OLEAN-PHENYLACRYLAMIDE DERIVATIVE, METHOD FOR PREPARING SAME, AND USE THEREOF

Abstract

The present invention relates to the fields of medicinal chemistry and pharmacotherapeutics, and in particular to a 2-cyano-3,12-dioxoolean-1,9(11)-dien-17-phenylacrylamide derivative and a preparation method thereof; and the present invention further relates to use of the novel compound in the preparation of an anticancer medicament.

Claims

1. A compound of formula I or a pharmaceutically acceptable salt thereof: ##STR00037## wherein R.sub.1, R.sub.2 and R.sub.3 are respectively and independently selected from the following substituents: H, C.sub.1-6 alkyl, C.sub.1-6 alkoxy, halogen, cyano, C.sub.1-6 alkyl substituted by halogen or cyano; H, C.sub.1-3 alkyl, C.sub.1-3 alkoxy, halogen, cyano, C.sub.1-3 alkyl substituted by halogen or cyano.

2. The compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein the R.sub.1 and R.sub.2 are respectively and independently selected from H or cyano; R.sub.3 is selected from H, C.sub.1-3 alkyl, alkoxy, halogen, C.sub.1-3 alkyl substituted by halogen; the alkoxy is an alkoxy containing 1-3 carbon atoms; and the halogen is selected from F, Cl, Br, I.

3. The compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein the R.sub.1 is H or cyano; R.sub.2 is H or cyano; and R.sub.3 is selected from H, methyl, methoxy, trifluoromethyl, Cl or F.

4. The compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein the R.sub.1 is H or cyano; R.sub.2 is H or cyano; and R.sub.3 is Cl, H or trifluoromethyl.

5. The compound or a pharmaceutically acceptable salt thereof according to claim 1, wherein the compound is selected from: 3-phenyl-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-methylphenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-methoxyphenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-trifluoromethylphenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-fluorophenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-chlorophenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 2-cyano-3-ylphenyl-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 2-cyano-3-(4-methylphenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 2-cyano-3-(4-methoxyphenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 2-cyano-3-(4-trifluoromethylphenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 2-cyano-3-(4-fluorophenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 2-cyano-3-(4-chlorophenyl)-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-phenyl-3-cyano-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-methylphenyl)-3-cyano-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-methoxyphenyl)-3-cyano-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-trifluoromethylphenyl)-3-cyano-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, 3-(4-fluorophenyl)-3-cyano-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide, and 3-(4-chlorophenyl)-3-cyano-N-(2-cyano-3,12-dioxoolean-1,9(11)-dien-19-yl) acrylamide.

6. A method for synthesizing the compound of formula I according to claim 1, comprising: reacting formula II with formula III via a condensation reaction to obtain the compound of formula I, ##STR00038## wherein the R.sub.1, R.sub.2 and R.sub.3 are as defined in claim 1, and the condensation agent is one or more selected from dicyclohexylcarbodiimide, N,N-diisopropylcarbodiimide, 1-ethyl-(3-dimethylaminopropyl) carbodiimide, benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate or benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate.

7. The synthesis method according to claim 6, wherein a method for synthesizing the formula II comprises: ##STR00039## subjecting CDDO to Curtius rearrangement, so as to obtain a derivative aminated at the C-17 position as the formula II.

8. A pharmaceutical composition, comprising the compound or a pharmaceutically acceptable salt thereof according to claim 1, and one or more pharmaceutically acceptable pharmaceutical adjuvants.

9. (canceled)

10. (canceled)

11. A method for treating tumor, comprising administering to a subject or patient a therapeutically effective dose of the compound or a pharmaceutically acceptable salt thereof according to claim 1.

12. The method according to claim 11, wherein the tumor is selected from lung cancer, liver cancer, ascitic tumor, brain metastases, colon cancer, pancreatic cancer, breast cancer, prostatic cancer, brain cancer, ovarian carcinoma, cervical cancer, testicular cancer, kidney cancer, head and neck cancer, lymphoma, melanoma or leukemia; or selected from lung cancer, liver cancer, breast cancer, ascitic tumor, pancreatic cancer, brain metastasis; or selected from non-small cell lung cancer, liver cancer, breast cancer, and ascitic tumor.

13. A method for treating tumor, comprising administering to a subject or patient a therapeutically effective dose of the compound or a pharmaceutically acceptable salt thereof according to claim 5.

14. The method according to claim 13, wherein the tumor is selected from lung cancer, liver cancer, ascitic tumor, brain metastases, colon cancer, pancreatic cancer, breast cancer, prostatic cancer, brain cancer, ovarian carcinoma, cervical cancer, testicular cancer, kidney cancer, head and neck cancer, lymphoma, melanoma or leukemia; or selected from lung cancer, liver cancer, breast cancer, ascitic tumor, pancreatic cancer, brain metastasis; or selected from non-small cell lung cancer, liver cancer, breast cancer, and ascitic tumor.

15. A pharmaceutical composition, comprising the compound or a pharmaceutically acceptable salt thereof according to claim 5, and one or more pharmaceutically acceptable pharmaceutical adjuvants.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] A series of examples are enumerated herein in order to give a clearer description of the present invention. These examples are exemplary and should not be construed as limiting the present invention.

Example 1: Synthesis of I-1

[0050] 0.080 g (0.170 mmol) of CDDO-NH.sub.2 was dissolved in 5 mL of dichloromethane, to which 0.046 g (0.260 mmol) of 3-phenylacrylic acid was added and stirred, then 0.177 g (0.340 mmol) of benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate (PyBop) and 0.074 mL (0.425 mmol) of N,N-diisopropylethylamine were added to react at room temperature for 12 h. Following the completion of the reaction as determined by thin layer chromatography (TLC), 5 mL of water and 5 mL of dichloromethane were added for extraction and separation, then the aqueous layer was further extracted with 5 mL of dichloromethane and the organic layers were combined. The organic layer was washed with 5 mL of saturated sodium chloride and dried with anhydrous sodium sulfate. Following suction filtration, the organic layer was evaporated under reduced pressure, subjected to column chromatography and rotary evaporation such that 0.036 g of a yellow-white solid was obtained with a yield of 44.9%.

[0051] ESI-MS: 593.4 [M+H].sup.+.

[0052] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.89 (3H, s), 1.04 (3H, s), 1.05 (3H, s), 1.17 (3H, s), 1.26 (3H, s), 1.42 (3H, s), 1.47 (3H, s), 6.01 (1H, s), 6.53 (1H, d, J=15.60 Hz), 7.35 (3H, m), 7.48 (2H, m), 7.60 (1H, d, J=15.54 Hz), 8.08 (1H, s).

##STR00007##

Example 2: Synthesis of I-2

[0053] By reference to the preparation method of compound I-1 and substitution of 3-(4-methylphenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.024 g of the target compound I-2, a pale yellow solid, was obtained with a yield of 28.8%.

[0054] ESI-MS: 607.4 [M+H].sup.+.

[0055] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.90 (3H, s), 1.05 (6H, s), 1.17 (3H, s), 1.27 (3H, s), 1.41 (3H, s), 1.47 (3H, s), 2.36 (3H, s), 6.01 (1H, s), 6.43 (1H, d, J=12.60 Hz), 7.19 (2H, s), 7.38 (2H, s), 7.57 (1H, d, J=15.27 HA 8.06 (1H, s).

##STR00008##

Example 3: Synthesis of I-3

[0056] By reference to the preparation method of compound I-1 and substitution of 3-(4-methoxyphenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.035 g of the target compound I-3, a yellow-white solid, was obtained with a yield of 41.2%.

[0057] ESI-MS: 623.4 [M+H].sup.+, 645.4 [M+Na].sup.+.

[0058] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.92 (3H, s), 1.06 (6H, s), 1.18 (3H, s), 1.27 (3H, s), 1.42 (3H, s), 1.48 (3H, s), 3.84 (3H, s), 6.01 (1H, s), 6.90 (1H, d, J=8.49 Hz), 7.45 (1H, d, J=8.43 HA 7.58 (4H, m), 8.05 (1H, s).

##STR00009##

Example 4: Synthesis of I-4

[0059] By reference to the preparation method of compound I-1 and substitution of 3-(4-trifluoromethylphenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.018 g of the target compound I-4, a pale yellow solid, was obtained with a yield of 20.4%.

[0060] ESI-MS: 661.4 [M+H].sup.+, 683.4 [M+Na].sup.+.

[0061] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.91 (3H, s), 1.06 (3H, s), 1.07 (3H, s), 1.18 (3H, s), 1.27 (3H, s), 1.44 (3H, s), 1.49 (3H, s), 6.03 (1H, s), 6.54 (1H, d, J=15.30 Hz), 7.61 (4H, m), 7.63 (1H, d, J=12.96 Hz), 8.09 (1H, s).

##STR00010##

Example 5: Synthesis of I-5

[0062] By reference to the preparation method of compound I-1 and substitution of 3-(4-fluorophenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.019 g of the target compound I-5, a pale yellow solid, was obtained with a yield of 23.4%.

[0063] ESI-MS: 611.4 [M+H].sup.+.

[0064] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.89 (3H, s), 1.05 (3H, s), 1.06 (3H, s), 1.17 (3H, s), 1.26 (3H, s), 1.45 (3H, s), 1.49 (3H, s), 6.01 (1H, s), 6.55 (1H, d, J=8.58 HA 7.59 (2H, s), 7.64 (2H, s), 7.63 (1H, d, J=8.61 Hz), 8.09 (1H, s).

##STR00011##

Example 6: Synthesis of I-6

[0065] By reference to the preparation method of compound I-1 and substitution of 3-(4-chlorophenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.025 g of the target compound I-6, a yellow-white solid, was obtained with a yield of 29.1%.

[0066] ESI-MS: 627.3 [M+H].sup.+.

[0067] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.90 (3H, s), 1.05 (3H, s), 1.06 (3H, s), 1.18 (3H, s), 1.27 (3H, s), 1.44 (3H, s), 1.49 (3H, s), 6.03 (1H, s), 6.53 (1H, d, J=8.66 Hz), 7.62 (2H, s), 7.68 (2H, s), 7.61 (1H, d, J=8.64 Hz), 8.09 (1H, s).

##STR00012##

Example 7: Synthesis of Intermediate III-1 2-cyano-3-phenylacrylic acid

[0068] 0.425 g (5 mmol) of cyanoacetic acid and 0.477 g (4.5 mmol) of benzaldehyde were dissolved with 20 mL of toluene, followed by addition of 0.058 g (0.75 mmol) of ammonium acetate. The mixture was heated under reflux to react for from 6-7 h, the completion of the reaction being determined by TLC. After cooling to room temperature, suction filtration was carried out, and the filter cake was vacuum dried to obtain 0.643 g of intermediate III-1, a white solid, with a yield of 82.4%.

[0069] ESI-MS: 174.0 [M+H].sup.+.

[0070] The reaction formula is as follows:

##STR00013##

Example 8: Synthesis of I-7

[0071] By reference to the preparation method of compound I-1 and substitution of 2-cyano-3-phenylacrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.026 g of the target compound I-7, a pale yellow solid, was obtained with a yield of 30.7%.

[0072] ESI-MS: 618.4 [M+H].sup.+, 640.4 [M+Na].sup.+, 616.4 [M−H].sup.−.

[0073] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.93 (3H, s), 1.06 (3H, s), 1.13 (3H, s), 1.18 (3H, s), 1.27 (3H, s), 1.34 (3H, s), 1.49 (3H, s), 6.01 (1H, s), 7.35 (3H, m), 7.48 (2H, m), 8.06 (1H, s), 8.21 (1H, s).

##STR00014##

Example 9: Synthesis of Intermediate III-2 2-cyano-3-(4-methylphenyl)acrylic acid

[0074] By reference to the synthesis method of intermediate III-1 2-cyano-3-phenylacrylic acid and substitution of 4-methylbenzaldehyde for benzaldehyde while other conditions remained unchanged, 0.727 g of intermediate III-2 was obtained with a yield of 86.3%.

[0075] ESI-MS: 188.0 [M+H].sup.+.

[0076] The reaction formula is as follows:

##STR00015##

Example 10: Synthesis of I-8

[0077] By reference to the preparation method of compound I-1 and substitution of 2-cyano-3-(4-methylphenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.031 g of the target compound I-8, a pale yellow solid, was obtained with a yield of 35.9%.

[0078] ESI-MS: 632.4 [M+H].sup.+, 654.4 [M+Na].sup.+, 630.4 [M−H].sup.−.

[0079] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.93 (3H, s), 1.06 (3H, s), 1.13 (3H, s), 1.18 (3H, s), 1.27 (3H, s), 1.34 (3H, s), 1.49 (3H, s), 2.43 (3H, s), 6.01 (1H, s), 6.99 (2H, d, J=8.48 Hz), 7.92 (2H, d, J=8.61 Hz), 8.06 (1H, s), 8.21 (1H, s).

##STR00016##

Example 11: Synthesis of Intermediate III-3 2-cyano-3-(4-methoxyphenyl)acrylic acid

[0080] By reference to the synthesis method of intermediate III-1 2-cyano-3-phenylacrylic acid and substitution of 4-methoxybenzaldehyde for benzaldehyde while other conditions remained unchanged, 0.794 g of intermediate III-3 was obtained with a yield of 86.8%.

[0081] ESI-MS: 204.0 [M+H].sup.+.

[0082] The reaction formula is as follows:

##STR00017##

Example 12: Synthesis of I-9

[0083] By reference to the preparation method of compound I-1 and substitution of 2-cyano-3-(4-methoxyphenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.030 g of the target compound I-9, a yellow solid, was obtained with a yield of 33.7%.

[0084] ESI-MS: 648.4 [M+H].sup.+, 670.4 [M+Na].sup.+.

[0085] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.93 (3H, s), 1.06 (3H, s), 1.12 (3H, s), 1.17 (3H, s), 1.27 (3H, s), 1.34 (3H, s), 1.49 (3H, s), 3.11 (3H, s), 6.01 (1H, s), 6.99 (2H, d, J=8.49 Hz), 7.92 (2H, d, J=8.67 Hz), 8.06 (1H, s), 8.21 (1H, s).

##STR00018##

Example 13: Synthesis of Intermediate III-4 2-cyano-3-(4-trifluoromethylphenyl)acrylic acid

[0086] By reference to the synthesis method of intermediate III-1 2-cyano-3-phenylacrylic acid and substitution of 4-trifluoromethylbenzaldehyde for benzaldehyde while other conditions remained unchanged, 0.872 g of intermediate III-4 was obtained with a yield of 80.4%.

[0087] ESI-MS: 242.0 [M+H].sup.+.

[0088] The reaction formula is as follows:

##STR00019##

Example 14: Synthesis of I-10

[0089] By reference to the preparation method of compound I-1 and substitution of 2-cyano-3-(4-trifluoromethylphenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.031 g of the target compound I-10, a white solid, was obtained with a yield of 32.9%.

[0090] ESI-MS: 686.4 [M+H].sup.+, 684.4 [M−H].sup.−.

[0091] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.91 (3H, s), 1.02 (3H, s), 1.08 (3H, s), 1.17 (3H, s), 1.27 (3H, s), 1.44 (3H, s), 1.50 (3H, s), 6.05 (1H, s), 7.68 (2H, d, J=8.07 Hz), 7.88 (2H, d, J=8.01 Hz), 8.09 (1H, s).

##STR00020##

Example 15: Synthesis of Intermediate III-5 2-cyano-3-(4-fluorophenyl)acrylic acid

[0092] By reference to the synthesis method of intermediate III-1 2-cyano-3-phenylacrylic acid and substitution of 4-fluorobenzaldehyde for benzaldehyde while other conditions remained unchanged, 0.683 g of intermediate III-5 was obtained with a yield of 79.4%/q.

[0093] ESI-MS: 192.0 [M+H].sup.+.

[0094] The reaction formula is as follows:

##STR00021##

Example 16: Synthesis of I-11

[0095] %1 By reference to the preparation method of compound I-1 and substitution of 2-cyano-3-(4-fluorophenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.022 g of the target compound I-11, a pale yellow solid, was obtained with a yield of 25.4%.

[0096] ESI-MS: 636.4 [M+H].sup.+, 658.4 [M+Na].sup.+, 635.4 [M−H].sup.−.

[0097] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.94 (3H, s), 1.07 (3H, s), 1.13 (3H, s), 1.18 (3H, s), 1.27 (3H, s), 1.44 (3H, s), 1.50 (3H, s), 6.05 (1H, s), 7.21 (4H, m), 8.06 (1H, s), 8.26 (1H, s).

##STR00022##

Example 17: Synthesis of Intermediate III-6 2-cyano-3-(4-chlorophenyl)acrylic acid

[0098] By reference to the synthesis method of intermediate III-1 2-cyano-3-phenylacrylic acid and substitution of 4-chlorobenzaldehyde for benzaldehyde while other conditions remained unchanged, 0.712 g of intermediate III-6 was obtained with a yield of 76.2%.

[0099] ESI-MS: 208.0 [M+H].sup.+.

[0100] The reaction formula is as follows:

##STR00023##

Example 18: Synthesis of I-12

[0101] By reference to the preparation method of compound I-1 and substitution of 2-cyano-3-(4-chlorophenyl)acrylic acid for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.033 g of the target compound I-12, a yellow-white solid, was obtained with a yield of 37.9%.

[0102] ESI-MS: 652.3 [M+H].sup.+, 674.3 [M+Na].sup.+, 650.3 [M−H].sup.−.

[0103] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.92 (3H, s), 1.02 (3H, s), 1.08 (3H, s), 1.17 (3H, s), 1.27 (3H, s), 1.44 (3H, s), 1.50 (3H, s), 6.05 (1H, s), 7.42 (2H, d, J=8.47 Hz), 7.82 (2H, d, J=8.51 Hz), 8.12 (1H, s).

##STR00024##

Example 19: Synthesis of Intermediate III-7 3-cyano-3-phenylacrylic acid

[0104] 0.735 g (5 mmol) of phenylacetonitrile was dissolved in 50 mL of methanol, to which 0.464 g (5 mmol) of glyoxylic acid was added, followed by the addition of 1.035 g (7.5 mmol) of potassium carbonate. The mixture was heated under reflux, the endpoint of the reaction being indicated by TLC results. Following suction filtration, the filter cake was washed with dichloromethane and dissolved in water, the pH being adjusted to 4 with dilute hydrochloric acid, and a white solid was precipitated. Extraction with ethyl acetate (30 mL×2) was executed, and the organic layers were combined and dried with anhydrous sodium sulfate. Through filtration, rotary evaporation and drying in a constant-temperature drying oven, 0.679 g of intermediate III-7, a white solid, was obtained with a yield of 78.5%.

[0105] ESI-MS: 174.0 [M+H].sup.+.

[0106] The reaction formula is as follows:

##STR00025##

Example 20: Synthesis of I-13

[0107] By reference to the preparation method of compound I-1 and substitution of intermediate III-7 for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.030 g of the target compound I-13, a pale yellow-white solid, was obtained with a yield of 36.2%.

[0108] ESI-MS: 618.4 [M+H].sup.+, 640.4 [M+Na].sup.+.

[0109] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.91 (3H, s), 1.04 (3H, s), 1.06 (3H, s), 1.18 (3H, s), 1.34 (3H, s), 1.42 (3H, s), 1.47 (3H, s), 6.00 (1H, s), 7.03 (1H, s), 7.47 (2H, m), 7.69 (3H, m), 8.04 (1H, s).

##STR00026##

Example 21: Synthesis of Intermediate III-8 3-cyano-3-(4-methylphenyl)acrylic acid

[0110] By reference to the synthesis method of intermediate III-7 3-cyano-3-phenylacrylic acid and substitution of 4-methylphenylacetonitrile for phenylacetonitrile as the reaction reagent while other conditions remained unchanged, 0.733 g of intermediate III-8 was obtained with a yield of 78.2%.

[0111] ESI-MS: 188.0 [M+H].sup.+.

[0112] The reaction formula is as follows:

##STR00027##

Example 22: Synthesis of I-14

[0113] By reference to the preparation method of compound I-1 and substitution of intermediate III-8 for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.035 g of the target compound I-14, a yellow-white solid, was obtained with a yield of 40.7%.

[0114] ESI-MS: 632.4 [M+H].sup.+, 654.4 [M+Na].sup.+.

[0115] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.90 (3H, s), 1.03 (3H, s), 1.06 (3H, s), 1.18 (3H, s), 1.27 (3H, s), 1.42 (3H, s), 1.47 (3H, s), 2.40 (3H, s), 6.00 (1H, s), 7.01 (1H, s), 7.26 (2H, d, J=8.16 Hz), 7.68 (2H, d, J=7.7 Hz), 8.04 (1H, s).

##STR00028##

Example 23: Synthesis of Intermediate III-9 3-cyano-3-(4-methoxyphenyl)acrylic acid

[0116] By reference to the synthesis method of intermediate III-7 3-cyano-3-phenylacrylic acid and substitution of 4-methoxyphenylacetonitrile for phenylacetonitrile as the reaction reagent while other conditions remained unchanged, 0.757 g of intermediate III-9 was obtained with a yield of 74.5%.

[0117] ESI-MS: 204.0 [M+H].sup.+.

[0118] The reaction formula is as follows:

##STR00029##

Example 24: Synthesis of I-15

[0119] By reference to the preparation method of compound I-1 and substitution of intermediate III-9 for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.031 g of the target compound I-15, a pale yellow-brown solid, was obtained with a yield of 35.4%.

[0120] ESI-MS: 648.4 [M+H].sup.+, 670.4 [M+Na].sup.+.

[0121] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.89 (3H, s), 0.99 (3H, s), 1.04 (3H, s), 1.17 (3H, s), 1.27 (3H, s), 1.40 (3H, s), 1.45 (3H, s), 3.85 (3H, s), 6.00 (1H, s), 6.94 (2H, d, J=8.76 Hz), 7.03 (1H, s), 7.65 (2H, d, J=8.85 Hz), 8.06 (1H, s).

##STR00030##

Example 25: Synthesis of Intermediate III-10 3-cyano-3-(4-trifluoromethylphenyl)acrylic acid

[0122] By reference to the synthesis method of intermediate III-7 3-cyano-3-phenylacrylic acid and substitution of 4-trifluoromethylphenylacetonitrile for phenylacetonitrile as the reaction reagent while other conditions remained unchanged, 0.833 g of intermediate III-10 was obtained with a yield of 69.1%.

[0123] ESI-MS: 242.0 [M+H].sup.+.

[0124] The reaction formula is as follows:

##STR00031##

Example 26: Synthesis of I-16

[0125] By reference to the preparation method of compound I-1 and substitution of intermediate III-10 for 3-phenylacrylic acid as the reaction reagent while other conditions remain unchanged, 0.056 g of a pale yellow-brown solid, target compound I-16, was obtained with a yield of 60.2%.

[0126] ESI-MS: 686.4 [M+H].sup.+, 708.4 [M+Na].sup.+.

[0127] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.89 (3H, s), 1.00 (3H, s), 1.06 (3H, s), 1.18 (3H, s), 1.28 (3H, s), 1.42 (3H, s), 1.47 (3H, s), 6.04 (1H, s), 7.15 (1H, s), 7.73 (2H, d, J=8.13 Hz), 7.82 (2H, d, J=7.89 Hz), 8.09 (1H, s).

##STR00032##

Example 27: Synthesis of Intermediate III-11 3-cyano-3-(4-fluorophenyl)acrylic acid

[0128] By reference to the synthesis method of intermediate III-7 3-cyano-3-phenylacrylic acid and substitution of 4-fluorophenylacetonitrile for phenylacetonitrile as the reaction reagent while other conditions remain unchanged, 0.956 g of intermediate III-11 was obtained with a yield of 81.9%.

[0129] ESI-MS: 192.0 [M+H].sup.+.

[0130] The reaction formula is as follows:

##STR00033##

Example 28: Synthesis of I-17

[0131] By reference to the preparation method of compound I-1 and substitution of intermediate III-11 for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.023 g of the target compound I-17, a yellow-white solid, was obtained with a yield of 27.0%.

[0132] ESI-MS: 636.4 [M+H].sup.+, 658.4 [M+Na].sup.+.

[0133] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.90 (3H, s), 1.01 (3H, s), 1.06 (3H, s), 1.18 (3H, s), 1.34 (3H, s), 1.43 (3H, s), 1.49 (3H, s), 6.04 (1H, s), 6.96 (1H, s), 7.15 (2H, d, J=8.49 Hz), 7.70 (2H, d, J=8.76 Hz), 8.09 (1H, s).

##STR00034##

Example 29: Synthesis of Intermediate III-12 3-cyano-3-(4-chlorophenyl)acrylic acid

[0134] By reference to the synthesis method of intermediate III-7 3-cyano-3-phenylacrylic acid and substitution of 4-chlorophenylacetonitrile for phenylacetonitrile as the reaction reagent while other conditions remained unchanged, 0.843 g of the intermediate III-12 was obtained with a yield of 81.2%.

[0135] ESI-MS: 208.0 [M+H].sup.+.

[0136] The reaction formula is as follows:

##STR00035##

Example 30: Synthesis of I-18

[0137] By reference to the preparation method of compound I-1 and substitution of intermediate III-12 for 3-phenylacrylic acid as the reaction reagent while other conditions remained unchanged, 0.027 g of the target compound I-18, a pale yellow-brown solid, was obtained with a yield of 30.3%.

[0138] ESI-MS: 652.3 [M+H].sup.+, 674.3 [M+Na].sup.+.

[0139] .sup.1H-NMR (300 MHz, CDCl.sub.3, TMS), δ ppm: 0.88 (3H, s), 0.96 (3H, s), 1.04 (3H, s), 1.17 (3H, s), 1.26 (3H, s), 1.40 (3H, s), 1.45 (3H, s), 6.02 (1H, s), 7.23 (1H, s), 7.40 (2H, d, J=8.40 Hz), 7.64 (2H, d, J=8.43 Hz), 8.09 (1H, s).

##STR00036##

Example 31: Pharmacological Experiments on the Compounds

[0140] The anti-tumor activity of the compounds of the present invention was determined by the method of methyl thiazolyl tetrazolium (MTT), Bardoxolone Methyl (CDDO-Me) being selected as a positive control medicament.

[0141] Instruments: ultra-clean bench (SW-CJ-1FD, AIRTECH, Suzhou Antai Airtech Co. Ltd.), constant-temperature CO.sub.2 incubator (3111, Thermo, USA), inverted biomicroscope (IX71, OLYMPUS, Japan), ELISA microplate reader (Model 680, BIO-RAD, USA), platform shaker (Kylin-bell lab Instruments), autoclave (YXO.SG4I.280, Shanghai Huaxian), and centrifuge (SIGMA).

[0142] Reagents: DMEM (GIBCO), fetal bovine serum (GIBCO), trypsin (SIGMA), and DMSO (SIGMA).

[0143] Cell strains: human non-small cell lung cancer cell strain A549, human liver cancer cell strain HepG2, human breast cancer cell strain MCF-7, human renal tubular epithelial cells HK-2, rat embryonic cardiomyocytes H9C2 (all provided by Jiangsu KeyGEN BioTECH Co., Ltd.).

[0144] Methods: the cryopreserved cell strains were resuscitated and cultured in a CO.sub.2 incubator at a constant temperature of 37° C. with liquid being changed once daily. Plating was carried out when the cell strains were in a good state in the exponential phase. 1 mL of 0.25% trypsin solution was added for digestion for 1-2 min. The cell status was observed under the microscope, and when the adherent cells became round and shrunk, the digestion solution was aspirated and 1-2 mL of a DMEM medium containing 10% fetal bovine serum was added to obtain a cell suspension, on which a cell count was performed. The amount of required cell suspension was calculated on the basis of 5×10.sup.4 cells per well and the total number of wells. The cell suspension was inoculated on a 96-well plate at 100 μL/well, the surroundings being blocked with PBS, followed by incubation in a CO.sub.2 incubator at a constant temperature of 37° C. for 24 h.

[0145] The test medicament, positive control medicament CDDO-Me, and blank control group DMSO were prepared in DMEM media to a final concentration of 5 μM/well, each medicament being placed in 3 replicate wells, followed by incubation for 48 h. The MTT reagent was added to the 96-well plate at 10 μL/well to further incubate for 4 h. The medium in the plate was aspirated and 100 μL of DMSO was added to each well, followed by shaking on the platform shaker for 10 min such that the crystals were dissolved. The absorbance of each well was examined by the ELISA microplate reader at a wavelength of 570 nm, and the cell inhibition rate was calculated according to the formula hereinafter. The mean value of three preliminary screening results was taken as the final inhibition rate thereof. Compounds with a preliminary screening inhibition rate greater than 60% were subjected to a concentration gradient screening (5-fold dilution) for the calculation of IC.sub.50 values of the test medicaments (calculated by the software graphpad), and the results of three replicate experiments were the final IC.sub.50 values of the tested compounds.

Cell inhibition rate (%)=[(OD value of blank control−OD value of dosing cohort)/OD value of blank control group]×100%

TABLE-US-00002 TABLE 1 Inhibitory activity (IC.sub.50, μM) of representative compounds of the present invention against proliferation of some tumor cells and cardiomyocytes. Compd A549 MCF-7 HepG2 HK-2 H9C2 I-1 0.599 ± 0.377 0.574 ± 0.021 0.409 ± 0.016 0.799 ± 0.092 0.251 ± 0.008 I-2 0.549 ± 0.010 0.547 ± 0.074 0.772 ± 0.063 1.388 ± 0.032 0.218 ± 0.007 I-3 0.367 ± 0.018 0.375 ± 0.038 0.527 ± 0.133 0.700 ± 0.016 0.174 ± 0.005 I-4 0.402 ± 0.020 0.562 ± 0.132 0.412 ± 0.006 0.516 ± 0.072 0.215 ± 0.004 I-5 0.788 ± 0.345 1.308 ± 0.127 0.785 ± 0.096 2.825 ± 0.004 0.316 ± 0.001 I-6 0.588 ± 0.036 0.738 ± 0.009 0.482 ± 0.002 0.727 ± 0.430 0.373 ± 0.002 I-7 0.315 ± 0.068 2.225 ± 0.022 2.723 ± 0.036 1.783 ± 0.259 3.170 ± 1.744 I-8 0.329 ± 0.047 0.789 ± 0.052 0.563 ± 0.023 0.423 ± 0.030 0.274 ± 0.002 I-9 0.624 ± 0.111 1.129 ± 0.040 0.816 ± 0.014 0.748 ± 0.341 0.417 ± 0.019 I-10 0.362 ± 0.012 0.460 ± 0.105 0.297 ± 0.011 0.234 ± 0.117 0.233 ± 0.010 I-11 0.609 ± 0.067 0.424 ± 0.129 0.337 ± 0.012 0.308 ± 0.071 0.052 ± 0.001 I-12 0.761 ± 0.032 1.637 ± 0.462 0.974 ± 0.058 2.432 ± 0.033 3.143 ± 1.525 I-13 0.414 ± 0.017 0.375 ± 0.130 0.328 ± 0.013 0.473 ± 0.630 0.007 ± 0.009 I-14 0.337 ± 0.015 0.432 ± 0.188 0.313 ± 0.035 0.939 ± 0.062 0.014 ± 0.001 I-15 0.658 ± 0.058 0.551 ± 0.140 0.524 ± 0.032 0.350 ± 0.037 0.146 ± 0.012 I-16 0.888 ± 0.021 0.958 ± 0.209 0.934 ± 0.011 0.618 ± 0.072 0.108 ± 0.007 I-17 0.345 ± 0.174 0.238 ± 0.008 0.114 ± 0.004 0.229 ± 0.126 0.005 ± ~0 .sup.  I-18 0.300 ± 0.013 0.500 ± 0.170 0.406 ± 0.017 0.647 ± 0.021 0.002 ± ~0 .sup.  CDDO-Me 0.448 ± 0.012 0.728 ± 0.288 0.326 ± 0.021 0.335 ± 0.034 0.308 ± 0.010

[0146] As can be seen from Table 1, most of the compounds of the present invention have greater or comparable inhibitory activities against cardiomyocytes H9C2 than CDDO-Me. The compounds I-1, I-2, I-3, I-4, I-5, I-6, I-7, I-8, I-9, I-12, I-13, I-14, I-16 and I-18 all exhibited lower toxicity on human renal tubular epithelial cells HK-2. In particular, compounds I-7 and I-12 had relatively small inhibitory activities against normal cardiomyocytes H9C2 (IC.sub.50 values of 3.176±1.74 μM and 3.143±1.53 μM, respectively), approximately 1/10 of the inhibitory activity of CDDO-Me (IC.sub.50 of 0.308±0.01 μM), demonstrating a relatively low myocardial toxicity.

Example 32 Inhibitory Effect of Compounds of Present Invention on Tumors in Tumor-Bearing Mice

[0147] 1) Experimental animals: 72 female ICR mice between 6 and 8 weeks of age; experimental cells: S180 ascitic tumor cells.

[0148] 8 animals were used as the normal group, and the rest of the mice were subjected to modeling by the following method.

[0149] 2) Proliferation and passaging of S180 ascitic tumor cells: S180 ascitic tumor cells cryopreserved at −80° C. were thawed in a water bath at 37° C., placed in a 12 mL centrifuge tube, to which an appropriate amount of saline was added, and centrifuged at 1200 rpm for 5 min. The supernatant was discarded, then the cells were resuspended in 300 μL of saline and intraperitoneally injected into an ICR mouse. As the mouse's abdomen swelled up, intraperitoneal injection of the cells in a second ICR mouse was performed, and the cells were ready for inoculation when the abdomen thereof swelled up.

[0150] 3) Inoculation of S180 tumor cells in the armpit of mice: S180 cells cultured to 2 passages were centrifuged and saline was added to obtain a concentration of 1×10.sup.7 cells/mL. A volume of 100 μL of the cells were injected subcutaneously into armpit of mice. A mouse tumor-bearing model was developed.

[0151] The model mice were divided into a tumor-bearing model group, a compound I-7 5 mg/kg group, a compound I-7 15 mg/kg group, a compound I-12 5 mg/kg group, a compound I-12 15 mg/kg group, a compound I-16 5 mg/kg group, a compound I-16 15 mg/kg group and a CDDO-Me 15 mg/kg group.

[0152] There were 8 mice in each group.

[0153] 4) Dosing: the medicaments were administered intragastrically when the tumor grew out.

[0154] Compound I-7 of 5 mg/kg was administered in the compound I-7 5 mg/kg group;

[0155] compound I-7 of 15 mg/kg was administered in the compound I-7 15 mg/kg group;

[0156] compound I-12 of 5 mg/kg was administered in the compound I-12 5 mg/kg group;

[0157] compound I-12 of 15 mg/kg was administered in the compound I-12 15 mg/kg group;

[0158] compound I-16 of 5 mg/kg was administered in the compound I-16 5 mg/kg group;

[0159] compound I-16 of 15 mg/kg was administered in the compound I-16 15 mg/kg group; and

[0160] CDDO-Me of 15 mg/kg was administered in the CDDO-Me 15 mg/kg group.

[0161] An equal volume of 0.5% croscarmellose sodium was administered to the normal group and the model group.

[0162] The dosing was executed for 7 consecutive days. The mice were dissected the next day following the last dosing.

[0163] Testing items: the body weight, spleen weight and tumor weight were measured. The spleens were ground on ice, followed by red blood cell lysis and incubation with FITC-CD11b, LY6C, and LY6G antibodies for 15 min, and then tested for CD11b+LY6Chi+ and CD11b+LY6G+ with flow cytometry.

[0164] Experimental results are shown in Tables 2 and 3.

TABLE-US-00003 TABLE 2 Inhibitory effect of the compounds of the present invention on tumors Tumor Mass Tumor inhibition rate Group (g) (%) Model group 2.64 ± 0.26   .sup.  — Compound I-7 1.53 ± 0.10.sup.##* .sup.  42.17 5 mg/kg group Compound I-7 1.45 ± 0.12.sup.###**  45.20 15 mg/kg group Compound I-12 1.33 ± 0.11.sup.###*** 49.55 5 mg/kg group Compound I-12 0.66 ± 0.14.sup.###*** 74.96 15 mg/kg group Compound I-16 1.49 ± 0.17.sup.##* .sup.  43.69 5 mg/kg group Compound I-16 0.96 ± 0.14.sup.###*** 63.60 15 mg/kg group CDDO-Me 1.67 ± 0.14.sup.##    36.75 15 mg/kg group Note: .sup.#P denotes P ≤ 0.05 versus the model group, .sup.##P denotes P ≤ 0.01 versus the model group, .sup.###P denotes P ≤ 0.001 versus the model group; *P denotes P ≤ 0.05 versus the CDDO-Me group, **P denotes P ≤ 0.01 versus the CDDO-Me group, ***P denotes P ≤ 0.001 versus the CDDO-Me group.

TABLE-US-00004 TABLE 3 Effect of compounds of present invention on M-MDSC, PMN-MDSC and splenic index M-MDSC PMN-MDSC Splenic index Group (%) (%) (10*mg/g) Normal group 0.48 ± 0.08.sup.###   5.44 ± 2.07.sup.###   43.59 ± 7.14.sup.###  Model group 1.63 ± 0.33   .sup.  15.53 ± 1.50   .sup.  59.18 ± 5.13   Compound I-7 5 0.68 ± 0.22.sup.###*** 8.72 ± 1.13.sup.###*  48.55 ± 4.62.sup.##* mg/kg group Compound I-7 0.59 ± 0.09.sup.###*** 6.34 ± 1.47.sup.###*** 47.03 ± 6.54.sup.##* 15 mg/kg group Compound I-12 0.63 ± 0.13.sup.###*** 8.86 ± 1.53.sup.###*  45.99 ± 7.68.sup.##* 5 mg/kg group Compound I-12 0.38 ± 0.23.sup.###*** 4.82 ± 0.62.sup.###***  .sup. 44.37 ± 5.27.sup.###** 15 mg/kg group Compound I-16 0.71 ± 0.08.sup.###*** 8.72 ± 2.09.sup.###*   .sup. 47.86 ± 5.73.sup.###* 5 mg/kg group Compound I-16 0.40 ± 0.07.sup.###*** 6.79 ± 1.55.sup.###*** .sup. 46.45 ± 5.20.sup.###* 15 mg/kg group CDDO-Me 15 1.15 ± 0.12.sup.##    10.91 ± 1.62.sup.###   53.61 ± 4.15   mg/kg group Note: .sup.#P denotes P ≤ 0.05 versus the model group, .sup.##P denotes P ≤ 0.01 versus the model group, .sup.###P denotes P ≤ 0.001 versus the model group; *P denotes P ≤ 0.05 versus the CDDO-Me group, **P denotes P ≤ 0.01 versus the CDDO-Me group, ***P denotes P ≤ 0.001 versus the CDDO-Me group.

[0165] Myeloid-derived suppressor cells (MDSCs) are a population of immature cells of myeloid origin. MDSCs can differentiate into mature macrophages, granulocytes and dendritic cells under normal conditions, but will be aggregated and activated under pathological conditions. In tumors, MDSCs can suppress T-cell immune responses, and can interact with other immune cells and promote, together, the formation of immunosuppression in the tumor microenvironment. In addition, MDSCs can also promote tumor proliferation and metastasis through non-immune pathways such as destruction of extracellular matrix, promoting angiogenesis, etc. Indoleamine 2,3-dioxygenase 1 (IDO1) as one of the key functional markers of MDSCs can catalyze tryptophan metabolism in the tumor microenvironment, leading to the release of soluble kynurenine and downstream metabolites thereof, and inducing immune tolerance by Treg and antigen-presenting cells, thereby resulting in tumor immune escape. As reported in some studies, MDSCs are involved in the progression of pancreatic cancer, breast cancer, brain metastases, etc., and have a great research value as a potential therapeutic target and a reliable prognostic marker.

[0166] The example studies of the present invention found that the compounds of the present invention can inhibit the expression of MDSCs and improve the tumor microenvironment, suggesting therapeutic effects thereof on lung cancer, liver cancer, pancreatic cancer, breast cancer, ascitic tumor, brain metastases, etc.

[0167] Furthermore, it is to be noted that the compounds selected in Example 32 are representative examples of the target compounds described herein and are not limitations on the present invention.