Hexahydrocyclobutyl quinoline derivative as well as preparation method and application thereof

Abstract

The invention discloses a hexahydrocyclobutyl quinoline derivative and a preparation method and application thereof, and the preparation method comprises the following steps (a) and (c) or (b) and (c): (a) mixing Bronsted acid, cyclobutanone, aniline and a solvent, heating to 70-80 DEG C, reacting for 4-6 hours, and purifying to obtain a hexahydrocyclobutyl quinoline product; (b) mixing Bronsted acid, cyclobutanone, aniline and a solvent, adding a dehydrating agent, reacting for 4-6 hours, and purifying to obtain a hexahydrocyclobutyl quinoline product; and (c) dissolving the hexahydrocyclobutyl quinoline product with dichloromethane, adding alkali, adding acetyl chloride or anhydride at 0-10 DEG C, reacting for 0.5-1 hour, and purifying to obtain the hexahydrocyclobutyl quinoline derivative. The preparation method is simple in reaction operation, the reaction catalyst is low in price and easy to obtain, metal catalysis is avoided, the reaction is rapid, and the yield is excellent and can reach 80% or above. The compound prepared by the method and the pharmaceutically acceptable salt thereof have relatively good promotion activity on cell differentiation, bone formation, bone repair and bone mass increase in an osteogenesis process.

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical chemistry, and in particular, relates to a hexahydrocyclobutanequinoline derivative, a preparation method and application thereof. Background Art

[0002] Tetrahydroquinoline derivatives play an important role in organic synthesis and have great applications in the manufacture of drugs. Tetrahydroquinoline (THQ) is considered to be a promising motif for the development of new drugs. Using THQ as a parent component to connect high-strain rings such as cyclobutane can not only increase the rigidity of the heterocyclic motif, but also cause changes in the physicochemical and pharmacokinetic properties of the compound. The tetrahydroquinoline structure containing a cyclobutane structure is a pharmaceutically interesting motif and has been used as a candidate motif for the treatment of lipoxygenase-based diseases and Alzheimer's disease (US Patent 2006 / 0128790 A1, 2006). The inhibition of G protein-coupled receptors (CRTH2) by tetrahydroquinoline derivatives can act on the treatment of inflammation, such as allergic asthma and allergic rhinitis (WO2004035543A1, 2004).

[0003] To construct the parent tetrahydroquinoline (THQ), there are many synthetic methods: (1) Akiyama reported the cyclization of aldimines with vinyl ethers (J. Am. Chem. Soc. 2006, 128, 13070–13071); (2) Gong achieved the cyclization of 2-(3-phenyl-2-propynyl)aniline with Hantzsch esters by combining gold with Brønsted acid catalysis (J. Am. Chem. Soc. 2009, 131, 9182–9183); (3) Huang et al. disclosed that chiral phosphoric acid promoted the reaction of aniline with 2-oxopropionate to generate cis-2,4-diquaternized THQ (J. Am. Chem. Soc. 2013, 135, 8193–8196); (4) Zhou et al. have demonstrated a strategy to form THQ by the cyclization of aminophenyldiazobutyrate and hydroxyaniline (Adv. Synth. Catal. 2016, 358, 2366–2370). The development of new tetrahydroquinoline compounds with cyclobutane structures plays an extremely important role in the field of organic synthesis and pharmaceutical development. Although progress has been made in the development of methods for forging substituted THQ, synthetic methods that can effectively obtain hexahydrocyclobutanequinoline derivatives have rarely been studied. There are only two examples: (1) Guan's team disclosed a pioneering example of the formation of isoindolinones by iridium / Brönsted acid co-catalyzed cyclization of carboxylic anilides (CCS Chem. 2021, 3, 1775–1786); (2) Zeng's team reported the diastereoselective domino cyclization of aniline with cyclobutanone and homologues catalyzed by chromium (Org. Lett. 2023, 25, 23,4241–4246). This method inevitably uses transition metals as catalysts, which may lead to metal residues in the product on the one hand, and the overall reaction time is long and the yield is low on the other hand. Summary of the invention

[0004] In view of the problems of metal residue, long reaction time and low yield in the above-reported synthesis method, the present invention provides a hexahydrocyclobutanequinoline derivative and a preparation method and application thereof. The method has a wide substrate application range, mild conditions, short reaction time and simple operation.

[0005] In order to achieve the above object, the present invention provides a method for preparing a hexahydrocyclobutanequinoline derivative, which comprises the following steps (a) and (c) or (b) and (c): (a), mixing Bronsted acid, cyclobutanone, aniline and solvent, heating to 70-80°C, reacting for 4-6 hours and then purifying to obtain hexahydrocyclobutanequinoline product; (b), mixing the Bronsted acid, cyclobutanone, aniline and solvent, adding a dehydrating agent, reacting at room temperature for 4 to 6 hours and then purifying to obtain a hexahydrocyclobutanequinoline product; (c) dissolving the hexahydrocyclobutanequinoline product with dichloromethane, adding a base, adding acetyl chloride or acid anhydride at 0-10° C., reacting for 0.5-1 h, and then purifying to obtain the hexahydrocyclobutanequinoline derivative.

[0006] Generally, the structure of cyclobutanone, i.e., the four-membered ring structure, is unstable under acidic conditions, and the four-membered ring will generally break, resulting in the inability of the reaction to occur. In the above technical scheme, Bronsted acid is used as a catalyst. Under the catalysis of Bronsted acid, cyclobutanone can quickly condense with aniline to form a Schiff base. The two molecules of Schiff base generated immediately undergo a condensation reaction under the action of acid to form a product. The specific reaction formula is as follows:

[0007] The reaction conditions are mild, the reaction time is short, the operation is simple, and the yield can reach more than 80%.

[0008] Preferably, in steps (a) and (b), the Bronsted acid is selected from one or more of formic acid, acetic acid, propionic acid, octanoic acid, boric acid, phenylboric acid, benzoic acid, p-toluenesulfonic acid, phosphoric acid, methanesulfonic acid, thioacetic acid, oxalic acid, 2-chloropropionic acid, methacrylic acid, 2-naphthalenesulfonic acid, lauric acid, phenylglycine, trifluoromethanesulfonic acid, glyoxylic acid, lactic acid, 2-pyridinecarboxylic acid, chlorophenylboric acid, leucine, trimethylacetic acid, nicotinic acid, valine, 6-bromohexanoic acid, citric acid, and methionine.

[0009] Preferably, in steps (a) and (b), the aniline is selected from one of aniline, halogenated aniline, C1-4 alkyl aniline, methoxy aniline and (methylthio) aniline.

[0010] Halogenated aniline such as 3-fluoroaniline, 4-fluoroaniline, 3-chloroaniline, 4-chloroaniline, 3-bromoaniline, 4-bromoaniline, 3-iodoaniline, 4-iodoaniline and the like.

[0011] C1-4 alkylaniline such as 3-methylaniline, 4-methylaniline, 3,4-dimethylaniline, 3,5-dimethylaniline, 3,4,5-trimethylaniline, 3-ethylaniline, 4-ethylaniline, 3,4-diethylaniline, 3-tert-butylaniline, 4-tert-butylaniline, 3-propylaniline, 4-propylaniline, 3-isopropylaniline, 4-isopropylaniline, 4-isobutylaniline and the like.

[0012] Anisidine such as 3-methoxyaniline, 4-methoxyaniline and the like.

[0013] (Methylthio)aniline such as 3-(methylthio)aniline, 4-(methylthio)aniline and the like.

[0014] The aniline is preferably aniline, 3-chloroaniline, 4-chloroaniline, 3-bromoaniline, 4-bromoaniline, 3-methylaniline, 4-methylaniline, 3,4-dimethylaniline, 3,5-dimethylaniline, 3-ethylaniline, 4-ethylaniline, 3-methoxyaniline, 4-methoxyaniline, 3-tert-butylaniline, 3-propylaniline, 4-tert-butylaniline, 4-propylaniline, 3-isopropylaniline, 4-isopropylaniline. By using these anilines, the yield of the product can reach more than 90%, and can reach up to 98%.

[0015] The above anilines can quickly condense with cyclobutanone to form Schiff bases under the catalysis of Bronsted acid.

[0016] Preferably, in steps (a) and (b), the solvent is selected from one or more of benzene, toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, nitrobenzene, dichloromethane, dichloroethane, chloroform, ethyl ether, tert-butyl methyl ether, ethylene glycol dimethyl ether, n-hexane, n-pentane, anhydrous methanol, anhydrous ethanol, cyclohexane, tetrahydrofuran, and dimethyl sulfoxide.

[0017] Specifically, in steps (a) and (b), the molar ratio of aniline, cyclobutanone and Bronsted acid is (2-2.2):1:(0.1-0.2); in step (c), the molar ratio of hexahydrocyclobutanequinoline product to base and acetyl chloride is 1:(2-3):(10-15), or the molar ratio of hexahydrocyclobutanequinoline product to base and acid anhydride is 1:(2-3):(10-15).

[0018] The purification operation in steps (a), (b) and (c) is as follows: a certain amount of saturated sodium bicarbonate solution is added to the reaction system, and then extracted with dichloromethane for several times. The obtained organic phases are combined, dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. The purified product is then obtained by silica gel column chromatography.

[0019] Preferably, in step (b), the dehydrating agent is a molecular sieve, which functions to accelerate the formation of Schiff's base, and is more preferably a 4A molecular sieve.

[0020] The second aspect of the present invention provides a hexahydrocyclobutanequinoline derivative prepared by the above-mentioned preparation method, which has the following structure: , In the formula, R1 is a fatty acyl group, C 6-8 Aryl, heteroaryl or aliphatic; R2, R3 are hydrogen, fatty acyl, C 6-8 Aryl, heteroaryl or aliphatic; R4, R5, R6 and R7 are hydrogen, halide, C 6-8 Aryl, heteroaryl or aliphatic; X is C, O, S.

[0021] The third aspect of the present invention provides a pharmaceutical composition, which includes the above-mentioned hexahydrocyclobutanequinoline derivative, or a salt thereof with a pharmaceutically acceptable acid, preferably, the acid includes an inorganic acid salt and an organic acid salt. The inorganic acid salt includes: hydrochloric acid, sulfuric acid, phosphoric acid, carbonic acid, bicarbonate, nitric acid, monohydrogen phosphate, dihydrogen phosphate, hydrobromic acid or hydroiodic acid; the organic acid includes: maleic acid, tartaric acid, citric acid, methanesulfonic acid, succinic acid, acetic acid, p-toluenesulfonic acid, mandelic acid, isobutyric acid, malonic acid, etc.

[0022] The fourth aspect of the present invention provides a use of the above-mentioned pharmaceutical composition in the preparation of drugs for treating bone defects and osteoporosis.

[0023] The compound prepared by the method of the present invention or a pharmaceutically acceptable salt thereof can effectively promote the differentiation and proliferation activity of bone marrow mesenchymal stem cells (BMSCs), induce them to differentiate into bone lineage cells, and promote bone formation.

[0024] The compound prepared by the method of the present invention or its pharmaceutically acceptable salt form is a small molecule that can effectively promote the functional activity of bone biomarkers such as alkaline phosphatase. Alkaline phosphatase is one of the characteristics of cell differentiation in the osteogenesis process. Generally speaking, its related activity increases as cells undergo osteogenesis, so the compound prepared by the present invention or its pharmaceutically acceptable salt form can promote bone formation and / or bone repair.

[0025] The compound prepared by the method of the present invention or a pharmaceutically acceptable salt thereof can effectively promote bone synthesis and increase bone mass, thereby improving osteoporosis.

[0026] Through the above technical solution, the present invention achieves the following beneficial effects: 1. The preparation method of the present invention has simple reaction operation, cheap and easily available reaction catalyst, no metal catalysis, rapid reaction and excellent yield, which can reach more than 80%.

[0027] 2. The compounds prepared by the method of the present invention and their pharmaceutically acceptable salts have good promoting activity on cell differentiation, bone formation, bone repair and bone mass increase in the process of osteogenesis. The biological activity evaluation showed that the prepared compound had a significant promoting effect on the proliferation and differentiation activity of bone marrow mesenchymal stem cells (BMSCs) (greater than 2.5 times), and had a significant inducing effect on the content of alkaline phosphatase after cell culture and differentiation of bone marrow mesenchymal stem cells (BMSCs) (greater than 2 times). The evaluation of cortical bone and cancellous bone mass showed that it had a significant promoting effect on the increase of mouse femoral bone mass (greater than 2 times). BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The results are as follows: the effects of some compounds of the present invention on the proliferation activity of mouse BMSCs; Figure 2 The results are the results of the determination of the effects of some compounds of the present invention on the alkaline phosphatase (ALP) content of mouse BMSCs cells; Figure 3 The results are the results of the determination of the effects of some compounds of the present invention on alkaline phosphatase (ALP) of mouse BMSCs cells; Figure 4 The results of in vivo experiments on the effects of some compounds of the present invention on osteoporosis in mice; Figure 5 The micro-CT photo of the femur of mice is shown in the following figure, showing administration of some compounds of the present invention to the medullary cavity of mice; Figure 6 The results of the systemic administration experiment of some compounds of the present invention to mice; Figure 7 This is a statistical diagram of the average number of femoral trabeculae in mice in a systemic administration experiment of some compounds of the present invention to mice; Figure 8 This is a micro-CT photo of the femur of mice in the systemic administration experiment of some compounds of the present invention to mice; Fig. 9 The results of in situ administration experiments on the effects of some compounds of the present invention on femoral defects in mice; Fig.10 This is a real picture of the in situ drug administration experiment on the effects of some compounds of the present invention on femoral defects in mice. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is described in detail below in conjunction with the examples. It should be understood that the specific implementation described herein is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0030] The raw materials and equipment used in the following examples are all known products, which are obtained by purchasing commercially available products. The present invention can be prepared in the form of salt by using a salt-forming method commonly used in the art, for example, dissolving a hexahydrocyclobutanequinoline derivative in hydrochloric acid and ethanol at room temperature to react to generate a hydrochloride; or adding benzenesulfonate thereto to react to generate a benzenesulfonate.

[0031] Example 1 Add 6.9 mg of p-toluenesulfonic acid, 28 μL of cyclobutanone and 19 μL of aniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 29 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product (see Table 1 for the product structure). The total yield is 92%.

[0032] Example 2 Add 6.9 mg of p-toluenesulfonic acid, 28 μL of cyclobutanone and 19 μL of aniline to the reaction bottle, then add 2 mL of dichloromethane solution, then add 4A molecular sieves, stir at room temperature for 6 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then obtain the pure product by silica gel column chromatography. Dissolve 29 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then obtain the pure product by silica gel column chromatography. The total yield is 95%.

[0033] Example 3 Add 1.8 mg of formic acid, 28 μL of cyclobutanone and 19 μL of 3-fluoroaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 70 ° C, and stop stirring after the reaction for 6 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 33 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, and stop stirring after stirring at room temperature for 1 hour. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 80%.

[0034] Example 4 Add 2.4 mg of acetic acid, 28 μL of cyclobutanone and 23 μL of 4-fluoroaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 5 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 33 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. The total yield is 85%.

[0035] Example 5 Add 3 mg of propionic acid, 28 μL of cyclobutanone and 21 μL of 3-chloroaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 36 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetic anhydride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 92%.

[0036] Example 6 Add 5.8 mg of octanoic acid, 28 μL of cyclobutanone and 18 μL of 4-chloroaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 36 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 95%.

[0037] Example 7 Add 2.5 mg of boric acid, 28 μL of cyclobutanone and 22 μL of 3-bromoaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 75 ° C, and stop stirring after the reaction for 5 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 45 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 93%.

[0038] Example 8 Add 4.9 mg of benzoic acid, 28 μL of cyclobutanone and 24 μL of 4-bromoaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 6 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 45 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 95%.

[0039] Example 9 Add 3.9 mg of phosphoric acid, 28 μL of cyclobutanone and 23 μL of 3-iodoaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 6 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 54 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 83%.

[0040] Example 10 Add 3.8 mg of methanesulfonic acid, 28 μL of cyclobutanone and 24 μL of 4-iodoaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 54 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 88%.

[0041] Embodiment 11 Add 3mg of thioacetic acid, 28μL of cyclobutanone and 21μL of 3-methylaniline to the reaction bottle, then add 2mL of dichloromethane solution, heat to 80℃, and stop stirring after the reaction for 4h. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 32mg of the product in 1mL of dichloromethane, add 35μL of triethylamine, add 1mL of acetyl chloride at 0℃, stir at room temperature for 0.5h, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 95%.

[0042] Example 12 Add 3.6 mg of oxalic acid, 28 μL of cyclobutanone and 20 μL of 4-methylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 5 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 32 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 98%.

[0043] Example 13 Add 4.3 mg of 2-chloropropionic acid, 28 μL of cyclobutanone and 23 μL of 3,4-dimethylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 35 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 92%.

[0044] Embodiment 14 Add 3.4 mg of methacrylic acid, 28 μL of cyclobutanone and 25 μL of 3,5-dimethylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 35 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 90%.

[0045] Embodiment 15 Add 8.3 mg of 2-naphthalenesulfonic acid, 28 μL of cyclobutanone and 27 μL of 3,4,5-trimethylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 37 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 86%.

[0046] Example 16 Add 7.5 mg of lauric acid, 28 μL of cyclobutanone and 25 μL of 3-ethylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 35 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. The total yield is 93%.

[0047] Embodiment 17 Add 6 mg of phenylglycine, 28 μL of cyclobutanone and 24 μL of 4-ethylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 35 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. The total yield is 95%.

[0048] Embodiment 18 Add 6 mg of trifluoromethanesulfonic acid, 28 μL of cyclobutanone and 32 μL of 3,4-diethylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 40 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. The total yield is 84%.

[0049] Embodiment 19 Add 3 mg of glyoxylic acid, 28 μL of cyclobutanone and 22 μL of 3-methoxyaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 35 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. The total yield is 90%.

[0050] Embodiment 20 Add 3.6 mg of lactic acid, 28 μL of cyclobutanone and 23 μL of 4-methoxyaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 35 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. The total yield is 92%.

[0051] Embodiment 21 Add 4.9 mg of 2-pyridinecarboxylic acid, 28 μL of cyclobutanone and 32 μL of 3-tert-butylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 40 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 90%.

[0052] Embodiment 22 Add 6.3 mg of chlorophenylboronic acid, 28 μL of cyclobutanone and 27 mg of 3-propylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 37 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 90%.

[0053] Embodiment 23 Add 5.3 mg of leucine, 28 μL of cyclobutanone and 30 mg of 4-tert-butylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. Dissolve 40 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry it with anhydrous sodium sulfate, filter it, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph it on a silica gel column to obtain a pure product. The total yield is 92%.

[0054] Embodiment 24 Add 4.1 mg of trimethylacetic acid, 28 μL of cyclobutanone and 27 mg of 4-propylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 37 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 92%.

[0055] Embodiment 25 Add 4.9 mg of nicotinic acid, 28 μL of cyclobutanone and 27 mg of 3-isopropylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 37 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 90%.

[0056] Embodiment 26 Add 4.7 mg of valine, 28 μL of cyclobutanone and 27 mg of 4-isopropylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 37 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 92%.

[0057] Embodiment 27 Add 7.8 mg of 6-bromohexanoic acid, 28 μL of cyclobutanone and 30 mg of 4-isobutylaniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 40 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 80%.

[0058] Embodiment 28 Add 7.7 mg of citric acid, 28 μL of cyclobutanone and 28 mg of 3-(methylthio)aniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 38 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 80%.

[0059] Embodiment 29 Add 6 mg of methionine, 28 μL of cyclobutanone and 28 mg of 4-(methylthio)aniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 38 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 82%.

[0060] Embodiment 30 Add 5.6 mg of 2,4-difluorophenylboronic acid, 28 μL of cyclobutanone and 19 μL of aniline to the reaction bottle, then add 2 mL of anhydrous methanol solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. Dissolve 23 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After the obtained organic phases are combined, they are dried with anhydrous sodium sulfate, filtered, and the solvent is removed under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography. The total yield is 86%.

[0061] Embodiment 31 Add 6.9 mg of p-toluenesulfonic acid, 24 μL of oxetane and 19 μL of aniline to the reaction bottle, then add 2 mL of dichloromethane solution, heat to 80 ° C, and stop stirring after the reaction for 4 hours. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 29 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 80%.

[0062] Embodiment 32 Add 6.9 mg of p-toluenesulfonic acid, 24 μL of oxetane and 19 μL of aniline to the reaction bottle, then add 2 mL of dichloromethane solution, then add 4A molecular sieves, stir at room temperature for 4 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. Dissolve 29 mg of the product in 1 mL of dichloromethane, add 35 μL of triethylamine, add 1 mL of acetyl chloride at 0 ° C, stir at room temperature for 0.5 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract it three times with dichloromethane. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, chromatograph the pure product on a silica gel column. The total yield is 85%.

[0063] Comparative Example 1 Add 15 mg of tri-tetrahydrofuran chromium chloride, 28 μL of cyclobutanone and 76 μL of aniline to the reaction bottle, then add 1 mL of tetrahydrofuran solution, stir at room temperature for 12 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract with dichloromethane three times. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography with a yield of 72%.

[0064] Comparative Example 2 Add 11.6 mg of copper trifluoroacetate, 28 μL of cyclobutanone and 19 μL of aniline to the reaction bottle, then add 1 mL of n-hexane solution, stir at 80 ° C for 12 hours, and then stop stirring. Add a certain amount of saturated sodium bicarbonate solution to the reaction system, and then extract with dichloromethane three times. After combining the obtained organic phases, dry them with anhydrous sodium sulfate, filter them, and remove the solvent under reduced pressure to obtain a crude product. Then, the pure product is obtained by silica gel column chromatography with a yield of 75%.

[0065] Table 1 Comparative Table of Example Compounds

[0066] The following is an evaluation of the biological activity of some compounds of this invention. 1. Effect of the compound of Example 1 on the proliferation activity of mouse BMSCs: The experimental method is as follows: First, BMSCs were prepared to a concentration of 5×10 7 / L of cell suspension, and inoculated in a 96-well plate with 100μL per well, and then added α-MEM medium containing 10% fetal bovine serum and 1% penicillin-streptomycin double antibody; cultured at 37℃ and 5% CO2 for 24h, discarded the original culture medium and non-adherent cells, and cultured according to experimental groups, with 3 replicates in each group, divided into normal group, 5μM, 500nM, 50nM drug group, and compound treatment group. 100μL of the corresponding compound was added to each well, and α-MEM medium containing 10% fetal bovine serum and 1% penicillin-streptomycin double antibody was added to the normal group. After 1, 3, and 5d of culture, 10μL of MTT was added to each well, incubated at 37℃ for 4h, and then the culture medium was aspirated, 150μLDMSO was added to each well, and gently shaken for 10min. Take 100μL from each well and place it on an enzyme reader at a wavelength of 490nm to measure the absorbance value. The results are as follows Figure 1 As shown in the figure, it can be seen that there is a significant difference in the absorbance values ​​measured between the high-dose group and the normal group. The absorbance value measured by the enzymatic method after 5 days of cell culture is 2.5 times greater than that of the normal group, indicating that the compound has obvious inducing activity on the differentiation and proliferation of BMSCs.

[0067] II. Determination of the effect of the compound of Example 7 on the alkaline phosphatase (ALP) content of mouse BMSCs cells: The experimental method is as follows: Cells were cultured and induced to differentiate according to the experimental groups. The cells were divided into normal group, 5μM, 500nM drug group, and positive control group. The cells were washed twice with PBS buffer, digested with 0.04g / L trypsin, added with 0.09mol / L p-nitrophenol phosphate, reacted at 37°C for 30min in a reaction solution with pH 10.3, and finally 0.1mol / L NaOH was added to terminate the reaction. The results were expressed as the absorbance (OD) value measured by an enzyme marker at 405 nm, and 3 replicates were performed in each group. The results are shown in Figure 2. Figure 2 and Figure 3 As shown in the figure, it can be seen that the absorbance values ​​measured in the high-dose group and the normal group are significantly different from those in the positive group. The absorbance value measured by the enzymatic method after cell culture is more than 2 times that of the normal group, indicating that the compound has a significant improvement in the ALP level (ALP is a marker of osteoblasts) after differentiation of BMSCs, showing significant induction activity. Compared with the normal group, the compound can significantly promote the expression of ALP in BMSCs cells at a concentration of 5uM, thereby promoting the growth of osteoblasts.

[0068] III. In vivo intramedullary administration experiment on the effect of the compound of Example 13 on osteoporosis in mice: The experimental method is as follows: Several 6-week-old female C57 mice were randomly divided into 6 groups, including a normal group, a model group, a 1.25 mg / kg compound group, a 2.5 mg / kg compound group, a 5 mg / kg compound group, and a 10 mg / kg compound group. After 3 days of adaptive feeding, the mice were anesthetized by intraperitoneal injection of 4% chloral hydrate and then underwent ovariectomy. The normal group underwent a sham operation. Subsequently, the drug was administered into the femoral bone marrow cavity with a dosage of 0.1 mL. After the operation, the mice were heated and allowed to eat freely. After 4 weeks of feeding, the mice were killed by dislocating the cervical vertebrae, and the femurs of the mice were removed, fixed with paraformaldehyde, and subjected to micro-CT examination. The results are as follows Figure 4 and Figure 5 As shown in the figure, it can be seen that after a single intramedullary administration of 1.25 mg / kg and 2.5 mg / kg of the compound, the femoral bone mass increased significantly, which was significantly different from that of the model group (more than 2 times), indicating that the compound prepared by the present invention has a significant effect of inducing and improving osteoporosis.

[0069] IV. Systemic administration experiment of the compound of Example 19 on osteoporosis in mice: The experimental method is as follows: Several 6-week-old female C57 mice were randomly divided into 6 groups: normal group (sham castration), model group, 300 mg / kg gavage group (ig), 150 mg / kg gavage group (ig), 300 mg / kg intraperitoneal injection group (ip), and 150 mg / kg intraperitoneal injection group (ip). After 3 days of adaptive feeding, the mice were anesthetized by intraperitoneal injection of 4% chloral hydrate and underwent ovariectomy. The normal group underwent sham castration. After the operation, the mice were heated and allowed to eat freely. After 4 weeks of feeding, the osteoporosis model was established, and the corresponding group medication was carried out: the model group and the normal group were gavaged with equal doses of normal saline; the medication group was administered every day. The medication treatment period was 4 weeks. During the 4 weeks, the mice were free to eat and drink. After 4 weeks, the mice were killed by cervical dislocation, and the femurs of the mice were taken, fixed with paraformaldehyde, and subjected to micro-CT examination. The results are as follows Figure 6~Figure 8 As shown in the figure, it can be seen that compared with the model group, the 150 mg / kg ig and 150 mg / kg ip groups can significantly improve the bone content and the average number of trabeculae in the femur of mice.

[0070] V. In situ administration experiment of the effect of the compound of Example 28 on femoral defects in mice: The experimental method is as follows: Several 12-week-old female ICR mice were randomly divided into 5 groups, with 3 mice in each group: model 0 day group (0d M), model 5 day group (5d M), medication 5 day group (5d), model 20 day group (20d M), medication 20 day group (20d). After 3 days of adaptive feeding, the mice were anesthetized by intraperitoneal injection of 4% chloral hydrate. The left hind limb of the mouse was depilated, disinfected, and the skin and muscles were cut to expose the femur. A 2mm hole was drilled with a drill bit at the upper end of the femoral shaft, rinsed with saline, and the broken bones were washed away. Except for the model group, which was not given any medicine, each mouse was given 2 mg of the compound in situ in the medullary cavity of the femoral defect. The wound was closed, the muscles and skin were sutured, and disinfected. The mice were heated and warmed, and after waking up from anesthesia, they were free to eat and drink water. The mice were killed on days 5 and 20, the femurs were removed, the defect size was measured, and compared. The results are as follows Fig. 9 and Fig.10 As shown in the figure, it can be seen that compared with the bone defect model group at the same period, the bone defect area of ​​mice in the 20-day drug administration group was significantly reduced, indicating that the compound can significantly promote new bone formation at the bone defect site.

[0071] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0072] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0073] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing a hexahydrocyclobutanequinoline derivative, characterized in that: The method comprises the following steps (a) and (c) or (b) and (c): (a) Mixing Bronsted acid, cyclobutanone, aniline and solvent, heating to 70-80°C, reacting for 4-6 hours and then purifying to obtain hexahydrocyclobutanequinoline product; (b), mixing the Bronsted acid, cyclobutanone, aniline and solvent, adding a dehydrating agent, reacting at room temperature for 4 to 6 hours and then purifying to obtain a hexahydrocyclobutanequinoline product; (c) dissolving the hexahydrocyclobutanequinoline product with dichloromethane, adding a base at 0-10° C., adding acetyl chloride or acid anhydride, reacting for 0.5-1 h, and then purifying to obtain the hexahydrocyclobutanequinoline derivative.

2. The preparation method according to claim 1, characterized in that: In steps (a) and (b), the Bronsted acid is selected from one or more of formic acid, acetic acid, propionic acid, octanoic acid, boric acid, phenylboric acid, benzoic acid, p-toluenesulfonic acid, phosphoric acid, methanesulfonic acid, thioacetic acid, oxalic acid, 2-chloropropionic acid, methacrylic acid, 2-naphthalenesulfonic acid, lauric acid, phenylglycine, trifluoromethanesulfonic acid, glyoxylic acid, lactic acid, 2-pyridinecarboxylic acid, chlorophenylboric acid, leucine, trimethylacetic acid, nicotinic acid, valine, 6-bromohexanoic acid, citric acid, and methionine.

3. The preparation method according to claim 1, characterized in that: In steps (a) and (b), the aniline is selected from one of aniline, halogenated aniline, C1-4 alkyl aniline, methoxy aniline and (methylthio) aniline; and the cyclobutanone is cyclobutanone or oxetanone.

4. The preparation method according to claim 1, characterized in that: In steps (a) and (b), the solvent is selected from one or more of benzene, toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, nitrobenzene, dichloromethane, dichloroethane, chloroform, ether, tert-butyl methyl ether, ethylene glycol dimethyl ether, n-hexane, n-pentane, anhydrous methanol, anhydrous ethanol, cyclohexane, tetrahydrofuran, and dimethyl sulfoxide.

5. The preparation method according to claim 1, characterized in that: In steps (a) and (b), the molar ratio of aniline, cyclobutanone and Bronsted acid is (2-2.2):1:(0.1-0.2); in step (c), the molar ratio of hexahydrocyclobutanequinoline product to base and acetyl chloride is 1:(2-3):(10-15), or the molar ratio of hexahydrocyclobutanequinoline product to base and acid anhydride is 1:(2-3):(10-15).

6. The preparation method according to any one of claims 1 to 5, characterized in that In step (b), the dehydrating agent is a molecular sieve.

7. The hexahydrocyclobutanequinoline derivative obtained by the preparation method according to any one of claims 1 to 6, characterized in that: Has the following structure: ， In the formula, R1 is a fatty acyl group, C 6-8 Aryl, heteroaryl or aliphatic; R2, R3 are hydrogen, fatty acyl, C 6-8 Aryl, heteroaryl or aliphatic; R4, R5, R6 and R7 are hydrogen, halide, C 6-8 Aryl, heteroaryl or aliphatic; X is C, O, S.

8. A pharmaceutical composition, characterized in that The invention comprises the hexahydrocyclobutanequinoline derivative according to claim 7 or 8, or a salt thereof with a pharmaceutically acceptable acid.

9. The pharmaceutical composition according to claim 8, characterized in that The acid includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, carbonic acid, bicarbonate, nitric acid, monohydrogen phosphate, dihydrogen phosphate, hydrobromic acid, hydroiodic acid, maleic acid, tartaric acid, citric acid, methanesulfonic acid, succinic acid, acetic acid, p-toluenesulfonic acid, mandelic acid, isobutyric acid, and malonic acid.

10. Use of the pharmaceutical composition according to claim 8 or 9 in the preparation of drugs for treating bone defects and osteoporosis.

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