms. Each chiral carbon atom may be defined as (R) -or (S) -, based on stereochemistry. The present invention is intended to include all possible isomers, as well as racemates and optically pure forms thereof. The compounds of the invention may be prepared by selecting racemates, diastereomers or enantiomers as starting materials or intermediates. Optically active isomers may be prepared using chiral synthons or chiral reagents, or resolved using conventional techniques, e.g., crystallization and chiral chromatography.

Conventional techniques for preparing/separating individual isomers include chiral synthesis from suitable optically pure precursors, or resolution of the racemate (or the racemate of a salt or derivative) using, for example, chiral high performance liquid chromatography.

The invention also includes isotopically-labeled compounds, equivalent to those disclosed herein for the original compound. In practice, however, it will often occur that one or more atoms are replaced by an atom having a different atomic weight or mass number. Examples of isotopes that can be listed as compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, fluorine and chlorine. The compounds of the present invention, or enantiomers, diastereomers, isomers, or pharmaceutically acceptable salts or solvates thereof, wherein isotopes or other isotopic atoms comprising such compounds are within the scope of the present invention. Certain isotopically-labeled compounds of the present invention, for example, radioisotopes, are also encompassed withinIs useful in tissue distribution experiments of drugs and substrates. For example tritium, i.e. ³ H and carbon 14, i.e. ¹⁴ C, their preparation and detection are relatively easy. Is the first choice among isotopes. Furthermore, heavier isotopes such as deuterium are substituted, i.e. ² H, due to its good metabolic stability, may be advantageous in certain therapies, such as increased half-life in vivo or reduced dose, and therefore, may be preferred in certain circumstances. Isotopically labeled compounds can be prepared by conventional methods using the protocols disclosed in the examples by substituting a readily available isotopically labeled reagent with a non-isotopically labeled reagent. In the present application, the term "pharmaceutically acceptable salts" includes pharmaceutically acceptable acid addition salts and pharmaceutically acceptable base addition salts.

As described herein, the compounds of the present invention can be substituted with any number of substituents or functional groups to extend their inclusion range. In general, the term "substituted", whether occurring before or after the term "optional", in the formula of the present invention including substituents, means that the hydrogen radical is replaced with a substituent of the indicated structure. When a plurality of the specified structures are substituted at a position with a plurality of the specified substituents, each position of the substituents may be the same or different. The term "substituted" as used herein includes all permissible substitutions of organic compounds. In a broad sense, permissible substituents include acyclic, cyclic, branched, unbranched, carbocyclic and heterocyclic, aromatic and nonaromatic organic compounds. In the present invention, the heteroatom nitrogen may have a hydrogen substituent or any permissible organic compound described hereinabove to supplement its valence state. Furthermore, the present invention is not intended to be limited in any way as to the permissible substitution of organic compounds. The present invention recognizes that the combination of substituents and variable groups is excellent in the treatment of diseases in the form of stable compounds. The term "stable" as used herein refers to compounds that are stable enough to maintain the structural integrity of the compound when tested for a sufficient period of time, and preferably are effective for a sufficient period of time, and are used herein for the purposes described above.

Metabolites of the compounds and pharmaceutically acceptable salts thereof to which this application relates, and prodrugs that can be converted in vivo to the structures of the compounds and pharmaceutically acceptable salts thereof to which this application relates, are also included in the claims of this application.

Pharmaceutical compositions and methods of administration

The pharmaceutical composition of the present invention is useful for preventing and/or treating neurodegenerative diseases (such as alzheimer's disease), neuroinflammatory diseases, and the like. In the present application, a "pharmaceutical composition" refers to a formulation of a compound of the present invention with a vehicle generally accepted in the art for delivery of biologically active compounds to a mammal (e.g., a human). The medium includes a pharmaceutically acceptable carrier. The purpose of the pharmaceutical composition is to facilitate administration to an organism, facilitate absorption of active ingredients and exert biological activity. The term "pharmaceutically acceptable" as used herein refers to a substance (e.g., carrier or diluent) that does not affect the biological activity or properties of the compounds of the present invention and is relatively non-toxic, i.e., the substance can be administered to an individual without causing an adverse biological response or interacting in an adverse manner with any of the components contained in the composition.

As used herein, "pharmaceutically acceptable excipient" includes, but is not limited to, any adjuvant, carrier, excipient, glidant, sweetener, diluent, preservative, dye/colorant, flavoring agent, surfactant, wetting agent, dispersing agent, suspending agent, stabilizing agent, isotonic agent, solvent, or emulsifying agent that is approved by the relevant governmental regulatory agency for human or livestock use.

The term "preventing" as used herein includes reducing the likelihood of occurrence or worsening of a disease or condition in a patient.

The term "treatment" and other similar synonyms as used herein include the following meanings:

(i) Preventing the occurrence of a disease or condition in a mammal, particularly when such mammal is susceptible to the disease or condition, but has not been diagnosed as having the disease or condition;

(ii) Inhibiting the disease or disorder, i.e., arresting its development;

(iii) Alleviating the disease or condition, i.e., causing regression of the state of the disease or condition; or

(iv) Alleviating the symptoms caused by the disease or disorder.

The terms "effective amount," "therapeutically effective amount," or "pharmaceutically effective amount" as used herein, refer to an amount of at least one agent or compound that is sufficient to alleviate one or more symptoms of the disease or disorder being treated to some extent after administration. The result may be a reduction and/or alleviation of signs, symptoms, or causes, or any other desired change in a biological system. For example, an "effective amount" for treatment is the amount of a composition comprising a compound disclosed herein that is clinically necessary to provide a significant remission effect of the condition. An effective amount suitable in any individual case can be determined using techniques such as a dose escalation assay.

The terms "administering," "administration," "administering," and the like as used herein refer to a method capable of delivering a compound or composition to a desired site for biological action. These methods include, but are not limited to, oral routes, via the duodenal route, parenteral injection (including intravenous, subcutaneous, intraperitoneal, intramuscular, intraarterial injection or infusion), topical administration, and rectal administration. Administration techniques useful for the compounds and methods described herein are well known to those skilled in the art. In a preferred embodiment, the compounds and compositions of the present invention are administered orally, and formulations of the compounds disclosed herein suitable for oral administration may be presented as discrete units, such as tablets, capsules, or cachets, each containing a predetermined amount of the active ingredient. In other preferred embodiments, the compounds and compositions of the present invention are injections and powders.

Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In these solid dosage forms, the active compound is mixed with at least one conventional inert excipient (or carrier), such as sodium citrate or dicalcium phosphate, or with the following ingredients: (a) Fillers or extenders, for example, starch, lactose, sucrose, glucose, mannitol and silicic acid; (b) Binders, for example, hydroxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose and acacia; (c) humectants, for example, glycerol; (d) Disintegrating agents, for example, agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain complex silicates, and sodium carbonate; (e) slow solvents, such as paraffin; (f) absorption accelerators, e.g., quaternary ammonium compounds; (g) Wetting agents, such as cetyl alcohol and glycerol monostearate; (h) adsorbents, for example, kaolin; and (i) lubricants, for example, talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, or mixtures thereof. In capsules, tablets and pills, the dosage forms may also comprise buffering agents.

Solid dosage forms such as tablets, dragees, capsules, pills, and granules can be prepared using coatings and shells such as enteric coatings and other materials well known in the art. They may contain opacifying agents and the release of the active compound or compounds in such compositions may be delayed in release in a certain part of the digestive tract. Examples of embedding components which can be used are polymeric substances and wax-like substances. If desired, the active compound may also be in microencapsulated form with one or more of the above-mentioned excipients.

Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups or tinctures.

In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly employed in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, propylene glycol, 1, 3-butylene glycol, dimethylformamide and oils, especially cottonseed, groundnut, corn germ, olive, castor and sesame oils or mixtures of such materials and the like.

In addition to these inert diluents, the compositions can also contain adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.

Suspensions, in addition to the active compounds, may contain suspending agents as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum methoxide and agar, or mixtures of these substances, and the like.

Compositions for parenteral injection may comprise physiologically acceptable sterile aqueous or anhydrous solutions, dispersions, suspensions or emulsions and sterile powders for reconstitution into sterile injectable solutions or dispersions. Suitable aqueous and nonaqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols and suitable mixtures thereof.

Dosage forms of the compounds of the present invention for topical administration include ointments, powders, patches, sprays, and inhalants.

The active ingredient is mixed under sterile conditions with a physiologically acceptable carrier and any preservatives, buffers, or propellants which may be required if necessary. The terms "drug combination", "administering other treatment", "administering other therapeutic agent" and the like as used herein refer to a drug treatment obtained by mixing or combining more than one active ingredient, including fixed and unfixed combinations of active ingredients. The term "fixed combination" refers to the simultaneous administration of at least one compound described herein and at least one co-agent to a patient in the form of a single entity or a single dosage form. The term "non-fixed combination" refers to the simultaneous administration, concomitant administration, or sequential administration at variable intervals of at least one compound described herein and at least one synergistic formulation to a patient as separate entities.

When using pharmaceutical compositions, a safe and effective amount of a compound of the invention is appropriate for use in a subject (including mammals, such as humans) in need of treatment. Of course, the particular dosage will also take into account factors such as the route of administration, the health of the subject in need of treatment, and the like, which are within the skill of the skilled practitioner.

The invention also provides a preparation method of the pharmaceutical composition, which comprises the following steps: mixing a pharmaceutically acceptable carrier with a compound of formula (I) as described herein or a crystalline form, hydrate or solvate thereof to form a pharmaceutical composition.

The present invention also provides a method of treatment comprising the steps of: administering to a subject in need of treatment an alpha-carboline compound as described herein, or a pharmaceutical composition as described herein, for inhibition of cholinesterase.

Process for the preparation of compounds of the general formula (I)

(i) In a proper solvent (such as toluene), benzotriazole and 2-bromopyridine are taken as raw materials, and the compound 3 is obtained by heating and refluxing;

(ii) In a proper solvent (such as polyphosphoric acid), the compound 3 is cyclized under the catalysis of acid to generate alpha-carboline,

namely compound 4;

(iii) Quaternization of compound 4 with compound 5 (benzyl halide) in a suitable solvent (e.g., acetonitrile) under heating provides compounds 6a-6p.

In some embodiments, the methods of preparing the α -carbolines of the present invention comprise:

(i) Dissolving 1.19g of benzotriazole in 30mL of toluene, adding 2.843g of 2-bromopyridine, stirring at 120 ℃, after the reaction is finished, concentrating, drying and carrying out column chromatography to obtain the target compound 3, namely a white solid with the yield of 97%.

The stirring can be uniform stirring, and the rotating speed is 500-700 r/min.

The completion of the reaction can be followed by TLC and the disappearance of the starting material 1 is detected.

The column chromatography can be silica gel column chromatography, petroleum ether: ethyl acetate (4.

(ii) Dissolving 1.96g of compound 3 in 10mL of polyphosphoric acid, stirring at 170 ℃, adding 200mL of ice water after the reaction is finished, dissolving with 30% potassium hydroxide to adjust the pH value to be alkaline, filtering to obtain a precipitate, dissolving, and performing column chromatography to obtain a target compound 4, namely a white solid, wherein the yield is 46%.

The stirring can be uniform stirring, and the rotating speed is 500-700 r/min.

The completion of the reaction can be followed by TLC and the disappearance of starting material 3 is detected.

The pH is adjusted to be alkaline, and the pH range is 9 to 10

The column chromatography can be silica gel column chromatography, petroleum ether: ethyl acetate (2.

(iii) Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of benzyl bromide or benzyl chloride (containing substituent), heating and stirring at 50 ℃, after the reaction is finished, concentrating, and carrying out column chromatography to obtain the compound 6a-6p.

The stirring can be uniform stirring, and the rotating speed is 500-700 r/min.

The completion of the reaction can be followed by TLC to detect the disappearance of starting material 4.

The column chromatography may be silica gel column chromatography, dichloromethane: methanol (20.

Examples

It is to be noted that, unless otherwise specified, various materials and reagents used in the following examples are those commonly used in the art and are commercially available in a conventional manner.

Example 1-benzyl-9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 a)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of benzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1-benzyl-9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 84-86 ℃ in 79% yield; ¹ H NMR(CDCl ₃ )δ:8.24(d,J＝10.0Hz,1H),8.06(d,J＝10.0Hz,1H),7.87(d,J＝5.0Hz,1H),7.56(d,J＝5.0Hz,1H),7.52(t,J＝5.0Hz,1H),7.34–7.28(m,5H),7.23(t,J＝7.5Hz,1H),6.69(t,J＝7.5Hz,1H),5.80(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.59,153.49,135.27,132.25,129.06,128.77,128.55,128.21,127.25,123.19,120.91,119.21,117.99,107.35,55.05.HRMS(ESI)m/z calcd for C ₁₈ H ₁₅ N ₂ [M-Br] ⁺ 259.1229,found 259.1230。

example 2- (4-methylbenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 b)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 4-methylbenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (4-methylbenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide, as a yellow solid, melting point 109-110 ℃ with a yield of 82%; ¹ H NMR(CDCl ₃ )δ:8.34(d,J＝10.0Hz,1H),8.12(d,J＝10.0Hz,1H),7.91(d,J＝5.0Hz,1H),7.63–7.58(m,2H),7.33(d,J＝10.0Hz,2H),7.28(t,J＝7.5Hz,1H),7.20(d,J＝10.0Hz,2H),6.79(t,J＝5.0Hz,1H),5.87(s,2H),2.37(s,3H)； ¹³ C NMR(CDCl ₃ )δ:153.51,138.52,132.10,132.04,130.44,129.77,128.78,128.68,128.19,127.24,123.14,120.85,119.18,117.97,107.32,54.88,21.19.HRMS(ESI)m/z calcd forC ₁₉ H ₁₇ N ₂ [M-Br] ⁺ 273.1386,found 273.1385。

example 3- (3-methylbenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 c)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 3-methylbenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (3-methylbenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 79-80 ℃ in 89% yield; ¹ H NMR(CDCl ₃ )δ:8.33(d,J＝10.0Hz,1H),8.13(d,J＝5.0Hz,1H),7.94(d,J＝5.0Hz,1H),7.64–7.59(m,2H),7.32–7.28(m,2H),7.21–7.18(m,3H),6.77(t,J＝7.5Hz,1H),5.86(s,2H),2.35(s,3H)； ¹³ C NMR(CDCl ₃ )δ:153.66,153.56,138.90,135.13,132.18,129.37,129.31,128.97,128.69,128.19,127.24,125.74,123.22,120.89,119.17,118.04,107.28,54.98,21.39.HRMS(ESI)m/z calcd forC ₁₉ H ₁₇ N ₂ [M-Br] ⁺ 273.1386,found 273.1387。

example 4- (2-methylbenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 d)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 2-methylbenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (2-methylbenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide, as a yellow solid, having a melting point of 131-133 ℃ and a yield of 71%; ¹ H NMR(CDCl ₃ )δ:8.36(d,J＝10.0Hz,1H),8.14(d,J＝5.0Hz,1H),7.93(d,J＝10.0Hz,1H),7.61(t,J＝7.5Hz,1H),7.42(d,J＝5.0Hz,1H),7.35(t,J＝7.5Hz,1H),7.31–7.29(m,2H),7.25(t,J＝7.5Hz,1H),7.16(d,J＝5.0Hz,1H),6.77(t,J＝7.5Hz,1H),5.91(s,2H),2.27(s,3H)； ¹³ C NMR(CDCl ₃ )δ:153.61,153.58,137.53,132.43,131.19,131.05,130.00,129.08,128.64,128.21,127.03,126.70,123.22,120.87,119.23,118.08,107.23,53.09,19.15.HRMS(ESI)m/z calcd forC ₁₉ H ₁₇ N ₂ [M-Br] ⁺ 273.1386,found 273.1384。

example 5- (4- (trifluoromethyl) benzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 e)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 4- (trifluoromethyl) bromobenzyl, heating and stirring at 50 ℃, after the reaction is finished, concentrating, and carrying out column chromatography to obtain a target product 1- (4- (trifluoromethyl) benzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 43-44 ℃ in 78% yield; ¹ H NMR(CDCl ₃ )δ:8.34(d,J＝10.0Hz,1H),8.08(d,J＝5.0Hz,1H),7.83(d,J＝5.0Hz,1H),7.63(d,J＝10.0Hz,1H),7.58–7.54(m,3H),7.47(d,J＝10.0Hz,2H),7.27–7.24(m,1H),6.82(t,J＝7.5Hz,1H),5.93(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.36,153.26,139.35,132.15,130.87( ¹ J _C-CF3 ＝32.5Hz),128.93,128.50,127.70,126.73,126.04( ² J _C-CF3 ＝3.8Hz),124.96(CF ₃ ,J＝270.0Hz),123.10,120.98,119.55,117.97,107.65,54.70.HRMS(ESI)m/z calcd forC ₁₉ H ₁₄ F ₃ N ₂ [M-Br] ⁺ 327.1103,found 327.1104。

example 6- (3- (trifluoromethyl) benzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 f)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 3- (trifluoromethyl) bromobenzyl, heating and stirring at 50 ℃, after the reaction is finished, concentrating, and carrying out column chromatography to obtain the target product 1- (3- (trifluoromethyl) benzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 128-129 ℃ in a yield of 70%; ¹ H NMR(CDCl ₃ )δ:8.34(d,J＝10.0Hz,1H),8.13(d,J＝5.0Hz,1H),7.89(d,J＝5.0Hz,1H),7.70(s,1H),7.63–7.58(m,4H),7.47(d,J＝7.5Hz,1H),7.31(t,J＝7.5Hz,1H),6.84(t,J＝7.5Hz,1H),5.95(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.78,153.52,136.48,131.91,131.70,131.51( ¹ J _C-CF3 ＝32.5Hz),129.67,128.76,128.45,127.79,125.45( ² J _C-CF3 ＝3.8Hz),125.03( ² J _C-CF3 ＝3.8Hz),124.90(CF ₃ ,J＝271.3Hz),123.22,120.96,119.42,118.10,107.43,54.58.HRMS(ESI)m/z calcd forC ₁₉ H ₁₄ F ₃ N ₂ [M-Br] ⁺ 327.1103,found 327.1105。

example 7- (2- (trifluoromethyl) benzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 g)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 2- (trifluoromethyl) bromobenzyl, heating and stirring at 50 ℃, after the reaction is finished, concentrating, and carrying out column chromatography to obtain a target product 1- (2- (trifluoromethyl) benzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 170-171 ℃ in 75% yield; ¹ H NMR(CDCl ₃ )δ:8.38(dd,J＝5.0Hz,2.5Hz,1H),8.11(d,J＝5.0Hz,1H),7.86(d,J＝10.0Hz,1H),7.77(dd,J＝5.0Hz,2.5Hz,1H),7.58(td,J＝7.5Hz,2.5Hz,1H),7.55(dd,J＝5.0Hz,2.5Hz,1H),7.45–7.39(m,2H),7.28(t,J＝5.0Hz,1H),7.14(d,J＝5.0Hz,1H),6.83(t,J＝7.5Hz,1H),6.15(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.69,153.34,133.77,132.77,132.27,129.77,128.97,128.60,128.55,128.47,128.35,127.62,126.33( ² J _C-CF3 ＝5.8Hz),125.36(CF ₃ ,J＝277.5Hz),120.96,119.59,118.04,107.75,51.25.HRMS(ESI)m/z calcd for C ₁₉ H ₁₄ F ₃ N ₂ [M-Br] ⁺ 327.1103,found 327.1103。

example 8- (4-Fluorobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6H)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 4-fluorobenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (4-fluorobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide, as a yellow solid, having a melting point of 87-88 ℃ and a yield of 72%; ¹ H NMR(CDCl ₃ )δ:8.26(d,J＝5.0Hz,1H),8.11(d,J＝5.0Hz,1H),7.83(d,J＝10.0Hz,1H),7.61(d,J＝5.0Hz,1H),7.52(t,J＝7.5Hz,1H),7.36(t,J＝7.5Hz,2H),7.21(t,J＝7.5Hz,1H),6.96(t,J＝7.5Hz,2H),6.75(t,J＝5.0Hz,1H),5.79(s,2H)； ¹³ C NMR(CDCl ₃ )δ:163.75( ¹ J _C-F ＝246.3Hz),152.98( ³ J _C-F ＝6.3Hz),132.29,131.15,130.49,129.02,128.33,127.20,123.00,120.94,119.42,117.78,116.05,115.88,107.77,54.52.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ FN ₂ [M-Br] ⁺ 277.1135,found 277.1136。

example 9- (3-Fluorobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 i)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 3-fluorobenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (3-fluorobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 79-80 ℃ in 77% yield; ¹ H NMR(CDCl ₃ )δ:8.35(d,J＝10.0Hz,1H),8.12(d,J＝5.0Hz,1H),7.89(d,J＝5.0Hz,1H),7.64–7.59(m,2H),7.34–7.28(m,2H),7.18(d,J＝10.0Hz,1H),7.10(d,J＝10.0Hz,1H),7.03(t,J＝10.0Hz,1H),6.82(t,J＝5.0Hz,1H),5.89(s,2H)； ¹³ C NMR(CDCl ₃ )δ:164.01( ¹ J _C-F ＝246.3Hz),153.38( ² J _C-F ＝13.8Hz),137.76( ³ J _C-F ＝7.5Hz),132.19,130.69( ³ J _C-F ＝7.5Hz),128.90,128.40,127.51,123.95( ⁴ J _C-F ＝2.5Hz),123.12,120.94,119.42,117.97,115.61,115.44,115.23,107.57,54.60.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ FN ₂ [M-Br] ⁺ 277.1135,found 277.1138。

example 10- (2-Fluorobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 j)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 2-fluorobenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (2-fluorobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 77-78 ℃ in a yield of 72%; ¹ H NMR(CDCl ₃ )δ:8.28(dd,J＝5.0Hz,2.5Hz,1H),8.06(d,J＝5.0Hz,1H),7.86(d,J＝5.0Hz,1H),7.67(d,J＝5.0Hz,1H),7.56(td,J＝7.5Hz,2.5Hz,1H),7.48(td,J＝7.5Hz,2.5Hz,1H),7.33–7.28(m,1H),7.24(t,J＝7.5Hz,1H),7.11(t,J＝7.5Hz,1H),7.07(t,J＝7.5Hz,1H),6.76(t,J＝5.0Hz,1H),5.92(s,2H)； ¹³ C NMR(CDCl ₃ )δ:161.94( ¹ J _C-F ＝246.3Hz),153.59( ² J _C-F ＝18.8Hz),132.23,131.44( ⁴ J _C-F ＝3.8Hz),130.68( ³ J _C-F ＝8.8Hz),128.76,128.27,127.43,124.82( ⁴ J _C-F ＝3.8Hz),123.19,122.44,122.32,120.89,119.26,118.01,115.75( ² J _C-F ＝21.3Hz),107.36,48.77.HRMS(ESI)m/zcalcd for C ₁₈ H ₁₄ FN ₂ [M-Br] ⁺ 277.1135,found 277.1135。

example 11- (4-chlorobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium chloride (Compound 6 k)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 4-chlorobenzyl chloride, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (4-chlorobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium chloride as a yellow solid with a melting point of 103-105 ℃ and a yield of 65%; ¹ H NMR(CDCl ₃ )δ:8.38(dd,J＝10.0Hz,2.5Hz,1H),8.13(d,J＝5.0Hz,1H),7.89(d,J＝10.0Hz,1H),7.65–7.59(m,2H),7.39–7.35(m,3H),7.31–7.28(m,2H),6.84(t,J＝7.5Hz,1H),5.90(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.69,153.51,134.60,133.89,131.87,129.85,129.27,128.70,128.39,127.67,123.17,120.92,119.35,118.04,107.36,54.44.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ ClN ₂ [M-Cl] ⁺ 293.0840,found 293.0842。

example 12- (3-chlorobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium chloride (Compound 6 l)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 3-chlorobenzyl chloride, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (3-chlorobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium chloride as a yellow solid with a melting point of 53-54 ℃ in a yield of 57%; ¹ H NMR(CDCl ₃ )δ:8.37(d,J＝5.0Hz,1H),8.13(d,J＝5.0Hz,1H),7.90(d,J＝10.0Hz,1H),7.64-7.60(m,2H),7.56(s,1H),7.50(d,J＝5.0Hz,1H),7.36(d,J＝10.0Hz,1H),7.31(d,J＝2.5Hz,1H),7.24(t,J＝7.5Hz,1H),6.84(t,J＝7.5Hz,1H),5.89(s,2H)； ¹³ C NMR(CDCl ₃ )δ:151.73,153.51,137.64,131.94,131.72,131.28,130.63,128.71,128.40,127.70,127.04,123.22,123.04,120.93,119.36,118.10,107.39,54.34.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ ClN ₂ [M-Cl] ⁺ 293.0840,found 293.0845。

example 13- (2-chlorobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium chloride (Compound 6 m)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 2-chlorobenzyl chloride, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain the target product 1- (2-chlorobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium chloride as a yellow solid with a melting point of 139-140 ℃ and a yield of 69%; ¹ H NMR(CDCl ₃ )δ:8.40(d,J＝10.0Hz,1H),8.14(d,J＝5.0Hz,1H),7.91(d,J＝10.0Hz,1H),7.68(d,J＝5.0Hz,1H),7.61(t,J＝7.5Hz,1H),7.52(d,J＝10.0Hz,1H),7.35–7.28(m,3H),7.24(t,J＝7.5Hz,1H),6.85(t,J＝7.5Hz,1H),6.08(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.65,153.57,133.92,132.85,131.99,130.63,129.99,129.90,128.76,128.33,127.57,127.54,123.22,120.88,119.32,118.10,110.30,107.31,52.40.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ ClN ₂ [M-Cl] ⁺ 293.0840,found 293.0844。

example 14- (4-bromobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 n)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 4-bromobenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (4-bromobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 176-178 ℃ in a yield of 72%; ¹ H NMR(CDCl ₃ )δ:8.33(d,J＝5.0Hz,1H),8.12(d,J＝5.0Hz,1H),7.90(d,J＝10.0Hz,1H),7.61(t,J＝7.5Hz,1H),7.57(d,J＝5.0Hz,1H),7.49(d,J＝10.0Hz,2H),7.31(d,J＝10.0Hz,1H),7.27(d,J＝5.0Hz,2H),6.79(t,J＝7.5Hz,1H),5.82(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.84,153.59,134.46,132.19,131.92,130.11,128.71,128.36,127.59,123.26,122.67,120.97,119.29,118.09,107.30,54.38.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ BrN ₂ [M-Br] ⁺ 337.0334,found 337.0332。

example 15- (3-bromobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 o)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 3-bromobenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (3-bromobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 111-112 ℃ in 82% yield; ¹ H NMR(CDCl ₃ )δ:8.35(d,J＝10.0Hz,1H),8.11(d,J＝5.0Hz,1H),7.87(d,J＝5.0Hz,1H),7.62–7.57(m,2H),7.53(s,1H),7.48(d,J＝10.0Hz,1H),7.33(d,J＝5.0Hz,1H),7.29–7.28(m,1H),7.21(t,J＝7.5Hz,1H),6.82(t,J＝7.5Hz,1H),5.87(s,2H)； ¹³ CNMR(CDCl ₃ )δ:153.73,153.52,137.64,131.94,131.72,131.28,130.63,128.71,128.40,127.70,127.04,123.22,123.04,120.93,119.36,118.10,107.39,54.34.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ BrN ₂ [M-Br] ⁺ 337.0334,found 337.0335。

example 16- (2-bromobenzyl) -9H-pyrido [2,3-b ] indole-1-ammonium bromide (Compound 6 p)

Dissolving 84mg of compound 4 in 15mL of acetonitrile, adding 1mmol of 2-bromobenzyl bromide, heating and stirring at 50 ℃, after the reaction is finished, concentrating and carrying out column chromatography to obtain a target product 1- (2-bromobenzyl) -9H-pyrido [2,3-b ]]Indole-1-ammonium bromide as a yellow solid with a melting point of 137-138 ℃ and a yield of 85%; ¹ H NMR(CDCl ₃ )δ:8.34(d,J＝5.0Hz,1H),8.11(d,J＝5.0Hz,1H),7.87(d,J＝5.0Hz,1H),7.66(d,J＝5.0Hz,1H),7.60–7.57(m,2H),7.29–7.27(m,1H),7.24–7.19(m,2H),7.17–7.15(m,1H),6.79(t,J＝7.5Hz,1H),6.00(s,2H)； ¹³ C NMR(CDCl ₃ )δ:153.78,153.64,134.52,133.21,131.98,130.43,130.17,128.81,128.31,128.19,127.49,123.98,123.29,120.93,119.29,118.13,107.29,54.73.HRMS(ESI)m/z calcd for C ₁₈ H ₁₄ BrN ₂ [M-Br] ⁺ 337.0334,found 337.0333。

example 17 evaluation of cholinesterase inhibitory Activity

The synthesized compounds 6a-6p were tested for cholinesterase inhibitory activity in vitro using the Ellman method, with the clinical drug galantamine as a control. The test method is as follows: taking 132 mu L of PBS buffer solution (pH 8.0), sequentially adding 2.5 mu L of cholinesterase solution (AChE or BuChE), 5 mu L of 15mM DTNB solution and 5 mu L of compound solution into a 96-well plate, slightly shaking and uniformly mixing, placing into a 37 ℃ constant temperature incubator, preheating for 2 minutes, then adding 5 mu L of iodothiobutyrylcholine or iodothioacetylcholine, preserving the temperature in the 37 ℃ constant temperature incubator for 20 minutes, and immediately adding 0.4% Sodium Dodecyl Sulfate (SDS) solution to stop the reaction. The experiment is divided into: control group (DMSO); sample set (compounds); sample blank (PBS instead of iodothioacetyl choline). For compounds with an inhibition rate higher than 50% at a concentration of 10. Mu.M, the half-inhibitory concentration value (IC) was further determined ₅₀ ) Compounds with an inhibition of less than 50% at a concentration of 10. Mu.M are considered to have an IC ₅₀ Value of>10 μ M. The test results are shown in tables 1 and 2.

TABLE 1. Alpha-carbolines on AChE ^a And BChE ^b Inhibition rate of ^c (10μM,％)

Compound numbering	AChE	BChE
			6a	49.88±0.12	81.38±0.71
6b	75.43±0.05	92.89±0.57
			6c	74.34±0.87	93.70±0.43
6d	49.81±0.07	43.05±0.33
			6e	54.60±0.53	96.83±0.41
6f	78.52±0.58	91.81±0.69
			6g	19.22±0.22	25.74±0.97
6h	63.11±0.99	85.39±0.31
			6i	30.98±0.22	98.05±0.41
6j	28.13±0.80	71.83±0.64
			6k	74.62±0.89	96.32±0.50
6l	64.24±0.87	89.27±0.41
			6m	18.52±0.36	29.67±1.47
6n	12.27±0.86	53.17±0.83
			6o	70.76±0.55	95.70±1.56
6p	37.54±0.49	84.89±1.61
			Galanthamine	92.60±0.13	38.63±0.69

Note: ache (e.c. 3.1.1.7) (BR, 200 u/mg) was from fly heads.

BuChE (E.C.3.1.1.8) (BR, 20 u/mg) was from horse serum.

c. All values are expressed as mean ± SD from at least three independent experiments.

TABLE 2 inhibitory Activity of alpha-carbolines on AChE and BChE (IC) ₅₀ ,μM)

/>

The alpha-carboline quaternary ammonium salt compounds have double cholinesterase inhibition activity, wherein 8 compounds have IC (integrated Circuit) on two cholinesterase ₅₀ The values are all less than 10 mu M, and the IC of 13 compounds for butyrylcholinesterase ₅₀ Values below 10. Mu.M, especially compound 6i, achieved 0.77. Mu.M inhibitory activity on BuChE. In general, the obtained compound has better activity on butyrylcholinesterase, which can excellently compensate the defect that most of currently marketed cholinergic drugs are selective AChE inhibitors.

Example 18 evaluation of anti-neuritic Activity

Mouse microglia (BV-2) is used as a nerve cell model, lipopolysaccharide (LPS) is used as endotoxin to induce cells to generate inflammatory reaction, excessive NO is secreted, and a nitric oxide kit is used in an experiment to detect the release amount of NO in a culture solution so as to determine the anti-neuritis activity of the compound. Cells were plated at 2X 10 ⁵ one/mL of the cells were seeded in 96-well plates (100. Mu.L/well) at 37 ℃ in 5% CO ₂ The culture was carried out in a constant temperature incubator for 24 hours. The experiment is divided into: control (DMSO), LPS treated (DMSO + 1. Mu.g/mL LPS), positive control (1. Mu.g/mL LPS + 10. Mu.M quercetin) and compound treated (1. Mu.g/mL LPS + 10. Mu.M compound) groups, after treatment and incubation for 24 hours, 50. Mu.L of supernatant was removed in a new 96-well plate, then 50. Mu.L each of Griess reagents I and II was added in sequence, and after 5 minutes of mixing on a shaker, absorbance (OD value) at 540nm was scanned on a microplate reader. The test results are shown in table 3.

TABLE 3 anti-neuritic Activity of alpha-carbolines

/>

The evaluation result of the anti-neuritis activity shows that all the alpha-carboline quaternary ammonium salt compounds related by the invention have the anti-neuritis activity, wherein the anti-neuritis activity of 15 compounds under the concentration of 10 mu M is stronger than that of positive control quercetin (the inhibition rate is 56.63 percent), and the optimal inhibition rate reaches 84.21 percent.

In conclusion, the compounds 6a-6p provided by the invention have better inhibitory activity on two cholinesterases (AchE and BuChE) and stronger activity on BuChE, wherein the IC of the optimal compound 6i ₅₀ The value reaches 0.77 mu M, which is far stronger than that of a positive drug galanthamine (13.7 mu M), all compounds show better anti-neuritis activity, the anti-neuritis effect of the compound 6b-6p is stronger than that of a positive control quercetin, and a new candidate drug lead for selectively inhibiting cholinesterase and resisting Alzheimer disease can be provided for clinic. Based on the current pathological mechanism hypothesis of resisting Alzheimer disease, namely the cholinergic hypothesis and the neuritis hypothesis, the compound disclosed by the invention can be developed into a medicine for preventing and/or treating related diseases such as neurodegenerative diseases (such as Alzheimer disease) and neuroinflammatory diseases, especially the potential application of the medicine for preventing and/or treating related neurological diseases such as Alzheimer disease, and can be used as an effective component for preparing the medicine for treating Alzheimer disease.

Finally, the above embodiments are only used to illustrate the technical solutions of the present invention, and do not limit the content of the present invention. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims (10)

1. An alpha-carboline compound, which is characterized in that the structure of the compound is shown as the general formula (I):

wherein R is ₁ Selected from hydrogen atoms, alkyl radicalsHaloalkyl and halogen, said R ₁ Is any of 2',3',4',5' and 6 ';

is halogen.

2. The α -carboline compound according to claim 1, wherein the alkyl group is C _1-6 Alkyl, said haloalkyl being fluoro C _1-6 Alkyl, chloro C _1-6 Alkyl, bromo C _1-6 An alkyl group.

3. The α -carboline compound according to claim 1, wherein the α -carboline compound is selected from the group consisting of

Selected from the group consisting of fluorine atoms, chlorine atoms and bromine atoms.

4. The α -carboline compound according to claim 3, wherein said α -carboline compound is selected from the group consisting of

Is a chlorine atom or a bromine atom.

5. The α -carboline-based compound according to claim 1, wherein said α -carboline-based compound is selected from the group consisting of

When it is a bromine atom, said R ₁ Selected from the group consisting of a hydrogen atom, a methyl group, a trifluoromethyl group, a fluorine atom and a bromine atom.

6. The α -carboline-based compound according to claim 1, wherein said α -carboline-based compound is selected from the group consisting of

When it is a chlorine atom, said R ₁ Is a chlorine atom.

7. The α -carboline-based compound of claim 1, wherein the compound is selected from the group consisting of:

/>

/>

8. a pharmaceutical composition comprising a therapeutically effective amount of an α -carboline compound according to any one of claims 1 to 7 and optionally a pharmaceutically acceptable excipient or a pharmaceutically acceptable carrier.

9. Use of an alpha-carboline compound according to any one of claims 1 to 7 in the preparation of a cholinesterase inhibitor.

10. Use of the α -carboline compound according to any one of claims 1 to 7 for the preparation of a medicament for the prevention and/or treatment of alzheimer's disease.