Isoxazolidine compound containing trifluoromethyl as well as synthesis method and pharmaceutical application thereof

Abstract

The invention discloses a trifluoromethyl-containing isoxazolidine compound as well as a synthesis method and pharmaceutical application thereof, and belongs to the technical field of pharmaceutical synthesis. Beta-trifluoromethyl-alpha, beta-unsaturated ketone compounds 1 and N-benzyl nitrone 2 are used as raw materials, and in the presence of chiral binaphthol ligands or tetrabenzocyclooctadiene ligands, triphenyl borate and molecular sieves, asymmetric [3 + 2] cycloaddition reaction is performed to obtain the optically active trifluoromethyl-containing isoxazolidine compounds 3. The synthesis route has the advantages of easily available raw materials, mild reaction conditions, high catalytic efficiency and the like, and the obtained product shows remarkable physiological activity on cervical cancer C33A, lung cancer A549, breast cancer MCF-7, colon cancer HCT116 cells and the like, and provides an effective way for development of novel anticancer lead compounds.

Description

Technical Field

[0001] The present invention belongs to the technical field of drug synthesis, and in particular relates to a trifluoromethyl-containing isoxazolidine compound, a synthesis method thereof, and a drug application thereof. Background Art

[0002] Isoxazole, a five-membered heterocyclic ring containing one nitrogen and one oxygen atom, is a common structure in active compounds. In the pharmaceutical field, isoxazolidine derivatives serve as important pharmacophores, present in many biologically active natural product molecules and pharmaceutical preparations.

[0003] Chiral compounds containing trifluoromethyl groups are widely found in biologically active and pharmaceutical molecules. Unfortunately, naturally occurring trifluoromethyl compounds are extremely rare. Therefore, developing universal and efficient methods for synthesizing trifluoromethyl compounds, particularly those containing a trifluoromethyl chiral center, is crucial in organic synthesis. One of the primary approaches to obtaining such compounds is to convert potentially chiral trifluoromethyl-containing substrates into chiral trifluoromethyl-containing products using asymmetric catalysis.

[0004] Isoxazole derivatives are synthesized via cycloadditions, but few methods have been reported for the synthesis of chiral trifluoromethyl-containing isoxazolidines. In 2017, Huang's group developed a highly efficient chiral Ni(ClO4)2 / (S,S)-Ph-dbfox complex catalytic system, enabling the asymmetric 1,3-dipolar cycloaddition of nitrones with β-fluoroalkyl-substituted α,β-unsaturated 2-pyridine sulfones, stereoselectively affording a series of fluoroalkyl-substituted isoxazolidine heterocycles (Angew. Chem. Int. Ed. 2017, 56, 1510–1514). In 2017, Shibasaki's group reported the asymmetric exo-selective 1,3-dipolar cycloaddition of α,β-unsaturated amides with nitrones catalyzed by In(OTf)3 and a chiral bishydroxamic acid ligand, affording a series of optically active isoxazolidines (Chem. Eur. J. 2017, 23, 12450–12455). However, the aforementioned methods require the use of transition metal catalysts, limiting their applicability.

[0005] Because isoxazole derivatives have a wide range of therapeutic activities, such as anticancer, antiviral, antibacterial, and anti-inflammatory, the development of reliable synthetic strategies to obtain more structurally complex and functionally diverse isoxazolidine compounds, especially the synthesis of optically active trifluoromethyl-containing isoxazolidine derivatives, will have significant practical value in drug development. Summary of the Invention

[0006] To overcome the above-mentioned technical deficiencies, the present invention provides an asymmetric [3+2] cycloaddition synthesis of optically active trifluoromethyl-containing isoxazolidine derivatives, as well as corresponding synthesis methods and biological activities. Using β-trifluoromethyl-α,β-unsaturated ketone 1 and N-benzyl nitrone 2 as raw materials, in the presence of a chiral binaphthol compound or a tetrabenzocyclooctatetraene compound as a ligand, triphenyl borate, and molecular sieves, an asymmetric [3+2] cycloaddition reaction is performed to synthesize optically active trifluoromethyl-containing isoxazolidine derivatives in a single step with high yield, high diastereoselectivity, and high enantioselectivity. The resulting products exhibit significant physiological activity against cervical cancer C33A, lung cancer A549, breast cancer MCF-7, and colon cancer HCT116 cells.

[0007] The trifluoromethyl isoxazolidine compound of the present invention has the following general formula:

[0008]

[0009] Where: R F Selected from trifluoromethyl or pentafluoroethyl; R 1 is selected from phenyl, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl or nitro; R 2 is selected from hydrogen, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl; R 3 is selected from benzyl, methyl, tert-butyl, phenyl, ethyl or cyclohexyl.

[0010] The present invention also provides the use of the above trifluoromethylisoxazolidine derivatives in preparing anti-tumor drugs.

[0011] Furthermore, in the above technical solution, the tumor is cervical cancer (C33A), lung cancer (A549), breast cancer (MCF-7) and colon cancer (HCT116).

[0012] The method for synthesizing optically active trifluoromethyl-containing cycloisoxazolidine derivatives of the present invention comprises the following steps: using β-trifluoromethyl-α,β-unsaturated ketone 1 and N-benzyl nitrone 2 as raw materials, reacting in an organic solvent in the presence of a chiral binaphthol ligand or a tetrabenzocyclooctatetraene ligand, triphenyl borate, and a molecular sieve to obtain a trifluoromethyl-containing cycloisoxazolidine compound 3. The synthetic route of the present invention is represented by the following reaction equation:

[0013]

[0014] Where: R F Selected from trifluoromethyl or pentafluoroethyl; R 1 is selected from phenyl, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl or nitro; R 2is selected from hydrogen, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl; R 3 is selected from benzyl, methyl, tert-butyl, phenyl, ethyl or cyclohexyl.

[0015] Furthermore, in the above technical solution, the chiral binaphthol compound is R=H, F, Cl, Br, I, Me, Ph, 3,5-Me2C6H3, 3,5-(MeO)2C6H3, 3,5-(CF3)2C6H3; under preferred conditions, the chiral binaphthol catalysts are the following four:

[0016]

[0017] Furthermore, in the above technical solution, the chiral tetrabenzocyclooctatetraenol compound is

[0018]

[0019] R=H, F, Cl, Br, I, Ph, 3,5-Me2C6H3, 3,5-(MeO)2C6H3, 3,5-(CF3)2C6H3.

[0020] Furthermore, in the above technical solution, the molar ratio of the N-benzyl nitrone 2 to the β-trifluoromethyl-α,β-unsaturated ketone 1 to the chiral ligand to triphenyl borate is 1:1.5-2.0:0.06-0.24:0.05-0.20. The amount of molecular sieve used per 0.1 mmol of N-benzyl nitrone 2 is 100 mg.

[0021] Furthermore, in the above technical solution, the organic solvent is selected from toluene, tetrahydrofuran, trifluorotoluene, o-xylene, m-xylene, chlorobenzene, 1,2-dichloroethane, methyl tert-butyl ether, acetonitrile or 1,4-dioxane. The preferred reaction solvent is o-xylene.

[0022] Furthermore, in the above technical solution, the reaction temperature is -20°C to 60°C, preferably 0°C.

[0023] Furthermore, the molecular screening or Molecular sieve. Molecular sieve is preferred molecular sieve.

[0024] Furthermore, in the above technical solution, the entire reaction process is carried out under nitrogen or argon, preferably nitrogen.

[0025] Advantageous Effects of the Invention

[0026] The reaction raw materials of the invention are easily available, the reaction conditions are mild, the post-treatment is simple, the chiral ligand can be recycled and reused, and the product yield, diastereoselectivity and enantioselectivity are good to excellent.

[0027] The present invention studies its anti-proliferative effect on a variety of different cancer cells (A549, HCT116, MCF-7 and C33A, etc.). The results show that the obtained product exhibits significant physiological activity and certain anti-tumor potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a graph showing the inhibition rate of trifluoromethylisoxazolidine derivatives on A549 cells in Example 1-9 (25 μM);

[0029] Figure 2 This is a graph showing the inhibition rate of the trifluoromethylisoxazolidine derivative on C33A cells in Example 1-9 (12.5 μM);

[0030] Figure 3 This is a graph showing the inhibition rate of the trifluoromethylisoxazolidine derivatives on HCT116 cells in Example 1-9 (25 μM);

[0031] Figure 4 This is a graph showing the inhibition rate of the trifluoromethylisoxazolidine derivatives of Example 1-9 on MCF-7 cells (25 μM). DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0033] Example 1

[0034]

[0035]

[0036] a β-trifluoromethyl-α,β-unsaturated ketone 1a (0.15 mmol), N-benzyl nitrone 2a (0.1 mmol), B(OPh)3 (0.01 mmol, 10 mol%), chiral ligand (0.012 mmol, 12 mol%), molecular sieves (100 mg), 1.0 mL of anhydrous solvent under N2 atmosphere; b Isolated yield; c dr was analyzed by H NMR spectroscopy; d ee was analyzed by HPLC chiral column; e 25℃ f -20℃;

[0037] During the reaction condition screening process, the effects of different chiral ligands on the reaction were first investigated (labels 1-9), and L6 was determined to be the optimal ligand. The effects of different solvents on the reaction were then investigated (labels 10-18), and o-xylene was ultimately selected as the solvent. The effects of temperature and catalyst dosage on the reaction were also investigated (labels 19-20), ultimately selecting a reaction temperature of 0°C and a catalyst dosage of 12 mol%. Typical reaction conditions:

[0038] Under nitrogen protection, 100 mg of Molecular sieves, catalyst L6 (12 mol%), and β-trifluoromethyl-α,β-unsaturated ketone 1a (0.20 mmol) were added and purged three times. B(OPh)3 (0.01 mmol) and dry o-xylene (1.0 mL) were then added and stirred at 100°C for 2 h. The mixture was then cooled to room temperature. N-benzyl nitrone 2a (0.1 mmol) was then added under nitrogen and stirred at 0°C for 24 h. TLC indicated the disappearance of 2. The solvent was removed under reduced pressure and purified by flash silica gel column chromatography (petroleum ether / dichloromethane = 20 / 1-8 / 3) to afford 42.7 mg of cgl-127 as a white solid in a 99% yield. The product had a mp of 93-94°C; HPLC (chiral column AD-H, n-hexane / isopropanol = 90:10, flow rate 1.0 mL / min, λ = 254 nm) yielded t R (minor)=4.8min,t R (major)=7.2min,2.8:97.2er;93.4%ee;[α] D 21 =–18.8(c 2.0,CHCl3); 1 H NMR (400MHz, CDCl3) δ12.08(s,1H),7.40-7.22(m,11H),6.95-6.93(m,1H),6.89-6.84(m,1H),6.52-6.48(m,1H),4. 99-4.93(m,1H),4.65(dd,J=5.2,8.8Hz,1H),4.04(d,J=14.8Hz,1H),3.93(d,J=8.8Hz,1H),3.83(d,J=14.8Hz,1H); 13 C NMR (100MHz, CDCl3) δ200.9,163.5,137.7,136.7,135.5,130.6,129.42,129.36,128.4,128.2,1 28.1,127.3,124.5(q,J=282.0Hz),119.0,118.8,118.6,76.7(q,J=33.0Hz),76.4,59.00,58.97;19 F NMR(376MHz, CDCl3)δ–75.6; HRMS(ESI)m / z:[MH] - Calcd for C 24 H 20 NO3F3 426.1323;Found 426.1324.

[0039] Example 2

[0040] According to the typical reaction operation of Example 1, different N-benzyl nitrone compounds 2 were reacted with β-trifluoromethyl-α,β-unsaturated ketone 1. The reaction results are as follows:

[0041]

[0042]

[0043] Example 3

[0044]

[0045] Under nitrogen protection, 100 mg of Molecular sieves, catalyst L6 (12 mol%), and β-trifluoromethyl-α,β-unsaturated ketone 1a (0.15 mmol) were added and purged three times. B(OPh)3 (0.01 mmol) and dry o-xylene (1.0 mL) were then added and stirred at 100°C for 2 h. The mixture was then cooled to room temperature. N-benzyl nitrone 2b (0.1 mmol) was then added under nitrogen and stirred at 0°C for 24 h. TLC indicated the disappearance of 2b. The solvent was removed under reduced pressure and purified by flash silica gel column chromatography (petroleum ether / dichloromethane = 10 / 1 to 8 / 3) to afford 46.1 mg of cgl-131 as a white solid in a 99% yield. The product had a mp of 72-73°C; HPLC (chiral column AD-H, n-hexane / isopropanol = 90:10, flow rate 1.0 mL / min, λ = 254 nm) yielded t R (minor)=4.7min,t R (major)=5.4min,1.9:98.1er;96%ee;[α] D 27 =-11.2 (c 2.0, CHCl3); 1H NMR (400MHz, CDCl3) δ12.04(s,1H),7.46-7.41(m,1H),7.35-7.20(m,9H),6.99-6.94(m,2H),6.61-6.57(m,1H),4.96-4.89(m,1 H),4.61(dd,J=4.8,8.8Hz,1H),4.04(d,J=15.2Hz,1H),4.93(d,J=8.8Hz,1H),3.87(d,J=14.8Hz,1H),1.41(s,3H),0.94(s,3H); 13 C NMR (100MHz, CDCl3) δ200.5,163.6,138.0,137.8,136.2,135.3,130.7,130.4,129.6,128.4,128.3,1 28.0,127.5,126.3,124.4(q,J=282.0Hz),119.2,118.8,118.7,76.8(q,J=33.0Hz),75.4,59.2,58.8; 19 F NMR(376MHz, CDCl3)δ-75.5,-96,6; HRMS(ESI)m / z:[MH] - C 24 H 19 ClNO3F3460.0933; Found 460.0935.

[0046] Example 4

[0047]

[0048] Under nitrogen protection, 100 mg of Molecular sieves, catalyst L6 (12 mol%), and β-trifluoromethyl-α,β-unsaturated ketone 1a (0.15 mmol) were added and purged three times. B(OPh)3 (0.01 mmol) and dry o-xylene (1.0 mL) were then added and stirred at 100°C for 2 h. The mixture was then cooled to room temperature. N-benzyl nitrone 2c (0.1 mmol) was added under nitrogen and stirred at 0°C for 24 h. TLC indicated the disappearance of 2c. The solvent was removed under reduced pressure, and then purified by flash silica gel column chromatography (petroleum ether / dichloromethane = 10 / 1 to 8 / 3) to afford 47.7 mg of cgl-135 as a white solid in a 99% yield. The product had a mp of 96-97°C; HPLC (chiral column AD-H, n-hexane / isopropanol = 90:10, flow rate 1.0 mL / min, λ = 254 nm) yielded t R (minor)=5.2min,t R(major)=8.7min,2.0:98.0er;96%ee;[α] D 27 =-34.3 (c 1.0, CHCl3); 1 H NMR (400MHz, CDCl3) δ12.11(s,1H),7.88-7.81(m,2H),7.72-7.67(m,2H),7.62-7.60(m,11H),7.51-7.44(m,2H),7.35-7.20(m,6H),6.92-6.86( m,2H),6.32-6.28(m,1H),5.09-4.96(m,1H),4.73(dd,J=5.2,8.8Hz,1H),4.13(d,J=8.8Hz,1H),4.07(d,J=15.2Hz,1H),3.87(d,J=15.2Hz,1H); 13 C NMR (100MHz, CDCl3) δ201.0,163.4,137.7,136.7,133.7,133.4,132.8,130.5,129.6,128.4,138.33,128.26,128.1,1 27.9,127.3,126.9,126.8,124.5(q,J=282.0Hz),124.48,119.0,118.8,118.6,76.9(q,J=32.0Hz),76.4,59.1,58.6; 19 FNMR (376MHz, CDCl3) δ-75.4; HRMS (ESI) m / z: [MH] - C 28 H 22 NO3F3 476.1479;Found 476.1480.

[0049] Example 5

[0050] According to the typical reaction operation of Example 1, different β-trifluoromethyl-α,β-unsaturated ketones 1 were reacted with N-benzyl nitrone compounds 2. The reaction results are as follows:

[0051]

[0052]

[0053] Under nitrogen protection, 100 mg of Molecular sieves, catalyst L6 (12 mol%), and β-trifluoromethyl-α,β-unsaturated ketone 1b (0.15 mmol) were added and purged three times. B(OPh)3 (0.01 mmol) and dry o-xylene (1.0 mL) were then added and stirred at 100°C for 2 h. The mixture was then cooled to room temperature. N-benzyl nitrone 2a (0.1 mmol) was then added under nitrogen and stirred at 0°C for 24 h. TLC indicated the disappearance of 2a. The solvent was removed under reduced pressure and purified by flash silica gel column chromatography (petroleum ether / dichloromethane = 10 / 1 to 8 / 3) to afford 44.5 mg of cgl-143 as a white solid in a 99% yield. The product had a mp of 97-98°C; HPLC (chiral column AD-H, n-hexane / isopropanol = 80:20, flow rate 1.0 mL / min, λ = 254 nm) yielded t R (minor)=4.2min,t R (major)=5.9min,4.8:95.2er;>99%ee;[α] D 27 =–4.6(c 1.0,CHCl3); [α] D 27 =-40.1 (c 1.0, CHCl3); 1 HNMR(400MHz, CDCl3)δ12.33(d,J=1.6Hz,1H),7.30-7.15(m,10H),6.79-6.76(m,1H),6.56-6.53(m,1H),6.16-6.11(m,1 H),4.93-4.86(m,1H),4.47(dd,J=5.2,8.8Hz,1H),3.97(d,J=14.8Hz,1H),3.82(d,J=9.2Hz,1H),3.75(d,J=15.2Hz,1H); 13 C NMR (100MHz, CDCl3) δ199.6,181.7(d,J=258.0Hz),166.1(d,J=15.0Hz),136.6,135.4,133.2(d,J=12.0Hz),129.53,129.50,128.4,128.2 ,128.1,127.4,124.5(q,J=282.0Hz),116.0(d,J=3.0Hz),107.5(d,J=23.0Hz),105.2(d,J=24.0Hz),76.5(q,J=32.0Hz),76.3,59.3,59.0; 19 F NMR(376MHz, CDCl3)δ-75.7,-96,6; HRMS(ESI)m / z:[MH] -Calcd for C 24 H 19 NO3F4444.1228;Found 444.1230.

[0054] Example 7

[0055]

[0056] Under nitrogen protection, 100 mg of Molecular sieves, catalyst L6 (12 mol%), and β-trifluoromethyl-α,β-unsaturated ketone 1c (0.15 mmol) were purged three times, followed by the addition of B(OPh)3 (0.01 mmol) and dry o-xylene (1.0 mL). The mixture was stirred at 100°C for 2 h, then cooled to room temperature. N-benzyl nitrone 2a (0.1 mmol) was added under nitrogen, and the mixture was stirred at 0°C for 24 h. TLC indicated the disappearance of 2a. The solvent was removed under reduced pressure, and purification followed by flash silica gel column chromatography (petroleum ether / dichloromethane = 10 / 3 to 8 / 3) afforded 46.1 mg of cgl-144 as a white solid in a 99% yield. mp 127-128°C; HPLC (chiral column AD-H, n-hexane / isopropanol = 80:20, flow rate 1.0 mL / min, λ = 254 nm). R (minor)=4.3min,t R (major)=5.5min,7.7:92.3er;84.5%ee;[α] D 27 =+2.9(c 1.0,CHCl3);;[α] D 27 =-40.1 (c 1.0, CHCl3); 1 HNMR (400MHz, CDCl3) δ11.93 (s, 1H), 7.39-7.22 (m, 11H), 6.89 (d, J = 8.8, 1H), 6.68 (d, J = 2.8Hz, 1H),5.05-4.99(m,1H),4.53(dd,J=5.2,8.8Hz,1H),4.05(d,J=15.2Hz,1H),3.84-3.79(m,2H); 13C NMR (100MHz, CDCl3) δ200.0,161.9,137.5,136.5,135.1,130.1,129.9,129.6,128.4,128.2,1 28.1,127.4,124.5(q,J=282.0Hz),123.9,120.1,119.1,76.2,76.1(q,J=33.0Hz),59.7,58.9; 19 F NMR (376MHz, CD Cl3) δ-75.6; HRMS (ESI) m / z: [MH] - Calcd for C 24 H 19 ClNO3F3 460.0933; Found460.0933.

[0057] Example 8

[0058]

[0059] Under nitrogen protection, 100 mg of Molecular sieves, catalyst L6 (12 mol%), and β-trifluoromethyl-α,β-unsaturated ketone 1d (0.15 mmol) were added and purged three times. B(OPh)3 (0.01 mmol) and dry o-xylene (1.0 mL) were then added and stirred at 100°C for 2 h. The mixture was then cooled to room temperature. N-benzyl nitrone 2a (0.1 mmol) was then added under nitrogen and stirred at 0°C for 24 h. TLC indicated the disappearance of 2a. The solvent was removed under reduced pressure and purified by flash silica gel column chromatography (petroleum ether / dichloromethane = 10 / 3 to 8 / 3) to afford 50.6 mg of cgl-145 as a white solid in a 99% yield. MP: 127-128°C; HPLC (chiral column AD-H, n-hexane / isopropanol = 80:20, flow rate 1.0 mL / min, λ = 254 nm) t R (minor)=4.4min,t R (major)=5.4min,12.2:87.8er;76%ee;[α] D 27 = +4.7 (c 2.0, CHCl3); 1 H NMR(400MHz, CDCl3)δ11.94(s,1H),7.45-7.22(m,11H),6.85-6.81(m,2H),5.07-5 .01(m,1H),4.53(dd,J=4.8,8.8Hz,1H),4.05(d,J=14.8Hz,1H),3.82-3.78(m,2H);13 C NMR (100MHz, CDCl3) δ200.0,162.3,140.3,136.5,135.1,133.2,130.0,129.7,128.4,128.2,1 28.1,127.4,124.5(q,J=282.0Hz),120.5,119.7,110.8,76.2,76.1(q,J=33.0Hz),59.7,58.9; 19 F NMR (376MHz, CDCl3) δ-75.5; HRMS (ESI) m / z: [MH] - Calcd for C 24 H 19 BrNO3F3 504.0428; Found 504.0429.

[0060] Example 9

[0061]

[0062] Under nitrogen protection, 100 mg of Molecular sieves, catalyst L6 (12 mol%), and β-trifluoromethyl-α,β-unsaturated ketone 1e (0.15 mmol) were added and purged three times. B(OPh)3 (0.01 mmol) and dry o-xylene (1.0 mL) were then added and stirred at 100°C for 2 h. The mixture was then cooled to room temperature. N-benzyl nitrone 2a (0.1 mmol) was then added under nitrogen and stirred at 0°C for 24 h. TLC indicated the disappearance of 2a. The solvent was removed under reduced pressure and purified by flash silica gel column chromatography (petroleum ether / dichloromethane = 10 / 3 to 8 / 3) to afford 52.2 mg of cgl-149 as a white solid in a 99% yield. The product had a mp of 98-99°C; HPLC (chiral column OJ-H, n-hexane / isopropanol = 90:10, flow rate 1.0 mL / min, λ = 254 nm) yielded t R (major)=7.9min,t R (minor)=14.1min,96.5:3.5er; 93%ee; [α] D 27 =-8.3 (c 0.5, CHCl3); 1H NMR (400MHz, CDCl3) δ12.57(s,1H),8.25-8.22(m,1H),7.76(d,J=2.8Hz,1H),7.38-7.23(m,10H),7.05(d,J=9. 2Hz, 1H), 5.18 (dt, J = 5.2, 20.4Hz, 1H), 4.82 (dd, J = 5.2, 9.2Hz, 1H), 4.03 (d, J = 15.2Hz, 1H), 3.80-3.75 (m, 2H); 13 C NMR (100MHz, CDCl3) δ200.6,167.7,139.5,136.1,134.5,131.9,130.1,130.0,128.5,12 8.3,128.0,127.5,127.3,119.7,117.3,76.3,74.8(dd,J=21.0,31.0Hz),59.12,59.07; 19 F NMR(376MHz, CDCl3)δ-82.3,-120.7(d,J=278.2Hz),-127.0(d,J=274.5Hz); HRMS(ESI)m / z:[MH] - Calcd for C 25 H 19 N2O5F5521.1141;Found 521.1141.

[0063] Example 10

[0064] This example presents the results of in vitro antiproliferative experiments (i.e., half-maximal inhibitory concentrations) of the compounds described in Examples 1-9 against various cancer cells. Materials and consumables listed in this example were commercially available unless otherwise specified. Cells were obtained from the cell and microbial resource libraries of the CTCC or other relevant institutions. The experimental methods used in this example follow standard molecular biology, cell biology, or virology procedures, readily understood and implemented by researchers in the field. The specific steps are as follows:

[0065] 1. Cells:

[0066] The cell lines used included the human breast cancer cell line MCF-7, the human colon cancer cell line HCT116, the human lung cancer cell line A549, and the human cervical cancer cell line C33A. C33A, MCF-7, A549, and HCT116 cell lines were cultured in complete DMEM medium. All cell lines were maintained at 37°C in a humidified incubator with 5% CO2.

[0067] 2. Main reagents:

[0068] DMEM medium; fetal bovine serum FBS

[0069] 3. In vitro anti-proliferation test steps of tumor cells:

[0070] After preliminary screening of the drug's inhibition rate, the half-maximal inhibition concentration test was performed. The specific experimental steps are as follows:

[0071] Step 1: Observe the cell status after passage. When the cells are in the logarithmic growth phase, digest and centrifuge them, then blow them evenly. Count them with a cell counter and dilute the cell suspension to 3-8×10 3 cells / well, seeded in 96-well plates.

[0072] Step 2: Cultivate cells: Place the 96-well plate inoculated with cells in a 37° C., 5% CO 2 saturated humidity cell incubator for 12 hours, and then treat with drugs after the cells are fully attached.

[0073] Step 3: Drug administration: Calculate the drug concentration according to experimental requirements and dilute the drug, maintaining consistent mixing techniques to achieve the desired drug concentration gradient and a DMSO concentration below 0.1%. Add the drug solution to the corresponding wells of a 96-well plate, setting up four replicates for each concentration and also including a blank control group. Gently shake to mix, then mark the wells and incubate in a 37°C, 5% CO2, saturated humidity incubator for 48 hours.

[0074] Step 4: Colorimetric assay: After 48 hours, the cell viability was determined using the CCK-8 assay. The absorbance (OD) at λ = 450 nm was measured using a microplate reader; the IC was estimated from the concentration-response curve using GraphPad Prizm 8.01 software. 50 Values ​​were analyzed using nonlinear regression with curve fitting.

[0075] 5. Test results:

[0076] The present invention discloses 23 trifluoromethylisoxazolidine derivatives with in vitro antiproliferative activity against tumor cells. Seven trifluoromethylisoxazolidine derivatives were screened from the 23 trifluoromethylisoxazolidine derivatives. The antiproliferative activity of the compounds against tumor cells at gradient concentrations in vitro was further studied. The results are as follows:

[0077]

[0078] The above embodiments illustrate the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the scope of the principles of the present invention, and all such changes and improvements fall within the scope of protection of the present invention.

Claims

1. A trifluoromethyl isoxazolidine compound, characterized in that: The general formula of the compound is as follows: Where: R F Selected from trifluoromethyl or pentafluoroethyl; R 1 is selected from phenyl, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl or nitro; R 2 is selected from hydrogen, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl; R 3 is selected from benzyl, methyl, tert-butyl, phenyl, ethyl or cyclohexyl.

2. Use of the trifluoromethyl isoxazolidine compound according to claim 1 in the preparation of anti-tumor drugs.

3. The use of the trifluoromethylisoxazolidine compound in tumor medicine according to claim 2, characterized in that: The tumors are cervical cancer, lung cancer, breast cancer and colon cancer.

4. The method for synthesizing a trifluoromethyl isoxazolidine compound according to claim 1, wherein: The method comprises the following steps: using β-trifluoromethyl-α,β-unsaturated ketone 1 and N-benzyl nitrone 2 as raw materials, reacting in an organic solvent in the presence of a chiral binaphthol ligand or a chiral tetrabenzocyclooctatetraene ligand, triphenyl borate and molecular sieves to obtain an isoxazolidine derivative 3; the reaction equation is expressed as follows: Where: R F Selected from trifluoromethyl or pentafluoroethyl; R 1 is selected from phenyl, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl or nitro; R 2 is selected from hydrogen, C1-C3 alkyl, C1-C3 alkoxy, halogen, trifluoromethyl; R 3 is selected from benzyl, methyl, tert-butyl, phenyl, ethyl or cyclohexyl.

5. The method for synthesizing an optically active trifluoromethyl-containing isoxazolidine derivative according to claim 4, characterized in that: Chiral binaphthol ligands and chiral tetrabenzocyclooctatetraenol ligands are wherein R is selected from H, F, Cl, Br, I, Me, Ph, 3,5-Me2C6H4, 3,5-(MeO)2C6H4 or 3,5-(CF3)2C6H4.

6. The method for synthesizing an optically active trifluoromethyl-containing isoxazolidine derivative according to claim 5, characterized in that: In the chiral binaphthol ligand, R is selected from Br, I, Me or 3,5-(CF3)2C6H4; in the chiral tetrabenzocyclooctatetraenol ligand, R is selected from H, Br, Cl.

7. The method for synthesizing optically active trifluoromethyl-containing isoxazolidine derivatives according to claim 1, characterized in that: The molar ratio of the N-benzyl nitrone 2, β-trifluoromethyl-α, β-unsaturated ketone 1, ligand and triphenyl borate is 1:1.5-2.0:0.06-0.24:0.05-0.

20.

8. The method for synthesizing optically active trifluoromethyl-containing isoxazolidine derivatives according to claim 1, characterized in that: The organic solvent is selected from toluene, tetrahydrofuran, trifluorotoluene, o-xylene, m-xylene, chlorobenzene, 1,2-dichloroethane, methyl tert-butyl ether, acetonitrile or 1,4-dioxane.

9. The method for synthesizing optically active trifluoromethyl-containing isoxazolidine derivatives according to claim 1, characterized in that: Molecular screening or molecular sieves; the reaction temperature was 0°C.

10. The method for synthesizing an optically active trifluoromethyl-containing isoxazolidine derivative according to any one of claims 4 to 9, characterized in that: The entire reaction process was carried out under nitrogen or argon.

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