Polyamide compound and use thereof

Abstract

The invention relates to a polyamide compound and a use thereof. Specifically, the invention relates to a type of polyamide compound (which preferably comprise one or more amide bonds formed by condensation of same or different L-amino acids or D-amino acids), or stereoisomers, crystalline polymorphs, solvates, metabolites, prodrugs or pharmaceutically acceptable salts or esters thereof, or pharmaceutical compositions thereof, as well as a method for preparing the polyamide compound and a use thereof in the prevention or treatment of diseases associated with κ-opioid receptor. The polyamide compound of the invention has excellent κ-opioid receptor agonistic activity and hydrophilicity, thus having a lesser ability of penetrating the blood-brain barrier and a lower capacity for entering the brain. The compound of the invention has higher selectivity for a κ-opioid receptor, lower addictiveness, improved pharmacokinetic properties, and improved safety (lower toxicity and/or fewer side effects), good patient compliance, and/or lesser propensity for developing tolerance, among other excellent medicinal properties.

Claims

1. A compound having a structure of Formula (II): ##STR00093## or a stereoisomer, a crystalline polymorph, a solvate, a prodrug, or a pharmaceutically acceptable salt or ester thereof, wherein R.sub.a, R.sub.b and R.sub.c are substituents independently selected from the group consisting of: (CH.sub.3).sub.2CHCH.sub.2— and ##STR00094## R.sub.d is selected from the group consisting of: H.sub.2NCH.sub.2—, H.sub.2NCH.sub.2CH.sub.2—, H.sub.2N(CH.sub.2).sub.2CH.sub.2—, H.sub.2N(CH.sub.2).sub.3CH.sub.2—, H.sub.2N(CH.sub.2).sub.4CH.sub.2—, H.sub.2N(CH.sub.2).sub.5CH.sub.2—, H.sub.2NC(═NH)CH.sub.2—, H.sub.2NC(═NH)NHCH.sub.2—, H.sub.2NC(═NH)NHCH.sub.2CH.sub.2—, H.sub.2NC(═NH)NH(CH.sub.2).sub.2CH.sub.2—, and H.sub.2NC(═NH)NH(CH.sub.2).sub.3CH.sub.2—, wherein R.sub.d is optionally substituted with one or more of C.sub.1-4 alkyl, and wherein R.sub.d is substituted with one or more W groups, wherein the W group is selected from the group consisting of HOCH.sub.2(CHOH).sub.nCH.sub.2—, (HOCH.sub.2).sub.2CH—, —(CH.sub.2).sub.aNH.sub.2, and R.sup.3O(CH.sub.2CH.sub.2O).sub.mCH.sub.2CH.sub.2—; R.sup.1 is selected from the group consisting of: ##STR00095## R.sup.2 is —H; R.sup.3 is C.sub.1-4alkyl; each n is independently an integer from 1 to 8; and, m is an integer from 1 to 20.

2. The compound of claim 1, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof wherein the compound has a structure of Formula (III): ##STR00096##

3. The compound of claim 1, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, wherein m is an integer 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11.

4. The compound of claim 1, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, wherein the compound is selected from the group consisting of: 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(((R)-2,3-dihydroxypropyl)amino)hexanoyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(((S)-2,3-dihydroxypropyl)amino)hexanoyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((2-aminoethyl)amino)hexanoyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((3-aminoprop yl)amino)hexano yl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((2-(2-methoxyethoxy)ethyl)amino)hexanoyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-28-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-2,5,8,11,14,17,20-heptaoxa-23-azanonacosan-29-oyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((1,3-dihydroxypropan-2-yl)amino)hexanoyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(di(2-(2-methoxyethoxy)ethyl)amino)hexanoyl)piperidin-4-carboxylic acid; 8-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(2-(methoxyethoxy)ethylamino)hexanoyl)-1,3,8-triaza-spiro[4.5]decane-2,4-dione; and 2-(6-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((2-(2-methoxyethoxy)ethyl)amino) hexanoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)acetic acid.

5. A pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 1 and one or more pharmaceutically acceptable carriers.

6. The pharmaceutical composition according to claim 5, wherein the pharmaceutical composition is administered orally, intravenously, intraarterially, subcutaneously, intraperitoneally, intramuscularly or transdermally.

7. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 1, wherein n is an integer from 1 to 5.

8. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 1, wherein W is HOCH.sub.2CH(OH)CH.sub.2—, (HOCH.sub.2).sub.2CH—, —CH.sub.2NH.sub.2, —(CH.sub.2).sub.2NH.sub.2, —(CH.sub.2).sub.3NH.sub.2, CH.sub.3O(CH.sub.2CH.sub.2O)CH.sub.2CH.sub.2—, CH.sub.3O(CH.sub.2CH.sub.2O).sub.2CH.sub.2CH.sub.2—, CH.sub.3O(CH.sub.2CH.sub.2O).sub.3CH.sub.2CH.sub.2—, CH.sub.3O(CH.sub.2CH.sub.2O).sub.6CH.sub.2CH.sub.2—, or CH.sub.3O(CH.sub.2CH.sub.2O).sub.11CH.sub.2CH.sub.2.

9. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 1, wherein the compound has a structure of Formula (III)-1: ##STR00097##

10. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9, wherein R.sub.d is substituted with one or two W groups.

11. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9, wherein substitution of R.sub.d with one W group forms a group, which is selected from the group consisting of: W—NHCH.sub.2—, W—NHCH.sub.2CH.sub.2—, W—NH(CH.sub.2).sub.2CH.sub.2—, W—NH(CH.sub.2).sub.3CH.sub.2—, W—NH(CH.sub.2).sub.4CH.sub.2—, W—NH(CH.sub.2).sub.5CH.sub.2—, W—NHC(═NH)CH.sub.2—, W—NHC(═NH)NHCH.sub.2—, W—NHC(═NH)NHCH.sub.2CH.sub.2—, W—NHC(═NH)NH(CH.sub.2).sub.2CH.sub.2—, and W—NHC(═NH)NH(CH.sub.2).sub.3CH.sub.2—, wherein W is selected from the group consisting of HOCH.sub.2(CHOH).sub.nCH.sub.2—, (HOCH.sub.2).sub.2CH—, —(CH.sub.2).sub.nNH.sub.2, and R.sup.3O(CH.sub.2CH.sub.2O).sub.mCH.sub.2CH.sub.2—, wherein n is independently an integer from 1-8; m is an integer from 1-20; and R.sup.3 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl.

12. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9, wherein substitution of R.sub.d with one W group forms a group, which is W—NH(CH.sub.2).sub.3CH.sub.2—; wherein W is selected from the group consisting of HOCH.sub.2(CHOH).sub.nCH.sub.2—, (HOCH.sub.2).sub.2CH—, —(CH.sub.2).sub.nNH.sub.2, and R.sup.3O(CH.sub.2CH.sub.2O).sub.mCH.sub.2CH.sub.2—, wherein n is an integer from 1-8; R.sup.3 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl; and m is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 20.

13. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9, wherein substitution of R.sub.d with one W group forms a group, which is W—NH(CH.sub.2).sub.3CH.sub.2—; wherein the W group is HOCH.sub.2CHOHCH.sub.2—, (HOCH.sub.2).sub.2CH—, —CH.sub.2NH.sub.2, —(CH.sub.2).sub.2NH.sub.2, —(CH.sub.2).sub.3NH.sub.2, CH.sub.3O(CH.sub.2CH.sub.2O)CH.sub.2CH.sub.2—, CH.sub.3O(CH.sub.2CH.sub.2O).sub.2CH.sub.2CH.sub.2—, CH.sub.3O(CH.sub.2CH.sub.2O).sub.3CH.sub.2CH.sub.2—, CH.sub.3O(CH.sub.2CH.sub.2O).sub.6CH.sub.2CH.sub.2—, or CH.sub.3O(CH.sub.2CH.sub.2O).sub.11CH.sub.2CH.sub.2—.

14. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9, wherein substitution of R.sub.d with one W group forms a group, which is W—NH(CH.sub.2).sub.3CH.sub.2—; wherein the W group is CH.sub.3O(CH.sub.2CH.sub.2O)CH.sub.2CH.sub.2—.

15. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9, wherein R.sup.1 is ##STR00098## R.sub.d is selected from group consisting of: H.sub.2NCH.sub.2—, H.sub.2NCH.sub.2CH.sub.2—, H.sub.2N(CH.sub.2).sub.2CH.sub.2—, H.sub.2N(CH.sub.2).sub.3CH.sub.2—, H.sub.2N(CH.sub.2).sub.4CH.sub.2—, H.sub.2N(CH.sub.2).sub.5CH.sub.2—, H.sub.2NC(═NH)CH.sub.2—, H.sub.2NC(═NH)NHCH.sub.2—, H.sub.2NC(═NH)NHCH.sub.2CH.sub.2—, H.sub.2NC(═NH)NH(CH.sub.2).sub.2CH.sub.2—, and H.sub.2NC(═NH)NH(CH.sub.2).sub.3CH.sub.2—; wherein R.sub.d is optionally substituted with one or more H or C.sub.1-4alkyl; wherein substitution of R.sub.d with one W group forms a group, which is R.sup.3O(CH.sub.2CH.sub.2O).sub.mCH.sub.2CH.sub.2—R.sub.d; R.sup.3 is methyl; and m is 1, 2, or 3.

16. The compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9, wherein R.sup.1 is ##STR00099##

17. A pharmaceutical composition, comprising a therapeutically effective amount of the compound according to claim 2 and one or more pharmaceutically acceptable carriers.

18. The pharmaceutical composition according to claim 17, wherein the pharmaceutical composition is administered orally, intravenously, intraarterially, subcutaneously, intraperitoneally, intramuscularly or transdermally.

19. A pharmaceutical composition, comprising a therapeutically effective amount of the compound according to claim 9 and one or more pharmaceutically acceptable carriers.

20. The pharmaceutical composition according to claim 19, wherein the pharmaceutical composition is administered orally, intravenously, intraarterially, subcutaneously, intraperitoneally, intramuscularly or transdermally.

21. A pharmaceutical composition, comprising a therapeutically effective amount of the compound according to claim 4 and one or more pharmaceutically acceptable carriers.

22. The pharmaceutical composition according to claim 21, wherein the pharmaceutical composition is administered orally, intravenously, intraarterially, subcutaneously, intraperitoneally, intramuscularly or transdermally.

23. The compound of claim 1, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharrmaceutically acceptable salt or ester thereof, wherein R.sup.1 is ##STR00100##

24. The compound of claim 23, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, wherein the compound is selected from the group consisting of: 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((2-aminoethyl)amino)hexanoyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((3-aminopropyl)amino)hexanoyl)piperidin-4-carboxylic acid; 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((2-(2-methoxyethoxy)ethyl)amino)hexanoyl)piperidin-4-carboxylic acid; and 4-amino-1-((R)-28-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-2,5,8,11,14,17,20-heptaoxa-23-azanonacosan-29-oyl)piperidin-4-carboxylic acid.

25. A pharmaceutical composition, comprising a therapeutically effective amount of the compound according to claim 24 and one or more pharmaceutically acceptable carriers.

26. A method for preparing the compound of claim 1, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, wherein R.sub.d is H.sub.2N(CH.sub.2).sub.3CH.sub.2— and is substituted with one or two W groups, comprising: obtaining a compound of formula i-2 from a compound of formula i-1 by a condensation reaction with an α-amino ester, wherein the compound of formula i-1 and the compound of formula i-2 are: ##STR00101## obtaining a compound of formula i-3 from the compound of formula i-2 by a hydrolysis reaction and a condensation reaction, wherein the compound of formula i-3 is: ##STR00102## obtaining a compound of formula i-4 from the compound of formula i-3 by a hydrolysis reaction and a condensation reaction, wherein the compound of formula i-4 is: ##STR00103## obtaining a compound of formula i-5 from the compound of formula i-4 by a hydrolysis reaction and a condensation reaction, wherein the compound of formula i-5 is: ##STR00104## removing Ry from the compound of formula i-5 and introducing one or two W groups to produce a compound of formula i-6, wherein the compound of formula i-6 is: ##STR00105##  and obtaining compound of formula i-7 from the compound of formula i-6 by a hydrolysis reaction and a deprotection reaction, wherein the compound of formula i-7 is: ##STR00106##  or obtaining a compound of formula iv-1 from the compound of formula i-3 by a hydrolysis reaction and a condensation reaction, wherein the compound of formula iv-1 is: ##STR00107## obtaining a compound of formula iv-2 from the compound of formula iv-1 by a hydrolysis reaction and a condensation reaction, wherein the compound of formula iv-2 is: ##STR00108##  and obtaining a compound of formula iv-3 from the compound of formula iv-2 by a deprotection reaction, wherein the compound of formula iv-3 is: ##STR00109## wherein Rx, Ry, and Rz, are independently amino-protecting groups, k is 1 or 2; and R.sup.1, R.sub.a, R.sub.b, and R.sub.c are as defined in claim 1.

27. A method for treating a disease associated with κ-opioid receptor, comprising administering to a subject having a disease associated with κ-opioid receptor an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 1 or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 1 and one or more pharmaceutically acceptable carriers, wherein, the disease associated with κ-opioid receptor is selected from the group consisting of pain, inflammation, itching, edema, hyponatremia, hypopotassaemia, intestinal obstruction, cough and glaucoma.

28. A method for enhancing the level or activity of κ-opioid receptor in a cell, comprising administering to the cell an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof according to claim 1, or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 1 and one or more pharmaceutically acceptable carriers.

29. The method according to claim 27, wherein the pain is selected from the group consisting of neuropathic pain, somatic pain, visceral pain and skin pain.

30. The method according to claim 27, wherein the pain is selected from the group consisting of arthritis pain, nephrolith pain, hysterotrismus, dysmenorrhea, endometriosis, post-surgical pain, pain after medical treatment, eye pain, otitis pain, cancer pain and pain associated with gastrointestinal dysfunction.

31. A method for treating a disease associated with κ-opioid receptor, comprising administering to a subject having a disease associated with κ-opioid receptor an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 2 or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 2 and one or more pharmaceutically acceptable carriers, wherein, the disease associated with κ-opioid receptor is selected from the group consisting of pain, inflammation, itching, edema, hyponatremia, hypopotassaemia, intestinal obstruction, cough and glaucoma.

32. A method for enhancing the level or activity of κ-opioid receptor in a cell, comprising administering to the cell an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 2, or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 2 and one or more pharmaceutically acceptable carriers.

33. The method according to claim 31, wherein the pain is selected from the group consisting of neuropathic pain, somatic pain, visceral pain and skin pain.

34. The method according to claim 31, wherein the pain is selected from the group consisting of arthritis pain, nephrolith pain, hysterotrismus, dysmenorrhea, endometriosis, post-surgical pain, pain after medical treatment, eye pain, otitis pain, cancer pain and pain associated with gastrointestinal dysfunction.

35. A method for treating a disease associated with κ-opioid receptor, comprising administering to a subject having a disease associated with κ-opioid receptor an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 9 or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 9 and one or more pharmaceutically acceptable carriers, wherein, the disease associated with κ-opioid receptor is selected from the group consisting of pain, inflammation, itching, edema, hyponatremia, hypopotassaemia, intestinal obstruction, cough and glaucoma.

36. A method for enhancing the level or activity of κ-opioid receptor in a cell, comprising administering to the cell an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof according to claim 9, or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 9 and one or more pharmaceutically acceptable carriers.

37. The method according to claim 35, wherein the pain is selected from the group consisting of neuropathic pain, somatic pain, visceral pain and skin pain.

38. The method according to claim 35, wherein the pain is selected from the group consisting of arthritis pain, nephrolith pain, hysterotrismus, dysmenorrhea, endometriosis, post-surgical pain, pain after medical treatment, eye pain, otitis pain, cancer pain and pain associated with gastrointestinal dysfunction.

39. A method for treating a disease associated with κ-opioid receptor, comprising administering to a subject having a disease associated with κ-opioid receptor an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 4 or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 4 and one or more pharmaceutically acceptable carriers, wherein, the disease associated with κ-opioid receptor is selected from the group consisting of pain, inflammation, itching, edema, hyponatremia, hypopotassaemia, intestinal obstruction, cough and glaucoma.

40. A method for enhancing the level or activity of κ-opioid receptor in a cell, comprising administering to the cell an effective amount of the compound, or the stereoisomer, the crystalline polymorph, the solvate, the prodrug or the pharmaceutically acceptable salt or ester thereof, according to claim 4, or a pharmaceutical composition comprising a therapeutically effective amount of the compound according to claim 4 and one or more pharmaceutically acceptable carriers.

41. The method according to claim 39, wherein the pain is selected from the group consisting of neuropathic pain, somatic pain, visceral pain and skin pain.

42. The method according to claim 39, wherein the pain is selected from the group consisting of arthritis pain, nephrolith pain, hysterotrismus, dysmenorrhea, endometriosis, post-surgical pain, pain after medical treatment, eye pain, otitis pain, cancer pain and pain associated with gastrointestinal dysfunction.

Description

EXAMPLE

(1) The invention is further described in the following examples, but these examples are not provided for the purpose of limiting the scope of the invention.

(2) The abbreviations in the invention have the following meanings:

(3) TABLE-US-00001 Abbreviation Meanings AllocCl Allyl chloroformate DIEA N,N-diisopropylethylamine HBTU O-benzotriazole-N,N,N′,N′-tetramethyluronium hexafluorophosphate HOBt 1-hydroxybenzotriazole

Example 1. 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(((R)-2,3-dihydroxypropyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 1)

(4) ##STR00059## ##STR00060## ##STR00061##

Step 1: Synthesis of methyl (R)-2-((R)-2-((tert-butoxycarbonyl)amino)-3-phenylpropanamido)-3-phenylpropanoate (1-2)

(5) (R)-2-((tert-butoxycarbonyl)amino)-3-phenylpropionic acid (1-1) (20.00 g, 75.38 mmol), (R)-2-amino-3-phenylmethyl propionate (17.07 g, 79.15 mmol), N,N-diisopropylethylamine (31.18 g, 241.23 mmol) and copper chloride dihydrate (14.14 g, 82.92 mmol) were dissolved in tetrahydrofuran (200 mL). Under the protection of nitrogen, the resultant mixture was cooled to about 0° C., to which HOBt (12.22 g, 90.46 mmol) was added, followed by an addition of HBTU (34.31 g, 90.46 mmol). The reaction was carried out at room temperature overnight. The title compound (a crude product, 21.55 g) was obtained after workup, and used directly in the next step.

(6) ESI-MS (m/z): 427 (M+H).sup.+.

Step 2: Synthesis of (R)-2-((R)-2-((tert-butoxycarbonyl)amino)-3-phenylpropanamido)-3-phenylpropionic acid (1-3)

(7) Compound (1-2) (21.50 g, 50.4 mmol) was dissolved in tetrahydrofuran (300 mL) and water (60 mL), and the resultant mixture was cooled to about 0° C., to which lithium hydroxide monohydrate (4.65 g, 111 mmol) was added. The reaction was carried out at 0° C. for 2 h. The reactant was adjusted to pH=3 with hydrochloric acid. The title compound (a crude product, 27 g) was obtained after workup, and used directly in the next step.

(8) ESI-MS (m/z): 413 (M+H).sup.+.

Step 3: Synthesis of methyl (R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylvalerate (1-4)

(9) Compound (1-3) (27.0 g, 50.4 mmol) and methyl (R)-2-amino-4-methylvalerate hydrochloride (9.62 g, 52.92 mmol) were dissolved in tetrahydrofuran (270 mL), and the resultant mixture was cooled to 0° C. Under the protection of nitrogen, N,N-diisopropylethylamine (20.85 g, 161.3 mmol), copper chloride dihydrate (9.45 g, 55.5 mmol) and HOBt (8.17 g, 60.5 mmol) were added, HBTU (22.9 g, 60.5 mmol) was added at last. The reaction was carried out overnight. Title compound (a crude product, 21.7 g) was obtained after workup, and used directly in the next step.

(10) ESI-MS (m/z): 540 (M+H).sup.+.

Step 4: Synthesis of (R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylvaleric acid (1-5)

(11) Compound (1-4) (21.7 g, 40.21 mmol) was dissolved in tetrahydrofuran (310 mL) and water (62 mL). The resultant mixture was cooled to 0° C., to which lithium hydroxide monohydrate (3.7 g, 88.46 mmol) was added. The reaction was carried out at 0° C. for 1.5 h. The reactant was adjusted to pH=3 with hydrochloric acid. The title compound (a crude product, 22.32 g) was obtained after workup, and used directly in the next step.

(12) ESI-MS (m/z): 526(M+H).sup.+.

Step 5: Synthesis of methyl (R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-benzyloxycarbonylamino hexanoate (1-6)

(13) (R)-2-amino-6-benzyloxycarbonylaminomethyl hexanoate (10.75 g, 32.56 mmol) was dissolved in tetrahydrofuran (50 mL), and added with N,N-diisopropylethylamine (12.8 g, 99.2 mmol). The resultant mixture was stirred at room temperature for 30 min, and then Compound (1-5) (16.3 g, 31 mmol), HOBt (5.0 g, 37.2 mmol), copper chloride dihydrate (5.8 g, 34.1 mmol) and HBTU (14.1 g, 37.2 mmol) were added. Under the protection of nitrogen, the resultant reaction mixture was reacted at 0° C. overnight. Water (500 mL), dichloromethane (500 mL) and diatomite were added, and stirred for 5 min. The title compound (a crude product, 17 g) was obtained after workup, and used directly in the next step.

(14) ESI-MS (m/z): 802 (M+H).sup.+.

Step 6: Synthesis of (R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-benzyloxycarbonylaminohexanoic acid (1-7)

(15) Compound (1-6) (9.84 g, 12.28 mmol) was dissolved in a mixed solvent of tetrahydrofuran:water=5:1 (120 mL), and lithium hydroxide monohydrate (1.14 g, 27 mmol) was added at 0° C. The resultant reaction mixture was reacted at room temperature overnight. The reactant was adjusted to pH=3 with hydrochloric acid. The title compound (8 g) was obtained after workup.

(16) ESI-MS (m/z): 788 (M+H).sup.+.

Step 7: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-benzyloxycarbonylaminohexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylate (1-8)

(17) Compound (1-7) (740 mg, 0.94 mmol) and methyl 4-tert-butoxycarbonylaminopiperidin-4-carboxylate (299 mg, 0.493 mmol) were dissolved in dichloromethane, and the resultant mixture was cooled to 0° C. Under the protection of nitrogen, N,N-diisopropylethylamine (485 mg, 3.76 mmol), copper chloride dihydrate (176 mg, 1.03 mmol) and HOBt (152 mg, 1.13 mmol) were added, HBTU (427 mg, 1.13 mmol) was added at last. The resultant reaction mixture was reacted overnight. Water (20 mL), dichloromethane (20 mL) and diatomite were added, and stirred for 5 min. The title compound (719 mg) was obtained after workup.

(18) ESI-MS (m/z): 1029 (M+H).sup.+.

Step 8: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-aminohexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylate (1-9)

(19) Compound (1-8) (1.5 g, 1.46 mmol) was dissolved in methanol (15 mL), and added with 10% Pd/C (150 mg). The reaction bottle was connected to a hydrogen balloon, the reaction was carried out at room temperature for 5 h. The title compound (1.38 g) was obtained after workup.

(20) ESI-MS (m/z): 895 (M+H).sup.+.

Step 9: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((R)-2,2-dimethyl-1,3-dioxolan-4-methylamino)hexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylate (1-10)

(21) Compound (1-9) (250 mg, 0.28 mmol) was dissolved in dichloromethane (10 mL), and (S)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde (47.3 mg, 0.36 mmol) was added. The resultant mixture was stirred for 5 min. Sodium triacetoxyborohydride (100 mg, 0.47 mmol) was then added. The resultant reaction mixture was reacted for 5 min, and then water was added to quench the reaction. The title compound (a crude product, 302 mg) was obtained after workup, and used directly in the next step.

(22) ESI-MS (m/z): 1009 (M+H).sup.+.

Step 10: Synthesis of 1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((R)-2,2-dimethyl-1,3-dioxolan-4-methylamino)hexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylic acid (1-11)

(23) Compound (1-10) (302 mg, 0.28 mmol) was dissolved in tetrahydrofuran (5 mL) and water (1 mL), and lithium hydroxide monohydrate (54 mg, 1.12 mmol) was added. The resultant mixture was kept at 14° C. and reacted for 72 h, and was adjusted to pH=3 with hydrochloric acid. The title compound (94 mg) was obtained after workup.

(24) ESI-MS (m/z): 995 (M+H).sup.+.

Step 11: Synthesis of 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(((R)-2,3-dihydroxypropyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 1)

(25) Compound (1-11) (94 mg, 0.095 mmol) was dissolved in 1,4-dioxane (10 mL), and a solution of 4M HCl/1,4-dioxane (10 mL) was added. The resultant reaction mixture was reacted for 2 h, and the reaction temperature was kept at 20° C. The hydrochloride of the title compound (60 mg) was obtained after workup.

(26) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.29-7.13 (m, 10H), 4.70-4.55 (m, 1H), 4.21-4.14 (m, 2H), 3.89-3.88 (m, 2H), 3.72-3.48 (m, 10H), 3.09-2.90 (m, 6H), 2.27-2.13 (m, 2H), 1.67-1.63 (m, 2H), 1.45-1.32 (m, 7H), 1.15-1.05 (m, 2H), 0.86-0.76 (m, 6H); ESI-MS (m/z): 755.5 (M+H).sup.+.

Example 2. 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(((S)-2,3-dihydroxypropyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 2)

(27) ##STR00062##

(28) In accordance with the preparation method in Example 1, the hydrochloride of the title compound (39 mg) is synthesized, wherein, (R)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde was used in Step 9.

(29) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.30-7.09 (m, 10H), 4.70-4.53 (m, 1H), 4.19-4.12 (m, 2H), 3.87-3.85 (m, 2H), 3.70-3.44 (m, 10H), 3.07-3.04 (m, 2H), 2.99-2.88 (m, 4H), 2.24-2.12 (m, 2H), 1.74-1.59 (m, 6H), 1.43-1.25 (m, 3H), 1.14-1.04 (m, 2H), 0.85-0.75 (m, 6H); ESI-MS (m/z): 755.5 (M+H).sup.+.

Example 3. 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((2-aminoethyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 3)

(30) ##STR00063##

(31) In accordance with the preparation method in Example 1, the title compound (25 mg) is synthesized, wherein, tert-butyl (2-oxoethyl)aminocarboxylate was used in Step 9.

(32) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.45-7.12 (m, 10H), 4.74-4.57 (m, 2H), 4.35-4.14 (m, 2H), 3.96-3.30 (m, 10H), 3.25-2.90 (m, 6H), 2.25-2.22 (m, 2H), 2.04-1.62 (m, 6H), 1.64-1.31 (m, 5H), 1.01-0.76 (m, 6H); ESI-MS (m/z): 724.3 (M+H).sup.+.

Example 4. 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((3-aminopropyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 4)

(33) ##STR00064##

(34) In accordance with the preparation method in Example 1, the hydrochloride of the title compound (60 mg) is synthesized, wherein, tert-butyl (3-oxopropyl)aminocarboxylate was used in Step 9.

(35) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.38-7.02 (m, 10H), 4.56-4.53 (m, 2H), 4.28-4.07 (m, 2H), 3.84-3.44 (m, 5H), 3.17-2.85 (m, 10H), 2.15-2.13 (m, 2H), 2.05-1.54 (m, 8H), 1.37-1.35 (m, 5H), 0.82-0.75 (m, 6H);

(36) ESI-MS (m/z): 738.4 (M+H).sup.+.

Example 5. 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((2-(2-methoxyethoxy)ethyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 5)

(37) ##STR00065##

(38) In accordance with the preparation method in Example 1, the hydrochloride of the title compound (45 mg) is synthesized, wherein, 1,1-dimethoxy-2-(2-methoxyethoxy)ethane was used in Step 9.

(39) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.38-7.05 (m, 10H), 4.63-4.51 (m, 2H), 4.27-4.06 (m, 2H), 3.88-3.42 (m, 10H), 3.19-3.02 (m, 4H), 2.93-2.91 (m, 4H), 1.94-1.53 (m, 6H), 1.37-1.35 (m, 5H), 0.92-0.69 (m, 6H)

(40) ESI-MS (m/z): 783.1 (M+H).sup.+

Example 6. 4-amino-1-((R)-28-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-2,5,8,11,14,17,20-heptaoxa-23-azanonacosan-29-oyl)piperidin-4-carboxylic acid (Compound 6)

(41) ##STR00066##

(42) In accordance with the preparation method in Example 1, the hydrochloride of the title compound (23 mg) is synthesized, wherein, CHO—CH.sub.2(OC.sub.2H.sub.4).sub.6OCH.sub.3 (which was a corresponding aldehyde to heptaethylene glycol monomethyl ether, with a structure of

(43) ##STR00067##
was used in Step 9.

(44) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.31-7.15 (m, 10H), 4.59-4.57 (m, 2H), 4.23-4.15 (m, 2H), 3.83-3.51 (m, 30H), 3.28 (s, 3H), 3.16-3.13 (m, 4H), 3.08-2.89 (m, 4H), 2.21-2.14 (m, 2H), 1.76-1.66 (m, 6H), 1.47-1.32 (m, 5H), 0.88-0.81 (m, 6H);

(45) ESI-MS (m/z): 501.9 (M/2+H).sup.+.

Example 7. 4-amino-1-((R)-43-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-2,5,8,11,14,17,20,23,26,29,32,35-dodecaoxa-38-azatetratetracontan-44-oyl)piperidin-4-carboxylic acid (Compound 7)

(46) ##STR00068##

(47) In accordance with the preparation method in Example 1, the hydrochloride of the title compound (19.4 mg) is synthesized, wherein, CHO—CH.sub.2(OC.sub.2H.sub.4).sub.11OCH.sub.3 (which was the corresponding aidehyde to dodecaethylene glycol monomethyl ether, with a structure of

(48) ##STR00069##
was used in Step 9.

(49) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.24-7.14 (m, 10H), 4.59-4.54 (m, 2H), 4.22-4.14 (m, 2H), 3.63-3.48 (m, 50H), 3.28 (s, 3H), 3.15-2.79 (m, 8H), 2.20-2.12 (m, 2H), 1.90-1.65 (m, 6H), 1.34-1.16 (m, 5H), 0.88-0.77 (m, 6H);

(50) ESI-MS (m/z): 612.0 (M/2+H).sup.+.

Example 8. 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((1,3-dihydroxypropan-2-yl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 8)

(51) ##STR00070##

(52) In accordance with the preparation method in Example 1, the hydrochloride of the title compound (85 mg) is synthesized, wherein, 2,2-dimethyl-1,3-dioxan-5-one was used in Step 9.

(53) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.37-7.03 (m, 10H), 4.54-4.51 (m, 2H), 4.27-4.07 (m, 2H), 3.87-3.43 (m, 8H), 3.15-2.81 (m, 6H), 2.27-2.03 (m, 2H), 1.90-1.53 (m, 6H), 1.37-1.35 (m, 5H), 0.92-0.70 (m, 6H);

(54) ESI-MS (m/z): 755.1 (M+H).sup.+.

Example 9. 1-((R)-6-amino-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)-4-((3-aminopropyl)amino)piperidin-4-carboxylic acid (Compound 9)

(55) ##STR00071## ##STR00072##

Step 1: Synthesis of methyl 1-tert-butyloxycarbonyl-4-(allyloxycarbonylamino)piperidin-4-carboxylate (9-2)

(56) Methyl 1-tert-butyloxycarbonyl-4-aminopiperidin-4-carboxylate (9-1) (0.5 g, 1.94 mmol) and potassium carbonate (0.402 g, 2.91 mmol) were dissolved in a mixed solvent of tetrahydrofuran/water (4:1) (40 mL), AllocCl (0.28 g, 2.32 mol) was added in an ice-bath. Under the protection of nitrogen, the resultant reaction mixture was reacted at room temperature overnight. The title compound (0.8 g) was obtained after workup.

(57) ESI-MS (m/z): 343.2 (M+H).sup.+.

Step 2: Synthesis of methyl 4-(Alloc-amino)piperidin-4-carboxylate (9-3)

(58) Compound (9-2) (0.8 g, 2.27 mmol) was dissolved in dioxane (6 mL), and a solution of HCl/dioxane was added dropwise (3 mL, 12 mmol). The reaction was carried out at room temperature overnight. After the reaction solution was concentrated under reduced pressure, the hydrochloride of the title compound (0.56 g) was obtained.

(59) ESI-MS (m/z): 243.1 (M+H).sup.+.

Step 3: Synthesis of methyl 4-(allyloxycarbonylamino)-1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-benzyloxycarbonylaminohexanoyl)piperidin-4-carboxylate (9-4)

(60) The hydrochloride of Compound (9-3) (0.56 g, 1.94 mmol) was dissolved in tetrahydrofuran (30 mL), and added with DIEA (1.05 g, 8.15 mmol). The resultant mixture was stirred at room temperature for 30 min. Compound 1-7 (1.61 g, 2.04 mmol), HOBt (0.315 g, 2.33 mmol), CuCl.sub.2.2H.sub.2O (0.363 g, 2.13 mmol), and HBTU (0.882 g, 2.33 mmol) were added. Under the protection of nitrogen, the resultant reaction mixture was reacted at 0° C. overnight. The title compound (1 g) was obtained after workup.

(61) ESI-MS (m/z): 1012.5 (M+H).sup.+.

Step 4: Synthesis of methyl 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-benzyloxycarbonylaminohexanoyl)piperidin-4-carboxylate (9-5)

(62) Compound (9-4) (2.66 g, 2.6 mmol) was dissolved in dichloromethane (30 mL), and added with 1,3-dimethylbarbituric acid (0.406 g, 2.6 mmol) and Pd (PPh.sub.3).sub.4 (0.065 g, 0.05 mmol). Under the protection of nitrogen, the resultant reaction mixture was reacted at room temperature for 3 h, and concentrated under reduced pressure. The resultant crude product was prepared by preparative HPLC to obtain the title compound (0.8 g).

(63) ESI-MS (m/z): 928.5 (M+H).sup.+.

Step 5: Synthesis of methyl 4-(3-(tert-butyloxycarbonylamino)propylamino)-1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-benzyloxycarbonylaminohexanoyl)piperidin-4-carboxylate (9-6)

(64) Compound (9-5) (0.2 g, 0.22 mmol) was dissolved in methanol (4 mL), and added with tert-butyl (3-oxopropyl)aminocarboxylate (0.038 g, 0.22 mmol), sodium cyanoborohydride (0.056 g, 0.88 mmol) and a little amount of glacial acetic acid. The resultant reaction mixture was reacted at room temperature overnight. The title compound (215 mg) was obtained after workup.

(65) ESI-MS (m/z): 1085.6 (M+H).sup.+.

Step 6: Synthesis of methyl 4-(3-(tert-butyloxycarbonylamino)propylamino)-1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)piperidin-4-carboxylate (9-7)

(66) Compound (9-6) (0.215 g, 0.2 mmol) was dissolved in methanol (5 mL), and added with Pd/C (0.02 g) and di-tert butyl dicarbonate (0.15 g, 0.7 mmol). The reaction bottle was connected to a hydrogen balloon, and the reaction was carried out at room temperature overnight. The title compound (118 mg) was obtained after workup.

(67) ESI-MS (m/z): 1051.6 (M+H).sup.+.

Step 7: Synthesis of 4-(3-(tert-butyloxycarbonylamino)propylamino)-1-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-benzyloxycarbonylaminohexanoyl)piperidin-4-carboxylic acid (9-8)

(68) Compound (9-7) (118 mg, 0.11 mmol) was dissolved in a mixed solvent of tetrahydrofuran/water (4:1) (3 mL), and LiOH (11 mg) was added. The reaction was carried out at room temperature for 48 h. The reaction mixture was diluted with water, and was adjusted to pH=3 with hydrochloric acid. The title compound (28 mg) was obtained after workup.

(69) ESI-MS (m/z): 1037.6 (M+H).sup.+.

Step 8: Synthesis of 1-((R)-6-amino-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)-4-((3-aminopropyl)amino)piperidin-4-carboxylic acid (Compound 9)

(70) Compound (9-8) (28 mg) was dissolved in 1,4-dioxane (4 mL), and HCl/1,4-dioxane (1 mL, 4 mmol) was added dropwise. The reaction was carried out at room temperature overnight. The hydrochloride of the title compound (8 mg) was obtained after workup.

(71) .sup.1H NMR (DMSO-d.sub.6, 400 MHz) δ 7.29-7.12 (m, 10H), 4.56-4.52 (m, 1H), 4.22-4.12 (m, 3H), 3.58-3.47 (m, 21H), 3.19-2.86 (m, 12H), 2.30-2.20 (m, 2H), 2.02-1.06 (m, 14H), 0.86-0.78 (m, 6H);

(72) ESI-MS (m/z): 369.2 (M/2+H).sup.+.

Example 10. 1-((R)-6-amino-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)-4-(((R)-2,3-dihydroxypropyl)amino)piperidin-4-carboxylic acid (Compound 10)

(73) ##STR00073##

(74) In accordance with the preparation method in Example 9, the hydrochloride of the title compound (29 mg) is synthesized, wherein, (S)-2,2-dimethyl-1,3-dioxolane-4-carboxaldehyde was used in Step 5.

(75) .sup.1H NMR (DMSO-d.sub.6, 400 MHz) δ 7.30-7.12 (m, 10H), 4.60-4.52 (m, 2H), 4.24-3.83 (m, 6H), 3.67-3.45 (m, 5H), 3.10-2.86 (m, 9H), 2.28-2.20 (m, 2H), 1.88-1.28 (m, 12H), 0.86-0.79 (m, 6H);

(76) ESI-MS (m/z): 754.4 (M+H).sup.+.

Example 11. 1-((R)-6-amino-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)-4-((2-aminoethyl)amino)piperidin-4-carboxylic acid (Compound 11)

(77) ##STR00074##

(78) In accordance with the preparation method in Example 9, the hydrochloride of the title compound (31 mg) is synthesized, wherein, tert-butyl (2-oxoethyl)aminocarboxylate was used in Step 5.

(79) .sup.1H NMR (DMSO-d.sub.6, 400 MHz) δ 7.38-7.14 (m, 10H), 4.59-4.54 (m, 2H), 4.22-4.12 (m, 3H), 3.99-3.55 (m, 4H), 3.30-2.88 (m, 12H), 2.29-2.19 (m, 2H), 1.69-1.59 (m, 6H), 1.46-1.32 (m, 5H), 0.88-0.81 (m, 6H);

(80) ESI-MS (m/z): 723.4 (M+H).sup.+.

Example 12. 1-((R)-6-amino-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)-4-((2-(2-methoxyethoxy)ethyl)amino)piperidin-4-carboxylic acid (Compound 12)

(81) ##STR00075##

(82) In accordance with the preparation method in Example 9, the hydrochloride of the title compound (40 mg) is synthesized, wherein, 1,1-dimethoxy-2-(2-methoxyethoxy)ethane was used in Step 5.

(83) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.40-7.09 (m, 10H), 4.59-4.55 (m, 2H), 4.34-4.10 (m, 3H), 3.96-3.94 (m, 1H), 3.81-3.45 (m, 7H), 3.32 (s, 1H), 3.21-2.86 (m, 9H), 2.27-2.25 (m, 2H), 1.91-1.57 (m, 6H), 1.58-1.25 (m, 5H), 0.85-0.82 (m, 6H);

(84) ESI-MS (m/z): 782.5 (M+H).sup.+.

Example 13. 4-(2,5,8,11,14,17,20-heptaoxadocosan-22-ylamino)-1-((R)-6-amino-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)piperidin-4-carboxylic acid (Compound 13)

(85) ##STR00076##

(86) In accordance with the preparation method in Example 9, the hydrochloride of the title compound (2 mg) is synthesized, wherein, CHO—CH.sub.2(OC.sub.2H.sub.4).sub.6OCH.sub.3 (which was the corresponding aldehyde to heptaethylene glycol monomethyl ether, with a structure of

(87) ##STR00077##
was used in Step 5.

(88) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.24-7.14 (m, 10H), 4.60-4.54 (m, 2H), 4.25-4.14 (m, 2H), 3.63-3.48 (m, 50H), 3.28 (s, 3H), 3.15-2.79 (m, 8H), 2.20-2.12 (m, 2H), 1.90-1.65 (m, 6H), 1.34-1.16 (m, 5H), 0.88-0.77 (m, 6H);

(89) ESI-MS (m/z): 501.9 (M/2+H).sup.+.

Example 14. 4-(2,5,8,11,14,17,20,23,26,29,32,35-dodecaoxaheptatriacontan-37-ylamino)-1-((R)-6-amino-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)piperidin-4-carboxylic acid (Compound 14)

(90) ##STR00078##

(91) In accordance with the preparation method in Example 9, the hydrochloride of the title compound (4 mg) is synthesized, wherein, CHO—CH.sub.2(OC.sub.2H.sub.4).sub.11OCH.sub.3 (which was the corresponding aldehyde to dodecaethylene glycol monomethyl ether, with a structure of

(92) ##STR00079##
was used in Step 5.

(93) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.27-7.06 (m, 10H), 4.52-4.47 (m, 1H), 4.22-4.16 (m, 1H), 4.06-3.26 (m, 55H), 3.06-2.76 (m, 7H), 2.66-2.61 (m, 2H), 2.10-1.96 (m, 2H), 1.66-1.27 (m, 11H), 0.86-0.78 (m, 6H);

(94) ESI-MS (m/z): 612.0 (M/2+H).sup.+.

Example 15: 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(di(2-(2-methoxyethoxy)ethyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 15)

(95) ##STR00080##

(96) In accordance with the preparation method in Example 1, the trifluoroacetate of the title compound (45 mg) is synthesized, wherein, (2-methoxyethoxy) acetaldehyde dimethyl acetal was used in Step 9.

(97) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.84-8.09 (m, 8H), 7.33-7.20 (m, 10H), 4.75-4.63 (m, 2H), 4.40-4.32 (m, 1H), 4.02-3.97 (m, 1H), 3.83-3.62 (m, 7H), 3.56-3.54 (m, 5H), 3.45-3.35 (m, 7H), 3.24 (s, 6H), 3.14-3.06 (m, 5H), 2.94-2.89 (m, 1H), 2.82-2.77 (m, 1H), 2.09-1.95 (m, 2H), 1.74-1.44 (m, 9H), 1.30-1.26 (m, 2H), 0.92-0.86 (m, 6H);

(98) ESI-MS (m/z): 884.5 (M+H).sup.+.

Example 16: 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(di(carboxymethyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 16)

(99) ##STR00081##

(100) In accordance with the preparation method in Example 1, the trifluoroacetate of the title compound (5.0 mg) is synthesized, wherein, ethyl glyoxylate was used in Step 9.

(101) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.85-8.03 (m, 10H), 7.29-7.22 (m, 10H), 4.70-4.63 (m, 2H), 4.34-4.33 (m, 1H), 4.02-3.99 (m, 1H), 3.90-3.34 (m, 8H), 3.13-3.05 (m, 2H), 2.96-2.91 (m, 1H), 2.84-2.72 (m, 2H), 2.09-2.20 (m, 2H), 1.81-1.71 (m, 2H), 1.68-1.55 (m, 2H), 1.53-1.40 (m, 5H), 1.26-1.22 (m, 3H), 0.92-0.85 (m, 6H);

(102) ESI-MS (m/z): 796.4 (M+H).

Example 17: 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-((carboxymethyl)amino)hexanoyl)piperidin-4-carboxylic acid (Compound 17)

(103) ##STR00082##

(104) In accordance with the preparation method in Example 1, the trifluoroacetate of the title compound (5 mg) is synthesized, wherein, ethyl glyoxylate was used in Step 9.

(105) .sup.1H NMR (400 MHz, D.sub.2O) δ 7.40-7.23 (m, 10H), 4.69-4.62 (m, 2H), 4.35-4.25 (m, 1H), 3.95-3.56 (m, 6H), 3.18 (d, J=8.0 Hz, 2H), 3.08-2.97 (m, 4H), 2.35-2.23 (m, 2H), 2.02-1.17 (m, 6H), 1.56-1.40 (m, 6H), 0.98-0.91 (m, 6H);

(106) ESI-MS (m/z): 738.4 (M+H).

Example 18: 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-(2-aminoethylamino)-3-phenylpropionyl)-3-phenylpropionyl)-4-methylpentanamido)-6-aminohexanoyl)piperidin-4-carboxylic acid (Compound 18)

(107) ##STR00083## ##STR00084##

Step 1: Synthesis of (R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylvaleric acid (18-1)

(108) Compound (1-5) (3 g, 5.7 mmol) was dissolved in 2M HCl/EA (30 mL), and reacted at room temperature for 4 h. The title compound (a crude product, 2.2 g) was obtained after workup, and was used directly in the next step.

(109) ESI-MS (m/z): 427 (M+H).sup.+.

Step 2: Synthesis of (R)-2-((R)-2-((R)-2-(benzyloxycarbonylamino)-3-phenylpropanamido)-3-phenylpropanamido)-4-methylvaleric acid (18-2)

(110) Compound (18-1) (2.755 g, 5.964 mmol) was dissolved in 1,4-dioxane (60 mL) and water (30 mL); and added sequentially with NaHCO.sub.3 (1.0 g, 11.93 mmol) and N-(Benzyloxycarbonyloxy)succinimide (1.56 g, 6.26 mmol). The reaction was carried out at room temperature for 0.5 h. The resultant mixture was then cooled to 0° C., and adjusted to pH=3 with 1N HCl aqueous solution. The title compound (a crude product, 3.38 g) was obtained after workup, and was used directly in the next step.

(111) ESI-MS (m/z): 560 (M+H).sup.+.

Step 3: Synthesis of methyl (R)-1-(2-(benzyloxycarbonylamino)-6-(tert-butyloxycarbonylamino)hexanoyl)-4-(tert-butyloxycarbonylamino)piperidin-4-carboxylate (18-4)

(112) N-benzyloxycarbonyl-N′-tert-butyloxycarbonyl-D-lysine (4 g, 10.5 mmol) and methyl4-N—BOC-piperidin-4-carboxylate (3 g, 5.0 mmol) were dissolved in dichloromethane (10 mL), and the resultant mixture was cooled to 0° C. Under the protection of nitrogen, DIEA (5.43 g, 42 mmol), copper dichloride dehydrate (1.88 g, 11 mmol), HOBt (1.62 g, 12 mmol), and HBTU (4.55 g, 12 mmol) were separately added. The reaction was carried out for 16 h. The title compound (a crude product, 6.69 g) was obtained after workup, and was used directly in the next step.

(113) ESI-MS (m/z): 621 (M+H).sup.+;

Step 4: Synthesis of methyl (R)-1-(2-amino-6-(tert-butyloxycarbonylamino)hexanoyl)-4-(tert-butyloxycarbonylamino)piperidin-4-carboxylate (18-5)

(114) Compound 18-4 (1.30 g, 2.09 mmol) was dissolved in methanol (25 mL), and added with 10% Pd/C (130 mg), and the replacement with H.sub.2 was performed. The reaction was carried out at room temperature for 4 h. Posttreatment was performed to obtain the title compound (1.38 g), which was used directly in the reaction in the next step.

(115) ESI-MS (m/z): 487 (M+H).sup.+.

Step 5: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-((R)-2-benzyloxycarbonylamino-3-phenylpropionyl)-3-phenylpropionyl)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylate (18-6)

(116) Compound 18-5 (700 mg, 1.25 mmol), and Compound 18-2 (609 mg, 1.25 mmol), were dissolved in dichloromethane (20 mL). The resultant mixture was cooled to −5° C., to which N-methylmorpholine (380 mg, 3.75 mmol), HOBt (253 mg, 1.88 mmol), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (360 mg, 1.88 mmol) were added. The resultant reaction mixture was reacted at 0° C. overnight. The title compound (a crude product, 1.20 g) was obtained after workup, and was used directly in the next step.

(117) ESI-MS (m/z): 1028.5 (M+H).sup.+.

Step 6: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropionyl)-3-phenylpropionyl)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylate (18-7)

(118) Compound 18-6 (1.42 g, 1.38 mmol) was dissolved in methanol (25 mL), 10% Pd/C (140 mg) was added, and the replacement with H.sub.2 was performed. The reaction was carried out at room temperature for 4 h. After filtration through diatomite, washing with methanol, and drying by rotary evaporation, the title compound (1.13 g) was obtained.

(119) ESI-MS (m/z): 894.5 (M+H).sup.+.

Step 7: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-((R)-2-((2-tert-butyloxycarbonylaminoethyl)amino)-3-phenylpropionyl)-3-phenylpropionyl)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)-4-tert-butyl oxycarbonylaminopiperidin-4-carboxylate (18-8)

(120) Compound 18-7 (200 mg, 0.22 mmol) was dissolved in dichloromethane (15 mL). Under the protection of nitrogen, the resultant solution was cooled to −5° C., to which N-tert-butyloxycarbonyl-2-aminoacetaldehyde (32 mg, 0.20 mmol) was added and stirred for 10 min, followed by an addition of sodium triacetoxyborohydride (94 mg, 0.44 mmol). The resultant reaction mixture was stirred at 0° C. overnight. The title compound (100 mg) was obtained after workup.

(121) ESI-MS (m/z): 1037.5 (M+H).sup.+.

Step 8: Synthesis of 1-((R)-2-((R)-2-((R)-2-((R)-2-((2-tert-butyloxycarbonylaminoethyl)amino)-3-phenylpropionyl)-3-phenylpropionyl)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)-4-tert-butyl oxycarbonylaminopiperidin-4-carboxylic acid (18-9)

(122) Compound 18-8 (180 mg, 0.17 mmol) was dissolved in tetrahydrofuran (20 mL) and water (4 mL). Under the protection of nitrogen, the resultant solution was cooled to −5° C., to which lithium hydroxide (16 mg, 0.69 mmol) was added. The reaction was carried out at 0° C. for 72 h. the reaction solution was adjusted to pH=3 with 0.5 mol/L HCl. The title compound (a crude product, 160 mg) was obtained after workup, and was used directly in the next step.

(123) ESI-MS (m/z): 1023.5 (M+H).sup.+.

Step 9: Synthesis of 4-amino-1-((R)-2-((R)-2-((R)-2-((R)-2-(2-aminoethylamino)-3-phenylpropionyl)-3-phenylpropionyl)-4-methylpentanamido)-6-aminohexanoyl)piperidin-4-carboxylic acid (Compound 18)

(124) Compound 18-9 (160 mg, 0.19 mmol) was dissolved in 1,4-dioxane (20 mL), and 4M HCl/1,4-dioxane (20 mL) was added and reacted for 4 h, then the reaction mixture was subjected to the suction filtration. The filter cake was freeze-dried to obtain the product (a crude product, 120 mg). The trifluoroacetate of the title compound (43 mg) was obtained after workup.

(125) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.65 (s, 4H), 8.39-8.37 (m, 1H), 8.22 (d, J=8 Hz, 1H), 8.11 (d, J=8 Hz, 1H), 7.84 (s, 4H), 7.28-7.11 (m, 10H), 4.73-4.67 (m, 2H), 4.36-4.30 (m, 1H), 3.81-3.80 (m, 1H), 3.73-3.65 (m, 2H), 3.07-2.95 (m, 6H), 2.76-2.64 (m, 5H), 2.07-1.82 (m, 4H), 1.52-1.45 (m, 8H), 1.32-1.31 (m, 2H), 0.94-0.87 (m, 6H);

(126) ESI-MS (m/z): 723.5 (M+H).

Example 19: 1-((R)-2-((R)-2-((R)-2-((R)-2-(3-aminopropylamino)-3-phenylpropionyl)-3-phenylpropionyl)-4-methylpentanamido)-6-aminohexanoyl)-4-aminopiperidin-4-carboxylic acid (Compound 19)

(127) ##STR00085##

(128) In accordance with the preparation method in Example 18, the trifluoroacetate of the title compound (47 mg) is synthesized, wherein, (3-oxopropyl)aminocarboxylate tert-butyl was used in Step 7.

(129) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.90-7.94 (m, 11H), 7.33-7.02 (m, 10H), 4.75-4.69 (m, 2H), 4.29-4.27 (m, 1H), 3.92-3.82 (m, 1H), 3.67-3.59 (m, 3H), 3.07-2.95 (m, 7H), 2.74-2.68 (m, 5H), 2.09-1.98 (m, 2H), 1.86-1.76 (m, 2H), 1.64-1.45 (m, 8H), 1.33-1.28 (m, 2H), 0.95-0.88 (m, 6H);

(130) ESI-MS (m/z): 737.5 (M+H).sup.+.

Example 20: 4-amino-1-((R)-6-amino-2-((R)-2-((R)-2-((S)-3-amino-2-benzylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)piperidin-4-carboxylic acid (Compound 21)

(131) ##STR00086## ##STR00087##

Step 1: Synthesis of methyl ((R)-2-((R)-2-(benzyloxycarbonylamino)-3-phenylpropanamido)-4-methylvalerate (21-2)

(132) N-benzyloxycarbonyl-D-phenylalanine (1.00 g, 3.33 mmol), D-leucine methyl ester hydrochloride (0.73 g, 4.00 mmol), DIEA (1.72 g, 13.30 mmol) and copper chloride dehydrate (0.68 g, 4.00 mmol) were dissolved in tetrahydrofuran (30 mL). Under the protection of nitrogen, the resultant mixture was cooled to −5° C., to which HOBt (0.68 g, 5.00 mmol), and HBTU (1.90 g, 5.00 mmol) were added. The reaction was carried out at 0° C. overnight. The title compound (a crude product, 1.40 g) was obtained after workup, and was used directly in the next step.

(133) ESI-MS (m/z): 427 (M+H).sup.+.

Step 2: Synthesis of (R)-2-((R)-2-(benzyloxycarbonylamino)-3-phenylpropanamido)-4-methylvaleric acid (21-3)

(134) Compound 21-2 (1.40 g, 3.28 mmol) was dissolved in a mixed solvent of tetrahydrofuran (30 mL) and water (6 mL). The resultant mixture was cooled to −5° C., to which lithium hydroxide (0.16 g, 6.57 mmol) was added. The reaction was carried out at 0° C. for 2 h. The resultant mixture was then diluted with 100 mL ice-water, and adjusted to pH=3 with 0.5 mol/L HCl. The title compound (a crude product, 1.28 g) was obtained after workup, and was used directly in the next step.

(135) ESI-MS (m/z): 413 (M+H).

Step 3: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-benzyloxycarbonylamino-3-phenylpropanamido)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanamido)-4-tert-butyloxycarbonylaminopiperidin-4-carboxyl ate (21-4)

(136) Compound 21-3 (1.28 g, 3.10 mmol) and Compound 18-5 (1.51 g, 3.10 mmol) were dissolved in dichloromethane (40 mL). Under the protection of nitrogen, the resultant mixture was cooled to −5° C., to which N-methylmorpholine (0.94 g, 9.30 mmol), HOBt (0.63 g, 4.65 mmol), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.89 g, 4.65 mmol) were added. The reaction was carried out at 0° C. overnight. The title compound (a crude product, 2.2 g) was obtained after workup, and was used directly in the next step.

(137) ESI-MS (m/z): 881.5 (M+H).sup.+.

Step 4: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylate (21-5)

(138) Compound 21-4 (600 mg, 0.68 mmol) was dissolved in methanol (15 mL), 10% Pd/C (60 mg) was added, and the replacement with H.sub.2 was performed. The reaction was carried out at room temperature for 3 h. After filtration through diatomite, washing with methanol, and drying by rotary evaporation, the title compound (480 mg) was obtained.

(139) ESI-MS (m/z): 747.5 (M+H).sup.+.

Step 5: Synthesis of methyl 1-((R)-2-((R)-2-((R)-2-((S)-3-tert-butyloxycarbonylamino-2-benzylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylate (21-6)

(140) Compound 21-5 (320 mg, 0.43 mmol) and (S)-2-benzyl-3-N-tert-butyloxycarbonylaminopropionic acid (120 mg, 0.43 mmol) were dissolved in dichloromethane (20 mL). Under the protection of nitrogen, the resultant mixture was cooled to −5° C., to which N-methylmorpholine (130 mg, 1.29 mmol), HOBt (87 mg, 0.64 mmol), and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (123 mg, 0.64 mmol) were added. The reaction was carried out at 0° C. overnight. The title compound (280 mg) was obtained after workup.

(141) ESI-MS (m/z): 1008.5 (M+H).sup.+

Step 6: Synthesis of 1-((R)-2-((R)-2-((R)-2-((S)-3-tert-butyloxycarbonylamino-2-benzylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-tert-butyloxycarbonylaminohexanoyl)-4-tert-butyloxycarbonylaminopiperidin-4-carboxylic acid (21-7)

(142) Compound 21-6 (260 mg, 0.26 mmol) was dissolved in a mixed solvent of tetrahydrofuran (20 mL) and water (4 mL). Under the protection of N.sub.2, the resultant mixture was cooled to −5° C., to which lithium hydroxide (25 m g, 1.05 mmol) was added. The reaction was performed at 0° C. for 72 h. The resultant mixture was adjusted to pH=3 with 0.5 mol/L hydrochloric acid. The title compound (a crude product, 0.20 g) was obtained after work up, and was used directly in the next step.

(143) ESI-MS (m/z): 994.5 (M+H).sup.+

Step 7: Synthesis of 4-amino-1-((R)-6-amino-2-((R)-2-((R)-2-((S)-3-amino-2-benzylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)piperidin-4-carboxylic acid (Compound 21)

(144) Compound 21-7 (200 mg, 0.201 mmol) was dissolved in 1,4-dioxane (5 mL), and added with 4M HCl/1,4-dioxane (5 mL). The reaction was carried out for 4 h. The hydrochloride of the title compound (a crude product, 150 mg) was obtained after workup. The crude product was purified by preparative HPLC to obtain the trifluoroacetate of the title compound (89 mg).

(145) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.46-7.71 (m, 9H), 7.28-7.16 (m, 10H), 4.70-4.58 (m, 2H), 4.36-4.30 (m, 1H), 3.10-3.03 (m, 2H), 2.93-2.67 (m, 9H), 2.09-1.97 (m, 3H), 1.73-1.45 (m, 11H), 1.30-1.27 (m, 2H), 0.90-0.85 (m, 6H).

(146) ESI-MS (m/z): 694.5 (M+H).sup.+.

Example 21: 4-amino-1-((R)-6-amino-2-((R)-2-((R)-2-((R)-3-amino-2-benzylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)hexanoyl)piperidin-4-carboxylic acid (Compound 22)

(147) ##STR00088##

(148) In accordance with the preparation method in Example 20, the hydrochloride of the title compound (a crude product, 250 mg) is synthesized, wherein, (R)-2-benzyl-3-N-tert-butyloxycarbonylaminopropionic acid was used in Step 5. The crude product was purified by preparative HPLC to obtain the trifluoroacetate of the title compound (184 mg).

(149) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.41-7.72 (m, 10H), 7.22-7.16 (m, 8H), 7.05-7.01 (m, 2H), 4.72-4.60 (m, 2H), 4.36-4.23 (m, 4H), 2.85-2.67 (m, 8H), 2.04-1.96 (m, 2H), 1.62-1.51 (m, 10H), 1.35-1.23 (m, 3H), 0.92-0.85 (m, 6H);

(150) ESI-MS (m/z): 694.5 (M+H).sup.+.

Example 22: 8-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(2-(methoxyethoxy)ethylamino)hexanoyl)-2,8-diaza-spiro[4.5]decan-3-one (Compound 23)

(151) ##STR00089## ##STR00090##

Step 1: Synthesis of 2-(2-methoxyethoxy)acetaldehyde (23-1)

(152) Oxalyl chloride (8.87 g, 69.91 mmol) was dissolved in dichloromethane (80 ml) under the protection of nitrogen, and was cooled to <−70° C. A solution of dimethyl sulfoxide (7.8 g, 99.87 mmol) in dichloromethane (10 mL) was added dropwise and stirred at the temperature for 60 min after the addition; then followed by an addition of a solution of diethylene glycol monomethyl ether (8.0 g, 66.58 mmol) in dichloromethane (10 mL) dropwisely. A further stirring of 60 min at the temperature was conducted; triethylamine (13.47 g, 133.16 mmol) was added dropwise. After the addition, the temperature was warmed to room temperature slowly. The stirring was performed for 20 min to obtain the solution of the title compound in dichloromethane (143 mL), in which the content of the title compound was about 54 mg/mL.

Step 2: Synthesis of methyl (R)-2-benzyloxycarbonylamino-6-(N-tert-butyloxycarbonyl-N-(2-(2-methoxyethoxy)ethyl)amino)hexanoate (23-2)

(153) To a solution of N-(9-benzyloxycarbonyl)-D-lysine hydrochloride (1.2 g, 3.63 mmol) in methanol (3.0 mL), a solution of Compound 23-1 in dichloromethane (15 mL, 5.63 mmol) was added. After stirring at room temperature for 30 min, sodium triacetoxyborohydride (1.9 g, 8.89 mmol) was added. The resultant reaction mixture was reacted at room temperature for 30 min. A mixture of DIEA (1.15 g, 8.89 mmol) and di-tert butyl dicarbonate (712 mg, 3.26 mmol) was cooled to 0° C., and then added to the solution above. After the addition, the resultant mixture was warmed to room temperature and reacted for 2 h. The title compound (750 mg) was obtained after workup.

Step 3: Synthesis of methyl (R)-2-amino-6-(N-tert-butyloxycarbonyl-N-(2-(2-methoxyethoxy)ethyl)amino)hexanoate (23-3)

(154) Compound 23-2 (750 mg, 1.51 mmol) was dissolved in 10 mL methanol, and added with Pd/C (10%). The reaction was performed at the atmosphere of hydrogen for 2 h. Pd/C was removed by filtration, and the title compound (520 mg) was obtained by concentration under reduced pressure.

Step 4: Synthesis of methyl (R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(N-tert-butyloxycarbonyl-N-(2-(2-methoxyethoxy)ethyl)amino) hexanoate (23-4)

(155) Compound 1-5 (750 mg, 1.43 mmol) and Compound 23-3 (520 mg, 1.43 mmol) were dissolved in 10 mL tetrahydrofuran. The resultant mixture was cooled to 0° C., to which DIEA (590 mg, 4.58 mmol), copper dichloride dihydrate (267 mg, 1.57 mmol), HOBt (232 mg, 1.72 mmol) and HBTU (652 mg, 1.72 mmol) were added. Under the protection of nitrogen, the reaction was performed at 0° C. for 12 h. The title compound (a crude product, 1.0 g) was obtained after workup.

Step 5: Synthesis of (R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(N-tert-butyloxycarbonyl-N-(2-(2-methoxyethoxy)ethyl)amino) hexanoic acid (23-5)

(156) Compound 23-4 (1.0 g, 1.15 mmol) was dissolved in a mixed solvent of 8 mL tetrahydrofuran and 2 mL water. Lithium hydroxide monohydrate (193 mg, 4.6 mmol) was added. The reaction was performed at 0° C. for 18 h. The resultant mixture was adjusted to pH=4-5 with 1.0 mol/L dilute hydrochloric acid. The title compound (a crude product, 980 mg) was obtained after workup, and was used directly in the next step.

Step 6: Synthesis of 8-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(N-tert-butyloxycarbonyl-N-(2-(2-methoxyethoxy)ethyl)amino) hexanoyl)-2,8-diaza-spiro[4.5]decan-3-one (23-6)

(157) Compound 23-5 (200 mg, 0.23 mmol) and 2,8-diazaspiro[4,5]decan-1-one (46 mg, 0.24 mmol) were dissolved in N,N-dimethyllformamide (10 mL). The resultant mixture was cooled to 0° C. DIEA (89 mg, 0.69 mmol) and HBTU (261 mg, 0.69 mmol) were added. The reaction was performed at 0° C. for 12 h. The title compound (a crude product, 220 mg) was obtained after workup, and was used directly in the next step.

Step 7: Synthesis of 8-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(2-(methoxyethoxy)ethylamino)hexanoyl)-2,8-diaza-spiro[4.5]decan-3-one (Compound 23)

(158) Compound 23-6 (220 mg, 0.22 mmol) was added in a 50 mL reaction bottle, followed by 10 mL HCl/1,4-dioxane (4.0 mol/L). The reaction was carried out at room temperature for 2 h. The crude product of the title compound (200 mg) was obtained directly by concentration under reduced pressure. After purification by preparative HPLC, the trifluoroacetate of the title compound (37 mg) was obtained.

(159) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.77 (t, J=8 Hz, 1H), δ 8.49 (s, 2H), 8.38 (d, J=8 Hz, 1H), 8.21-8.02 (m, 4H), 7.64 (d, J=9.6 Hz, 1H), 7.32-7.20 (m, 10H), 4.72-4.63 (m, 2H), 4.42-4.34 (m, 1H), 4.23-4.09 (m, 1H), 4.00 (s, 1H), 3.91-3.83 (m, 1H), 3.63 (t, J=5.2 Hz, 2H), 3.57-3.55 (m, 2H), 3.47-3.45 (m, 2H), 3.24 (s, 3H), 3.20-3.07 (m, 7H), 2.94-2.77 (m, 5H), 1.99-1.96 (m, 2H), 1.64-1.60 (m, 5H), 1.55-1.42 (m, 4H), 1.40-1.25 (m, 4H), 0.92-0.82 (m, 6H);

(160) ESI-MS (m/z): 792.49 (M+H).sup.+.

Example 23: 8-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(2-(methoxyethoxy)ethylamino)hexanoyl)-1,3,8-triaza-spiro[4.5]decane-2,4-dione (Compound 24)

(161) ##STR00091##

(162) In accordance with the preparation method in Example 22, a crude product of the title compound (200 mg) was obtained, wherein, 1,3,8-triaza-spiro[4.5]decane-2,4-dione was used in Step 6. After purification by preparative HPLC, the trifluoroacetate of the title compound (31 mg) was obtained.

(163) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 10.77 (d, J=12 Hz, 1H), 8.75 (t, J=4 Hz, 1H), 8.65 (d, J=12 Hz, 1H), 8.46 (s, 2H), 8.37 (d, J=4 Hz, 1H), 8.31-8.15 (m, 1H), 8.01 (s, 3H), 7.30-7.22 (m, 10H), 4.72-4.67 (m, 2H), 4.41-4.34 (m, 1H), 4.26-4.13 (m, 1H), 3.99-3.87 (m, 2H), 3.63 (t, J=4 Hz, 2H), 3.58-3.55 (m, 2H), 3.47-3.45 (m, 2H), 3.24 (s, 3H), 3.12-3.05 (m, 5H), 2.99-2.77 (m, 5H), 1.83-1.74 (m, 1H), 1.64-1.44 (m, 10H), 1.32-1.28 (m, 2H), 0.92-0.87 (m, 6H);

(164) ESI-MS (m/z): 807.47 (M+H).

Example 24: 2-(6-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methyl pentanamido)-6-((2-(2-methoxyethoxy)ethyl)amino)hexanoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)acetic acid (Compound 25)

(165) ##STR00092##

Step 1: Synthesis of ethyl 2-(6-tert-butyloxycarbonyl-3,6-diaza bicyclo[3.1.1]heptan-3-yl)acetate (25-2)

(166) 6-Tert-butyloxycarbonyl-3,6-diazabicyclo[3.1.1]heptane (100 mg, 0.50 mmol) and ethyl glyoxylate (50% toluene, wt %) (103 mg, 1.0 mmol) were dissolved in 10 mL dichloromethane, and a little amount of glacial acetic acid was added. The resultant mixture was stirred at room temperature for 20 min, followed by an addition of sodium triacetoxyborohyride (534 mg, 2.52 mmol). The reaction was carried out at room temperature for 30 min. The title compound (a crude product, 300 mg) was obtained after workup, and was used directly in the next step.

Step 2: Synthesis of ethyl 2-(3,6-diazabicyclo[3.1.1]heptan-3-yl)acetate (25-3)

(167) Compound 25-2 (300 mg, 1.06 mmol) was dissolved in 3 mL dichloromethane, and added with 1.0 mL trifluoroacetic acid. The resultant reaction mixture was stirred at room temperature for 2 h. The title compound (a crude product, 200 mg) was obtained after workup, and was used directly in the next step.

Step 3: Synthesis of ethyl 2-(6-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(N-tert-butyloxycarbonyl-N-(2-(2-methoxyethoxy)ethyl)amino)hexanoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)acetate (25-4)

(168) Compound 23-5 (220 mg, 0.25 mmol) and Compound 25-3 (56 mg, 0.31 mmol) were dissolved in 10 mL N,N-dimethyllformamide. The resultant mixture was cooled to 0° C., and added with DIEA (105 mg, 0.81 mmol) and HBTU (308 mg, 0.81 mmol). The reaction was carried out at 0° C. for 12 h. The title compound (a crude product, 250 mg) was obtained after workup, and was used directly in the next step.

Step 4: Synthesis of 2-(6-((R)-2-((R)-2-((R)-2-((R)-2-tert-butyloxycarbonylamino-3-phenylpropanamido)-3-phenylpropanamido)-4-methylpentanamido)-6-(N-tert-butyloxycarbonyl-N-(2-(2-methoxyethoxy)ethyl)amino)hexanoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)acetic acid (25-5)

(169) Compound 25-4 (250 mg, 0.24 mmol) was dissolved in 8 mL tetrahydrofuran, and added with 2 mL water. The resultant mixture was cooled to 0° C., to which lithium hydroxide (40 mg, 0.96 mmol) was added. The reaction was carried out overnight at this temperature. The resultant mixture was adjusted to pH=4-5 with 1.0 mol/L diluted hydrochloric acid. The title compound (a crude product, 230 mg) was obtained after workup, and was directly used in the next step.

Step 5: Synthesis of 2-(6-((R)-2-((R)-2-((R)-2-((R)-2-amino-3-phenylpropanamido)-3-phenylpropanamido)-4-methyl pentanamido)-6-((2-(2-methoxyethoxy)ethyl)amino)hexanoyl)-3,6-diazabicyclo[3.1.1]heptan-3-yl)acetic acid (Compound 25)

(170) Compound (25-5) 230 mg was added in a 50 mL reaction bottle, and added with 10 mL HCl/1, 4-dioxane (4.0 mol/L). The reaction was carried out at room temperature for 2 h. A crude product of the title compound (200 mg) was obtained directly by concentration under reduced pressure. After purification by preparative HPLC, the trifluoroacetate of the title compound (37 mg) was obtained.

(171) .sup.1H NMR (400 MHz, DMSO-d.sub.6) δ 8.75-8.73 (m, 1H), 8.48-8.42 (m, 2H), 8.37-8.33 (m, 1H), 8.25-8.23 (m, 1H), 8.01 (s, 3H), 7.29-7.20 (m, 10H), 4.67-4.63 (m, 1H), 4.55-4.53 (m, 1H), 4.43-4.32 (m, 1H), 4.26-3.95 (m, 4H), 3.65-3.47 (m, 10H), 3.25 (s, 3H), 3.09-3.01 (m, 5H), 2.92-2.76 (m, 4H), 1.99-1.80 (m, 1H), 168-1.29 (m, 10H), 0.92-0.87 (m, 6H);

(172) ESI-MS (m/z): 794.47 (M+H).sup.+.

(173) The other compounds could be synthesized by reference to the methods in the above Examples.

(174) Biological Experiments

(175) 1. Experiment on κ-Opioid Receptor Agonistic Effect

(176) The efficacy of the compounds of the invention as κ-opioid receptor agonists was determined by measuring the ability of the compounds of Examples to inhibit adenylate cyclase activity.

(177) Cell culture: hamster ovary cells CHO stably expressing human κ-opioid receptor (KOR) gene were cultured in MEMα plus nucleosides medium (Invitrogen) containing 5% FBS.

(178) Stimulation: the test compound was 4-fold diluted in a gradient manner to obtain 11 concentrations, and 100 nl of each was transferred to a 384-well plate, and then a stimulating solution (5 uL) containing NKH477 (Tocris) was added; the cells were digested, re-suspended, and counted; and then the cells (5 uL) were added to wells, mixed gently, and incubated at 37° C. for 30 min.

(179) Detection: cAMP Assay Kit (Cisbio) was used, cAMP-D.sub.2 and Anti-cAMP-Cryptate were added separately, and the resultant mixture was incubated for 1 h at room temperature. The plate was read using envision (Perkin Elmer) and EC.sub.50 was obtained by means of fitting with a four-parameter equation.

(180) TABLE-US-00002 Experimental result Example No. ED.sub.50 (nM) Example 1 0.09 Example 2 0.08 Example 3 0.06 Example 4 0.07 Example 5 0.05 Example 6 0.11 Example 8 0.03 Example 15 0.06 Example 17 0.42 Example 23 0.016 Example 24 0.005

(181) It could be seen from the above result of EC.sub.50: the compounds of Examples had an excellent agonistic effect for κ-opioid receptor. The other compounds of the invention had a similar agonistic effect for κ-opioid receptor.

(182) 2. Experiment on Selectivity for Opioid Receptors

(183) The selectivity of the compounds of the invention for κ opioid receptors was determined by measuring the inhibitory effect of the compounds of Examples on the enzyme of KOR, MOR, and DOR.

(184) Experimental Method

(185) The compounds of Examples at different concentrations were incubated with the cell membrane with high expression of KOR, MOR, DOR and the corresponding radioligand (KOR: 3H-diprenophrine; MOR: 3H-DAMGO; DOR: 3H-DADLE) for 1 h, the compounds of Examples competed with the radioligands for binding to KOR, MOR, DOR. After the incubation, Cell harvest was used to collect cell membranes onto a Unifilter-96 GF/C filter plate, and the unbound radioligands were washed away. The plate was placed in a 50-degree oven for 1 h, and finally the scintillation solution Microscint 20 cocktail was added and the isotope signal was detected by MicroBeta2 Reader.

(186) According to the intensity of the isotope signal at different concentrations, the IC.sub.50 was calculated by means of fitting with a four-parameter equation, and the Ki value was calculated.

(187) The Ki value was calculated according to the formula Ki=IC.sub.50/(1+[radioligand]/Kd), and Kd was the equilibrium dissociation constant of radioligand.

(188) TABLE-US-00003 Experimental result DOR MOR KOR IC.sub.50 Ki IC.sub.50 Ki IC.sub.50 Ki Example No. (nM) (nM) (nM) (nM) (nM) (nM) Example 3 >20000 >12048 >20000 >7182 <0.03 <0.01 Example 4 >20000 >12048 >20000 >7182 <0.03 <0.01 Example 5 >20000 >12048 >20000 >7182 0.05 0.02 Example 6 >20000 >12048 >20000 >7182 0.33 0.11

(189) It could be seen from the above results: the compounds of Example 3, 4, 5, and 6 had an excellent KOR selectivity for κ opioids. Other compounds of the invention had a similar KOR selectivity to κ opioids.

(190) 3. Acetic Acid-Induced Writhing Test in Mice (Evaluation of In Vivo Efficacy)

(191) The analgesic effect of the compound of the invention was evaluated by measuring the ED50 of the compounds of Examples in the acetic acid-induced writhing test in mice.

(192) Experimental Method

(193) The commercial glacial acetic acid solution was diluted with physiological saline to 0.6% glacial acetic acid solution. The male ICR mice were randomly separated into the drug group and the model group (to which physiological saline was administration). 15 minutes after iv administration, 0.6% acetic acid solution was intraperitoneally injected at 10 ml/kg, and the mice was immediately recorded with DV camera for 15 min. After the recording, the number of writhes of the mice within 15 min was counted from the video by blind method, the inhibition rate for the writhes was calculated according to Formula (I), and the ED50 of the compound was calculated according to Formula (II).

(194) (I) The inhibition rate for the writhes was calculated by the formula: Inhibition rate (%)=(the number of writhes in a model group−the number of writhes in a drug group)/the number of writhes in a model group*100.

(195) (II) The ED.sub.50 was calculated by the formula:

(196) $1g{\mathrm{LD}}_{55}=x_m-d\left({\Sigma }_p-\frac{3-\mathrm{pm}-\mathrm{pm}}{4}\right),$
wherein Xm was the logarithm of the highest dose, d was the difference in the logarithm of two adjacent doses, p was the inhibition rate for each dose group, pm was the highest-dose inhibition rate, and pn was the lowest-dose inhibition rate.

(197) TABLE-US-00004 Experimental result Example No. ED.sub.50 (nM) Example 3 0.041 Example 4 0.029 Example 5 0.017 Example 6 0.036

(198) As seen from the above result, the compounds of Examples 3, 4, 5, and 6 had significant analgesic effect. Other compounds of the invention had similar significant analgesic effect.

(199) 4. Pharmacokinetic (PK) Study in Rats

(200) The pharmacokinetic profile of the compounds of Examples was studied by intravenous administration of the compounds of Examples to male SD rats. The dose for IV administration was 1 mg/kg, and the solvent was 5% DMSO: 5% solutol: 90% physiological saline. After IV administration, blood samples were collected at different time points for PK study. Plasma were treated by protein precipitation and then analyzed by LC-MS/MS.

(201) In LC-MS/MS, mass spectrum was API 5500, and liquid chromatography was Shimadzu LC-30AD system. The column used for the test groups of Compound 3 and Compound 4 was Thermo C18 column (4.6 mm×100 mm, 3 μm); for mobile phases, phase A was water+0.1% formic acid, and phase B was methanol; the flow rate was 0.8 mL/min, and the column temperature was 40° C. The column used for the test group of Compound 5 was Agela AQ C18 column (2.1 mm×50 mm, 1.9 μm); for mobile phases, phase A was water+0.05% formic acid+5 mM acetic acid ammonium, and phase B was methanol+0.05% formic acid; the flow rate was 0.6 mL/min, and the column temperature was 40° C. The ion source used was the ESI source in positive ion mode, and the scanning mode was Multiple Reaction Monitoring (MRM).

(202) TABLE-US-00005 Experimental result / Example 3 Example 4 Example 5 Example 6 Administration route Intra- Intra- Intra- Intra- venous venous venous venous admin- admin- admin- admin- istration istration istration istration Gender male male male male Dose mg/kg 1 1 1 1 AUC.sub.last h*ng/ml 1790 2410 783 2180 C.sub.max ng/ml 2650 3590 1690 3660 T.sub.1/2 h 0.34 1.22 0.28 0.29 V.sub.d l/kg 0.28 0.74 0.53 0.20

(203) It was found by the PK study in rats that, the compounds of Example 3, 4, 5, and 6 had good exposure amount and Cmax, as well as other parameters. It indicated that the compounds of the present invention had good pharmacokinetics and absorption, and had significant pharmacokinetic and absorption effect.

(204) 5. Experiment on the Ability of Compounds to Pass Through the Blood-Brain Barrier

(205) After peripheral intravenous administration of the compound of each Example to the animal, samples of peripheral plasma and brain tissue were taken to determine the concentration of the compound in the peripheral plasma and brain tissue.

(206) After intravenously injected with the compound of Example 5 at 1 mg/kg to male rats, samples of plasma and brain tissues were taken at various time points, and the contents of the test compound in the peripheral plasma and brain tissue were determined. The results were shown in the following table:

(207) TABLE-US-00006 Concentration of the Concentration compound of of the compound Time after Example 5 in of Example administration peripheral plasma 5 in brain (min) ng/mL tissue ng/mL 5 1310 0 15 716 0 30 386 0.20 60 136 0.00

(208) The experimental result above showed that the concentration of the test compound in the peripheral plasma was significantly higher than that in the brain tissue. It indicated that the compound of the invention could effectively reduce the toxic side effects (such as analgesia, sedation, hallucination or addiction, etc.) to the central nervous system whilst remaining the peripheral analgesic effect.

(209) In addition to those described herein, various modifications of the invention will be apparent to those skilled in the art according to the contents as described above. It is also intended that such modifications fall into the scope of the set of claims attached.