CN110872263A - A compound and preparation method and application - Google Patents

Abstract

其中，R¹选自F、Cl、Br、C₁～C₅的烷基、具有式(1)所示结构式的基团中的任意一种；n＝0、1、2、3、4或5；R²选自具有式(1)所示结构式的基团、具有式(2)所示结构式的基团、具有式(3)所示结构式的基团中的任意一种。所述化合物制备方法简单，可作为神经氨酸酶抑制剂，具有良好的抗病毒活性。The application discloses a compound whose structural formula is shown in the following formula:

Wherein, R ¹ is selected from any one of F, Cl, Br, C ₁ -C ₅ alkyl groups, and groups having the structural formula shown in formula (1); n=0, 1, 2, 3, 4 or 5; R ² is selected from any one of the group having the structural formula represented by the formula (1), the group having the structural formula represented by the formula (2), and the group having the structural formula represented by the formula (3). The compound has a simple preparation method, can be used as a neuraminidase inhibitor, and has good antiviral activity.

Description

A compound and preparation method and application

technical field

The present application relates to a compound, preparation method and application, and belongs to the field of chemistry.

Background technique

Influenza virus has become one of the most serious diseases threatening human life and health, causing hundreds of thousands of deaths every year and causing huge losses to social property every year. At present, although many drugs have been marketed, the development of new high-efficiency and low-toxicity anti-influenza virus drugs has become a top priority because influenza viruses are prone to produce drug-resistant strains.

Neuraminidase has attracted widespread attention in medicine as one of the targets for the treatment of influenza virus. Neuraminidase is closely related to virus replication, and inhibition of neuraminidase can inhibit influenza virus replication to a certain extent. Therefore, it is very important to design and synthesize new neuraminidase inhibitors for the prevention and treatment of influenza virus.

SUMMARY OF THE INVENTION

According to one aspect of the present application, there is provided a compound useful as a neuraminidase inhibitor.

The compound is characterized in that its structural formula is shown in formula I:

Wherein, R ¹ is selected from any one of F, Cl, Br, C ₁ -C ₅ alkyl groups, and groups having the structural formula shown in formula (1); n=0, 1, 2, 3, 4 or 5;

R ² is selected from any one of the group having the structural formula represented by the formula (1), the group having the structural formula represented by the formula (2), and the group having the structural formula represented by the formula (3);

*-OM ¹¹ formula (1)

Wherein, M ¹¹ is selected from H or C ₁ -C ₅ alkyl;

wherein, M ²¹ , M ²² , M ²³ , M ²⁴ , M ²⁵ , M ²⁶ , M ²⁷ , and M ²⁸ are independently selected from H or C ₁ -C ₅ alkyl groups;

Wherein, M ³¹ is selected from any one of H, F, Cl, Br, an alkyl group of C ₁ -C ₅ , and a group having the structural formula shown in formula (1); M ³² , M ³³ , and M ³⁴ are independently is selected from H or C ₁ -C ₅ alkyl.

Optionally, wherein, R ¹ is selected from any one of F, Cl, Br, methyl, ethyl, and groups having the structural formula shown in formula (1); n=0, 1, 2, 3, 4 or 5.

Optionally, n=0 in formula I.

Optionally, R ¹ in formula I is selected from one of F, Cl, Br, methyl, ethyl, methoxy and ethoxy; n=1 or 2.

Optionally, R ¹ in formula I is selected from at least one of 4-F, 4-Cl, 4-Br, 4-CH ₃ , 4-OCH ₃ , 3-F, 2-F, 3,4-2F kind.

Optionally, M ¹¹ in formula (1) is selected from C ₁ -C ₄ alkyl groups.

Optionally, M ¹¹ in formula (1) is selected from methyl or ethyl.

Optionally, in formula (2), M ²¹ , M ²² , M ²³ , M ²⁴ , M ²⁵ , M ²⁶ , M ²⁷ , and M ²⁸ are all hydrogen.

Optionally, M ²¹ , M ²² , M ²³ , M ²⁴ , M ²⁵ , M ²⁶ , M ²⁷ , and M ²⁸ in formula (2) are independently selected from C ₁ -C ₄ alkyl groups.

Optionally, M ²¹ , M ²² , M ²³ , M ²⁴ , M ²⁵ , M ²⁶ , M ²⁷ , and M ²⁸ in formula (2) are independently selected from hydrogen, methyl or ethyl.

Optionally, M ³¹ in formula (3) is selected from any one of H, F, Cl, Br, C ₁ -C ₄ alkyl groups, and groups having the structural formula shown in formula (1).

Optionally, M ³¹ in formula (3) is selected from any one of H, F, Cl, Br, methyl, ethyl, and groups having the structural formula shown in formula (1).

Optionally, M ³¹ in formula (3) is selected from any one of H, F, Cl, Br, methyl, ethyl, methoxy and ethoxy.

Optionally, M ³² , M ³³ , and M ³⁴ in formula (3) are independently selected from H, methyl or ethyl.

Optionally, R ¹ is selected from at least one of F, Cl, Br, *-CH ₃ , and *-OCH ₃ .

Optionally, R ¹ is selected from one of F, Cl, Br, *-CH ₃ , and *-OCH ₃ , and n=2.

Optionally, R ¹ is selected from one of F, Cl, Br, *-CH ₃ , and *-OCH ₃ , and n=1.

或具有式(3)所示结构式的基团中的任意一种；其中，式(3)中M³²、M³³、M³⁴均为H，M³¹选自H、F、Cl、Br、甲氧基、甲基中的任意一种。Optionally, in formula I R ² is selected from *-OCH ₃ ,

Or any one of the groups with the structural formula shown in formula (3); wherein, in formula (3), M ³² , M ³³ , M ³⁴ are all H, and M ³¹ is selected from H, F, Cl, Br, methyl Either an oxy group or a methyl group.

Optionally, R ² in formula I is *-OCH ₃ .

As one of the specific embodiments, the structural formula of the compound is shown in formula I-5:

Optionally, R ¹ is selected from 4-F, 4-Cl, 4-Br, 4-CH ₃ , 4-OCH ₃ , 3-F, 2-F or 3,4-2F, and n=1 or n =0.

Optionally, its structural formula is shown in formula I-1:

Optionally, the R ¹ is selected from at least one of F, Cl, *-CH ₃ , and *-OCH ₃ , and n=1; or n=0.

Optionally, the R ¹ is selected from 4-F, 4-Cl, 4-OCH ₃ , 4-CH ₃ or 3-F.

Optionally, its structural formula is shown in formula I-2:

Optionally, its structural formula is shown in formula I-3:

Optionally, the M ³¹ is selected from H, 4-F, 4-Cl, 4-Br, 4-OCH ₃ , 4-CH ₃ , 3-F or 2-F.

Optionally, its structural formula is shown in formula I-4:

Optionally, R ¹ in formula I-4 is selected from at least one of Cl and *-OCH ₃ .

Optionally, R ¹ in formula I-4 is selected from 4-Cl or 4-OCH ₃ .

Another aspect of the present application provides a method for preparing the compound described in any of the above, characterized in that it includes:

(1) the mixture I containing substituted phenylacetic acid and ethyl haloacetate is esterified in the presence of a catalyst to obtain an intermediate I, and the structural formula of the intermediate I is shown in formula II-1:

(II) will contain the raw material I of intermediate I, through Dieckmann reaction, obtain intermediate II, the structural formula of described intermediate II is as shown in formula II-2:

Optionally, in the mixture I described in step (1), also include solvent I and acid binding agent;

The molar ratio of the substituted phenylacetic acid, the halogenated ethyl acetate and the acid binding agent is 1-2:1-2:1-2;

The conditions of the esterification reaction are: reflux reaction at 60-80°C.

Optionally, the solvent I includes at least one of tetrahydrofuran, dichloromethane, DMF, ethyl acetate, acetone, methanol, and ethanol;

The acid binding agent includes at least one of triethylamine, pyridine, anhydrous potassium carbonate, sodium acetate, and anhydrous sodium carbonate;

The mol ratio of described substituted phenylacetic acid, haloethyl acetate and acid binding agent is 1:1.2:1.2;

The conditions of the esterification reaction are: heating and refluxing at 75°C under stirring conditions.

As one of the specific embodiments, the synthetic route of intermediate I is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

a: (Et) _3N , THF, 75°C, 98%.

As one of the specific embodiments, the synthetic route of intermediate I is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

a: (Et) _3N , THF, 75°C, 98%.

As one of the specific embodiments, the synthetic route of intermediate I is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

a: (Et) _3N , THF, 75°C, 98%.

Optionally, the synthetic method of the intermediate I comprises: heating the mixture containing substituted phenylacetic acid, ethyl haloacetate, solvent I and acid binding agent under stirring conditions; TCL monitors the degree of reaction; the reaction finishes After cooling, the triethylamine salt was removed, extracted, washed, dried, and suction filtered to obtain the target product.

As a kind of specific embodiment, take commercially available substituted phenylacetic acid and ethyl chloroacetate as raw materials, tetrahydrofuran as solvent, triethylamine as acid binding agent, charging ratio n (substituted phenylacetic acid): n (ethyl chloroacetate) ): n (triethylamine) = 1:1.2:1.2 under stirring at 75°C under reflux. TLC monitoring showed that the reaction was a single-point quantitative reaction, and the reaction was complete in about 6 hours. After the reaction was completed, it was cooled to room temperature, and the triethylamine salt generated in the reaction was removed by suction filtration. It was concentrated under reduced pressure, extracted with ethyl acetate, washed with saturated brine three times, and dried over anhydrous sodium sulfate overnight. Suction filtration, concentrated under reduced pressure to obtain a dark red liquid, which is directly used in the next reaction without purification.

Optionally, the raw material I in step (II) also includes solvent II and base I;

The molar ratio of the intermediate I to the base I is 1:1.5-3;

The conditions of the Dieckmann reaction are: stirring in an ice bath for 20-50 min, and then continuing the reaction at room temperature.

Optionally, the solvent II includes at least one of DMF, THF, t-BuOH, methanol, acetone, CH ₂ Cl ₂ , DMSO, and EtOAc;

The base I includes at least one of potassium tert-butoxide, anhydrous K ₂ CO ₃ , anhydrous Na ₂ CO ₃ , CH ₃ ONa, C ₂ H ₅ ONa, NaOH, NaHCO ₃ , and NaH;

The mol ratio of the intermediate I to the base I is 1:2;

The conditions of the Dieckmann reaction are: stirring in an ice bath for 30 min, and then continuing the reaction at room temperature for 4-6 hours.

Optionally, intermediate I has an active methylene structure and is synthesized by Dieckmann reaction.

As one of the specific embodiments, the synthetic route of intermediate II is as follows:

其中，反应条件和产率为：

Wherein, the reaction conditions and yields are:

b: t-BuOK, DMF, 0°C to room temperature, 80 to 90%.

As one of the specific embodiments, the synthetic route of intermediate II is as follows:

其中，反应条件和产率为：

Wherein, the reaction conditions and yields are:

b: t-BuOK, DMF, 0°C to room temperature, 80 to 90%.

As one of the specific embodiments, the synthetic route of intermediate II is as follows:

其中，反应条件和产率为：

Wherein, the reaction conditions and yields are:

b: t-BuOK, DMF, 0°C to room temperature, 80 to 90%.

Optionally, the preparation method of the intermediate II comprises: adding the base I to the mixture containing the intermediate I and the base I under ice-bath conditions, stirring, and then reacting at room temperature, and after the completion of the reaction is detected by thin layer chromatography , stop the reaction.

will contain a mixture of intermediate I, base I and solvent II

As one of the specific embodiments, the synthesis method of the intermediate II includes: using DMF (or t-BuOH, THF) as a solvent, the feeding ratio n (intermediate I): n (potassium tert-butoxide)=1 : 2, under ice bath condition, add potassium tert-butoxide in the reaction system in 6 times within half an hour. Under ice bath conditions, after stirring and reacting for 30 min, the system was allowed to continue to react at room temperature for 4-6 hours. This reaction is a single-point quantitative reaction, and the reaction is stopped after the completion of the reaction detected by thin layer chromatography.

Optionally, in the post-treatment, 1 times the amount of water is firstly added to the reaction system to dilute the reaction system. Add 5% dilute hydrochloric acid dropwise to the system under ice bath stirring to adjust the pH to about 2 to 3. During the pH adjustment process, solids will continue to separate out. After the pH adjustment is completed, add a large amount of water to the system until there is no solid. Precipitate. Place in the refrigerator to cool for about 2 hours, filter with suction, and recrystallize from dichloromethane to obtain intermediate 3. However, this post-treatment method is not suitable for the substrates used, and some products do not precipitate solids during pH adjustment. If no solid was formed, it was extracted with saturated NaCl, dried over anhydrous Na ₂ SO ₄ overnight, and purified by column chromatography.

Optionally, the preparation method of the compound also includes:

(III-1) The mixture II containing intermediate II and dimethyl sulfate is subjected to methylation reaction to obtain intermediate III-1, and the structural formula of the intermediate III-1 is shown in formula II-3-1:

(IV-1) The mixture III containing intermediate III-1, sodium methoxide and paraformaldehyde is reacted to obtain the compound shown in formula I; wherein, in formula I, R ² is *-OCH ₃ . That is, the compound represented by formula I-5.

Optionally, it is characterized in that the mixture II in step (III-1) also includes solvent III and base II;

The molar ratio of the intermediate II, the base II and the dimethyl sulfate is 1:1-2:1-2;

The conditions of the methylation reaction are: reaction at room temperature under dark conditions.

Optionally, the solvent III includes at least one of acetone, methanol, CH ₂ Cl ₂ , THF, DMF, and EtOAc;

The base II includes at least one of anhydrous K ₂ CO ₃ , anhydrous Na ₂ CO ₃ , CH ₃ ONa, NaOH, NaHCO ₃ , and NaH;

The molar ratio of the intermediate II, base II and dimethyl sulfate is 1:1.2:1.2;

The conditions of the methylation reaction are: reaction at room temperature for 8 to 10 hours under a dark condition.

As a specific embodiment, the synthetic route of intermediate III-1 is as follows:

其中，反应条件和产率为：

Wherein, the reaction conditions and yields are:

c1: Me ₂ SO ₄ , K ₂ CO ₃ , acetone, 70-80%.

As a specific embodiment, the synthetic route of intermediate III-1 is as follows:

其中，反应条件和产率为：

Wherein, the reaction conditions and yields are:

c1: Me ₂ SO ₄ , K ₂ CO ₃ , acetone, 70-80%.

As a specific embodiment, the synthetic route of intermediate III-1 is as follows:

其中，反应条件和产率为：

Wherein, the reaction conditions and yields are:

c1: Me ₂ SO ₄ , K ₂ CO ₃ , acetone, 70-80%.

Optionally, the preparation method of the intermediate III-1 includes: under a dark condition, dropping dimethyl sulfate into a mixed solution containing intermediate II, base II and solvent III, and reacting at room temperature; Chromatographic detection of the reaction was complete. The product obtained after the reaction is concentrated, extracted, washed, dried, suction filtered, rotary evaporated, and recrystallized to obtain intermediate III-1.

As a specific embodiment, the preparation method of the intermediate III-1 includes: using acetone as a solvent, and anhydrous K ₂ CO ₃ as a base, because dimethyl sulfate is easily decomposed when exposed to light, this reaction needs to be protected from light. Under the conditions, the acetone solution of dimethyl sulfate was slowly added dropwise with a constant pressure dropping funnel, and the feeding ratio n (intermediate II): n (anhydrous K ₂ CO ₃ ): n (dimethyl sulfate)=1:1.2: 1.2. The reaction was performed in the dark at room temperature for about 9 h. After the completion of the reaction was detected by thin layer chromatography, the acetone was removed by concentration under reduced pressure, extracted with ethyl acetate, washed with saturated NaCl, and dried over anhydrous Na ₂ SO ₄ overnight. The solid was obtained by suction filtration and rotary evaporation, and ethyl acetate:petroleum ether=1:1 was recrystallized to obtain the intermediate compound III-1.

Optionally, solvent IV is also included in mixture III described in step (IV-1);

The molar ratio of the intermediate III-1, sodium methoxide and paraformaldehyde is 1:0.1-1:0.1-0.5;

The reaction conditions are: reflux reaction at 60-100°C.

Optionally, the reaction conditions are 60-80°C.

Optionally, the solvent IV includes at least one of methanol, acetone, CH ₂ Cl ₂ , THF, DMF, and EtOAc;

The conditions of the reaction are as follows: the molar ratio of intermediate III-1, sodium methoxide and paraformaldehyde is 1:0.6:0.3, reflux stirring at 75°C, adding paraformaldehyde and sodium methoxide at intervals, and reacting for 70 to 75 hours .

Optionally, during the reaction: 0.3 moles of paraformaldehyde and sodium methoxide are added every 8 hours, and the reaction is performed for 72 hours.

Optionally, the synthetic route of described step (IV-1) is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

d: (CH ₂ O)n, CH ₃ ONa, 75°C, 45-50%.

Optionally, the synthetic route of described step (IV-1) is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

d: (CH ₂ O)n, CH ₃ ONa, 75°C, 45-50%.

Optionally, the synthetic route of described step (IV-1) is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

d: (CH ₂ O)n, CH ₃ ONa, 75°C, 45-50%.

Optionally, the step (IV-1) comprises: stirring and refluxing the mixture containing solvent IV, sodium methoxide, and intermediate III-1, and adding paraformaldehyde and sodium methoxide at intervals; after TLC monitors the complete disappearance of the reactants, Methanol was removed, extracted, washed, dried, suction filtered, concentrated and purified to obtain the target product.

As a specific embodiment, the step (IV-1) includes: using methanol as a solvent, sodium methoxide as an alkali, and feeding ratio n (intermediate III-1): n (sodium methoxide): n (paraformaldehyde )=1:0.6:0.3, stirring at 75°C under reflux. 0.3N paraformaldehyde and sodium methoxide were added every 8h, and the reaction was carried out for about 48h. After monitoring the complete disappearance of the reactant by TLC, the mixture was concentrated under reduced pressure to remove methanol, extracted with ethyl acetate, washed with saturated brine, and dried over anhydrous sodium sulfate overnight. Suction filtration, concentration, and column chromatography to obtain the target compound.

Optionally, the γ-position of the butenolide in the intermediate III-1 can attack the carbonyl cation in the paraformaldehyde, and a condensation reaction occurs to synthesize the target compound.

As one of the specific embodiments, the synthetic route of the compound shown in formula I-5 is as follows:

其中，各步骤反应及产率为：a：(Et)₃N，THF，75℃，98％；b：t-BuOK，DMF，0～室温，80～90％；c1：Me₂SO₄，K₂CO₃，丙酮，70～80％；d：(CH₂O)n，CH₃ONa，75℃，45～50％。

The reaction and yield of each step are: a: (Et) ₃ N, THF, 75°C, 98%; b: t-BuOK, DMF, 0-room temperature, 80-90%; c1: Me ₂ SO ₄ , K ₂ CO ₃ , acetone, 70-80%; d: (CH ₂ O)n, CH ₃ ONa, 75°C, 45-50%.

Optionally, in the synthetic route of the compound represented by the above formula I-5, R ¹ is replaced by H.

Optionally, the preparation method of the compound also includes:

(III-2) The raw material II containing the intermediate II is subjected to a chloronucleophilic reaction to obtain the intermediate III-2; the structural formula of the intermediate III-2 is shown in the formula II-3-2:

(IV-2) The mixture IV containing intermediate III-2 and morpholine is subjected to nucleophilic substitution under basic conditions to obtain intermediate IV-1; the structural formula of the intermediate IV-1 is as formula II-4- 1 shows:

(V-2) The mixture V containing the intermediate IV-1, sodium methoxide and paraformaldehyde is reacted to obtain the compound represented by the formula I-1.

Optionally, the raw material II in step (III-2) also includes: solvent V and nucleophile I;

The molar ratio of the intermediate III-2 to the nucleophile I is 1:1-4;

The conditions for the chloronucleophilic reaction are: stirring in an ice bath for 20-50 min, and then reacting at room temperature.

Optionally, the solvent V is selected from DMF with a volume ratio of 1:1 and at least one of CH ₂ Cl ₂ , methanol, acetone, THF, DMF, and EtOAc;

The nucleophile I is selected from at least one of oxalyl chloride, POCl ₃ and thionyl chloride;

The mol ratio of the intermediate III-2 to the nucleophile I is 1:2;

The conditions for the chloronucleophilic reaction are: stirring in an ice bath for 30 min, and then reacting at room temperature for 6 hours.

Optionally, the chlorination nucleophilic reaction can be obtained by other means, such as: under the condition of POCl ₃ , use a mixed solvent of NaOH and H ₂ O as the reaction solvent for chlorination, Me ₃ SiCl as the chlorination reagent, DMSO As a catalyst, POCl ₃ is used as a chlorination reagent in the reaction, POCl ₃ is also used as a reaction solvent in the reaction, and diisopropylamine is used as a base to generate acid in the neutralization reaction.

Alternatively, the synthetic route of the intermediate III-2 is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

c2: oxalyl chloride, DMF: _CH2Cl2 (1: ₁ by volume), 95%.

Alternatively, the synthetic route of the intermediate III-2 is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

c2: oxalyl chloride, DMF: _CH2Cl2 (1: ₁ by volume), 95%.

Optionally, the preparation method of the intermediate III-2 comprises: adding the nucleophile I to the mixture containing the intermediate II and the solvent V under ice bath conditions, stirring, then reacting at room temperature, and detecting by TLC The reaction was completed, extracted, washed, dried, suction filtered and purified to obtain intermediate III-2.

As a specific embodiment, with DMF/CH ₂ Cl ₂ (1:1) as a solvent, oxalyl chloride is slowly added dropwise under ice bath conditions, and the feeding ratio is n (intermediate II): n (oxalyl chloride)=1: 2. After stirring in an ice bath for about half an hour, the system was brought to room temperature to continue the reaction for about 6 hours. After the completion of the reaction was detected by TLC, the pH of the system was adjusted to neutral with saturated NaHCO ₃ , and then extracted three times with CH ₂ Cl ₂ . The organic phases were combined, washed with 15 ml of saturated brine, dried over anhydrous sodium sulfate overnight, filtered with suction, and subjected to column chromatography. The pure intermediate compound III-2 was obtained.

Optionally, solvent VI and base III are also included in mixture IV described in step (IV-2);

The molar ratio of the intermediate III-2, base III and morpholine is 1:1-4:1-4;

The reaction time of the nucleophilic substitution is 3 to 6 hours.

Optionally, the solvent VI includes at least one of THF, methanol, acetone, CH ₂ Cl ₂ , DMF, and EtOAc;

The base III includes: at least one of anhydrous K ₂ CO ₃ , anhydrous Na ₂ CO ₃ , CH ₃ ONa, NaOH, NaHCO ₃ , and NaH;

The molar ratio of the intermediate III-2, base III and morpholine is 1:2:2;

The reaction time of the nucleophilic substitution is 4h.

Alternatively, the synthetic route of the intermediate IV-1 is as follows:

其中，反应条件：

Among them, the reaction conditions:

d1: morpholine, K ₂ CO ₃ , THF.

Alternatively, the synthetic route of the intermediate IV-1 is as follows:

Among them, the reaction conditions:

d1: morpholine, K ₂ CO ₃ , THF.

Optionally, the preparation method of the intermediate IV-1 includes: adding the base III to the solution containing the intermediate III-2 and the solvent VI, then adding morpholine dropwise, stirring, and reacting; TLC spotting detects that the reaction is complete After that, suction filtration/concentration, extraction, washing, drying, and purification are performed.

As a specific embodiment, the preparation method of the intermediate IV-1 includes: THF is used as a solvent, anhydrous K ₂ CO ₃ is used as a base, and the intermediate compound III-2 is added to 2 ml of THF solution to be completely dissolved, Then add anhydrous K ₂ CO ₃ to the system, and slowly add morpholine dropwise under stirring conditions. The feeding ratio is n (intermediate III-2): n (anhydrous K ₂ CO ₃ ): (morpholine) = 1:2 :2. During the dropwise addition, the system gradually turned yellow, and a yellow solid was continuously precipitated during the stirring process, and the reaction was carried out for about 4 hours. After TLC spot plate detection reaction is complete, the intermediate compound 8 is obtained by suction filtration, if no solid can be precipitated, concentrated, extracted with ethyl acetate, washed with saturated brine, dried over anhydrous sodium sulfate, and purified by column chromatography.

Optionally, solvent VII is also included in mixture V described in step (V-2);

The molar ratio of the intermediate IV-1, sodium methoxide and paraformaldehyde is 1:0.1-1:0.1-0.5;

The reaction conditions are: reflux reaction at 60-100°C.

Optionally, the solvent VII includes at least one of methanol, THF, acetone, CH ₂ Cl ₂ , DMF, and EtOAc;

The conditions of the reaction are as follows: the molar ratio of intermediate IV-1, sodium methoxide and paraformaldehyde is 1:0.6:0.3, reflux stirring at 75°C, adding paraformaldehyde and sodium methoxide at intervals, and reacting for 70 to 75 hours .

Optionally, during the reaction: 0.3 moles of paraformaldehyde and sodium methoxide are added every 8 hours, and the reaction is performed for 72 hours.

Optionally, the synthetic route of described step (V-2) is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

e1: (CH ₂ O)n, CH ₃ ONa, 75°C, 30-40%.

Optionally, the synthetic route of described step (V-2) is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

e1: (CH ₂ O)n, CH ₃ ONa, 75°C, 30-40%.

Optionally, the preparation method of step (V-2) comprises: stirring and refluxing the mixture containing solvent VII, sodium methoxide and intermediate IV-1, adding paraformaldehyde and sodium methoxide at intervals; , remove methanol, extract, wash, dry, suction filter, concentrate and purify to obtain the target product.

As a specific embodiment, step (V-2) specifically includes: using methanol as solvent, sodium methoxide as alkali, feeding ratio n (intermediate IV-1): n (sodium methoxide): n (paraformaldehyde) =1:0.6:0.3, reflux stirring at 75°C. 0.3N paraformaldehyde and sodium methoxide were added every 8h, and the reaction was carried out for about 72h. After the thin layer monitoring was completed, the methanol was concentrated under reduced pressure to remove methanol, extracted with ethyl acetate (3×15ml), washed with saturated brine, and washed with anhydrous sodium sulfate. Dry overnight. Suction filtration, concentration, and column chromatography to obtain the target compound.

As a specific embodiment, the synthetic route of the compound shown in formula I-1 is as follows:

其中，反应条件和产率为：

Wherein, the reaction conditions and yields are:

a: (Et) _3N , THF, 75℃, 98%; b: t-BuOK, DMF, 0℃～room temperature, 80～90%; c2: oxalyl chloride, DMF: _{CH2Cl2 (} volume ratio 1: 1), 95%; d1: morpholine, K ₂ CO ₃ , THF; e1: (CH ₂ O)n, CH ₃ ONa, 75°C, 30-40%.

Optionally, in the synthetic route of the compound represented by the above formula I-1, R ¹ is replaced by H.

Optionally, the preparation method of the compound also includes:

(III-2) The raw material II containing the intermediate II is subjected to a chloronucleophilic reaction to obtain the intermediate III-2; the structural formula of the intermediate III-2 is shown in the formula II-3-2:

(IV-3) The mixture VI containing intermediate III-2 and benzylamine or substituted benzylamine is subjected to nucleophilic substitution under basic conditions to obtain intermediate IV-2; the structural formula of the intermediate IV-2 is as follows II-4-2 shows:

(V-3) The mixture VII containing the intermediate IV-2, sodium methoxide and paraformaldehyde is reacted to obtain the compound represented by the formula I-2.

Optionally, solvent VIII and base IV are also included in mixture VI described in step (IV-3);

The molar ratio of intermediate III-2, base IV, benzylamine or substituted benzylamine is 1:1-4:1-4;

The reaction time of the nucleophilic substitution is 3 to 6 hours.

Optionally, the solvent VIII includes at least one of THF, methanol, acetone, CH ₂ Cl ₂ , DMF, and EtOAc;

The base IV comprises: at least one of anhydrous K ₂ CO ₃ , anhydrous Na ₂ CO ₃ , CH ₃ ONa, NaOH, NaHCO ₃ , NaH,

The molar ratio of described intermediate III-2, base IV, benzylamine or substituted benzylamine is 1:2:2;

The reaction time of the nucleophilic substitution is 4h.

Alternatively, the synthetic route of the intermediate IV-2 is as follows:

Among them, the reaction conditions:

d3: benzylamine or substituted benzylamine (eg 4-methylbenzylamine or benzylamine), K ₂ CO ₃ , THF.

Optionally, the preparation method of the intermediate IV-2 comprises: adding benzylamine or substituted benzylamine dropwise to the mixture containing intermediate III-2, solvent VIII and base IV, stirring the reaction at room temperature, and detecting that the reaction is complete by TLC Then, suction filtration, washing, and it is obtained.

As a specific embodiment, the preparation method of the intermediate IV-2 includes: adding THF to the intermediate III-2 container, adding anhydrous K ₂ CO ₃ under stirring conditions, and then slowly adding benzylamine or Substituted benzylamine (such as 4-methylbenzylamine), yellow solids are continuously formed during the dropwise addition. After the dropwise addition is completed, stir at room temperature for 3 hours. After the detection reaction is complete, suction filtration and wash with saturated brine to obtain .

Optionally, solvent IX is also included in mixture VII described in step (V-3);

The molar ratio of the intermediate IV-2, sodium methoxide and paraformaldehyde is 1:0.1-1:0.1-0.5;

The reaction conditions are: reflux reaction at 60-100°C.

Optionally, the solvent IX includes at least one of methanol, acetone, CH ₂ Cl ₂ , THF, DMF, and EtOAc;

The conditions of the reaction are as follows: the molar ratio of intermediate IV-2, sodium methoxide and paraformaldehyde is 1:0.6:0.3, reflux stirring at 75°C, adding paraformaldehyde and sodium methoxide at intervals, and reacting for 70 to 75 hours .

Optionally, the reaction conditions further include: adding 0.3 moles of paraformaldehyde and sodium methoxide every 8 hours, and reacting for 72 hours.

Optionally, the synthetic route of described step (V-3) is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

e2: (CH ₂ O)n, CH ₃ ONa, 75°C, 30-40%.

Optionally, the preparation method of step (V-2) comprises: stirring and refluxing the mixture containing solvent IX, sodium methoxide, and intermediate IV-2, adding paraformaldehyde and sodium methoxide at intervals; , remove methanol, extract, wash, dry, suction filter, concentrate and purify to obtain the target product.

As a specific embodiment, step (V-3) specifically includes: using methanol as solvent, sodium methoxide as alkali, feeding ratio n (intermediate IV-2): n (sodium methoxide): n (paraformaldehyde) =1:0.6:0.3, reflux stirring at 75°C. 0.3N paraformaldehyde and sodium methoxide were added every 8h, and the reaction was carried out for about 72h. After the thin layer monitoring was completed, the methanol was concentrated under reduced pressure to remove methanol, extracted with ethyl acetate (3×15ml), washed with saturated brine, and washed with anhydrous sodium sulfate. Dry overnight. Suction filtration, concentration, and column chromatography to obtain the target compound.

Alternatively, the synthetic route of the compound shown in formula I-2 is as follows:

其中，反应条件和产率：

Among them, the reaction conditions and yields:

a: (Et) _3N , THF, 75℃, 98%; b: t-BuOK, DMF, 0℃～room temperature, 80～90%; c2: oxalyl chloride, DMF: _{CH2Cl2 (} volume ratio is 1 : 1), 95%; d2: benzylamine or substituted benzylamine, K ₂ CO ₃ , THF; e2: (CH ₂ O)n, CH ₃ ONa, 75° C., 30-40%.

Optionally, in the synthetic route of the compound represented by the above formula I-2, R ¹ is replaced by H.

Alternatively, the synthetic route of the compound shown in formula I-2 is as follows:

Among them, the reaction conditions and yields:

_d2 ': benzylamine, K2CO3, _THF ; e: (CH2O ₎ n, _CH3ONa , 75°C, 30-40%.

_d2 ": ₄ -methylbenzylamine, K2CO3, _THF ; e: (CH2O)n, _CH3ONa , 75°C, 42.6%.

_d2 "': ₄ -methylbenzylamine, K2CO3, _THF ; e: (CH2O)n, _CH3ONa , 75°C, 44.3%.

Another aspect of the present application provides a neuraminidase inhibitor, characterized by comprising at least one of the compounds described in any one of the above and the compounds prepared according to any of the methods described above .

Optionally, the neuraminidase inhibitor is at least one of the compounds described in any one of the above and the compounds prepared according to any of the methods described above.

The in vivo animal experiments of the neuraminidase inhibitor also proved that the compound has a good therapeutic effect, which is of significance for further research.

In the present application, the alkyl group is a group formed by the loss of any hydrogen atom of an alkane compound. The alkane compounds include straight-chain alkanes, branched-chain alkanes, and cycloalkanes.

In the present application, C ₁ to C ₅ represent the number of carbon atoms contained in the group.

In this application, "4-F", "3-F", etc. are the substitution positions of the corresponding groups in the compounds described in this application; wherein, the substitution positions are numbered as the relative positions of the substituents on the benzene ring, as follows :

如，“3-F”即为化合物的苯环上碳3上面的一个氢原子被F取代。“3,4-2F”即为化合物的苯环上碳3和碳4上面的氢原子被F取代。

For example, "3-F" means that a hydrogen atom above carbon 3 on the benzene ring of the compound is replaced by F. "3,4-2F" means that the hydrogen atoms on carbon 3 and carbon 4 on the benzene ring of the compound are replaced by F.

In the present application, "CC ₅₀ " refers to the ability of a drug to inhibit virus replication, and refers to the drug concentration at which 50% of virus replication can be inhibited.

In this application, " _EC50 " refers to the half-effect concentration, the dose of a drug that elicits a specific effect in 50% of subjects.

The beneficial effects that this application can produce include:

1) The compound provided in this application, with butenolide as the nucleus, can be used as a neuraminidase inhibitor; the compound not only has no cytotoxicity, but also has a high safety index and inhibits neuraminidase. The rate is comparable to that of oseltamivir.

2) The EC ₅₀ of the compounds provided in this application can reach 6.68±1.32 μM, which is better than that of the positive drug ribavirin (EC ₅₀ =105±51 μM), and also has a higher safety index SI=85.6.

3) The preparation method of the compound provided by the present application is simple, and the raw materials are readily available.

Description of drawings

Fig. 1 is the ¹ HNMR spectrogram of compound Ia in one embodiment of the application;

Fig. 2 is the ¹³ CNMR spectrogram of compound Ia in one embodiment of the application;

Fig. 3 is the ¹ H NMR spectrum of compound Ib in one embodiment of the application;

Fig. 4 is the ¹³ C NMR spectrum of compound Ib in one embodiment of the application;

Fig. 5 is the ¹ H NMR spectrum of compound Ic in one embodiment of the application;

Fig. 6 is the ¹³ C NMR spectrum of compound Ic in one embodiment of the application;

Fig. 7 is the ¹ H NMR spectrum of compound Id in one embodiment of the application;

Fig. 8 is the ¹³ C NMR spectrum of compound Id in one embodiment of the application;

Fig. 9 is the ¹ H NMR spectrum of compound Ie in one embodiment of the application;

Fig. 10 is the ¹³ C NMR spectrum of compound Ie in one embodiment of the application;

Fig. 11 is the 1H NMR spectrum of compound If in one embodiment of the application;

Fig. 12 is the ¹³ C NMR spectrum of compound If in one embodiment of the application;

Fig. 13 is the ¹ H NMR spectrum of compound Ig in one embodiment of the application;

Fig. 14 is the ¹³ C NMR spectrum of compound Ig in one embodiment of the application;

Fig. 15 is the ¹ H NMR spectrum of compound Ih in one embodiment of the application;

Figure 16 is the ¹³ C NMR spectrum of compound Ih in one embodiment of the application;

Fig. 17 is the ¹ H NMR spectrum of compound Ii in one embodiment of the application;

Fig. 18 is the ¹³ C NMR spectrum of compound Ii in one embodiment of the application;

Fig. 19 is the ¹ H NMR spectrum of compound II-1 in one embodiment of the application;

Fig. 20 is the ¹³ C NMR spectrum of compound II-1 in one embodiment of the application;

Figure 21 is the ¹ H NMR spectrum of compound II-2 in one embodiment of the application;

Figure 22 is the ¹³ C NMR spectrum of compound II-2 in one embodiment of the application;

Figure 23 is the ¹ H NMR spectrum of compound II-3 in one embodiment of the application;

Figure 24 is the ¹³ C NMR spectrum of compound II-3 in one embodiment of the application;

Figure 25 is the ¹ H NMR spectrum of compound II-4 in one embodiment of the application;

Figure 26 is the ¹³ C NMR spectrum of compound II-4 in one embodiment of the application;

Figure 27 is the ¹ H NMR spectrum of compound II-5 in one embodiment of the application;

Figure 28 is the ¹³ C NMR spectrum of compound II-5 in one embodiment of the application;

Figure 29 is the ¹ H NMR spectrum of compound II-6 in one embodiment of the application;

Figure 30 is the ¹ HNMR spectrum of compound II-7 in one embodiment of the application;

Figure 31 is the ¹ H NMR spectrum of compound II-8 in one embodiment of the application;

Figure 32 is the ¹ H NMR spectrum of compound II-9 in one embodiment of the application;

Figure 33 is the ¹ H NMR spectrum of compound II-10 in one embodiment of the application;

Figure 34 is the ¹ H NMR spectrum of compound II-11 in one embodiment of the application;

Figure 35 is the ¹ H NMR spectrum of compound II-12 in one embodiment of the application;

Figure 36 is the ¹ H NMR spectrum of compound II-13 in one embodiment of the application;

Figure 37 is the ¹ H NMR spectrum of compound II-14 in one embodiment of the application;

Figure 38 is the ¹ H NMR spectrum of compound II-15 in one embodiment of the application;

Figure 39 is the EC ₅₀ of α-aryl-β-methoxy-γ-methoxy compounds (Ia, Ib, Id, If, Ig) in the application;

Figure 40: A is the EC ₅₀ of compound II-1-4; B is the concentration-dependent change of compound II-3 on virus inhibition rate;

Figure 41 is the inhibition rate of compound II--3 on neuraminidase;

Figure 42 and Figure 43 are the results of molecular docking of compound II-3 (grey: oseltamivir, purple: II-3), wherein, Figure 42 is the result of molecular docking of compound II-3 (grey: oseltamivir, purple: II-3), Figure 43 shows the result of molecular docking of compound II-3 (purple: II-3).

Figure 44 shows the results of the in vivo experiment of II-3; wherein, (a) the changes in body temperature of the mice in the medication group and the control group, and (b) the changes in the body weight of the mice in the medication group and the control group.

Detailed ways

The present application will be described in detail below with reference to the examples, but the present application is not limited to these examples.

Unless otherwise specified, the raw materials and catalysts in the examples of the present application are purchased through commercial channels.

The analytical method in the embodiment of the application is as follows:

Melting point analysis was carried out by X5 type microscopic digital melting point tester (Beijing Keyi Electro-optical Instrument Factory).

Nuclear magnetic resonance analysis was performed using a DPX-400 superconducting nuclear magnetic resonance apparatus (Bruker, Sweden).

The 0.3N mentioned in the examples represents 0.3 moles.

Example 1 Synthesis of Intermediate Ia'-i'

Weigh 2.00g (13.3mmol) of p-methylphenylacetic acid in a 50ml round-bottomed flask, add 10ml of tetrahydrofuran (THF) to dissolve completely, then add 1.956g (16mmol) of ethyl chloroacetate and 1.624g (16mmol) of triethylamine , 60 ℃ heating under reflux for 6.5h. The reaction was completed by TLC dot plate monitoring and cooled to room temperature. The triethylamine salt generated in the reaction was removed by suction filtration, the filter cake was washed three times with THF, and concentrated under reduced pressure to obtain a light yellow transparent liquid. (3×15) ethyl acetate extraction, washed with saturated brine, dried over anhydrous sodium sulfate overnight, suction filtered and concentrated to obtain intermediate Ie'.

分子式为C₁₃H₁₆O₄。The structural formula of the intermediate Ie' described in this embodiment is

The molecular formula is C ₁₃ H ₁₆ O ₄ .

In the above method, p-methylphenylacetic acid is replaced with phenylacetic acid, and all other operations and conditions are the same as the preparation method of Ie' to obtain intermediate Ia'.

In the above-mentioned method, p-methylphenylacetic acid is replaced with p-fluorophenylacetic acid, and all other operations and conditions are the same as the preparation method of Ie to obtain intermediate Ib'.

In the above-mentioned method, p-methylphenylacetic acid is replaced with p-chlorophenylacetic acid, and all other operations and conditions are the same as the preparation method of Ie to obtain intermediate Ic'.

In the above-mentioned method, p-methylphenylacetic acid is replaced with p-bromophenylacetic acid, and all other operations and conditions are the same as the preparation method of Ie to obtain intermediate Id'.

In the above method, p-methylphenylacetic acid is replaced with p-methoxyphenylacetic acid, and all other operations and conditions are the same as the preparation method of Ie to obtain intermediate If'.

In the above method, p-methylphenylacetic acid is replaced with 3-fluorophenylacetic acid, and all other operations and conditions are the same as the preparation method of Ie to obtain intermediate Ig'.

In the above-mentioned method, p-methylphenylacetic acid is replaced with 2-fluorophenylacetic acid, and all other operations and conditions are the same as the preparation method of Ie to obtain intermediate Ih'.

In the above-mentioned method, p-methylphenylacetic acid is replaced with 3,4-difluorophenylacetic acid, and other operations and conditions are the same as the preparation method of Ie to obtain intermediate Ii'.

Example 2 Synthesis of Intermediate IIa-i

Taking IIe as an example, weigh 3.50 g (18.3 mmol) of the intermediate I (Ia'-i') prepared in Example 1 into a 50 ml round-bottomed flask, add 15 ml of N,N-dimethylformamide ( DMF) was dissolved, stirred under ice bath conditions, and potassium tert-butoxide was added in 6 times within 30 min, a total of 3.42 g (36.6 mmol). The reaction was stirred under ice bath for 30 min, and then stirred at room temperature for 3 h. TLC monitored the completion of the reaction, added 20 ml of water to dilute the reaction system, and then adjusted the pH to 2-3 with 5wt% dilute HCl under ice-bath conditions. During the pH adjustment, a pale yellow solid was continuously precipitated in the system. Then water was slowly added to the system until no obvious solid was precipitated (100 ml of water). It was placed in the refrigerator overnight, filtered with suction, and the filter cake was washed three times with water (3*10 ml) to obtain a pale yellow solid, which was dried to obtain the crude compound. The crude compound was added to 20 ml of dichloromethane for recrystallization and stirred for 15 min. Suction filtration, and the filter cake is washed with dichloromethane to obtain pure intermediate II.

The intermediates Ia'-i' obtained in the examples were respectively prepared according to the above method in this example to prepare the intermediates II, corresponding to the intermediates IIa-i.

分子式为C₁₁H₁₀O₃。Wherein, the structural formula of intermediate IIe is

The molecular formula is C ₁₁ H ₁₀ O ₃ .

The ¹ H NMR spectral data of the above intermediate IIe: the doublet at δ7.37-7.47 (d, J=8.2Hz, 2H) is the two hydrogens at the 6-position and the 10-position of the benzene ring; δ7.18-7.26 (d , J=7.9Hz, 2H) is the doublet at the 7-position and 9-position of the benzene ring; δ5.01-4.85 (q, J=6.7Hz, 2H) is the hydrogen on the 3-position carbon; δ1 .79(s) is the hydrogen on the 11th carbon of the benzene ring; ^13C NMR spectrum data: δ184.7(s) is the peak of the 4th carbon; δ168.5(s) is the peak of the 4th carbon; δ137 .4(s) is the peak of carbon at position 8; δ134.5(s) is the peak of carbon at position 6 and 10 of benzene ring; δ131.5(s) is the peak of carbon at position 5; δ128.2( s) is the peak of the carbon at the 7th and 9th positions of the benzene ring; δ102.8(s) is the peak of the carbon at the 1st position; δ68.4(s) is the peak of the carbon at the 4th position; δ22.6(s) is The peak of the carbon at position 11.

Example 3 Synthesis of Intermediate III-1a-i

Taking III-1e as an example, weigh 1.50g (7.88mmol) of Intermediate II (obtained in Example 2) in a 50ml round-bottomed flask, add 15ml of acetone to dissolve it completely, add 1.525g (11.1mmol) of anhydrous under stirring conditions Potassium carbonate. 1.193 g (9.5 mmol) of dimethyl sulfate was dissolved in 10 ml of acetone, and the constant pressure dropping funnel was slowly added dropwise to the reaction system, and the dropwise addition was completed in 30 min. The reaction was carried out for 10 h at room temperature in the dark. TLC monitored the completion of the reaction, concentrated under reduced pressure to remove the reaction solvent, then added 25 ml of water, dissolved in anhydrous potassium carbonate, and simultaneously precipitated a large amount of pale yellow solids, suction filtered, and the filter cake was washed three times with water (3×10 ml) to obtain pale yellow solids. Petroleum ether:ethyl acetate (1:1) was recrystallized to obtain pure intermediate III-1.

The intermediates IIa-i obtained in Example 2 were respectively prepared according to the above methods in this example to prepare the intermediates III-1, corresponding to the obtained intermediates III-1a-i.

分子式为C₁₂H₁₂O₃。Wherein, the structural formula of intermediate III-1e is

The molecular formula is C ₁₂ H ₁₂ O ₃ .

The intermediate III-1e in this example was tested by H NMR and C NMR; wherein, the H NMR spectrum of the intermediate III-1 was compared with the ¹ H NMR spectrum of the intermediate II described in Example 2, Intermediate III-1e added a single peak at δ3.86(s,3H), indicating the existence of a methoxy group at the γ-position of the butenolide ring.

Example 4 Synthesis of Compound Ia-i (Formula I-5)

Weigh 400 mg (2.1 mmol) of intermediate III-1 (prepared in Example 3) in a 25 ml round-bottomed flask, add 2 ml of anhydrous methanol to dissolve, and add 34 mg (0.63 mmol) of sodium methoxide and 37.8 mg (1.26 mmol) paraformaldehyde. The mixture was stirred at 75°C under reflux, 0.3N sodium methoxide and paraformaldehyde were added every 8 hours, and the reaction was carried out for about 48 hours. After the completion of the reaction was monitored by TLC, concentrated under reduced pressure to remove methanol, extracted with ethyl acetate (3×15 ml), washed with 20 ml of saturated brine, and dried over anhydrous Na ₂ SO ₄ . Suction filtration, concentration, and purification by column chromatography (petroleum ether:ethyl acetate=4:1) to obtain the obtained product.

The intermediate III-1a-i prepared in Example 3 was respectively prepared according to the above method in this example to prepare compound I, corresponding to compound Ia-i.

Among them, the structural formula, yield, melting point and nuclear magnetic data of Ia-i are shown below, and please refer to Fig. 1-18 for details.

化合物Ia白色固体，45.7％，m.p.185.7-186.8℃。¹H NMR(400MHz,CDCl₃)δ7.53(m,2H),7.41–7.33(m,3H),3.89(s,3H),3.34(s,3H),1.76(s,3H).¹³C NMR(100MHz,CDCl₃)δ169.86,169.68,129.90,128.86,128.39,128.21，105.71,103.24,60.08,51.00,22.80.

Compound Ia white solid, 45.7%, mp 185.7-186.8°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.53(m, 2H), 7.41-7.33(m, 3H), 3.89(s, 3H), 3.34(s, 3H), 1.76(s, 3H). ¹³ C NMR (100MHz, CDCl ₃ ) δ169.86, 169.68, 129.90, 128.86, 128.39, 128.21, 105.71, 103.24, 60.08, 51.00, 22.80.

化合物Ib淡黄色固体，50.9％，m.p.174.3-174.8℃。¹H NMR(400MHz,CDCl₃)δ7.59–7.56(m,2H),7.11–7.07(m,2H),3.95(s,3H),3.34(s,3H),1.78(s,3H).¹³C NMR(100MHz,CDCl₃)δ169.86,169.45,162.5(d,J＝247Hz),131.42(d,J＝8.1Hz),124.82(d,J＝3.4Hz),115.31(d,J＝22Hz),104.76,103.21,59.81,51.05,22.87.

Compound Ib pale yellow solid, 50.9%, mp 174.3-174.8°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.59–7.56 (m, 2H), 7.11–7.07 (m, 2H), 3.95 (s, 3H), 3.34 (s, 3H), 1.78 (s, 3H). ¹³ C NMR (100 MHz, CDCl ₃ ) δ 169.86, 169.45, 162.5 (d, J=247 Hz), 131.42 (d, J=8.1 Hz), 124.82 (d, J=3.4 Hz), 115.31 (d, J=22 Hz) ,104.76,103.21,59.81,51.05,22.87.

化合物Ic白色固体，49.8％，m.p.189.6-190.7℃。¹H NMR(400MHz,DMSO)δ7.62(d,J＝8.1Hz,2H),δ7.49(d,J＝8.1Hz,2H),3.93(s,3H),3.24(s,3H),1.72(s,3H).13C NMR(100MHz,DMSO)δ170.11,168.52,132.73,131.25,128.05,127.86,103.42,103.00,60.10,50.65,22.60.

Compound Ic white solid, 49.8%, mp 189.6-190.7°C. ¹ H NMR(400MHz,DMSO)δ7.62(d,J=8.1Hz,2H),δ7.49(d,J=8.1Hz,2H),3.93(s,3H),3.24(s,3H), 1.72(s,3H).13C NMR(100MHz,DMSO)δ170.11,168.52,132.73,131.25,128.05,127.86,103.42,103.00,60.10,50.65,22.60.

化合物Id淡黄色固体，50.2％，m.p.251.9-253.3℃。¹H NMR(400MHz,CDCl₃)δ7.53(d,J＝8.1Hz,2H),δ7.49(d,J＝8.1Hz,2H),3.97(s,3H),3.33(s,3H),1.77(s,3H).¹³C NMR(100MHz,CDCl₃)δ170.21,169.07,131.43,131.06,127.79,122.55,104.62,103.19,59.85,51.09,22.88.

Compound Id pale yellow solid, 50.2%, mp 251.9-253.3°C. ¹ H NMR (400MHz, CDCl ₃ ) δ7.53(d, J=8.1Hz, 2H), δ7.49(d, J=8.1Hz, 2H), 3.97(s, 3H), 3.33(s, 3H) , 1.77(s, 3H). ¹³ C NMR (100MHz, CDCl ₃ )δ170.21, 169.07, 131.43, 131.06, 127.79, 122.55, 104.62, 103.19, 59.85, 51.09, 22.88.

化合物Ie白色固体，52.4％，m.p.212.6-213.1℃。¹H NMR(400MHz，DMSO)δ7.42(d，J＝8.1Hz,2H),7.22(d,J＝8.1Hz,2H),3.86(s,3H),3.23(s,3H),2.33(s,3H),1.69(s,3H).¹³C NMR(100MHz,DMSO)δ169.30,168.97,137.45,129.62,128.52,125.97,104.62,102.86,59.97,50.48,22.61,20.79.

Compound Ie white solid, 52.4%, mp 212.6-213.1°C. ¹ H NMR (400MHz, DMSO) δ 7.42(d, J=8.1Hz, 2H), 7.22(d, J=8.1Hz, 2H), 3.86(s, 3H), 3.23(s, 3H), 2.33( s, 3H), 1.69 (s, 3H). ¹³ C NMR (100MHz, DMSO) δ169.30, 168.97, 137.45, 129.62, 128.52, 125.97, 104.62, 102.86, 59.97, 50.48, 22.61, 20.79.

Among them, ¹ H NMR spectral data: the doublet at δ7.37-7.47 (d, J=8.1 Hz, 2H) is two hydrogens at the 9-position and 113-position of the benzene ring; δ7.18-7.26 (d, J= The doublet at 7.9Hz, 2H) is two hydrogens at the 12th and 10th positions of the benzene ring; the singlet at δ3.86 (3H,s) is the hydrogen on the 7th carbon; δ3.23 (3H,s) The singlet at δ2.33 (3H,s) is hydrogen on carbon 14; the singlet at δ1.69 (3H,s) is hydrogen on 5 carbon. ¹³ C NMR spectrum data: δ169.3(s) is the peak of carbon 1; δ168.9(s) is the peak of carbon 3; δ137.4(s) is the peak of 11 carbon; δ129.7(s) is the peak on the 10 and 12 carbons of the benzene ring, 128.5(s) is the peak on the 11 carbon; δ125.9(s) is the peak on the 10 and 12 carbons of the benzene ring; δ104.6(s) is the 2-position δ102.8(s) is the peak of the carbon on the 4th position; δ59.9(s) is the peak of the carbon on the 7th position; δ50.5(s) is the peak of the carbon on the 6th position; δ22.6 (s) is the peak for the carbon at the 14th position; δ20.79(s) is the peak for the carbon at the 5th position.

化合物If淡黄色固体，48.6％，m.p.165.8-166.4℃。¹H NMR(400MHz,CDCl₃)δ7.47(d,J＝8.7Hz,2H),6.93(d,J＝8.8Hz,2H),3.91(s,3H),3.82(s,3H),3.33(s,3H),1.75(s,3H).¹³C NMR(100MHz,CDCl₃)δ169.97,169.19,159.56,131.03,120.97,113.72,105.46,103.19,59.83,55.30,50.97,22.86.

Compound If pale yellow solid, 48.6%, mp 165.8-166.4°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.47 (d, J=8.7 Hz, 2H), 6.93 (d, J=8.8 Hz, 2H), 3.91 (s, 3H), 3.82 (s, 3H), 3.33 (s,3H),1.75(s,3H). ¹³ C NMR (100MHz, CDCl ₃ )δ169.97,169.19,159.56,131.03,120.97,113.72,105.46,103.19,59.83,55.30,50.97,22.86.

化合物Ig淡黄色固体，46.2％，m.p.198.1-198.8℃。¹H NMR(400MHz,CDCl3)δ7.43–7.35(m,3H),7.04(t,J＝8Hz,1H),4.00(s,3H),3.34(s,3H),1.79(s,3H).¹³CNMR(100MHz,CDCl3)δ170.41,168.97,162.40(d,J＝244Hz),130.85(d,J＝8.6Hz),129.73(d,J＝8.4Hz),125.23(d,J＝3Hz),116.47(d,J＝22Hz),115.32(d,J＝21Hz),104.59(d,J＝2Hz),103.12,59.82,51.10,22.93.

Compound Ig pale yellow solid, 46.2%, mp 198.1-198.8°C. ¹ H NMR(400MHz, CDCl3)δ7.43-7.35(m,3H),7.04(t,J=8Hz,1H),4.00(s,3H),3.34(s,3H),1.79(s,3H) . ¹³ CNMR(100MHz,CDCl3)δ170.41,168.97,162.40(d,J=244Hz),130.85(d,J=8.6Hz),129.73(d,J=8.4Hz),125.23(d,J=3Hz), 116.47(d, J＝22Hz), 115.32(d, J＝21Hz), 104.59(d, J＝2Hz), 103.12, 59.82, 51.10, 22.93.

化合物Ih淡黄色固体，47.5％，m.p.176.7-177.9℃。¹H NMR(400MHz,DMSO)δ7.52–7.47(m,2H),7.33–7.26(m,2H),3.77(s,3H),3.23(s,3H),1.66(s,3H).¹³C NMR(100MHz,DMSO)δ171.00,168.33,159.92(d,J＝244Hz),132.97(d,J＝2.2Hz),131.07(d,J＝8.1Hz),124.21(d,J＝3.4Hz),116.84(d,J＝16Hz),115.34(d,J＝21Hz),103.5,98.4,59.9,50.4,22.3.

Compound Ih pale yellow solid, 47.5%, mp 176.7-177.9°C. ¹ H NMR (400MHz, DMSO) δ 7.52–7.47 (m, 2H), 7.33–7.26 (m, 2H), 3.77 (s, 3H), 3.23 (s, 3H), 1.66 (s, 3H). ¹³ C NMR(100MHz, DMSO)δ171.00,168.33,159.92(d,J=244Hz),132.97(d,J=2.2Hz),131.07(d,J=8.1Hz),124.21(d,J=3.4Hz), 116.84(d, J＝16Hz), 115.34(d, J＝21Hz), 103.5, 98.4, 59.9, 50.4, 22.3.

化合物Ii淡黄色固体，44.3％，m.p.187.3-188.6℃。¹HNMR(400MHzCDCl₃)δ7.60–7.55(m,1H),7.49–7.46(m,1H),7.21-7.15(m，1H),3.97(s,3H),3.36(s,3H),1.79(s,3H).¹³CNMR(100MHz,CDCl₃)δ170.30,168.75,151.39-148.62(overlap,2c),125.76-125.48(overlap,2c),118.31-117.01(overlap,2c),103.79,103.04,59.53,51.15,23.04.

Compound Ii pale yellow solid, 44.3%, mp 187.3-188.6°C. ¹ HNMR(400MHzCDCl ₃ )δ7.60-7.55(m,1H),7.49-7.46(m,1H),7.21-7.15(m,1H),3.97(s,3H),3.36(s,3H),1.79 (s, 3H). ¹³ CNMR (100 MHz, CDCl ₃ ) δ 170.30, 168.75, 151.39-148.62 (overlap, 2c), 125.76-125.48 (overlap, 2c), 118.31-117.01 (overlap, 2c), 103.79, 103.04, 59.53 , 51.15, 23.04.

Example 5 Synthesis of Intermediate III-2

Weigh 1.50 g (7.73 mmol) of Intermediate II (prepared in Example 2) into a 25 ml round-bottom flask, and add 10 ml (1:1) of a mixed solution of DMF and CH ₂ Cl ₂ . 1.18 g (6.44 mmol) of oxalyl chloride was slowly added dropwise with stirring in an ice bath. The reaction was carried out for about 7 h. After the completion of the reaction was monitored by TLC, the pH was adjusted to neutral with saturated NaHCO ₃ , extracted with ethyl acetate (3×15 ml), washed with saturated brine, and dried over anhydrous Na ₂ SO ₄ . Suction filtration, concentration, and separation by silica gel column chromatography (petroleum ether:ethyl acetate=2:1) to obtain intermediate III-2.

The intermediate IIb, intermediate IIc, intermediate IIf, intermediate IIe, and intermediate IIg prepared in Example 2 were respectively prepared according to the above-mentioned method in this example to prepare intermediate III-2, correspondingly to obtain intermediate III-2b, Intermediate III-2c, Intermediate III-2f, Intermediate III-2e, Intermediate III-2g.

Example 6 Synthesis of Intermediate IV-1

Weigh 1.00g (4.71mmol) of Intermediate III-2 (prepared in Example 5) into a 25ml round-bottomed flask, add 2ml of THF to dissolve, add 778mg (5.64mmol) of anhydrous K ₂ CO ₃ under stirring, and then slowly Morpholine 492 mg (5.64 mmol) was added dropwise. During the dropwise addition, a yellow solid was continuously formed. After the dropwise addition was completed, the mixture was stirred at room temperature for 3 h. After the completion of the reaction was monitored by TLC, the crude compound Intermediate IV-1 was obtained by suction filtration.

Intermediate III-2b, intermediate III-2c, intermediate III-2f, intermediate III-2e, intermediate III-2g prepared in Example 5 were prepared according to the above method in this example to prepare intermediate IV- 1. Correspondingly, intermediate IV-1b, intermediate IV-1c, intermediate IV-1f, intermediate IV-1e and intermediate IV-1g are obtained.

分子式为C₁₄H₁₄FNO₃。Wherein, the structural formula of intermediate IV-1b is

The molecular formula is C ₁₄ H ₁₄ FNO ₃ .

The ¹ H NMR spectral data of the above intermediate IV-1b: the double peaks at δ7.35 (d, J=8.4Hz, 2H) are two hydrogens on the 7 and 9 carbons of the benzene ring, δ7.31 (d , J=8.4Hz, 2H) is two hydrogens on the 6 and 10 carbons of the benzene ring, δ5.02(s, 2H) is the hydrogen on the 4th carbon on the butenolide ring, δ3 .69-3.63(m,4H) are the four hydrogens on the 12 and 14 carbons on the morpholine ring, δ3.52-3.46(m,2H) and δ3.32-3.26(m,2H) are respectively Hydrogens on the 11th and 13th positions on the phenoline ring, ¹³ CNMR spectral data: δ168.72(s) is the peak on the 1st carbonyl carbon, δ161.55(d, J=236Hz) is the 8th carbon cleavage on the benzene ring δ166.45(s) is the peak of the carbon on the ethylenic bond connected to the N atom at the 3rd position, δ130.83(d, J=8.1Hz) is the peak of the carbon on the 7th and 9th positions on the benzene ring, δ125.19(d, J=3.2Hz) is the peak at the 6th and 10th positions of the benzene ring, δ113.21(d, J=24Hz) is the peak at the 5th position of the benzene ring, δ67.12(s) It is the peak of 12 and 14 carbons on morpholine, and δ64.23 is the peak of 4 carbon on butenolide.

Example 7 Synthesis of compound II-1-5

Weigh 400 mg (1.52 mmol) of Intermediate IV-1 (prepared in Example 6) into a 25 ml round-bottomed flask, add 2 ml of methanol, reflux at 65°C to 80°C, and then add 0.6N paraformaldehyde and 0.3N sodium methoxide ; Add 0.3N paraformaldehyde and sodium methoxide every 8h, and the reaction is about 72h. After monitoring the completion of the reaction by TLC, the solution was concentrated under reduced pressure to remove methanol, dissolved in 15 ml of ethyl acetate, extracted with (3×15 ml) saturated NaCl, and dried over anhydrous sodium sulfate overnight. Suction filtration, concentrated under reduced pressure, and separated by silica gel column chromatography (petroleum ether:ethyl acetate=4:1).

The intermediate IV-1b, intermediate IV-1c, intermediate IV-1f, intermediate IV-1e and intermediate IV-1g prepared in Example 6 were prepared according to the above method in this example to prepare compound II, corresponding to Compound II-1, Compound II-2, Compound II-3, Compound II-4, Compound II-5.

The structural formula, yield, melting point and nuclear magnetic data of Compound II-1, Compound II-2, Compound II-3, Compound II-4, and Compound II-5 are shown below, and see Figures 19-28 for details.

化合物II-1黄色固体，42.6％，m.p.196.4-196.8℃。¹H NMR(400MHz,CDCl₃)δ7.27(m,2H),7.08(t,J＝8.7Hz,2H),3.73–3.63(m,4H),3.53–3.45(m,2H),3.36(s,3H),3.34–3.25(m,2H),1.81(s,3H).¹³C NMR(100MHz,CDCl₃)δ170.33,162.17(d,J＝245Hz),159.60,132.13(d,J＝8.1Hz),127.83(d,J＝3.5Hz),115.35(d,J＝22Hz),103.61,98.45,66.69,50.89,48.39,24.90.

Compound II-1 yellow solid, 42.6%, mp 196.4-196.8°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.27 (m, 2H), 7.08 (t, J=8.7 Hz, 2H), 3.73-3.63 (m, 4H), 3.53-3.45 (m, 2H), 3.36 ( s, 3H), 3.34–3.25 (m, 2H), 1.81 (s, 3H). ¹³ C NMR (100 MHz, CDCl ₃ ) δ 170.33, 162.17 (d, J=245 Hz), 159.60, 132.13 (d, J=8.1 Hz), 127.83(d, J＝3.5Hz), 115.35(d, J＝22Hz), 103.61, 98.45, 66.69, 50.89, 48.39, 24.90.

Among them, ¹ H NMR spectral data: the double peaks at δ7.35 (d, J=8.4Hz, 2H) are two hydrogens on the 7th and 9th carbons of the benzene ring, δ7.31 (d, J=8.4Hz) ,2H) are two hydrogens on the 6 and 10 carbons of the benzene ring, δ3.69-3.63(m,4H) are four hydrogens on the 12 and 14 carbons on the morpholine ring, δ3 .52-3.46(m,2H) and δ3.32-3.26(m,2H) are the hydrogens on the 11th and 13th positions of the morpholine ring, respectively, and δ3.36(s,3H) is the three hydrogens on the 16th carbon. One hydrogen, δ1.80(s,3H) is three hydrogens on the 15th carbon. ¹³ C NMR spectral data: δ168.72(s) is the peak on the 4-position carbonyl carbon, δ161.55(d, J=236Hz) is the doublet of the 8-position carbon cleavage on the benzene ring, δ166.45(s) It is the peak of the carbon on the ethylenic bond connected to the N atom at the 3rd position, δ130.83 (d, J=8.1Hz) is the peak of the carbon at the 7th and 9th positions on the benzene ring, δ125.19 (d, J=3.2Hz) are the peaks at the 6th and 10th positions of the benzene ring, δ113.21(d, J=24Hz) is the peak at the 5th carbon of the benzene ring, δ109.82(s) is the peak at the 3rd carbon, δ101.95 (s) is the peak at carbon 2, δ67.12(s) is the peak at carbon 12 and 14 of morpholine, δ52.81(s) is the peak at carbon 11 and 13, δ49.25(s) is the peak on the carbon at the 16-position methoxy group, and δ22.64(s) is the peak at the 15-position methyl carbon.

化合物II-2黄色固体，35.2％，m.p.162.9-163.4℃。¹H NMR(400MHz,CDCl₃)δ7.35(d,J＝12Hz,2H),7.23(d,J＝8.4Hz,2H),3.73–3.63(m,4H),3.54–3.42(m,2H),3.36(s,3H),3.33–3.25(m,2H),1.80(s,3H).¹³C NMR(100MHz,CDCl₃)δ170.07,159.76,133.55,131.73,130.42,128.47,128.42,103.62,98.10,66.65,50.92,48.47,40.98 24.89.

Compound II-2 yellow solid, 35.2%, mp 162.9-163.4°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.35 (d, J=12 Hz, 2H), 7.23 (d, J=8.4 Hz, 2H), 3.73-3.63 (m, 4H), 3.54-3.42 (m, 2H) _The ^_ 98.10, 66.65, 50.92, 48.47, 40.98 24.89.

化合物II-3黄色固体，38.9％，m.p.153.6-154.0℃。¹H NMR(400MHz,CDCl₃)δ7.20(d,J＝8.6Hz,2H),6.91(d,J＝8.7Hz,2H),3.82(s,3H),3.71–3.60(m,4H),3.54-3.45(m,2H),3.35(s,3H),3.32-3.27(m,2H),1.79(s,3H).¹³C NMR(100MHz,CDCl₃)δ170.74,159.08,159.04,131.58,123.98,113.78,103.56,99.24,66.75,55.29,50.83,48.26,29.83,24.93.

Compound II-3 yellow solid, 38.9%, mp 153.6-154.0°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.20 (d, J=8.6 Hz, 2H), 6.91 (d, J=8.7 Hz, 2H), 3.82 (s, 3H), 3.71-3.60 (m, 4H) , 3.54-3.45(m, 2H), 3.35(s, 3H), 3.32-3.27(m, 2H), 1.79(s, 3H). ¹³ C NMR(100MHz, CDCl ₃ )δ170.74,159.08,159.04,131.58, 123.98,113.78,103.56,99.24,66.75,55.29,50.83,48.26,29.83,24.93.

化合物II-4黄色固体，40.2％，m.p.149.5-149.7℃。¹H NMR(400MHz,CDCl₃)δ7.20-7.15(overlap,4H),3.72-3.62(m,4H),3.53-3.47(m,2H),3.35(s,3H),3.33-3.27(m,2H),2.37(s,3H),1.80(s,1H).¹³C NMR(100MHz,CDCl₃)δ170.74,159.04,137.47,130.30,128.98,128.83,103.56,99.23,66.75,50.83,48.26,24.93,21.23.

Compound II-4 yellow solid, 40.2%, mp 149.5-149.7°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.20-7.15 (overlap, 4H), 3.72-3.62 (m, 4H), 3.53-3.47 (m, 2H), 3.35 (s, 3H), 3.33-3.27 (m , 2H), 2.37(s, 3H), 1.80(s, 1H). ¹³ C NMR (100MHz, CDCl ₃ )δ170.74, 159.04, 137.47, 130.30, 128.98, 128.83, 103.56, 99.23, 66.75, 50.83, 48.26, 24.93 , 21.23.

化合物II-5黄色固体，40.9％，m.p.168.3-169.4℃。¹H NMR(400MHz,CDCl₃)δ7.28-7.23(m,1H),6.99–6.88(m,3H),3.67–3.53(m,4H),3.45–3.36(m,2H),3.28(s,3H),3.25–3.16(m,2H),1.72(s,3H).¹³C NMR(100MHz,CDCl₃)δ169.90,162.43(d,J＝245Hz),159.93,134.07(d,J＝8Hz),129.68(d,J＝8.6Hz),126.26(d,J＝2.9Hz),117.40(d,J＝21Hz),114.63(d,J＝21Hz),103.59,98.30,66.64,50.92,48.51,24.89.

Compound II-5 yellow solid, 40.9%, mp 168.3-169.4°C. ¹ H NMR (400MHz, CDCl ₃ )δ7.28-7.23(m,1H),6.99-6.88(m,3H),3.67-3.53(m,4H),3.45-3.36(m,2H),3.28(s , 3H), 3.25–3.16(m, 2H), 1.72(s, 3H). ¹³ C NMR(100MHz, CDCl ₃ )δ169.90, 162.43(d, J=245Hz), 159.93, 134.07(d, J=8Hz) ,129.68(d,J＝8.6Hz),126.26(d,J＝2.9Hz),117.40(d,J＝21Hz),114.63(d,J＝21Hz),103.59,98.30,66.64,50.92,48.51,24.89 .

Example 8 Synthesis of Intermediate IV-2

Weigh 1.00g (4.71mmol) of Intermediate III-2g (prepared in Example 5) into a 25ml round-bottomed flask, add 2ml of THF to dissolve, add 778mg (5.64mmol) of anhydrous K ₂ CO ₃ under stirring, and then slowly Aniline (5.64 mmol) was added dropwise. During the dropwise addition, solids were continuously formed. After the dropwise addition was completed, the mixture was stirred at room temperature for 3 h. After the completion of the reaction monitored by TLC, the crude compound Intermediate IV-2g was obtained by suction filtration.

The aniline in the above-mentioned method of the present embodiment is replaced by 4-fluoroaniline, and the remaining operation and condition parameters are the same, and the prepared product is intermediate IV-2h.

The aniline in the above-mentioned method of the present embodiment is replaced with 4-chloroaniline, and other operations and condition parameters are the same, and the prepared product is intermediate IV-2i.

The aniline in the above-mentioned method of the present embodiment is replaced with 4-bromoaniline, and other operations and condition parameters are the same, and the prepared product is intermediate IV-2j.

The aniline in the above-mentioned method of the present embodiment is replaced with 4-methylaniline, and other operations and condition parameters are the same, and the prepared product is intermediate IV-2k.

The aniline in the above-mentioned method of the present embodiment is replaced by 4-methoxyaniline, and other operations and condition parameters are the same, and the prepared product is intermediate IV-21.

The aniline in the above-mentioned method of the present embodiment is replaced by 2-fluoroaniline, and the remaining operation and condition parameters are the same, and the prepared product is intermediate IV-2m.

The aniline in the above-mentioned method of the present embodiment is replaced with 3-fluoroaniline, and other operations and condition parameters are the same, and the prepared product is intermediate IV-2n.

Weigh 1.00g (4.71mmol) of Intermediate III-2c (prepared in Example 5) into a 25ml round-bottomed flask, add 2ml of THF to dissolve, add 778mg (5.64mmol) of anhydrous K ₂ CO ₃ under stirring, and then slowly p-Toluidine (5.64 mmol) was added dropwise. During the dropwise addition, solids were continuously formed. After the dropwise addition was completed, the mixture was stirred at room temperature for 3 h. After monitoring the completion of the reaction by TLC, the crude compound intermediate IV-2c was obtained by suction filtration.

Weigh 1.00g (4.71mmol) of intermediate III-2e (prepared in Example 5) into a 25ml round-bottomed flask, add 2ml of THF to dissolve, add 778mg (5.64mmol) of anhydrous K ₂ CO ₃ under stirring, and then slowly p-Toluidine (5.64 mmol) was added dropwise. During the dropwise addition, solids were continuously formed. After the dropwise addition was completed, the mixture was stirred at room temperature for 3 h. After the completion of the reaction was monitored by TLC, the crude compound intermediate IV-2e was obtained by suction filtration.

Example 9 Compound II6-15

Weigh 400mg (1.52mmol) of Intermediate IV-2 (prepared in Example 8) into a 25ml round-bottomed flask, add 2ml of methanol, reflux at 70°C, and then add 0.6N paraformaldehyde and 0.3N sodium methoxide; 0.3N paraformaldehyde and sodium methoxide were added for 8h, and the reaction was carried out for about 48h. After monitoring the completion of the reaction by TLC, the solution was concentrated under reduced pressure to remove methanol, dissolved in 15 ml of ethyl acetate, extracted with (3×15 ml) saturated NaCl, and dried over anhydrous sodium sulfate overnight. Suction filtration, concentrated under reduced pressure, and separated by silica gel column chromatography (petroleum ether:ethyl acetate=4:1).

The intermediate IV-2g, intermediate IV-2h, intermediate IV-2i, intermediate IV-2j, intermediate IV-2k, intermediate IV-2l, intermediate IV-2m, Intermediate IV-2n is prepared by the above method in this example to prepare compound II, corresponding to compound II-6, compound II-7, compound II-8, compound II-9, compound II-10, compound II-11, compound II -12. Compound II-13.

The intermediate IV-2c and the intermediate IV-2e prepared in Example 8 are used to prepare compound II by the above method in this example, and compound II-14 and compound II-15 are correspondingly obtained.

Among them, compound II-6, compound II-7, compound II-8, compound II-9, compound II-10, compound II-11, compound II-12, compound II-13, compound II-14, compound II-15 The structural formula, yield, melting point and nuclear magnetic data of .

化合物II-6白色固体，48.6％，m.p.191.2-191.5.1℃。¹H NMR(400MHz,DMSO)δ8.10(t,J＝6.4Hz,1H),7.35-7.28(m,1H),7.27–7.17(overlap,3H),7.11-7.08(m,1H),6.99-6.90(overlap,3H),4.23(s,2H),3.17(s,3H),1.68(s,3H).

Compound II-6 White solid, 48.6%, mp 191.2-191.5.1°C. ¹ H NMR (400MHz, DMSO) δ8.10 (t, J=6.4Hz, 1H), 7.35-7.28 (m, 1H), 7.27-7.17 (overlap, 3H), 7.11-7.08 (m, 1H), 6.99 -6.90(overlap, 3H), 4.23(s, 2H), 3.17(s, 3H), 1.68(s, 3H).

化合物II-7白色固体，42.3％，m.p.157.6-158.1℃。¹H NMR(400MHz,CDCl₃)δ7.39–7.31(m,1H),7.17–6.98(overlap,7H),5.03(s,1H),4.33(s,2H),3.32(s,3H),1.76(s,3H).

Compound II-7 White solid, 42.3%, mp 157.6-158.1°C. ¹ H NMR (400MHz, CDCl ₃ )δ7.39-7.31(m,1H),7.17-6.98(overlap,7H),5.03(s,1H),4.33(s,2H),3.32(s,3H), 1.76(s,3H).

化合物II-8白色固体,40.6％，m.p.119.8-120.3℃。¹H NMR(400MHz,CDCl₃)δ7.47(d,J＝8.4Hz,2H),7.38-7.28(m,1H),7.15–6.94(overlap,5H),5.07(s,1H),4.33(s,2H),3.30(s,3H),1.72(s,3H).

Compound II-8 white solid, 40.6%, mp 119.8-120.3°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.47 (d, J=8.4 Hz, 2H), 7.38-7.28 (m, 1H), 7.15-6.94 (overlap, 5H), 5.07 (s, 1H), 4.33 ( s,2H),3.30(s,3H),1.72(s,3H).

化合物II-9白色固体,41.6％，m.p.208.3-208.5℃。¹H NMR(400MHz,CDCl₃)δ7.45(d,J＝8.3Hz,2H),7.35-7.29(m,1H),7.12–6.93(overlap,5H),5.02(s,1H),4.30(s,2H),3.30(s,3H),1.73(s,3H).

Compound II-9 white solid, 41.6%, mp 208.3-208.5°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.45 (d, J=8.3 Hz, 2H), 7.35-7.29 (m, 1H), 7.12-6.93 (overlap, 5H), 5.02 (s, 1H), 4.30 ( s,2H),3.30(s,3H),1.73(s,3H).

化合物II-10白色固体，42.8％，m.p.135.3-135.7℃。¹H NMR(400MHz,CDCl₃)δ7.35-7.30(m,1H),7.14(d,J＝7.7Hz,3H),7.09(d,J＝9.7Hz,1H),7.01(d,J＝7.9Hz,3H),6.99–6.94(m,1H),4.98(s,1H),4.29(s,2H),3.29(s,3H),2.34(s,3H),1.74(s,3H).

Compound II-10 White solid, 42.8%, mp 135.3-135.7°C. ¹ H NMR (400MHz, CDCl ₃ ) δ 7.35-7.30 (m, 1H), 7.14 (d, J=7.7Hz, 3H), 7.09 (d, J=9.7Hz, 1H), 7.01 (d, J= 7.9Hz, 3H), 6.99–6.94(m, 1H), 4.98(s, 1H), 4.29(s, 2H), 3.29(s, 3H), 2.34(s, 3H), 1.74(s, 3H).

化合物II-11白色固体，44.9％，m.p.127.5-128.3℃。¹H NMR(400MHz,DMSO)8.03(t,J＝4Hz,1H),7.37-7.32(m,1H),7.12-7.07(m,1H),7.03-6.73(overlap,5H),4.15(s,2H),3.70(s,3H),3.15(s,3H),1.66(s,3H).

化合物II-12白色固体，45.6％，m.p.155.9-156.2℃。¹H NMR(400MHz,CDCl₃)δ7.38-7.27(m,2H),7.14(d,J＝7.7Hz,1H),7.12–6.91(overlap,5H),5.09(s,1H),4.40(s,2H),3.25(s,3H),1.72(s,3H).

Compound II-11 White solid, 44.9%, mp 127.5-128.3°C. ¹ H NMR (400MHz, DMSO) 8.03(t, J=4Hz, 1H), 7.37-7.32(m, 1H), 7.12-7.07(m, 1H), 7.03-6.73(overlap, 5H), 4.15(s, 2H), 3.70(s, 3H), 3.15(s, 3H), 1.66(s, 3H).

Compound II-12 White solid, 45.6%, mp 155.9-156.2°C. ¹ H NMR (400MHz, CDCl ₃ ) δ 7.38-7.27 (m, 2H), 7.14 (d, J=7.7Hz, 1H), 7.12-6.91 (overlap, 5H), 5.09 (s, 1H), 4.40 ( s,2H),3.25(s,3H),1.72(s,3H).

化合物II-13白色固体，42.1％，m.p.200.8-201.9℃。¹H NMR(400MHz,DMSO)8.05(m,1H),7.30-7.25(m,2H),7.16-7.14(m,2H),7.09–7.00(m,2H),6.95(brs,1H),6.86(brs,1H),4.25(s,2H),3.20(s,3H),1.69(s,3H).

Compound II-13 White solid, 42.1%, mp 200.8-201.9°C. ¹ H NMR (400MHz, DMSO) 8.05 (m, 1H), 7.30-7.25 (m, 2H), 7.16-7.14 (m, 2H), 7.09-7.00 (m, 2H), 6.95 (brs, 1H), 6.86 (brs,1H),4.25(s,2H),3.20(s,3H),1.69(s,3H).

化合物Ⅱ-14白色固体，41.6％，m.p.188.2-190.0℃。¹H NMR(400MHz,CDCl₃)δ7.37-7.26(m,4H),7.14(d,J＝7.7Hz,2H),7.00(d,J＝9.7Hz,2H),4.90(s,1H),4.29(s,2H),3.29(s,3H),2.34(s,3H),1.74(s,3H).

Compound II-14 White solid, 41.6%, mp 188.2-190.0°C. ¹ H NMR (400MHz, CDCl ₃ ) δ 7.37-7.26 (m, 4H), 7.14 (d, J=7.7Hz, 2H), 7.00 (d, J=9.7Hz, 2H), 4.90 (s, 1H) ,4.29(s,2H),3.29(s,3H),2.34(s,3H),1.74(s,3H).

化合物II-15白色固体，44.3％，m.p.172.7-174.1℃。¹H NMR(400MHz,CDCl₃)δ7.26(d,J＝7.9Hz,2H),7.18(d,J＝7.9Hz,2H),7.05(d,J＝8.4Hz,2H),6.84(d,J＝8.6Hz,2H),4.84(s,1H),4.25(s,2H),3.80(s,3H),3.28(s,3H),2.35(s,3H),1.72(s,3H).

Compound II-15 White solid, 44.3%, mp 172.7-174.1°C. ¹ H NMR (400 MHz, CDCl ₃ ) δ 7.26 (d, J=7.9 Hz, 2H), 7.18 (d, J=7.9 Hz, 2H), 7.05 (d, J=8.4 Hz, 2H), 6.84 (d , J=8.6Hz, 2H), 4.84(s, 1H), 4.25(s, 2H), 3.80(s, 3H), 3.28(s, 3H), 2.35(s, 3H), 1.72(s, 3H) .

Example 10 Evaluation of anti-influenza virus activity and inhibition of neuraminidase

The compounds Ia-i and compounds II-1 to II-15 obtained in the Examples were evaluated for their anti-H1N1 virus activity and their inhibitory effects on neuraminidase as neuraminidase inhibitors.

The specific in vitro antiviral activity experimental steps are as follows.

Viral Amplification:

1. Passing cells: After MDCK cells were digested, they were inoculated into a 2×75cm large culture flask;

After 2.24h, inoculate the virus: when the cells grow to a monolayer (about 70%), discard the medium and wash with PBS three times; add virus solution (Influenza A virus, A/Weiss/43, Wuhan National Center for Type Culture Collection), Shake once every 15 minutes for a total of 3 times; after 2 hours, discard the culture medium, add 12 mL of DMEM with 2% FBS (fetal bovine serum, GBICO, USA) to each, observe and record daily;

3. Toxin collection when the lesions are 70% to 90%: put the culture bottle at -80°C, freeze and thaw for 3 times, centrifuge at 4°C and 4500r for 15 minutes, take the supernatant, and store it at -80°C for later use.

Viral TCID ₅₀ Determination:

1. Plate: plate MDCK cells in a 96-well plate, 2.5×10 ⁴ cells per well, 5% CO ₂ , and incubate at 37°C;

2. Virus infection: After 24 hours, wash 3 times with PBS, add 100 μL of virus solution diluted with pure DMEM to each well (the expanded virus solution is serially diluted to make it 10 ^-1 , 10 ^-2 , 10 ^-3 , 10 ^-3 , 10 ^-4 , 10 ^-5 , 10 ^-6 , 10 ^-7 , 10 ^-8 , 10 ^-9 to 10 ^-10 ), 8 duplicate wells for each concentration, and set up a control;

After 3.2 hours, the virus solution was removed, and 100 μL of DMEM with 2% FBS was added to each well;

4. Observe daily, and test with Giemsa stain after 72 hours. The degree of cytopathic changes was assessed according to the following criteria in Table 1:

Table 1

Reed-Muench formula to calculate virus TCID ₅₀

Distance Proportion = (Percentage of Positives Greater than 50% - 50%)/(Percentage of Positives Greater than 50% - Percentage of Positives Less than 50%)

Log of TCID ₅₀ = log of high dilution of percent positive > 50% + distance ratio x log of dilution factor

Cytotoxicity detection CC ₅₀ :

1. Plate: plate 96-well plate with MDCK, 2.5×10 ⁴ per well, 5% CO ₂ , incubate at 37°C;

2. Dosing: After 24 hours, remove the culture medium, add 200 μL of the drug to be tested prepared in DMEM with 2% FBS to each well, and dilute to 9 concentrations of 200, 100, 50-0.78 (μM), each concentration 3 duplicate wells, and set up a control;

3. Detection: After 48 hours, the cell survival was determined by MTT method.

Antiviral activity detection EC ₅₀ :

1. Plate: MDCK plate 96-well plate, 2.5×10 ⁴ per well;

2. Virus infection: After 24 hours, remove the culture medium, wash 3 times with PBS, and add 100 μL of 100 TCID ₅₀ virus solution prepared with pure DMEM to each well;

3. Dosing: After 2 hours, remove the virus solution, add 200 μL of the drug to be tested prepared in DMEM with 2% FBS to each well, set 6 concentrations of 50, 25, 12.5, 6.25, 3.12, 1.56 (μM), each Concentration 3 duplicate wells;

4. Detection: After 48 hours, the virus inhibition rate was determined by MTT method.

Antiviral activity and cytotoxicity test results are shown in Figure 39, Figure 40 (A and B), Table 2 and Table 3.

Table 2 Antiviral activity and cytotoxicity of compounds Ia-i

Com EC₅₀(μM) CC₅₀(μM) SI Ia 26.30±4.44 168.12±9.65 6.4 Ib 16.17±1.648 736.01±69.57 46 IC - 98.33±3.52 - Id 61.06±5.01 265.96±18.39 13.9 Ie - 183.8±5.12 - If 7.54±0.88 307.24±19.30 40.9 Ig 9.38±0.82 19.80±0.96 2.1 Ih - 204.34±3.16 - Ii 33.35±1.02 108.95±7.62 3.24 Ribavirin 105±51 532±20.27 5.06

"-" means inactive.

SI: Therapeutic Index. Therapeutic index = _CC50 (μM)/ _EC50 (μM).

From the EC ₅₀ in Table 1 above, it can be seen that the synthesized I series compounds (Ia-i) have no obvious cytotoxicity, and most of the compounds have a good inhibitory effect on influenza A H1N1 virus. The optimal EC ₅₀ of compound If activity was 7.54±0.88 μM. Overall analysis 1) In terms of substituents, when the substituent on the benzene ring is an electron withdrawing group (CH ₃ O, F), the activity is better than that of an electron withdrawing group (CH ₃ ) and unsubstituted benzene ring; 2) Comparing compounds Ib, Ig and Ih, the activity of meta-substitution is better than that of para-substitution and ortho-substitution; 3) Comparing the activities of compounds Ib and Ii, mono-substitution is better than double-substitution.

It was found by computer simulation that the series I compounds can act on the neuraminidase active pocket.

Table 3 Antiviral activity and cytotoxicity of compounds II-1 to II-15

Com EC₅₀(μM) CC₅₀(μM) SI II-1 14.30±1.718 776.23±63.15 54.2 II-2 34.71±5.86 209.37±14.09 6.0 II-3 6.68±1.32 536.32±15.14 85.6 II-4 14.05±2.47 218.70±8.65 15.6 II-5 - 146.57±8.09 - II-6 - 309.80±3.98 - II-7 - 105.42±4.10 - II-8 - 36.13±1.35 - II-9 - 294.5±9.38 - II-10 - 57.4±3.48 - II-11 - 72.30±2.52 - II-12 - 186.3±3.78 - II-13 - 124.97±5.42 - II-14 23.17±1.03 90.82±3.42 12.0 II-15 - 23.50±1.87 - Ribavirin 105±51 532±20.27 5.06

"-" means inactive.

SI: Therapeutic Index. Therapeutic index = _CC50 (μM)/ _EC50 (μM).

As can be seen from Table 2 above, this type of compound has no obvious cytotoxicity, among which compound II-3 has the best activity, EC ₅₀ =6.68±1.32μM, which is better than the positive drug ribavirin (EC ₅₀ =105±51μM), and at the same time There is also a higher therapeutic index SI = 85.6) In terms of substituents, the activity of morpholine substitution is generally the best; 2) When β is modified with benzylamine, the compound has almost no antiviral activity, and only compound II-14 shows Antiviral activity (EC ₅₀ =23.17±1.03μM/L), but its therapeutic index is much lower than compound II-3; 3) Comparing compounds II-a and II-e, it is found that the para-substituted benzene ring is better than compound II-3 Meta-substitution; 4) Comparing the activities of compounds II-1, II-2, II-3, and II-5, it can be seen that the para-substituents of the benzene ring are CH ₃ O>CH ₃ >F>Cl.

The targeting of the compound of Example 11 to neuraminidase

In this example, the targeting properties of compounds Ia-i and II-1 to II-15 to neuraminidase were verified, and the typical test results of If, Ig and II-3 are shown in Table 4.

Testing process:

1. According to the instructions of "Neuraminidase Inhibitor Screening Kit" (Biyuntian, Shanghai), add 70 μL neuraminidase detection buffer, 10 μL neuraminidase, 5 μL sample to be tested (blank group plus DMSO), 5 μL Milli -Q water, shake and mix for 1min, incubate for 2min;

2. Add 10 μL of neuraminidase fluorescent substrate, shake and mix for 1 min, incubate in an incubator for 30 min, and measure the fluorescence.

3. The emission wavelength is 450nm, and the excitation wavelength is 322nm. The NA inhibitory amount X of the compound was calculated from the standard curve.

4. NA inhibition rate=(10-X)/10×100%.

Table 4

ID MW EC₅₀ CC₅₀ SI tPSA Log S If 264 7.54±0.88 307.24±19.30 40.9 53.99 -2.767 Ig 252 9.38±0.82 19.80±0.96 2.1 44.76 -2.99 II-3 319 6.68±1.32 536.32±15.14 85.6 57.23 -3.233

Among them, tPSA is the topological polar surface area, which is a parameter commonly used in medicinal chemistry, which is defined as the total surface area of polar molecules in a compound, mostly oxygen and nitrogen atoms, including hydrogen atoms attached to them.

Log S is the hydrophilicity index, S: concentration of compound in saturated aqueous solution, 85% drug: LogS is between -1 and -5.

The experimental results show that the inhibitory effect of compound II-3 on NA (Neuraminidase) is concentration-dependent, and the inhibition rate is comparable to that of Oseltamivir as a positive drug, see Figure 41 (in the figure OSe is Oseltamivir). seltamivir).

Example 12 Molecular docking results of compound II-3

The detection method of compound II-3 molecular docking results is: computer simulation of molecular docking.

The results of molecular docking of compound II-3 are shown in FIG. 42 and FIG. 43 . It can be seen from the figure that compound II-3 can act on the same active pocket as oseltamivir acts on neuraminidase, and the methoxy group at the β-position of butenolide can form with Arg371 and Arg292 amino acids in the active pocket. hydrogen bonding interactions.

Example 13 Inhibitory effect of compound II-3 on different stages of virus replication

The specific experimental methods are:

1. Take the MDCK cell suspension in the logarithmic growth phase, inoculate it in a 24-well plate at 40,000 cells per well, and place it in a 37°C, 5% CO ₂ incubator for 24 hours. Compounds of different concentrations (50 μM, 25 μM, 12.5 μM, 6.25 μM, 3.12 μM, 1.56 μM) were added 2 hours before the virus infection, at the same time as the virus, and 2 hours after the virus infection, respectively, to test whether the compounds have inhibitory, direct and therapeutic effects on the virus. .

2. Preventive effect: Compounds of different concentrations (50 μM, 25 μM, 12.5 μM, 6.25 μM, 3.12 μM, 1.56 μM) were added 2 hours before virus infection; the medium was removed, washed three times with PBS, and infected cells with 100 TCID ₅₀ virus at 37°C , 5% CO ₂ incubator for 2h; remove the virus liquid, add 2% FBS medium, and measure the OD _450nm value by MTT method after 72h.

3. Direct effect: wash 3 times with PBS before infecting the virus, add different concentrations of compounds containing 100 TCID ₅₀ virus (diluted to 50 μM, 25 μM, 12.5 μM, 6.25 μM, 3.12 μM, 1.56 μM with pure DMEM medium). ) incubate for 2h; remove the supernatant, add 2% FBS medium, and measure the OD _450nm value by MTT method after 72h.

4. Therapeutic effect: wash 3 times with PBS before infecting the virus, infect cells with 100TCID ₅₀ virus, incubate for 1.5-2h in a 37°C, 5% CO ₂ incubator; remove the virus solution, add the medium prepared with 2% FBS Compounds of different concentrations (diluted to 50 μM, 25 μM, 12.5 μM, 6.25 μM, 3.12 μM, 1.56 μM with 2% FBS in DMEM medium) were measured for OD _450nm value by MTT method after 72 h.

5. Virus inhibition rate formula

Virus inhibition rate=(OD 450nm of drug treatment group-OD _450nm of virus control group)/(OD _450nm of normal control group- _{OD 450nm} of virus control group)×100%.

In order to explore which stage of virus replication compound II-3 acts on, compound II-3 was added before cell infection, during infection, and after infection. The experimental results showed that before H1N1 infection, the addition of compound II-3 to the cells had almost no therapeutic effect on the cells; while the addition of compound II-3 during and after the infection showed a concentration-dependent therapeutic effect on the cells. It shows that compound II-3 does not act on the adsorption stage of the virus replication cycle, but acts on the replication stage after the virus enters the cell.

Example 14 In vivo animal experiment of compound II-3

The specific experimental methods are:

1. SPF 7-week-old Balb/c female mice with a body weight of 14 ± 2 g were randomly divided into 6 groups (normal control group, virus control group, ribavirin group, high-dose group, medium-dose group) , low-dose group), 10 in each group.

2. Virus infection: Mice were anesthetized with ether, and the virus was infected by intranasal method. The normal control group was given an equal volume of normal saline.

3. Administration: 2 hours after infection with the virus, different amounts of compounds were administered by intragastric administration for 5 consecutive days, once a day. The body temperature and body weight of the mice were monitored and recorded every day during the administration period.

4. Material collection: On the sixth day of virus infection, mice were euthanized, and lung tissues were collected and stored at -80°C for future use.

In vivo animal experiments showed that compound II-3 mice had a body weight close to the normal group, and compared with the virus control group, II-3 could reduce the expression of RIG-I. Compared with the control ribavirin group, II-3 was able to increase the expression of IL-1β. Meanwhile, II-3 was able to reduce inflammation by inhibiting the excessive secretion of TNF-α in the lung tissue of infected mice, see Figure 44(a) and Figure 44(b).

The above are only a few embodiments of the present application, and are not intended to limit the present application in any form. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Without departing from the scope of the technical solution of the present application, any changes or modifications made by using the technical content disclosed above are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims (10)

1. a compound, is characterized in that, its structural formula is as shown in formula I:

Wherein, R ¹ is selected from any one of F, Cl, Br, C ₁ -C ₅ alkyl groups, and groups having the structural formula shown in formula (1); n=0, 1, 2, 3, 4 or 5; R ² is selected from any one of the group having the structural formula represented by the formula (1), the group having the structural formula represented by the formula (2), and the group having the structural formula represented by the formula (3); *-OM ¹¹ formula (1) Wherein, M ¹¹ is selected from H or C ₁ -C ₅ alkyl;

wherein, M ²¹ , M ²² , M ²³ , M ²⁴ , M ²⁵ , M ²⁶ , M ²⁷ , and M ²⁸ are independently selected from H or C ₁ -C ₅ alkyl groups;

Wherein, M ³¹ is selected from any one of H, F, Cl, Br, alkyl groups of C ₁ -C ₅ , and groups having the structural formula shown in formula (1); M ³² , M ³³ , and M ³⁴ are independently is selected from H or C ₁ -C ₅ alkyl. 2. The compound according to claim 1, wherein _n =0 in formula I; Preferably, R ¹ in formula I is selected from one of F, Cl, Br, methyl, ethyl, methoxy and ethoxy; n=1 or 2; Preferably, R ¹ in formula I is selected from at least one of 4-F, 4-Cl, 4-Br, 4-CH ₃ , 4-OCH ₃ , 3-F, 2-F, 3,4-2F ; Preferably, M ¹¹ in formula (1) is selected from methyl or ethyl; Preferably, M ²¹ , M ²² , M ²³ , M ²⁴ , M ²⁵ , M ²⁶ , M ²⁷ , M ²⁸ in formula (2) are independently selected from H, methyl or ethyl; Preferably, M ³¹ in formula (3) is selected from H, F, Cl, Br, methyl, ethyl, methoxy or ethoxy; M ³² , M ³³ , M ³⁴ are independently selected from hydrogen, methyl or ethyl; Preferably, in formula I, R ² is selected from *-OCH ₃ ,

Or any one of the groups with the structural formula shown in formula (3); wherein, in formula (3), M ³² , M ³³ , M ³⁴ are all H, and M ³¹ is selected from H, F, Cl, Br, methyl Either an oxy group or a methyl group. 3. compound according to claim 1 is characterized in that, its structural formula is as shown in formula I-5:

Preferably, R ¹ is selected from 4-F, 4-Cl, 4-Br, 4-CH ₃ , 4-OCH ₃ , 3-F, 2-F or 3,4-2F, and n=1; or n =0. 4. compound according to claim 1, is characterized in that, its structural formula is as shown in formula I-1:

Preferably, the R ¹ is selected from at least one of F, Cl, *-CH ₃ , and *-OCH ₃ , and n=1; or n=0; Preferably, the R ¹ is selected from 4-F, 4-Cl, 4-OCH ₃ , 4-CH ₃ or 3-F. 5. compound according to claim 1 is characterized in that, its structural formula is as shown in formula I-2:

Preferably, its structural formula is shown in formula I-3:

Preferably, the M ³¹ is selected from H, 4-F, 4-Cl, 4-Br, 4-OCH ₃ , 4-CH ₃ , 3-F or 2-F; Preferably, its structural formula is shown in formula I-4:

Preferably, the R ¹ is selected from at least one of Cl, *-OCH ₃ ; Preferably, the R ¹ is selected from 4-Cl or 4-OCH ₃ . 6. the preparation method of the compound described in any one of claim 1 to 5, is characterized in that, comprises: (1) the mixture I containing substituted phenylacetic acid and ethyl haloacetate is esterified in the presence of a catalyst to obtain an intermediate I, and the structural formula of the intermediate I is shown in formula II-1:

(II) will contain the raw material I of intermediate I, through Dieckmann reaction, obtain intermediate II, the structural formula of described intermediate II is as shown in formula II-2:

Preferably, solvent I and acid binding agent are also included in the mixture I described in step (1); The molar ratio of the substituted phenylacetic acid, the halogenated ethyl acetate and the acid binding agent is 1-2:1-2:1-2; The conditions of the esterification reaction are: reflux reaction under the condition of 60～80℃; Preferably, the solvent I includes one of tetrahydrofuran, dichloromethane, DMF, ethyl acetate, acetone, methanol, and ethanol; The acid binding agent includes at least one of triethylamine, pyridine, anhydrous potassium carbonate, sodium acetate, and anhydrous sodium carbonate; The mol ratio of described substituted phenylacetic acid, haloethyl acetate and acid binding agent is 1:1.2:1.2; The conditions of the esterification reaction are: heating and refluxing at 75°C under stirring conditions; Preferably, the raw material I in step (II) also includes solvent II and base I; The molar ratio of the intermediate I to the base I is 1:1.5-3; The conditions for the Dieckmann reaction are: stirring in an ice bath for 20-50 min, and then continuing the reaction at room temperature; Preferably, the solvent II includes at least one of DMF, THF, t-BuOH, acetone, EtOAc, CH ₂ Cl ₂ , DMSO, and methanol; The base I includes at least one of potassium tert-butoxide, anhydrous Na ₂ CO ₃ , CH ₃ ONa, C ₂ H ₅ ONa, NaOH, NaHCO ₃ , NaH, and anhydrous K ₂ CO ₃ ; The mol ratio of the intermediate I to the base I is 1:2; The conditions of the Dieckmann reaction are: stirring in an ice bath for 30 min, and then continuing the reaction at room temperature for 4-6 hours. 7. method according to claim 6, is characterized in that, the preparation method of described compound also comprises: (III-1) The mixture II containing intermediate II and dimethyl sulfate is subjected to methylation reaction to obtain intermediate III-1, and the structural formula of the intermediate III-1 is shown in formula II-3-1:

(IV-1) react the mixture III containing intermediate III-1, sodium methoxide and paraformaldehyde to obtain the compound shown in formula I-5; Preferably, the mixture II in step (III-1) also includes solvent III and base II; The molar ratio of the intermediate II, the base II and the dimethyl sulfate is 1:1-2:1-2; The conditions of the methylation reaction are: reaction at room temperature under dark conditions; Preferably, the solvent III includes at least one of acetone, methanol, CH ₂ Cl ₂ , THF, DMF, and EtOAc; The base II includes at least one of anhydrous K ₂ CO ₃ , anhydrous Na ₂ CO ₃ , CH ₃ ONa, NaOH, NaHCO ₃ , and NaH; The molar ratio of the intermediate II, base II and dimethyl sulfate is 1:1.2:1.2; The conditions of the methylation reaction are as follows: the reaction is performed at room temperature for 8-10 hours under the dark condition; Preferably, the mixture III in step (IV-1) also includes solvent IV; The molar ratio of the intermediate III-1, sodium methoxide and paraformaldehyde is 1:0.1-1:0.1-0.5; The reaction conditions are: 60～100 ℃ reflux reaction; Preferably, the solvent IV includes at least one of methanol, acetone, CH ₂ Cl ₂ , THF, DMF, and EtOAc; The reaction conditions are as follows: the molar ratio of intermediate III-1, sodium methoxide and paraformaldehyde is 1:0.6:0.3, reflux stirring at 75°C, adding paraformaldehyde and sodium methoxide at intervals, and reacting for 70 to 75 hours ; Preferably, during the reaction, 0.3 moles of paraformaldehyde and sodium methoxide are added every 8 hours, and the reaction is performed for 72 hours. 8. method according to claim 6, is characterized in that, the preparation method of described compound also comprises: (III-2) The raw material II containing the intermediate II is subjected to a chloronucleophilic reaction to obtain the intermediate III-2; the structural formula of the intermediate III-2 is shown in the formula II-3-2:

(IV-2) The mixture IV containing intermediate III-2 and morpholine is subjected to nucleophilic substitution under basic conditions to obtain intermediate IV-1; the structural formula of the intermediate IV-1 is as formula II-4- 1 shown:

(V-2) The mixture V containing intermediate IV-1, sodium methoxide and paraformaldehyde is reacted to obtain the compound shown in formula I-1; Preferably, the raw material II in step (III-2) further comprises: solvent V and nucleophile I; The molar ratio of the intermediate III-2 to the nucleophile I is 1:1-4; The conditions for the chloronucleophilic reaction are: stirring in an ice bath for 20-50 min, and then reacting at room temperature; Preferably, the solvent V is selected from DMF with a volume ratio of 1:1 and at least one of CH ₂ Cl ₂ , THF, DMF, EtOAc, methanol, and acetone; The nucleophile I is selected from at least one of oxalyl chloride, POCl ₃ and thionyl chloride; The mol ratio of the intermediate III-2 to the nucleophile I is 1:2; The conditions for the chloronucleophilic reaction are: stirring in an ice bath for 30 min, and then reacting at room temperature for 6 hours; Preferably, the mixture IV in step (IV-2) also includes solvent VI and base III; The molar ratio of the intermediate III-2, base III and morpholine is 1:1-4:1-4; The reaction time of the nucleophilic substitution is 3 to 6 hours; Preferably, the solvent VI includes at least one of THF, methanol, acetone, CH ₂ Cl ₂ , DMF, and EtOAc; The base III includes: at least one of anhydrous K ₂ CO ₃ , anhydrous Na ₂ CO ₃ , CH ₃ ONa, NaOH, NaHCO ₃ , and NaH; The molar ratio of the intermediate III-2, base III and morpholine is 1:2:2; The reaction time of the nucleophilic substitution is 4h; Preferably, the mixture V in step (V-2) also includes solvent VII; The molar ratio of the intermediate IV-1, sodium methoxide and paraformaldehyde is 1:0.1-1:0.1-0.5; The reaction conditions are: 60～100 ℃ reflux reaction; Preferably, the solvent VII includes at least one of methanol, acetone, CH ₂ Cl ₂ , THF, DMF, and EtOAc; The conditions of the reaction are as follows: the molar ratio of intermediate IV-1, sodium methoxide and paraformaldehyde is 1:0.6:0.3, reflux stirring at 75°C, adding paraformaldehyde and sodium methoxide at intervals, and reacting for 70 to 75 hours ; Preferably, during the reaction, 0.3 moles of paraformaldehyde and sodium methoxide are added every 8 hours, and the reaction is performed for 72 hours. 9. method according to claim 6, is characterized in that, the preparation method of described compound also comprises: (III-2) The raw material II containing the intermediate II is subjected to a chloronucleophilic reaction to obtain the intermediate III-2; the structural formula of the intermediate III-2 is shown in the formula II-3-2:

(IV-3) The mixture VI containing intermediate III-2 and benzylamine or substituted benzylamine is subjected to nucleophilic substitution under basic conditions to obtain intermediate IV-2; the structural formula of the intermediate IV-2 is as follows II-4-2 shows:

(V-3) The mixture VII containing intermediate IV-2, sodium methoxide and paraformaldehyde is reacted to obtain the compound shown in formula I-2; Preferably, the mixture VI in step (IV-3) also includes solvent VIII and base IV; The molar ratio of intermediate III-2, base IV, benzylamine or substituted benzylamine is 1:1-4:1-4; The reaction time of the nucleophilic substitution is 3 to 6 hours; Preferably, the solvent VIII includes at least one of THF, methanol, acetone, CH ₂ Cl ₂ , DMF, and EtOAc; The base IV includes: at least one of anhydrous K ₂ CO ₃ , anhydrous Na ₂ CO ₃ , CH ₃ ONa, NaOH, NaHCO ₃ , and NaH; The molar ratio of described intermediate III-2, base IV, benzylamine or substituted benzylamine is 1:2:2; The reaction time of the nucleophilic substitution is 4h; Preferably, solvent IX is also included in the mixture VII in step (V-3); The molar ratio of the intermediate IV-2, sodium methoxide and paraformaldehyde is 1:0.1-1:0.1-0.5; The reaction conditions are: 60～100 ℃ reflux reaction; Preferably, the solvent IX includes at least one of methanol, acetone, CH ₂ Cl ₂ , THF, DMF, and EtOAc; The reaction conditions are as follows: the molar ratio of intermediate IV-2, sodium methoxide and paraformaldehyde is 1:0.6:0.3, reflux stirring at 75° C., adding paraformaldehyde and sodium methoxide at intervals, and reacting for 70 to 75 hours ; Preferably, the reaction conditions further include: adding 0.3 moles of paraformaldehyde and sodium methoxide every 8 hours, and reacting for 72 hours. 10. A neuraminidase inhibitor, characterized in that it comprises at least one of the compound according to any one of claims 1 to 6 and the compound prepared by the method according to any one of claims 7 to 9 kind.

Images