Pyrrolidone dihydroisoxazole compound as well as preparation method and application thereof

Abstract

The invention provides a pyrrolidone dihydroisoxazole compound as well as a preparation method and application thereof, and belongs to the technical field of organic synthesis. Specifically, under the catalytic action of Lewis base, beta-oxoacrylamide and 4-nitroisoxazole serve as raw materials, and the pyrrolidone dihydroisoxazole compound is synthesized through a one-step method. Beta-oxoacrylamide and 4-nitroisoxazole which are simple and easy to obtain are adopted as starting raw materials, dearomatization [3 + 2]-cycloaddition reaction is carried out under the catalysis of Lewis base, the pyrrolidone dihydroisoxazole compound is synthesized, the method is easy and convenient to operate and mild in reaction condition, the used reagents and raw materials are economical and easy to obtain, and the method is suitable for industrial production. The target product yield is high, the substrate application range is wide, and the in-vitro anti-tumor activity is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis, and particularly relates to a pyrrolidone-fused dihydroisoxazole compound, a preparation method thereof, and an application thereof. Background Art

[0002] Dihydroisoxazole is a class of important five-membered heterocyclic compounds, which are widely present in the structures of natural products and drug molecules. It is often used as a pharmacophore to enhance molecular stability, improve solubility, or participate in target hydrogen bond interactions, and has various biological and pharmacological activities such as antibacterial, antitumor, antimalarial, analgesic, and anti-amoebic activities. In addition, pyrrolidone is also an important functional module, which is widely present in drug molecules, bioactive molecules, and functional materials. For example, phenylpiracetam and piracetam are antidepressant drugs that improve brain function and are used to treat sequelae of cerebrovascular diseases and Alzheimer's disease; phenyramidone is a dual inhibitor of cyclooxygenase and lipoxygenase and is an organic compound mainly used as a developer; doxapram is a central nervous stimulant used to treat acute respiratory depression; levetiracetam is a novel antiepileptic drug mainly used to treat partial-onset and generalized-onset epilepsy. Therefore, developing an efficient synthetic strategy for pyrrolidone-fused dihydroisoxazole hybrid skeletons will provide key technical support for drug discovery and development.

[0003] The Caramella research group reported a base-mediated [3+2] cycloaddition reaction of five-membered cyclic α,β-unsaturated amides and nitrile oxides, and synthesized a series of pyrrolidone-fused dihydroisoxazole compounds with moderate regioselectivity (Tetrahedron 1999, 55, 7027-7044). The Zhang research group reported an asymmetric [3+2] cycloaddition reaction of 4-ester-5-aminoisoxazole and quinone imine catalyzed by chiral phosphoric acid, which underwent a tandem cyclization / lactamization reaction process, and synthesized polybridged ring compounds containing a pyrrolidone-fused dihydroisoxazole skeleton with moderate yields and excellent enantioselectivity (Chem. Commun., 2020, 56, 13591-13594). Although certain progress has been made in the synthesis research of pyrrolidone-fused dihydroisoxazole compounds, the existing systems still have deficiencies such as poor regioselectivity, the use of excessive bases, and narrow substrate expansion ranges.

[0004] Therefore, further developing an efficient method for synthesizing pyrrolidone-fused dihydroisoxazole compounds has important application value, especially developing an efficient, economical, green, and wide substrate expansion range synthesis method is of great significance. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a pyrrolidinone-fused dihydroisoxazole compound, a preparation method and an application thereof. Using readily available β-oxoacrylamide and 4-nitroisoxazole as starting materials, a dearomatizing [3+2]-cycloaddition reaction occurs under the catalysis of a Lewis base to synthesize a pyrrolidinone-fused dihydroisoxazole compound.

[0006] The present invention is achieved through the following technical solutions: The present invention provides a pyrrolidinone-fused dihydroisoxazole compound, and the structural formula of the pyrrolidinone-fused dihydroisoxazole compound is shown as follows: Wherein, R 1 is one of phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-trifluoromethylphenyl, 3-methylphenyl, 3-methoxyphenyl, 3-chlorophenyl, 2-methylphenyl, 2-fluorophenyl, 2-bromophenyl, 2-naphthyl, 2-thienyl, methyl, tert-butyl, benzyl; R 2 is one of C1-C5 alkyl, C3-C12 cycloalkyl, allyl, propargyl, benzyl, 4-methylbenzyl, 4-chlorobenzyl, 4-bromobenzyl, 4-trifluorobenzyl, 2-naphthylmethyl; R 3 is one of phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-trifluoromethylphenyl, 4-trifluoromethoxy, 3-methylphenyl, 3-methoxyphenyl, 3-chlorophenyl, 2-methylphenyl, 2-bromophenyl, 2-naphthyl, 2-thienyl, cyclohexyl.

[0007] In the present invention, a preparation method of the pyrrolidinone-fused dihydroisoxazole compound is further provided. Under the catalytic action of a Lewis base, β-oxoacrylamide and 4-nitroisoxazole are used as raw materials to synthesize a pyrrolidinone-fused dihydroisoxazole compound by a one-step method; The structural formula of the β-oxoacrylamide is: ; The structural formula of the 4-nitroisoxazole is: .

[0008] Furthermore, the molar ratio of β-oxoacrylamide, 4-nitroisoxazole, and the Lewis base is 1~1.2:1:0.05~0.2; the Lewis base is one or more of triethylamine, diisopropylethylamine, tributylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylenediamine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 4-dimethylaminopyridine, pyridine, cesium carbonate, potassium carbonate, sodium carbonate.

[0009] Furthermore, the molar ratio of β-oxopropenamide, 4-nitroisoxazole, and Lewis base is 1.2:1:0.1; the Lewis base is triethylamine.

[0010] Furthermore, the solvent for the one-step synthesis of pyrrolidinone-fused dihydroisoxazole compounds is one of acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, acetone, toluene, p-xylene, dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, and tert-butyl methyl ether.

[0011] Furthermore, the solvent for the one-step synthesis of pyrrolidinone-fused dihydroisoxazole compounds is acetonitrile.

[0012] Furthermore, the reaction temperature for the one-step synthesis of pyrrolidinone-fused dihydroisoxazole compounds is 0-40 °C, and the stirring reaction time is 8-12 h.

[0013] Furthermore, after the reaction for the one-step synthesis of pyrrolidinone-fused dihydroisoxazole compounds is completed, the reaction solution is concentrated under vacuum, and the residue is passed through a silica gel column chromatography with 200 mesh to obtain the pyrrolidinone-fused dihydroisoxazole compounds.

[0014] Furthermore, the silica gel column chromatography uses a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent.

[0015] In the present invention, there is also provided the use of the pyrrolidinone-fused dihydroisoxazole compounds in the preparation of anti-tumor drugs.

[0016] The beneficial effects achieved by the present invention are as follows: By using easily available β-oxopropenamide and 4-nitroisoxazole as starting materials, the present invention synthesizes pyrrolidinone-fused dihydroisoxazole compounds through a dearomatizing [3+2]-cycloaddition reaction catalyzed by a Lewis base. This method is simple to operate, has mild reaction conditions, uses economically available reagents and raw materials, has a high yield of the target product, a wide substrate scope, and has a good effect of inhibiting tumor activity. Description of the Drawings

[0017] Figure 1 1H NMR spectrum of pyrrolidinone-fused dihydroisoxazole compound 3aa in Example 1 1 1H NMR spectrum; Figure 2 13C NMR spectrum of pyrrolidinone-fused dihydroisoxazole compound 3aa in Example 1 13 13C NMR spectrum; Figure 3 1H NMR spectrum of pyrrolidinone-fused dihydroisoxazole compound 3ab in Example 2 1 1H NMR spectrum; Figure 4 13C NMR spectrum of pyrrolidinone-fused dihydroisoxazole compound 3ab in Example 213 CNMR spectrum; Figure 5 For the 1 HNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ac in Example 3; Figure 6 For the 13 CNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ac in Example 3; Figure 7 For the 1 HNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ad in Example 4; Figure 8 For the 13 CNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ad in Example 4; Figure 9 For the 1 HNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ae in Example 5; Figure 10 For the 13 CNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ae in Example 5; Figure 11 For the 1 HNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ba in Example 6; Figure 12 For the 13 CNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ba in Example 6; Figure 13 For the 1 HNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ca in Example 7; Figure 14 For the 13 CNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ca in Example 7; Figure 15 For the 1 HNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3da in Example 8; Figure 16 For the 13 CNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3da in Example 8; Figure 17 For the 1 HNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ea in Example 9; Figure 18 For the 13 CNMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ea in Example 9; Figure 19 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3fa in Example 10 1 ; Figure 20 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3fa in Example 10 13 13C NMR spectrum; Figure 21 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ga in Example 11 1 ; Figure 22 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ga in Example 11 13 13C NMR spectrum; Figure 23 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ha in Example 12 1 ; Figure 24 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ha in Example 12 13 13C NMR spectrum; Figure 25 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ia in Example 13 1 ; Figure 26 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ia in Example 13 13 13C NMR spectrum; Figure 27 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ja in Example 14 1 ; Figure 28 1H NMR spectrum of pyrrolidone-fused dihydroisoxazole compound 3ja in Example 14 13 13C NMR spectrum. Detailed implementation manners

[0018] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0019] Example 1 β-(4-Methylbenzoyl)-N-methoxyacrylamide 1a (26.3 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube. 1 mL of dry acetonitrile (0.1 M) was added, and the mixture was stirred at room temperature until the solids were completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 10 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out for separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidinone-fused dihydroisoxazole compound 3aa, a white solid. The isolated yield was 32.7 mg, and the yield was 80%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 1 and Figure 2 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.93 –7.85 (m, 2H), 7.82 (d, J J = 7.9 Hz, 2H), 7.71 (d, J J = 7.8 Hz, 0.2H), 7.62 – 7.58(m, 0.2H), 7.48 (dt, J J = 14.4, 7.0 Hz, 3H), 7.39 (q, J J = 5.2, 4.1 Hz, 0.3H), 7.24(s, 2H), 7.18 (d, J J = 7.8 Hz, 0.2H), 6.99 (s, 1H), 4.29 (dd, J J = 18.7, 4.4 Hz,1H), 4.17 (s, 0.3H), 4.12 (d, J J = 4.6 Hz, 0.1H), 4.00 (s, 3H), 3.93 (dd, J J =18.6, 4.1 Hz, 1H), 3.80 – 3.75 (m, 0.1H), 3.67 – 3.61 (m, 0.1H), 3.53 (t, J J =4.2 Hz, 1H), 2.40 (s, 3H), 2.35 (s, 0.3H); 1313C NMR (126 MHz, CDCl3) δ 197.26, 166.14, 154.98, 145.44, 132.65, 131.75, 129.49, 129.38, 128.47, 127.66, 124.81, 97.79, 96.78, 64.73, 41.15, 37.61, 21.76; HRMS (ESI) m / z [M+Na] + calcd for C 21 H 19 N3O6Na: 432.1172, Found: 432.1175; The structure of 3aa is as follows: 。

[0020] Example 2 β-(4-Methylbenzoyl)-N-methoxyacrylamide 1a (26.3 mg, 0.12 mmol, 1.2 equiv.) and 3-(4-methylphenyl)-4-nitroisoxazole 2b (20.4 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube, and 1 mL of dry acetonitrile (0.1 M) was added. The mixture was stirred at room temperature until the solids were completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 11 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was performed for separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ab, a white solid. The isolated yield was 33.0 mg, and the yield was 78%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 3 and Figure 4 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.81 (d, J J = 7.9 Hz, 2H), 7.76 (d, J J = 8.0 Hz, 2H), 7.26 (dd, J J = 14.2, 8.1 Hz, 4H), 6.97 (s, 1H), 4.28 (dd, J J = 18.7, 4.4 Hz, 1H), 4.00 (s, 3H), 3.92 (dd, J J = 18.7, 4.1 Hz, 1H), 3.52 (t, J= 4.2 Hz, 1H), 2.39 (d, J = 2.3 Hz, 6H); 13 13C NMR (126 MHz, CDCl3) δ 197.22, 166.16, 154.98, 145.40, 142.41, 132.69, 130.08, 129.48, 128.46, 127.58, 121.90, 97.87, 96.66, 64.74, 41.20, 37.58, 21.76, 21.52; HRMS (ESI) m / z [M+Na] + calcd for C 22 H 21 N3O6Na: 446.1328, Found: 446.1330; The structural formula of 3ab is as follows: .

[0021] Example 3 β-(4-Methylbenzoyl)-N-methoxyacrylamide 1a (26.3 mg, 0.12 mmol, 1.2 equiv.) and 3-(4-chlorophenyl)-4-nitroisoxazole 2c (22.5 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube, 1 mL of dry acetonitrile (0.1 M) was added, and the mixture was stirred at room temperature until the solid was completely dissolved; then triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 9 h; after the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out for separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ac, a white solid, with a separated yield of 36.8 mg and a yield of 83%. The 1 1H NMR and 13 13C NMR spectra are shown as Figure 5 and Figure 6 shown respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.82 – 7.75 (m, 2H), 7.76 – 7.71 (m, 2H), 7.66 – 7.61 (m, 0.33H), 7.48 – 7.44 (m, 0.31H), 7.42 – 7.35 (m, 2H), 7.30 – 7.25 (m, 0.31H), 7.18 (d, J= 8.3 Hz, 2H), 7.14 – 7.10 (m, 0.32H), 6.89 (s, 1H), 4.14 (dd, J = 18.6, 4.3 Hz, 1H), 4.08 (s, 0.45H), 4.06 – 4.04 (m, 0.18H), 3.92 (s, 3H), 3.86 (dd, J = 18.7, 4.5 Hz, 1H), 3.65 (dd, J = 18.1, 3.9 Hz, 0.16H), 3.54 (dd, J = 18.1, 5.5 Hz, 0.17H), 3.41 (t, J = 4.4 Hz, 1H), 2.33 (s, 3H), 2.29 (s, 0.45H) ; 13 C NMR (126 MHz, CDCl3) δ195.95, 193.97, 166.76, 164.88, 156.72, 153.18, 144.50, 143.81, 137.07, 135.56, 132.15, 131.55, 128.66, 128.48, 128.40, 128.29, 127.99, 127.65, 127.43, 127.15, 125.33, 122.29, 96.61, 95.76, 91.70, 64.59, 63.78, 40.09, 38.31, 37.05, 36.61, 20.74, 20.63;HRMS (ESI) m / z [M+Na] + calcd for C 21 H 18 N3O6NaCl: 466.0782, Found: 466.0786;The structural formula of 3ac is as follows: 。

[0022] Example 4 β-(4-Methylbenzoyl)-N-methoxyacrylamide 1a (26.3 mg, 0.12 mmol, 1.2 equiv.) and 3-(4-trifluoromethylphenyl)-4-nitroisoxazole 2d (25.8 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube, and 1 mL of dry acetonitrile (0.1 M) was added. The mixture was stirred at room temperature until the solids were completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 10 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ad, a white solid. The isolated yield was 28.6 mg, and the yield was 60%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 7 and Figure 8 respectively; 1 1H NMR (500 MHz, CDCl3) δ 8.08 (d, J J = 8.3 Hz, 2H), 7.85 – 7.79 (m, 2H), 7.75 (d, J J = 8.3 Hz, 2H), 7.26 (d, J J = 8.1 Hz, 2H), 6.99 (s, 1H), 4.22 (dd, J J = 18.6, 4.3 Hz, 1H), 4.00 (s, 3H), 3.95 (dd, J J = 18.7, 4.8 Hz, 1H), 3.51 (t, J J = 4.5 Hz, 1H), 2.41 (s, 3H); 13 13C NMR (126 MHz, CDCl3) δ 196.93, 165.84, 154.09, 145.61, 133.24 (q, J J = 33.0 Hz), 132.54, 129.54, 128.47, 128.40, 128.20, 123.48 (q, J J = 272.7 Hz), 126.27 (q, J J = 3.8 Hz), 97.52, 96.98, 64.84, 41.10, 37.68, 21.75; HRMS (ESI) m / z [M+Na] +Calculated for C 22 H 18 F3N3O6Na: 500.1045, Found: 500.1047; The structural formula of 3ad is as follows: 。

[0023] Example 5 Add β-(4-methylbenzoyl)-N-methoxyacrylamide 1a (26.3 mg, 0.12 mmol, 1.2 equiv.) and 3-(3-chlorophenyl)-4-nitroisoxazole 2e (22.5 mg, 0.1 mmol, 1.0 equiv.) into a 10 mL reaction tube, add 1 mL of dry acetonitrile (0.1 M), stir at room temperature until the solid is completely dissolved; then add triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) into the reaction system, stir at room temperature for 12 h; after the reaction is completed, remove acetonitrile under reduced pressure, and then carry out column chromatography (200-mesh silica gel column chromatography) separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ae, white solid, the isolated yield is 33.2 mg, and the yield is 75%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 9 and Figure 10 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.94 (t, J J = 1.9 Hz, 1H), 7.85 – 7.80 (m, 2H), 7.79 (dt, J J = 7.8, 1.4 Hz, 1H), 7.50 (ddd, J J = 8.1, 2.1, 1.1 Hz, 1H), 7.44 (t, J J = 8.0 Hz, 1H), 7.28 (s, 2H), 6.98 (s,1H), 4.23 (dd, J J = 18.7, 4.3 Hz, 1H), 4.00 (s, 3H), 3.95 (dd, J J = 18.6, 4.5 Hz,1H), 3.49 (t, J J = 4.3 Hz, 1H), 2.42 (s, 3H); 1313C NMR (126 MHz, CDCl3) δ 196.98, 165.93, 154.04, 145.55, 135.53, 132.58, 131.78, 130.58, 129.52, 128.49, 127.81, 126.62, 125.71, 97.47, 96.95, 64.87, 41.08, 37.65, 21.79; HRMS (ESI) m / z [M+Na] + calcd for C 21 H 18 N3O6NaCl: 466.0782, Found: 466.0786; The structure of 3ae is as follows: 。

[0024] Example 6 β-(4-Methylbenzoyl)-N-benzyloxyacrylamide 1b (35.4 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube, and 1 mL of dry acetonitrile (0.1 M) was added. The mixture was stirred at room temperature until the solids were completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 9 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidinone-fused dihydroisoxazole compound 3ba, a white solid. The isolated yield was 38.8 mg, and the yield was 80%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 11 and Figure 12 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.81–7.76 (m, 2H), 7.72–7.67 (m, 2H), 7.43–7.34 (m, 5H), 7.30–7.24 (m, 3H), 7.14 (d, J J = 1.2 Hz, 2H), 6.88 (s, 1H), 5.11–5.04 (m, 2H), 4.13 (dd, J J = 18.7, 4.4 Hz, 1H), 3.80 (dd, J= 18.7, 4.4 Hz, 1H), 3.40 (t, J = 4.3 Hz, 1H), 2.28 (s, 3H); 13 C NMR (126 MHz, CDCl3) δ 197.12, 166.28, 155.15, 145.41, 134.16, 132.70, 131.76, 129.85, 129.50, 129.39, 129.18, 128.55, 128.48, 127.76, 124.91, 97.79, 97.19, 79.42, 41.15, 37.67, 21.79; HRMS (ESI) m / z [M+Na] + calcd for C 27 H 23 N3O6Na: 508.1485, Found: 508.1488; The structural formula of 3ba is as follows: .

[0025] Example 7 Add β-(4-methoxybenzoyl)-N-benzyloxyacrylamide 1c (37.3 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) into a 10 mL reaction test tube, add 1 mL of dry acetonitrile (0.1 M), and stir at room temperature until the solid is completely dissolved; then add triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) into the reaction system and stir at room temperature for 10 h; after the reaction is completed, remove acetonitrile under reduced pressure, and then carry out column chromatography (200-mesh silica gel column chromatography) separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ca, a white solid, with a separation yield of 32.6 mg and a yield of 65%. The 1 1H NMR and 13 13C NMR spectra are respectively as Figure 13 and Figure 14 shown; 11H NMR (500 MHz, CDCl3) δ 7.95–7.84 (m, 4H), 7.86 – 7.70 (m, 0.4H), 7.60 – 7.54 (m, 0.5H), 7.54 – 7.44 (m, 5H), 7.40 – 7.34 (m, 3.3H), 6.99 (s, 1H), 6.92 – 6.87 (m, 2H), 6.86 – 6.82 (m, 0.2H), 5.33 – 5.30 (m, 0.2H), 5.22 – 5.13 (m, 2H), 4.22 (dd, J J = 18.6, 4.4Hz, 1H), 4.11 (dd, J J = 5.1, 4.1 Hz, 0.1H), 3.88 (dd, J J = 18.5, 4.3 Hz, 1.12H), 3.83 (s, 3H), 3.80 (s, 0.3H), 3.56 (dd, J J = 18.0, 5.2 Hz, 0.1H), 3.48 (t, J J = 4.3Hz, 1H); 13 13C NMR (126 MHz, CDCl3) δ 195.72, 193.91, 167.98, 166.37, 164.44, 163.94, 158.55, 155.12, 134.15, 134.09, 131.74, 130.76, 130.46, 129.84, 129.39, 129.16, 129.04, 128.69, 128.53, 128.17, 127.73, 127.38, 124.91, 113.99, 113.87, 113.84, 97.76, 97.26, 92.82, 79.91, 79.43, 55.60, 55.53, 41.17, 39.47, 37.83, 37.39;HRMS (ESI) m / z [M+Na] + calcd for C 27 H 23 N3O7Na: 524.1434, Found: 524.1436;The structural formula of 3ca is shown below: 。

[0026] Example 8 β-(4-Fluorobenzoyl)-N-benzyloxyacrylamide 1d (35.9 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube. 1 mL of dry acetonitrile (0.1 M) was added and the mixture was stirred at room temperature until the solids were completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system and the mixture was stirred at room temperature for 10 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (silica gel column chromatography with 200 mesh) was carried out for separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3da, as a white solid, with a separated yield of 35.7 mg and a yield of 73%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 15 and Figure 16 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.90 – 7.82 (m, 2H), 7.79 (dt, J J = 6.9, 1.6 Hz, 2H), 7.49 – 7.36 (m, 5H), 7.34 – 7.26 (m, 3H), 7.03 (t, J J = 8.6 Hz, 2H), 6.88 (s, 1H), 5.09 (d, J J = 2.0 Hz, 2H), 4.15 (dd, J J = 18.6, 4.4 Hz, 1H), 3.81 (dd, J J = 18.6, 4.3 Hz, 1H), 3.42 (t, J J = 4.3 Hz, 1H); 13 13C NMR (126 MHz, CDCl3) δ 194.88, 165.38 (d, J J = 256.9 Hz), 165.06, 153.97, 132.97, 130.74, 130.47 (d, J J = 3.0 Hz), 130.08 (d, J J = 9.7 Hz), 128.79, 128.35, 128.15, 127.48, 126.63, 123.76, 115.00 (d, J= 22.0 Hz), 96.58, 96.14, 78.49, 39.97, 36.61; HRMS (ESI) m / z [M+Na] + calcd for C 26 H 20 FN3O6Na: 512.1234, Found: 512.1236; The 3D structural formula is shown as follows: 。

[0027] Example 9 β-(4-Chlorobenzoyl)-N-benzyloxyacrylamide 1e (35.9 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube, and 1 mL of dry acetonitrile (0.1 M) was added. The mixture was stirred at room temperature until the solid was completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 11 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out for separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ea, a white solid. The separated yield was 38.4 mg, and the yield was 76%. The 1 1H NMR and 13 13C NMR spectra are shown as Figure 17 and Figure 18 shown; 1 1H NMR (500 MHz, CDCl3) δ 7.80 – 7.75 (m, 2H), 7.76 – 7.71 (m, 2H), 7.44 – 7.35 (m, 5H), 7.33 – 7.25 (m, 5H), 6.86 (s, 1H), 5.08 (d, J J = 2.2 Hz, 2H), 4.12 (dd, J J = 18.7, 4.4 Hz, 1H), 3.79 (dd, J J = 18.7, 4.4 Hz, 1H), 3.41 (t, J J = 4.3 Hz, 1H); 1313C NMR (126 MHz, CDCl3) δ 196.48, 166.08, 155.04, 140.94, 134.03, 133.36, 131.83, 129.87, 129.76, 129.43, 129.24, 129.20, 128.57, 127.71, 124.80, 97.66, 97.18, 79.57, 41.01, 37.77; HRMS (ESI) m / z [M+Na] + calcd for C 26 H 20 N3O6NaCl: 528.0938, Found: 528.0940; The structure of 3ea is shown as follows: 。

[0028] Example 10 Add β-(4-bromobenzoyl)-N-benzyloxyacrylamide 1f (35.9 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) into a 10 mL reaction tube, add 1 mL of dry acetonitrile (0.1 M), and stir at room temperature until the solid is completely dissolved; then add triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) into the reaction system and stir at room temperature for 10 h; after the reaction is completed, remove acetonitrile under reduced pressure, and then carry out column chromatography (200-mesh silica gel column chromatography) separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone and dihydroisoxazole compound 3fa, a white solid, with a separation yield of 37.3 mg and a yield of 68%. The 1 1H NMR and 13 13C NMR spectra are shown as Figure 19 and Figure 20 shown below; 1 1H NMR (500 MHz, CDCl3) δ 7.83 – 7.77 (m, 2H), 7.73 – 7.67 (m, 2H), 7.56 – 7.51 (m, 2H), 7.48 – 7.41 (m, 5H), 7.31 (dd, J J = 6.7, 4.6 Hz, 3H), 6.87 (s, 1H), 5.10 (d, J J = 1.7 Hz, 2H), 4.15 (dd, J J = 18.7, 4.4 Hz, 1H), 3.80 (dd,J = 18.7, 4.4 Hz, 1H), 3.43 (t, J = 4.3 Hz, 1H); 13 C NMR(126 MHz, CDCl3) δ 195.54, 164.98, 153.96, 132.95, 132.71, 131.16, 130.76, 128.81, 128.73, 128.37, 128.17, 127.49, 126.65, 123.76, 96.53, 96.13, 78.54, 39.93, 36.68; HRMS (ESI) m / z [M+Na] + calcd for C 26 H 20 BrO6N3Na: 572.0433, Found: 572.0437; The structural formula of 3fa is as follows: .

[0029] Example 11 1 g (35.9 mg, 0.12 mmol, 1.2 equiv.) of β-(3-chlorobenzoyl)-N-benzyloxyacrylamide and 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) of 3-phenyl-4-nitroisoxazole were added into a 10 mL reaction tube, and 1 mL of dry acetonitrile (0.1 M) was added. The mixture was stirred at room temperature until the solid was completely dissolved; then triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 10 h; after the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out for separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidinone and dihydroisoxazole compound 3ga, a white solid. The separated yield was 35.4 mg, and the yield was 70%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 21 and Figure 22 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.78 (dt, J = 6.8, 1.7 Hz, 3H), 7.69 (dt, J = 7.8, 1.3 Hz, 1H), 7.46 (ddd, J= 8.0, 2.2, 1.1 Hz, 1H), 7.45 – 7.37 (m, 5H), 7.33 – 7.27 (m, 4H), 6.86 (s, 1H), 5.12 – 5.04 (m, 2H), 4.14 (dd, J = 18.8, 4.4 Hz, 1H), 3.80 (dd, J = 18.8, 4.4 Hz, 1H), 3.42 (t, J = 4.3 Hz, 1H); 13 C NMR (126 MHz, CDCl3) δ 196.51, 165.95, 155.01, 136.48, 135.20, 134.28, 134.01, 131.84, 130.22, 129.86, 129.44, 129.24, 128.56, 128.46, 127.71, 126.44, 124.79, 97.61, 97.13, 79.54, 40.98, 37.91; HRMS (ESI) m / z [M+Na] + calcd for C 26 H 20 N3O6NaCl: 528.0938, Found: 528.0940; The structural formula of 3ga is as follows: .

[0030] Example 12 Add β-(2-methylbenzoyl)-N-benzyloxyacrylamide 1h (35.9 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) into a 10 mL reaction tube, add 1 mL of dry acetonitrile (0.1 M), and stir at room temperature until the solid is completely dissolved; then add triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) into the reaction system and stir at room temperature for 13 h; after the reaction is completed, remove acetonitrile under reduced pressure, and then perform column chromatography (200-mesh silica gel column chromatography) separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ha, a white solid, with a separation yield of 29.1 mg and a yield of 60%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 23 and Figure 24 respectively; 11H NMR (500 MHz, CDCl3) δ 7.82– 7.77 (m, 2H), 7.64 (dd, J J = 7.9, 1.4 Hz, 1H), 7.45 – 7.36 (m, 5H), 7.33 –7.26 (m, 4H), 7.18 (td, J J = 7.7, 1.3 Hz, 1H), 7.16 – 7.12 (m, 1H), 6.91 (s,1H), 5.15 – 5.05 (m, 2H), 4.09 (dd, J J = 18.7, 4.4 Hz, 1H), 3.82 (dd, J J = 18.7,4.3 Hz, 1H), 3.39 (t, J J = 4.3 Hz, 1H), 2.32 (s, 3H) ; 13 13C NMR (126 MHz, CDCl3) δ200.89, 166.27, 155.04, 139.53, 135.10, 134.12, 132.69, 132.38, 131.76,129.87, 129.40, 129.25, 129.21, 128.56, 127.73, 125.89, 124.88, 97.79, 97.19,79.43, 41.33, 40.09, 21.54;HRMS (ESI) m / z [M+Na] + calcd for C 27 H 23 N3O6Na:508.1485, Found: 508.1487;The structural formula of 3ha is as follows: 。

[0031] Example 13 β-(2-Bromobenzoyl)-N-benzyloxyacrylamide 1i (35.9 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube, and 1 mL of dry acetonitrile (0.1 M) was added. The mixture was stirred at room temperature until the solids were completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 12 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ia, a white solid. The isolated yield was 41.2 mg, and the yield was 75%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 25 and Figure 26 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.83 – 7.75 (m, 2H), 7.54 (dd, J J = 7.8, 1.3 Hz, 1H), 7.47 – 7.36 (m, 6H), 7.33 – 7.23 (m, 5H), 6.84 (s, 1H), 5.14 – 5.06 (m, 2H), 4.08 (dd, J J = 19.2, 4.4 Hz, 1H), 3.88 (dd, J J = 19.2, 4.5 Hz, 1H), 3.43 (t, J J = 4.5 Hz, 1H); 13 13C NMR (126 MHz, CDCl3) δ 199.75, 164.54, 153.95, 137.50, 133.22, 132.94, 131.84, 130.74, 128.80, 128.44, 128.35, 128.16, 127.49, 126.69, 126.54, 123.71, 118.35, 96.52, 95.75, 78.33, 40.17, 40.11; HRMS (ESI) m / z [M+Na] + calcd for C 26 28 20 H BrO6N3Na: 572.0433, Found: 572.0437; The structural formula of 3ia is shown as follows: .

[0032] Example 14 β-(4-Methylbenzoyl)-N-allyloxyacrylamide 1j (29.4 mg, 0.12 mmol, 1.2 equiv.) and 3-phenyl-4-nitroisoxazole 2a (19.0 mg, 0.1 mmol, 1.0 equiv.) were added into a 10 mL reaction tube, and 1 mL of dry acetonitrile (0.1 M) was added. The mixture was stirred at room temperature until the solids were completely dissolved. Subsequently, triethylamine (1.01 mg, 0.01 mmol, 0.1 equiv.) was added to the reaction system, and the mixture was stirred at room temperature for 10 h. After the reaction was completed, acetonitrile was removed under reduced pressure, and then column chromatography (200-mesh silica gel column chromatography) was carried out for separation (using a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent) to obtain the product pyrrolidone-fused dihydroisoxazole compound 3ja, a white solid. The isolated yield was 33.1 mg, and the yield was 76%. The 1 1H NMR and 13 13C NMR spectra are shown in Figure 27 and Figure 28 respectively; 1 1H NMR (500 MHz, CDCl3) δ 7.94–7.85 (m, 2H), 7.82 (d, J J = 8.0 Hz, 2H), 7.50 (ddd, J J = 14.5, 7.9, 6.2 Hz, 3H),7.26 (d, J J = 8.1 Hz, 2H), 6.98 (s, 1H), 6.07 (ddt, J J = 16.9, 10.2, 6.6 Hz, 1H),5.41 (dd, J J = 17.3, 1.7 Hz, 1H), 5.34 (dd, J J = 10.2, 1.5 Hz, 1H), 4.67 (d, J J = 6.6Hz, 2H), 4.25 (dd, J J = 18.6, 4.4 Hz, 1H), 3.92 (dd, J J = 18.6, 4.4 Hz, 1H), 3.52(t, J J = 4.3 Hz, 1H), 2.41 (s, 3H); 1313C NMR (126 MHz, CDCl3) δ 197.02, 166.46, 155.18, 145.40, 132.70, 131.71, 131.52, 129.49, 129.37, 128.47, 127.73, 124.92, 121.54, 97.64, 97.19, 78.37, 41.12, 37.64, 21.78; HRMS (ESI) m / z [M+Na] + calcd for C 23 H 21 N3O6Na: 458.1328, Found: 458.1329; The structural formula of 3ja is as follows: 。

[0033] Application Example: Antitumor Activity Test The human non-small cell lung cancer cell line (A549) was selected as the research object (Table 1) to evaluate the in vitro antitumor activity of pyrrolidone-dihydroisoxazole compounds.

[0034] The counted A549 cell suspension was dropped into a 96-well plate, seeded at 3000 - 5000 cells per well, and the liquid in each well was added to 100 μL and then placed in a cell incubator for culture; different compounds were added to the wells at a final concentration of 2.5 μM and incubated in the incubator for 24 h. After incubation, 10 μL of MTT solution (5 mg / mL, i.e., 0.5% MTT) was added to each well and the culture was continued for 4 h. The culture was terminated and the culture medium in the wells was aspirated. 100 μL of dimethyl sulfoxide was added to each well and shaken on a shaker at low speed for 30 min to fully dissolve the crystals; the absorbance of each well was measured at 490 nm using an enzyme-linked immunosorbent assay detector, and the inhibition rate was calculated. The results are shown in Table 1 below: Table 1 In vitro antitumor activity (inhibition rate %) of pyrrolidone-dihydroisoxazole compounds As can be seen from Table 1, pyrrolidone-dihydroisoxazole compounds showed good cytotoxicity against the human non-small cell lung cancer cell line, and the highest inhibition rate was 83.54% (3ae).

[0035] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A pyrrolidone-fused dihydroisoxazole compound, characterized in that, The structural formula of the pyrrolidone-fused dihydroisoxazole compound is as follows: Among them, R 1 is one of phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-trifluoromethylphenyl, 3-methylphenyl, 3-methoxyphenyl, 3-chlorophenyl, 2-methylphenyl, 2-fluorophenyl, 2-bromophenyl, 2-naphthyl, 2-thienyl, methyl, tert-butyl, benzyl; R 2 is one of C1-C5 alkyl, C3-C12 cycloalkyl, allyl, propargyl, benzyl, 4-methylbenzyl, 4-chlorobenzyl, 4-bromobenzyl, 4-trifluorobenzyl, 2-naphthylmethyl; R 3 is one of phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 4-bromophenyl, 4-trifluoromethylphenyl, 4-trifluoromethoxy, 3-methylphenyl, 3-methoxyphenyl, 3-chlorophenyl, 2-methylphenyl, 2-bromophenyl, 2-naphthyl, 2-thienyl, cyclohexyl.

2. A method for preparing the pyrrolidone isoxazole compound according to claim 1, characterized in that: Under the catalysis of a Lewis base, β-oxopropenamide and 4-nitroisoxazole are used as raw materials to synthesize the pyrrolidone-fused dihydroisoxazole compound in one step; The structural formula of the said β-oxopropenamide is as follows: ; The structural formula of the 4-nitroisoxazole is as follows: .

3. The preparation method of the pyrrolidone and dihydroisoxazole compounds according to claim 2, characterized in that, The molar ratio of β-oxopropenamide, 4-nitroisoxazole, and the Lewis base is 1-1.2:1:0.05-0.2; the Lewis base is one or more of triethylamine, diisopropylethylamine, tributylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene, triethylenediamine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 4-dimethylaminopyridine, pyridine, cesium carbonate, potassium carbonate, and sodium carbonate.

4. The preparation method of the pyrrolidone and dihydroisoxazole compound according to claim 3, characterized in that, The molar ratio of β-oxopropenamide, 4-nitroisoxazole, and the Lewis base is 1.2:1:0.1; the Lewis base is triethylamine.

5. The preparation method of the pyrrolidone and dihydroisoxazole compound according to claim 2, characterized in that, The solvent for the one-step synthesis of the pyrrolidone-fused dihydroisoxazole compound is one of acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, acetone, toluene, p-xylene, dichloromethane, chloroform, tetrahydrofuran, ethyl acetate, and tert-butyl methyl ether.

6. The method for preparing a pyrrolidinone-fused dihydroisoxazole compound according to claim 5, characterized in that, The solvent for the one-step synthesis of the pyrrolidone-fused dihydroisoxazole compound is acetonitrile.

7. The preparation method of the pyrrolidone and dihydroisoxazole compounds according to claim 2, characterized in that, The reaction temperature for the one-step synthesis of the pyrrolidone-fused dihydroisoxazole compound is 0-40°C, and the stirring reaction time is 8-12 h.

8. The method for preparing the pyrrolidone and dihydroisoxazole compounds according to claim 2, characterized in that, After the reaction of the one-step synthesis of the pyrrolidone-fused dihydroisoxazole compound is completed, the reaction solution is concentrated under vacuum, and the residue is passed through a silica gel column chromatography with 200 mesh to obtain the pyrrolidone-fused dihydroisoxazole compound.

9. The preparation method of the pyrrolidone and dihydroisoxazole compounds according to claim 2, characterized in that, The silica gel column chromatography uses a mixture of petroleum ether and ethyl acetate with a volume ratio of 5:1 as the eluent.

10. Use of the pyrrolidone-fused dihydroisoxazole compound according to claim 1 in the preparation of an anti-tumor drug.

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