Method for preparing a drug linker complex and intermediate thereof

Abstract

The present invention provides a method for preparing a drug linker complex. The present invention further provides a method for preparing an intermediate or a salt thereof to be used and the use of the intermediate or a salt thereof. The raw materials according to the preparation method described in the present invention are easy to obtain, simple to operate, have high product purity, and are suitable for large-scale synthesis.

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 2022106005234 with a filing date of May 30, 2022 and Chinese Patent Application No. 2022110295935 with a filing date of August 25, 2022. The full text of the above Chinese patent applications is incorporated herein by reference. This application belongs to the field of medicinal chemistry. Specifically, this application relates to a method for preparing a drug linker complex or a salt thereof and related intermediates or salts thereof.

Background Art

[0002] An antibody-drug conjugate (ADC) is a conjugate of an antibody and a small molecule drug, which fuses the tumor targeting effect of the antibody and the activity of the bioactive molecule to become a biological missile and has very promising therapeutic effects and safety advantages. The antibody induces binding of the ADC to the target cell / tissue, and then the small molecule drug is released intracellularly / tissue by the action of a specific enzyme to treat the disease. Among them, the drug linker complex (including a cytotoxic payload and a linker) plays an extremely important role in the preparation of ADCs. Therefore, the development of a synthetic method for drug linker complexes that is simple, efficient, low-cost, and suitable for large-scale synthesis has important significance for the development and application of ADC drugs.

[0003] Ds8201a is an already commercially available ADC molecule, and its toxin linker has a relatively specific azaacetal structure (

[0004]

Chemical Formula

[0005] ) is included and has a good therapeutic effect on breast cancer with high expression in Her2. However, the synthetic methods for the azaacetal structure contained in the ADC molecule are limited. One is that Pb(OAc)4 oxidizes and rearranges the carboxylic acid to obtain an acetic acid ester structure, and then the target molecule is obtained by an acid catalyst. The Pb(OAc)4 used in this method has strict restrictions on the substrate and cannot contain oxidizable groups (such as amino groups, substituted amino groups) in the molecule, otherwise the reaction yield is extremely low. The other is that Pb(OAc)4 oxidizes and rearranges to obtain an acetic acid ester structure, reacts with a halogenating reagent (such as TMSCl, TMSBr) to obtain a halide, and further undergoes a nucleophilic substitution reaction with the hydroxy group of the substrate under basic conditions. In addition to using Pb(OAc)4, this method uses a base (such as potassium tert-butoxide) in the nucleophilic substitution reaction, which is not suitable for substrates unstable to bases such as camptothecin-based compounds. At the same time, the above methods all use Pb(OAc)4 and Pb remains in the system. Therefore, when removing the amino protecting group by metal-catalyzed hydrogenation in the subsequent reaction, it causes poisoning of the corresponding metal catalyst and greatly affects the reaction yield. Therefore, in order to solve problems such as large limitations on the substrate and low reaction yield and meet the demand for large-scale production, the development of a new method for synthesizing azaacetal is eagerly desired.

[0006] WO2022170971 discloses an ADC molecule containing an azaacetal structure with good antitumor activity. The synthetic route of the drug linker complex used in the preparation of the ADC molecule is shown below:

[0007]

Chemical Structure

[0008] When this route uses A1.9 as the starting material and the target compound is obtained through a three-step reaction, 1. A1.9 is a cytotoxic compound, belonging to highly active molecules, and it is necessary to use an isolator in the three-step reaction during the scale-up production of the process, and the operation is difficult; 2. B1.14-A is one of the important intermediates in this route and needs to be purified by column chromatography, with a large amount of solvent used and difficult to scale up production; 3. B1.14 is the second important intermediate in this route, with relatively poor chemical stability, rapid polymerization, and difficult quality control during the scale-up production of the process; 4. The overall yield of this route is <5% (calculated based on A1.9), and there is a defect of high cost.

[0009] To sum up, the above route cannot carry out scale-up production. How to reduce the reaction steps involving highly active molecules, avoid the appearance of unstable intermediates, simplify the purification method, and improve the yield is directly related to whether the subsequent scale-up production of the process can be carried out smoothly. Therefore, it is urgent to develop a new synthetic route to meet the demand for scale-up production.

Summary of the Invention

[0010] The present application provides a method for preparing a compound of formula I as a drug linker complex, as well as a method for preparing an intermediate or a salt thereof used, and the use of the intermediate or a salt thereof. The preparation method described in the present application has a wide adaptability of the substrate, is easier to operate, and is suitable for large-scale production.

[0011] In one aspect, the present application provides a method for preparing a compound of formula I or a salt thereof,

[0012]

Chemical formula

[0013] In the formula, D is a fragment of a bioactive molecule, preferably a fragment of a bioactive molecule of the formula I-A camptothecin system,

[0014] [Chemistry]

[0015] In the formula, R1 and R2 are each independently selected from H, halogen, -OH, an optionally substituted C1-6 alkyl group, and an optionally substituted C1-6 alkoxy group, or R1 and R2, together with the carbon atom to which they are attached, form a 5- to 7-membered carbocyclic ring or a 5- to 7-membered heterocyclic ring, and the heterocyclic ring contains one or more of O, S, N, a carbonyl group, a sulfoxide group or a sulfone group, or any combination thereof, R3 is selected from H, halogen, -OH, -NH2, an optionally substituted C1-6 alkyl group, and an optionally substituted C1-6 alkoxy group, or R3 and X, together with the carbon atom to which they are attached, form a 5- to 7-membered carbocyclic ring or a 5- to 7-membered heterocyclic ring, and the heterocyclic ring contains one or more of O, S, N, a carbonyl group, a sulfoxide group or a sulfone group, or any combination thereof, or R3 and R2, together with the carbon atom to which they are attached, form a 5- to 7-membered carbocyclic ring or a 5- to 7-membered heterocyclic ring, and the heterocyclic ring contains one or more of O, S, N, a carbonyl group, a sulfoxide group or a sulfone group, or any combination thereof, W is absent or present, and when W is present, W is

[0016] [Chemistry]

[0017] selected from, the 1-position is linked to X, and the 2-position is linked to an oxygen atom, X is a direct bond, an optionally substituted -O-(CH2) n3 -, -N(R4)-(CH2) n3 -, -S-(CH2) n3 -, carbonyl-(CH2) n3 , -SO2-(CH2)n3 -,

[0018] [ka]

[0019] -(CH2) n1 -, a C3-6 cycloalkyl group, a C6-10 aryl group, a 5-10 membered heteroaryl group, and a 4-10 membered heterocyclic group, the 1-position is linked to a parent ring, the 2-position is linked to W or an oxygen atom, and the above substituents are selected from one or more C1-4 alkyl groups, C3-6 cycloalkyl groups, or the multiple C1-4 alkyl groups together with the carbon atoms linked thereto form a C3-6 cycloalkyl group; Each M independently represents a direct bond and -CR 5a R 5b - selected from R4, R5, R 5a , R 5b , R6, R7 are each independently selected from H, an optionally substituted C1-4 alkyl group, an optionally substituted C1-4 alkoxy group, and an optionally substituted C3-6 cycloalkyl group; n, n', n1, n2, and n3 are each independently selected from any integer between 0 and 6; More preferably, formula IA is

[0020] [ka]

[0021] The structure is selected from L 1 teeth,

[0022] [ka]

[0023] and the first position is linked to Lg and the second position is L 2 Connect to Lg is a leaving group when reacting with an antibody, and Lg is selected from halogen, sulfone group, tertiary amine base (Me3N + , Et3N + ), diazonium base, -OMs, MeSO2-, CF3SO3-, preferably, Lg is selected from F, Cl, MeSO2-, more preferably, Lg is MeSO2-, L 1 is

[0024]

Chemical formula

[0025] when it is, Lg does not exist, L 2 is

[0026]

Chemical formula

[0027] selected from, the 1st position is linked to L 1 and the 2nd position is linked to L 3 , n4 is selected from any integer between 0 and 10, Y is selected from -CH2-, -OCH2CH2-, Z is selected from CR m R n , NR m , R m , R n are each independently selected from H, deuterium, C1-4 alkyl group, C2-4 alkenyl group, C2-4 alkynyl group, C3-6 cycloalkyl group, 3-6 membered heterocyclic group, or, R m and R n together with the carbon atom to which they are both linked form a 3-6 membered carbocyclic ring or a 3-6 membered heterocyclic ring, L 3 is selected from short peptides consisting of 2 to 10 amino acid residues, and the above amino acid residues are natural amino acid residues, unnatural amino acid residues, or AA1 selected from the amino acid residues shown in AA 1 The structure of the amino acid residue shown in

[0028] [Chemical formula]

[0029] wherein R a , R b are each independently H and

[0030] [Chemical formula]

[0031] selected from, and R a , R b are not both H at the same time, or, R a and R b together with the carbon atom to which they are both attached form a 4- to 10-membered heterocyclic ring, and the above 4- to 10-membered heterocyclic ring is optionally substituted with one or more R 0 , r, r 1 are each independently selected from any integer between 0 and 20, R m1 , R n1 are each independently selected from H, a C1-6 alkyl group, and a C3-6 cycloalkyl group, or, R m1 and R n1 together with the nitrogen atom to which they are both attached form a 4- to 10-membered heterocyclic ring, and the above 4- to 10-membered heterocyclic ring is optionally substituted with one or more R 0’ , R 0 , R 0’ are each independently a C1-6 alkyl group, a C3-6 cycloalkyl group, -NR m2 R n2and is selected from a 4- to 10-membered heterocyclic group optionally substituted with a C1-6 alkyl group, R m2 and R n2 are each independently selected from H and C1-6 alkyl groups.

[0032] The above preparation method comprises reacting a compound of formula I-1 or a salt thereof with a compound of formula X-3 or a salt thereof to obtain a compound of formula I or a salt thereof,

[0033]

Chemical formula

[0034] wherein R8 is hydrogen, a C1-30 alkyl group, a C3-7 cycloalkyl group, a 3- to 20-membered heterocyclic group, a 5- to 10-membered heteroaryl group, a C6-10 aryl group, a C1-6 alkyl group-C3-6 cycloalkyl group, a C1-6 alkyl group-4- to 6-membered heterocyclic group, a C1-6 alkyl group-5- to 10-membered heteroaryl group, a C1-6 alkyl group-C6-10 aryl group,

[0035]

Chemical formula

[0036] selected from, and the above alkyl group, cycloalkyl group, heterocyclic group, heteroaryl group, aryl group are optionally substituted with one or more R x and R x is selected from hydrogen, deuterium, halogen, hydroxy group, C1-4 alkyl group, C1-4 alkoxy group, C2-4 alkenyl group, C2-4 alkynyl group, -NR m2 R n2 nitro group, cyano group, azide group, oxo group, ester group and carboxy group, t 1 is selected from any integer between 0 and 10, Lg, L 1 L 2 L 3 D, Rm2 and R n2 is defined as described in any one of the forms of the present application.

[0037] In another aspect, the present application provides a method for preparing a compound of formula II or a salt thereof,

[0038]

Chemical formula

[0039] comprising step i) of reacting a compound of formula III or a salt thereof with a compound of formula X-3 or a salt thereof to obtain a compound of formula II or a salt thereof,

[0040]

Chemical formula

[0041] wherein Lg, L 1 , L 2 , L 3 , and the definition of R8 are as described in any one of the forms of the present application.

[0042] In some embodiments, in step i), the compound or its salt represented by the above formula X-3 is

[0043]

Chemical formula

[0044] selected from the structure of, and correspondingly, the compound of formula II or its salt is

[0045]

Chemical formula

[0046] selected from the structure of, That is, step i) relates to a reaction of a compound of formula III or a salt thereof with a compound of formula X-3a or a salt thereof to obtain a compound of formula IIa or a salt thereof.

[0047]

Chemical formula

[0048] In another aspect, the present application provides a method for preparing a compound of formula X-3 or a salt thereof. Step m-1) of obtaining a compound of formula X-3-1 or a salt thereof from the reaction of a compound of formula IV-2 or a salt thereof.

[0049]

Chemical formula

[0050] Including step m-2) of reacting a compound of formula X-3-1 or a salt thereof with a compound of formula X-1 to obtain a compound of formula X-3 or a salt thereof.

[0051]

Chemical formula

[0052] Wherein E is selected from a hydroxy group, a halogen, an activated hydroxy group, for example, a hydroxy group, chlorine, bromine.

[0053]

Chemical formula

[0054] Selected from. PG2 is selected from an amino protecting group. Lg, L 1 、L 2 、L 3 The definitions of R8 are as described in any one of the forms of the present application.

[0055] In some embodiments, in steps m-1) and m-2), the compound represented by the above formula IV-2 or a salt thereof is

[0056]

Chemical formula

[0057] selected from the structure of, and correspondingly, the compound represented by the above formula X-3-1 or a salt thereof is

[0058]

Chemical formula

[0059] selected from the structure of, and correspondingly, the compound represented by the above formula X-3 or a salt thereof is

[0060]

Chemical formula

[0061] selected from the structure of That is, step m-1) relates to a reaction of removing the protecting group Cbz from the compound of formula IV-2-A or a salt thereof under a metal reagent-hydrogen system to obtain the compound of formula X-3-1-A or a salt thereof

[0062]

Chemical formula

[0063] Step m-2) relates to a reaction of reacting the compound of formula X-3-1-A or a salt thereof with the compound of formula X-1-A under basic conditions to obtain the compound of formula X-3a or a salt thereof

[0064]

Chemical formula

[0065] In another aspect, the present application provides a method for preparing a compound of formula IV-2 or a salt thereof, when R8 is not H, step k-1) of obtaining a compound of formula IV-2-1 or a salt thereof from the reaction of a compound of formula IV-1 or a salt thereof,

[0066]

Chemical formula

[0067] step k-2) of reacting the compound of formula IV-2-1 or a salt thereof with a compound of formula IV-2-2 or a salt thereof to obtain a compound of formula IV-2 or a salt thereof,

[0068]

Chemical formula

[0069] wherein, PG2-L 3 is, that is, PG2-L 3-2 -L 3-1 and when R8 is H, IV-2 is IV-2a, and includes the following method 1 or method 2: Method 1 includes step k-3) of obtaining a compound of formula IV-2a or a salt thereof from the reaction of a compound of formula IV-2-3 or a salt thereof,

[0070]

Chemical formula

[0071] Method 2 includes step k-4) of obtaining a compound of formula IV-2-5 or a salt thereof from the reaction of a compound of formula IV-2-4 or a salt thereof,

[0072]

Chemical formula

[0073] Step k-5) of reacting a compound of Formula IV-2-5 or a salt thereof with a compound of Formula IV-2-2 or a salt thereof to obtain a compound of Formula IV-2-6 or a salt thereof,

[0074]

Chemical formula

[0075] including Step k-6) of obtaining a compound of Formula IV-2a or a salt thereof from the reaction of a compound of Formula IV-2-6 or a salt thereof,

[0076]

Chemical formula

[0077] In Method 2, PG2-L 3 is, that is, PG2-L 3-2 -L 3-1 and wherein L 3-1 is selected from an amino acid residue or a short peptide consisting of 2 to 9 amino acid residues, and the amino acid residue is selected from a natural amino acid residue, a non-natural amino acid residue, or an amino acid residue shown in AA 1 or a stereoisomer thereof, PG1 is selected from amino protecting groups, L 3-2 is selected from an amino acid residue or a short peptide consisting of 2 to 9 amino acid residues, and the amino acid residue is selected from a natural amino acid residue, a non-natural amino acid residue, or an amino acid residue shown in AA 1 or a stereoisomer thereof, L 3 The definitions of PG2, R8, and E are as described in any one of the forms of the present application, PG3 is a hydroxy protecting group such as a benzyl group, a substituted benzyl group, or an allyl group.

[0078] In some embodiments, in Steps k-1) and k-2), the compound of Formula IV-1 or a salt thereof

[0079]

Chem.

[0080] selected from the structure of, the compound of formula IV-2-2 or a salt thereof is

[0081]

Chem.

[0082] selected from the structure of, correspondingly, the compound of formula IV-2-1 or a salt thereof is

[0083]

Chem.

[0084] selected from the structure of, correspondingly, the compound of formula IV-2 shown or a salt thereof is

[0085]

Chem.

[0086] selected from the structure of That is, step k-1) relates to the reaction of removing the protecting group Cbz from the compound of formula IV-1-A or a salt thereof under a metal reagent-hydrogen system to obtain the compound of formula IV-2-1-A or a salt thereof.

[0087]

Chem.

[0088] Step k-2) relates to the reaction of reacting the compound of formula IV-2-1-A or a salt thereof with the compound of formula IV-2-2-B or a salt thereof under basic or neutral conditions under the action of a condensing agent and / or a racemization inhibitor to obtain the compound of formula IV-2-A or a salt thereof.

[0089]

Chem.

[0090] In another aspect, the present application provides a method for preparing two types of compounds of formula IV-1 or salts thereof, comprising the following method 1 or method 2: Method 1 includes step j) of reacting a compound of formula IV-1-1 or a salt thereof with a compound of formula R8OH or a salt thereof to obtain a compound of formula IV-1 or a salt thereof,

[0091]

Chem.

[0092] Method 2 is step j-1) of obtaining a compound of formula IV-1-3 or a salt thereof from the reaction of a compound of formula IV-1-2 or a salt thereof,

[0093]

Chem.

[0094] and step j-2) of obtaining a compound of formula IV-1 or a salt thereof from the reaction of a compound of formula IV-1-3 or a salt thereof,

[0095]

Chem.

[0096] wherein the definitions of L 3-1 , PG1, and R8 are as described in any one form of the present application.

[0097] In some embodiments, in steps j-1) and j-2), the compound of formula IV-1-2 or a salt thereof is

[0098]

Chem.

[0099] selected from the structure of, and correspondingly, the compound of formula IV-1-3 or a salt thereof is

[0100]

Chemical formula

[0101] selected from the structure of, and correspondingly, the compound of formula IV-1 or a salt thereof is

[0102]

Chemical formula

[0103] selected from the structure of That is, step j-1) relates to the reaction of reacting a compound of formula IV-1-A-2 or a salt thereof with formaldehyde in water and under basic conditions to obtain a compound of formula IV-1-A-3 or a salt thereof

[0104]

Chemical formula

[0105] Step j-2) relates to the reaction of reacting a compound of formula IV-1-A-3 or a salt thereof with CF3CH2OH under acidic conditions to obtain a compound of formula IV-1-A or a salt thereof

[0106]

Chemical formula

[0107] In some embodiments, L 1 is

[0108]

Chemical formula

[0109] selected from, the first position is linked to Lg, and the second position is linked to L2.

[0110] In some embodiments, L 1 is

[0111]

Chemical formula

[0112] and the first position is linked to Lg, and the second position is linked to L 2 to.

[0113] In some embodiments, L 1 is

[0114]

Chemical formula

[0115] selected from, and the second position is linked to L 2 to.

[0116] In some embodiments, L 2 is

[0117]

Chemical formula

[0118] selected from, the first position is linked to L 1 to, and the second position is linked to L 3 to.

[0119] In some embodiments, L 2 is

[0120]

Chemical formula

[0121] selected from, the first position is linked to L 1 to, and the second position is linked to L3 is connected to

[0122] In some embodiments, L 2 is

[0123]

Chemical formula

[0124] and the first position is connected to L 1 is connected to the second position is L 3 is connected to.

[0125] In some embodiments, Y is -CH2-.

[0126] In some embodiments, n4 is selected from 0, 1, 2, 3.

[0127] In some embodiments, Z is selected from -CH2-, -C(CH3)2-, -N(CH3)- and -NH-.

[0128] In some embodiments, R m , R n are each independently selected from H, a C1-4 alkyl group, a C2-4 alkenyl group, a C2-4 alkynyl group, a C3-6 cycloalkyl group, and a 3-6 membered heterocyclic group,

[0129] or, R m and R n together with the carbon atom to which they are both attached form a 3-6 membered carbocyclic ring or a 3-6 membered heterocyclic ring.

[0130] In some embodiments, R m , R n are each independently selected from H and Me.

[0131] In some embodiments, L 1 -L 2 is

[0132] [Chemical formula]

[0133] When selected from, the first position is linked to Lg, and the second position is linked to L 3 to.

[0134] In some embodiments, L 1 -L 2 is

[0135] [Chemical formula]

[0136] selected from, and the second position is linked to L 3 to.

[0137] In some embodiments, L 1 -L 2 is

[0138] [Chemical formula]

[0139] selected from, the first position is linked to Lg, the second position is linked to L 3 to, and further

[0140] [Chemical formula]

[0141] may be selected from, and the second position is linked to L 3 to.

[0142] In some embodiments, L 1 -L 2 is

[0143] [Chemical formula]

[0144] selected from, the first position is linked to Lg, and the second position is linked to L 3 , and further

[0145] [Chemical formula]

[0146] may be selected from, and the second position is linked to L 3 .

[0147] In some embodiments, L 1 -L 2 is

[0148] [Chemical formula]

[0149] , the first position is linked to Lg, and the second position is linked to L 3 .

[0150] In some embodiments, L 3 is selected from short peptides consisting of 2 to 4 amino acid residues such as dipeptides, tripeptides, or tetrapeptides, and the amino acid residues are selected from natural amino acid residues, unnatural amino acid residues, or amino acid residues shown in AA 1 or their stereoisomers.

[0151] In some embodiments, L 3 is Val-Ala, AA 1 -Val-Ala, Val-AA 1 -Gly, Ala-AA 1 -Gly, Gly-AA 1 -Gly, Val-AA 1 -Ala, Val-AA 1 -Val, Ala-AA 1 -Ala, Ala-AA 1 -Val, Gly-AA 1 -Ala, Gly-AA 1-Val, Ala-Ala-Ala, Ala-Ala-Asn, Gly-Gly-Phe-Gly, and Gly-Gly-Val-Ala.

[0152] In some embodiments, L 3 is Val-AA 1 -Gly, Ala-AA 1 -Gly, Gly-AA 1 -Gly, Val-AA 1 -Ala, Val-AA 1 -Val, Ala-AA 1 -Ala, Ala-AA 1 -Val, Gly-AA 1 -Ala, Gly-AA 1 -Val, Ala-Ala-Ala, Ala-Ala-Asn, and Gly-Gly-Phe-Gly.

[0153] In some embodiments, L 3 is Ala-Ala-Ala, Ala-Ala-Asn, Val-AA 1 -Gly and Gly-Gly-Phe-Gly.

[0154] In some embodiments, L 3 is Val-AA 1 -Gly.

[0155] In some embodiments, L 3 is

[0156]

Chemical formula

[0157]

Chemical formula

[0158] selected from, the 1-position is linked to L 2 and the 2-position is linked to NH.

[0159] In some embodiments, L 3 is

[0160]

Chem.

[0161] selected from, with the first position linked to L 2 and the second position linked to NH.

[0162] In some embodiments, L 3 is

[0163]

Chem.

[0164] and the first position is linked to L 2 and the second position is linked to NH.

[0165] In some embodiments, one of R a , R b is H and the other is

[0166]

Chem.

[0167] as follows.

[0168] In some embodiments, R a and R b , together with the carbon atom to which they are both linked, form a 5- to 6-membered heterocyclic ring substituted with R 0 as follows.

[0169] In some embodiments, R a and R b , together with the carbon atom to which they are both linked, form a piperidine ring or a piperazine ring substituted with R 0 as follows.

[0170] In some embodiments, R a and R b together with the carbon atom to which they are both attached form a piperidine ring substituted with R 0 .

[0171] In some embodiments, R a and R b together with the carbon atom to which they are both attached

[0172]

Chemical formula

[0173] to form, where the first carbon atom is the carbon atom to which R a and R b are both attached.

[0174] In some embodiments, r, r 1 are each independently selected from 0, 1, 2, 3, 4, and 5.

[0175] In some embodiments, r, r 1 are each independently selected from 0 and 4.

[0176] In some embodiments, r is 0 and r 1 is 4.

[0177] In some embodiments, R m1 , R n1 are each independently selected from H and C1-6 alkyl groups.

[0178] In some embodiments, R m1 , R n1 are each independently selected from H, methyl group, ethyl group, n-propyl group, and n-butyl group.

[0179] In some embodiments, R m1 and R n1together with the nitrogen atom to which they are both attached, optionally form a 5- to 6-membered heterocyclic ring substituted with R 0’

[0180] In some embodiments, R m1 and R n1 together with the nitrogen atom to which they are both attached, optionally form a piperidine ring or a piperazine ring substituted with R 0’

[0181] In some embodiments, R m1 and R n1 together with the nitrogen atom to which they are both attached,

[0182]

Chemical formula

[0183] form, and the first nitrogen atom is the nitrogen atom that is both attached to R m1 and R n1

[0184] In some embodiments, R 0 , R 0’ are each independently selected from a C1-6 alkyl group, -NR m2 R n2 and a 5- to 6-membered heterocyclic group optionally substituted with a C1-6 alkyl group.

[0185] In some embodiments, R 0 is selected from a C1-6 alkyl group and a 5- to 6-membered heterocyclic group substituted with a C1-6 alkyl group, and the 5- to 6-membered heterocyclic group is selected from a piperidinyl group and a piperazinyl group.

[0186] In some embodiments, R 0 is selected from a methyl group, an ethyl group, and a 5- to 6-membered heterocyclic group substituted with a methyl group, and the 5- to 6-membered heterocyclic group is a piperidinyl group.

[0187] ​​​In some embodiments, R 0 is a methyl group, an ethyl group, and

[0188]

Chem.

[0189] is selected from

[0190] In some embodiments, R 0’ is a C1-6 alkyl group and -NR m2 R n2 is selected from

[0191] In some embodiments, R 0’ is a methyl group and -NR m2 R n2 is selected from

[0192] In some embodiments, R m2 , R n2 is a methyl group

[0193] In some embodiments, the structure of the amino acid residue shown in AA 1 is shown as follows

[0194]

Chem.

[0195] wherein R a , R b either one of them is H, and the other is

[0196]

Chem.

[0197] and r 1 is 4 or, R a and R btogether with the carbon atoms to which they are both linked forms a 5- to 6-membered heterocyclic ring substituted with R 0 and R m1 and R n1 are each independently selected from H, a C1-6 alkyl group, and a C3-6 cycloalkyl group R 0 is selected from a C1-6 alkyl group, a C3-6 cycloalkyl group, -NR m2 R n2 , and a 5- to 6-membered heterocyclic group optionally substituted with a C1-6 alkyl group R m2 and R n2 are each independently selected from H and a C1-6 alkyl group

[0198] In some embodiments, the amino acid residue shown in AA 1 is

[0199]

Chemical formula

[0200] selected from

[0201] In some embodiments, the amino acid residue shown in AA 1 is

[0202]

Chemical formula

[0203] selected from

[0204] In some embodiments, the amino acid residue shown in AA 1 is

[0205]

Chemical formula

[0206] as follows

[0207] In some embodiments, L 3-1 is selected from amino acid residues, and the amino acid residues are

[0208]

Chemical formula

[0209] selected from, and the 1-position is linked to L 3-2 and the 2-position is linked to NH.

[0210] In some embodiments, L 3-1 is selected from amino acid residues, and the amino acid residues are

[0211]

Chemical formula

[0212] selected from, and the 1-position is linked to L 3-2 and the 2-position is linked to NH.

[0213] In some embodiments, L 3-1 is Gly.

[0214] In some embodiments, L 3-2 is selected from amino acid residues or short peptides consisting of 2 to 3 amino acid residues, and the amino acid residues are selected from natural amino acid residues, unnatural amino acid residues, or amino acid residues shown in AA 1 or their stereoisomers.

[0215] In some embodiments, L 3-2 is Val, Val-AA 1 , Ala-AA 1 , Gly-AA 1 , Ala-Ala, AA 1 -Val, Gly-Gly-Val, and Gly-Gly-Phe.

[0216] In some embodiments, L 3-2 is Val-AA 1 , Ala-AA 1 , Gly-AA 1 , Ala-Ala, and Gly-Gly-Phe.

[0217] In some embodiments, L 3-2 is Val-AA 1 , Ala-Ala, and Gly-Gly-Phe.

[0218] In some embodiments, L 3-2 is Val-AA 1 .

[0219] In some embodiments, L 3-2 is

[0220]

Chemical formula

[0221] selected from, with the 1-position linked to L 2 and the 2-position linked to L 3-1 .

[0222] In some embodiments, L 3-2 is

[0223]

Chemical formula

[0224] selected from, with the 1-position linked to L 2 and the 2-position linked to L 3-1 .

[0225] In some embodiments, L 3-2 is

[0226]

Chemical formula

[0227] and the first position is L 2 is linked to, and the second position is L 3-1 is linked to.

[0228] In some embodiments, PG1 and PG2 are each independently selected from a benzyloxycarbonyl group (Cbz), a tert-butoxycarbonyl group (Boc), a 9-fluorenylmethoxycarbonyl group (Fmoc), an allyloxycarbonyl group (Alloc), a trimethylsilylethoxycarbonyl group (Teoc), a methoxycarbonyl group, or an ethoxycarbonyl group.

[0229] In some embodiments, PG1 and PG2 are each independently selected from a benzyloxycarbonyl group (Cbz), a 9-fluorenylmethoxycarbonyl group (Fmoc), and an allyloxycarbonyl group (Alloc).

[0230] In some embodiments, PG1 and PG2 are 9-fluorenylmethoxycarbonyl groups (Fmoc).

[0231] In some embodiments, PG1 and PG2 are benzyloxycarbonyl groups (Cbz).

[0232] In some embodiments, R8 is selected from hydrogen, a C1-30 alkyl group, a C3-7 cycloalkyl group, a 3-20 membered heterocyclic group, a C1-6 alkyl group-C3-6 cycloalkyl group, a C1-6 alkyl group-4-6 membered heterocyclic group, a C1-6 alkyl group-C5-10 heteroaryl group, and a C1-6 alkyl group-C6-10 aryl group, and the alkyl group, cycloalkyl group, heterocyclic group, and aryl group are optionally substituted with one or more R x groups.

[0233] In some embodiments, R8 is selected from hydrogen, a C1-30 alkyl group (e.g., a C1-6 alkyl group), and a C1-6 alkyl group-C6-10 aryl group, and the alkyl group and aryl group are optionally substituted with one or more Rx is replaced by

[0234] In some embodiments, R8 is selected from hydrogen, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoro-1-propyl, and a benzyl group.

[0235] In some embodiments, R8 is selected from hydrogen, an isopropyl group, a tert-butyl group, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoro-1-propyl, and a benzyl group.

[0236] In some embodiments, R x is selected from hydrogen, deuterium, fluorine, chlorine, bromine, a methyl group, a methoxy group, an amino group, a dimethylamino group, a nitro group, a cyano group, and an azide group.

[0237] In some embodiments, R x is selected from hydrogen, fluorine, a methyl group, and a methoxy group.

[0238] In some embodiments, PG3 is selected from benzyl groups substituted with one or more R Y s.

[0239] In some embodiments, PG3 is selected from a benzyl group and a p-methoxybenzyl group.

[0240] In some embodiments, R Y is selected from hydrogen, fluorine, chlorine, bromine, a methyl group, a methoxy group, a dimethylamino group, and a nitro group.

[0241] In some embodiments, in step i), the compound of formula III or a salt thereof is reacted with the compound of formula X-3 or a salt thereof after azeotropic dehydration to obtain the compound of formula II or a salt thereof.

[0242] In some embodiments, in step i), the azeotropic solvent is selected from toluene, xylene, chloroform, acetonitrile, ethyl acetate, dichloroethane, preferably toluene and xylene.

[0243] In some embodiments, in step i), the compound of formula III or a salt thereof and the compound of formula X-3 or a salt thereof are reacted under conditions without adding an acid to obtain the compound of formula II or a salt thereof, and the reaction temperature is selected from 110 to 150 °C, preferably 120 to 130 °C.

[0244] In some embodiments, in step i), the compound of formula III or a salt thereof and the compound of formula X-3 or a salt thereof are reacted under acidic conditions to obtain the compound of formula II or a salt thereof.

[0245] In some embodiments, in step i), the compound of formula III or a salt thereof and the compound of formula X-3 or a salt thereof are reacted under acidic conditions to obtain the compound of formula II or a salt thereof, and the reaction temperature is selected from 15 to 40 °C, preferably 20 to 35 °C.

[0246] In some embodiments, in step i), the acid is a protic acid or an aprotic acid, for example, hydrogen chloride, hydrobromic acid, sulfuric acid, boron trifluoride diethyl ether, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl3), ferric chloride (FeCl3), ytterbium trifluoromethanesulfonate (Yb(OTf)3) triethylamine hydrochloride, boron trifluoride acetonitrile, boron trifluoride tetrahydrofuran, hydrogen chloride pyridine, hydrobromic acid pyridine, preferably hydrogen chloride, hydrobromic acid, sulfuric acid, trifluoroacetic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl3), ferric chloride (FeCl3), boron trifluoride diethyl ether (BF3·Et2O) and ytterbium trifluoromethanesulfonate (Yb(OTf)3), and also for example, hydrogen chloride or boron trifluoride diethyl ether, more preferably hydrogen chloride, sulfuric acid, most preferably boron trifluoride diethyl ether.

[0247] In some embodiments, in step i), the molar ratio of the compound of formula III or a salt thereof to the acid selected for the reaction is selected from 1:0.2 to 1:6, preferably 1:2 to 1:5, for example 1:2.5, 1:3 or 1:5.

[0248] In some embodiments, in step i), the molar ratio of the compound of formula III or a salt thereof to the compound of formula X-3 or a salt thereof is selected from 1:1 to 1:5, preferably 1:2 to 1:3.

[0249] In some embodiments, in step i), the reaction solvent is selected from one of an ether solvent, a nitrile solvent, an amide solvent, a sulfone solvent or water, or any combination thereof, preferably an amide or sulfone solvent, more preferably N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) or dimethyl sulfoxide (DMSO), and even more preferably N,N-dimethylformamide.

[0250] In some embodiments, in step i), the mass-to-volume ratio (g / mL) of the compound of formula III or its salt to the selected solvent is selected from 1:2 to 1:10, preferably 1:2.5 to 1:7.

[0251] In some embodiments, in step i), the reaction temperature is selected from 0 to 80 °C, preferably 15 to 40 °C, more preferably 25 to 35 °C.

[0252] In some embodiments, in step j), the compound of formula IV-1-1 or its salt and the compound of formula R8OH or its salt are used to obtain the compound of formula IV-1 or its salt under acidic or basic conditions.

[0253] In some embodiments, in step j), the acid is a protic acid or an aprotic acid, preferably hydrogen chloride, hydrobromic acid, sulfuric acid, trifluoroacetic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl3), ferric chloride (FeCl3), boron trifluoride diethyl ether (BF3·Et2O) and ytterbium trifluoromethanesulfonate (Yb(OTf)3), and more preferably hydrogen chloride, sulfuric acid, zinc acetate, such as hydrogen chloride.

[0254] In some embodiments, in step j), the base is an organic base or an inorganic base, preferably sodium hydroxide, potassium tert-butoxide, potassium carbonate, triethylamine (Et3N), N,N-diisopropylethylamine (DIPEA), and pyridine, preferably potassium tert-butoxide.

[0255] In some embodiments, in step j), the molar ratio of the compound of formula IV-1-1 or a salt thereof to the acid selected for the reaction is selected from 1:0.01 to 1:0.2, for example 1:0.05.

[0256] In some embodiments, in step j), the molar ratio of the compound of formula IV-1-1 or a salt thereof to the base selected for the reaction is selected from 1:0.9 to 1:5.

[0257] In some embodiments, in step j), the molar ratio of the compound of formula IV-1-1 or a salt thereof to the compound of formula R8OH or a salt thereof is selected from 1:1 to 1:20, preferably 1:2 to 1:15.

[0258] In some embodiments, in step j), the reaction solvent is selected from alcohol-based, ether-based, haloalkane-based, aromatic hydrocarbon-based, nitrile-based, amide-based, or sulfone-based solvents, more preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, ethylene glycol diethyl ether, tetrahydrofuran, 1,4-dioxane, dichloromethane, 1,2-dichloroethane, toluene, acetonitrile, DMF, DMAc, NMP, or DMSO, even more preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, toluene, tetrahydrofuran, acetonitrile, DMF, DMAc, NMP, for example, 2,2,2-trifluoroethanol, DMF.

[0259] In some embodiments, in step j), the mass-volume ratio (g / mL) of the compound of formula IV-1-1 or a salt thereof to the selected solvent is selected from 1:2 to 1:10, preferably 1:2.5 to 1:7.

[0260] In some embodiments, in step j), the reaction temperature is selected from 0 to 120 °C, for example 10 to 50 °C.

[0261] In some embodiments, in step j-1), the compound of formula IV-1-2 or a salt thereof reacts with formaldehyde in water and under basic conditions to obtain the compound of formula IV-1-3 or a salt thereof.

[0262] In some embodiments, in step j-1), the base is selected from potassium carbonate, potassium bicarbonate, potassium phosphate, sodium carbonate, sodium bicarbonate, triethylamine, diisopropylethylamine, etc., preferably potassium carbonate.

[0263] In some embodiments, in step j-1), the molar ratio of the compound of formula IV-1-2 or a salt thereof to the base is 1:0.05 to 1:1, preferably 1:0.1 to 1:0.5.

[0264] In some embodiments, in step j-1), the molar ratio of the compound of formula IV-1-2 or a salt thereof to formaldehyde is 1:0.5 to 1:2.5, preferably 1:1 to 1:2, for example 1:1.8.

[0265] In some embodiments, in step j-1), the mass-volume ratio (g / mL) of the compound of formula IV-1-2 or a salt thereof to water is 1:3 to 1:50, preferably 1:5 to 1:20, for example 1:15.

[0266] In some embodiments, in step j-1), the reaction temperature is 0 to 80 °C, preferably 10 to 50 °C.

[0267] In some embodiments, in step j-2), the compound of formula IV-1-3 or a salt thereof reacts with a compound of formula R8OH or a salt thereof under acidic conditions to obtain the compound of formula IV-1 or a salt thereof.

[0268] In some embodiments, in step j-2), the acid is a protic acid or an aprotic acid, preferably hydrogen chloride, hydrobromic acid, sulfuric acid, trifluoroacetic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl3), ferric chloride (FeCl3), boron trifluoride diethyl ether (BF3·Et2O), and ytterbium trifluoromethanesulfonate (Yb(OTf)3), more preferably hydrogen chloride, sulfuric acid, zinc acetate, such as hydrogen chloride.

[0269] In some embodiments, in step j-2), the molar ratio of the compound of formula IV-1-3 or a salt thereof to the acid selected for the reaction is selected from 1:0.01 to 1:0.2, for example 1:0.05.

[0270] In some embodiments, in step j-2), the molar ratio of the compound of formula IV-1-3 or a salt thereof to the compound of formula R8OH or a salt thereof is selected from 1:1 to 1:50, preferably 1:2 to 1:30.

[0271] In some embodiments, in step j-2), the reaction solvent is selected from alcohol-based, ether-based, haloalkane-based, aromatic hydrocarbon-based, nitrile-based, amide-based or sulfone-based solvents, more preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, ethylene glycol diethyl ether, tetrahydrofuran, 1,4-dioxane, dichloromethane, 1,2-dichloroethane, toluene, acetonitrile, DMF, DMAc, NMP or DMSO, even more preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, toluene, tetrahydrofuran, acetonitrile, DMF, DMAc, NMP, for example, 2,2,2-trifluoroethanol, DMF.

[0272] In some embodiments, in step j-2), the mass-volume ratio (g / mL) of the compound of formula IV-1-3 or its salt to the selected solvent is selected from 1:2 to 1:10, preferably 1:2.5 to 1:7.

[0273] In some embodiments, in step j-2), the reaction temperature is selected from 0 to 120 °C, for example 0 to 50 °C.

[0274] In some embodiments, in step k-1), the protecting group PG1 on the amino group is removed from the compound of formula IV-1 or its salt to obtain the compound of formula IV-2-1 or its salt.

[0275] In some embodiments, in step k-1), the reaction of removing the protecting group PG1 on the amino group from the compound of formula IV-1 or a salt thereof can be carried out using conventional reaction conditions well known to those skilled in the art. For example, it can be removed under acidic conditions, and the above acid includes protic acids and aprotic acids; it can be removed under basic conditions, and the above base includes organic bases and inorganic bases; it can be removed under the conditions of a metal reagent, and the above metal reagent is preferably selected from palladium-based reagents or platinum-based reagents, more preferably selected from palladium on carbon, platinum on carbon, platinum dioxide, and palladium hydroxide.

[0276] In some embodiments, in step k-1), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the compound of formula IV-1 or a salt thereof removes the protecting group PG1 under basic conditions. The above base is selected from organic bases or inorganic bases, preferably piperidine, diethylamine, morpholine, diisopropylamine, DBU, triethylamine, and N,N-diisopropylethylamine, more preferably piperidine, diethylamine, or morpholine, such as diethylamine, DBU.

[0277] In some embodiments, in step k-1), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the molar ratio of the compound of formula IV-1 or a salt thereof to the selected base is selected from 1:0.2 to 1:40. For example, 1:0.2 to 1:2, preferably 1:1 to 1:10, such as 1:0.4.

[0278] In some embodiments, in step k-1), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction solvent is selected from one of DMF, DMAc, NMP, dichloromethane, tetrahydrofuran, 1,4-dioxane, acetonitrile, or any combination thereof. For example, DMF, tetrahydrofuran.

[0279] In some embodiments, in step k-1), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the mass-to-volume ratio (g / mL) of the compound of formula IV-1 or its salt to the selected reaction solvent is selected from 1:5 to 1:50, preferably 1:6 to 1:20.

[0280] In some embodiments, in step k-1), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction temperature is selected from 0 to 50 °C, preferably 15 to 30 °C.

[0281] In some embodiments, in step k-1), when the above PG1 is a benzyloxycarbonyl group (Cbz), the compound of formula IV-1 or its salt removes the protecting group PG1 under a metal reagent-hydrogen system. The above metal reagent is selected from palladium-based reagents or platinum-based reagents, preferably palladium on carbon, platinum on carbon, platinum dioxide, palladium hydroxide, for example, palladium on carbon, palladium hydroxide.

[0282] In some embodiments, in step k-1), when the above PG1 is a benzyloxycarbonyl group (Cbz), the mass ratio of the compound of formula IV-1 to the metal reagent is 1:0.01 to 1, preferably 1:0.03 to 0.5, for example 1:0.05, 1:0.1.

[0283] In some embodiments, in step k-1), when the above PG1 is a benzyloxycarbonyl group (Cbz), the hydrogen gas used is 1 atm to 50 atm.

[0284] In some embodiments, in step k-1), when the above PG1 is a benzyloxycarbonyl group (Cbz), the reaction temperature is 0 °C to 100 °C, preferably 20 °C to 70 °C.

[0285] In some embodiments, in step k-1), when the above PG1 is a benzyloxycarbonyl group (Cbz), the reaction solvent is selected from any one of alcohol-based, ether-based, ester-based, amide-based or water, or is a mixture of any proportion of the above substances, preferably methanol, ethanol, tetrahydrofuran, ethyl acetate, DMF, DMAc, NMP or water, such as methanol, tetrahydrofuran.

[0286] In some embodiments, in step k-1), when the above PG1 is a benzyloxycarbonyl group (Cbz), the mass-volume ratio (g / mL) of the compound of formula IV-1 or its salt to the selected reaction solvent is selected from 1:3 to 1:20, preferably 1:5 to 1:10.

[0287] In some embodiments, in step k-1), when the above PG1 is an allyloxycarbonyl group (Alloc), the compound of formula IV-1 or its salt removes the protecting group PG1 under the conditions of a metal reagent. The above metal reagent is selected from palladium-based reagents, preferably tetrakistriphenylphosphine palladium, bistriphenylphosphine dichloropalladium.

[0288] In some embodiments, in step k-2), the compound of formula IV-2 is obtained by a condensation reaction of the compound of formula IV-2-1 or its salt and the compound of formula IV-2-2 or its salt.

[0289] In some embodiments, in step k-2), when E is a hydroxy group, the reaction occurs under basic or neutral conditions under the action of a condensing agent and / or a racemization inhibitor. The above condensing agent is a reagent well-known to those skilled in the art, preferably DMTMM, HATU, HBTU, EDCI, COMU, N-ethynyl-N-methylmethanesulfonamide, EEDQ and T3P, more preferably DMTMM, HBTU.

[0290] In some embodiments, in step k-2), when E is a hydroxy group, the racemization inhibitor is selected from HOAt and HOBt.

[0291] In some embodiments, in step k-2), when E is a hydroxy group, the base is selected from DBU, triethylamine, N,N-diisopropylethylamine, and N-methylmorpholine.

[0292] In some embodiments, in step k-2), when E is a hydroxy group, the molar ratio of the compound of formula IV-2-2 or a salt thereof to the condensing agent is selected from 1:1 to 1:5, preferably 1:1 to 1:1.5.

[0293] In some embodiments, in step k-2), when E is a hydroxy group, the molar ratio of the compound of formula IV-2-1 or a salt thereof to the compound of formula IV-2-2 or a salt thereof is selected from 1:0.8 to 1:3, preferably 1:0.8 to 1:1.2.

[0294] In some embodiments, in step k-2), when E is a hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, methanol, dichloromethane, and water, or any combination thereof, preferably DMF or tetrahydrofuran.

[0295] In some embodiments, in step k-2), when E is a hydroxy group, the mass-volume ratio (g / mL) of the compound of formula IV-2-1 or a salt thereof to the selected reaction solvent is selected from 1:5 to 1:20.

[0296] In some embodiments, in step k-2), when E is a hydroxy group, the reaction temperature is selected from -20 to 100 °C, preferably -15 to 50 °C, and most preferably lower than -15 °C.

[0297] In some embodiments, in step k-2), when E is an activated hydroxy group, the compound of formula IV-2-1 or a salt thereof reacts with the compound of formula IV-2-2 or a salt thereof under basic or neutral conditions, and the base is selected from organic bases or inorganic bases, preferably triethylamine, N,N-diisopropylethylamine, DBU, and N-methylmorpholine.

[0298] In some embodiments, in step k-2), when E is an activated hydroxy group, the reaction solvent is selected from one of DMF, tetrahydrofuran, and dichloromethane, or any combination thereof.

[0299] In some embodiments, in step k-2), when E is an activated hydroxy group, the molar ratio of the compound of formula IV-2-1 or a salt thereof to the compound of formula IV-2-2 or a salt thereof is selected from 1:0.8 to 1:1.2.

[0300] In some embodiments, in step k-3), the compound of formula IV-2-3 or a salt thereof reacts with an aldehyde-based reagent under basic conditions to obtain the compound of formula IV-2a or a salt thereof.

[0301] In some embodiments, in step k-3), the aldehyde-based reagent is selected from aqueous formaldehyde solution, paraformaldehyde, and trioxane.

[0302] In some embodiments, in step k-3), the base is an inorganic base, preferably potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium tert-butoxide, potassium phosphate, dipotassium hydrogen phosphate, and potassium dihydrogen phosphate.

[0303] In some embodiments, in step k-3), the molar ratio of the compound of formula IV-2-3 or a salt thereof to the aldehyde-based reagent is selected from 1:20 to 1:200, preferably 1:40 to 1:90.

[0304] In some embodiments, in step k-3), the reaction solvent is selected from one of alcohol-based, ether-based, nitrile-based, amide-based or water, or any combination thereof, preferably one of methanol, ethanol, tetrahydrofuran, 1,4-dioxane, acetonitrile, DMF or any combination thereof.

[0305] In some embodiments, in step k-3), the reaction temperature is selected from 25 to 100 °C, preferably 25 to 80 °C.

[0306] In some embodiments, in step k-4), the protecting group PG1 on the amino group is removed from the compound of formula IV-2-4 or its salt to obtain the compound of formula IV-2-5 or its salt.

[0307] In some embodiments, in step k-4), the reaction of removing the protecting group PG1 on the amino group from the compound of formula IV-2-4 or its salt can be carried out using conventional reaction conditions well known to those skilled in the art. For example, it can be removed under acidic conditions, under basic conditions, or under the conditions of a metal reagent.

[0308] In some embodiments, in step k-4), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the compound of formula IV-2-4 or its salt removes the protecting group PG1 under basic conditions. The base is selected from an organic base or an inorganic base, preferably piperidine, diethylamine, morpholine, diisopropylamine, DBU, and more preferably diethylamine.

[0309] In some embodiments, in step k-4), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the molar ratio of the compound of formula IV-2-4 or its salt to the selected base is selected from 1:0.2 to 1:40, preferably 1:1 to 1:10.

[0310] In some embodiments, in step k-4), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction solvent is selected from DMF, DMAc, NMP, dichloromethane, tetrahydrofuran, 1,4-dioxane, and acetonitrile, preferably DMF.

[0311] In some embodiments, in step k-4), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the mass-to-volume ratio (g / mL) of the compound of formula IV-2-4 or its salt to the selected reaction solvent is selected from 1:5 to 1:50, preferably 1:6 to 1:20.

[0312] In some embodiments, in step k-4), when the above PG1 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction temperature is selected from 0 to 50 °C, preferably 15 to 30 °C.

[0313] In some embodiments, in step k-4), when the above PG1 is a benzyloxycarbonyl group (Cbz), the compound of formula IV-2-4 or its salt removes the protecting group PG1 under a metal reagent-hydrogen system. The above metal reagent is selected from palladium-based reagents or platinum-based reagents, preferably palladium on carbon, platinum on carbon, platinum dioxide, and palladium hydroxide.

[0314] In some embodiments, in step k-4), when the above PG1 is an allyloxycarbonyl group (Alloc), the compound of formula IV-2-4 or its salt removes the protecting group PG1 under palladium reagent conditions. The above metal reagent is selected from palladium-based reagents, preferably tetrakistriphenylphosphine palladium and bistriphenylphosphine dichloropalladium.

[0315] In some embodiments, in step k-5), a compound of formula IV-2-6 is obtained by a condensation reaction of a compound of formula IV-2-5 or its salt with a compound of formula IV-2-2 or its salt.

[0316] In some embodiments, in step k-5), when E is a hydroxy group, the reaction occurs under basic or neutral conditions under the action of a condensing agent and / or a racemization inhibitor, and the condensing agent is a reagent well-known to those skilled in the art, preferably DMTMM, HATU, HBTU, EDCI, COMU, N-ethynyl-N-methylmethanesulfonamide, EEDQ and T3P, more preferably DMTMM, HBTU.

[0317] In some embodiments, in step k-5), when E is a hydroxy group, the racemization inhibitor is selected from HOAt, HOBt.

[0318] In some embodiments, in step k-5), when E is a hydroxy group, the base is selected from triethylamine, N,N-diisopropylethylamine, N-methylmorpholine.

[0319] In some embodiments, in step k-5), when E is a hydroxy group, the molar ratio of the compound of formula IV-2-2 or a salt thereof to the condensing agent is selected from 1:1 to 1:5, preferably 1:1 to 1:1.5.

[0320] In some embodiments, in step k-5), when E is a hydroxy group, the molar ratio of the compound of formula IV-2-5 or a salt thereof to the compound of formula IV-2-2 or a salt thereof is selected from 1:0.8 to 1:1.2.

[0321] In some embodiments, in step k-5), when E is a hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, methanol, dichloromethane and water, or any combination thereof, preferably DMF.

[0322] In some embodiments, in step k-5), when E is a hydroxy group, the mass-to-volume ratio (g / mL) of the compound of formula IV-2-5 or a salt thereof to the selected reaction solvent is selected from 1:5 to 1:20.

[0323] In some embodiments, in step k-5), when E is a hydroxy group, the reaction temperature is selected from -20 to 100 °C, preferably -15 to 50 °C.

[0324] In some embodiments, in step k-5), when E is an activated hydroxy group, the compound of formula IV-2-5 or a salt thereof reacts with the compound of formula IV-2-2 or a salt thereof under basic or neutral conditions, and the base is selected from organic bases or inorganic bases, preferably triethylamine, N,N-diisopropylethylamine, and N-methylmorpholine.

[0325] In some embodiments, in step k-5), when E is an activated hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, dichloromethane, and water, or any combination thereof.

[0326] In some embodiments, in step k-5), when E is an activated hydroxy group, the molar ratio of the compound of formula IV-2-5 or a salt thereof to the compound of formula IV-2-2 or a salt thereof is selected from 1:0.8 to 1:1.2.

[0327] In some embodiments, in step k-6), the compound of formula IV-2-6 or a salt thereof removes the protecting group on the hydroxy group under acidic conditions in a metal catalyst-hydrogen system to obtain the compound of formula IV-2a.

[0328] In some embodiments, in step k-6), the acid is a protonic acid, preferably formic acid, acetic acid, trifluoroacetic acid, or hydrochloric acid.

[0329] In some embodiments, in step k-6), the molar ratio of the compound of formula IV-2-6 or its salt to the acid is 1:0.2 to 1:2.

[0330] In some embodiments, in step k-6), the metal catalyst is selected from palladium on carbon, platinum on carbon, platinum dioxide, and palladium hydroxide.

[0331] In some embodiments, in step k-6), the ratio of the compound of formula IV-2-6 or its salt to the metal catalyst is 0.5% to 20%.

[0332] In some embodiments, in step k-6), the hydrogen source is selected from hydrogen gas and formic acid.

[0333] In some embodiments, in step k-6), the hydrogen source pressure is selected from 1 to 5 atm.

[0334] In some embodiments, in step k-6), the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, methanol, and ethyl acetate, or any combination thereof.

[0335] In some embodiments, in step m-1), the protecting group PG2 on the amino group is removed from the compound of formula IV-2 or its salt to obtain the compound of formula X-3-1 or its salt.

[0336] In some embodiments, in step m-1), the reaction of removing the protecting group PG2 on the amino group from the compound of formula IV-2 or its salt can be carried out using conventional reaction conditions well known to those skilled in the art. For example, it can be removed under acidic conditions, and the acid includes protonic acids and aprotic acids; it can be removed under basic conditions, and the base includes organic bases and inorganic bases; it can be removed under the conditions of metal reagents, and the metal reagent is preferably selected from palladium-based reagents or platinum-based reagents, and more preferably selected from palladium on carbon, platinum on carbon, platinum dioxide, and palladium hydroxide.

[0337] In some embodiments, in step m-1), when the above PG2 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the compound of formula IV-2 or a salt thereof removes the protecting group PG2 under basic conditions. The base is selected from piperidine, diethylamine, morpholine, and DBU, and preferably diethylamine.

[0338] In some embodiments, in step m-1), when the above PG2 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the molar ratio of the compound of formula IV-2 or a salt thereof to the selected base is selected from 1:0.2 to 1:40, and preferably 1:1 to 1:10.

[0339] In some embodiments, in step m-1), when the above PG2 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction solvent is selected from DMF, dichloromethane, tetrahydrofuran, and 1,4-dioxane, and preferably DMF.

[0340] In some embodiments, in step m-1), when the above PG2 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the mass-volume ratio (g / mL) of the compound of formula IV-2 or a salt thereof to the selected reaction solvent is selected from 1:5 to 1:50, and preferably 1:6 to 1:20.

[0341] In some embodiments, in step m-1), when the above PG2 is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction temperature is selected from 0 to 50 °C, and preferably 15 to 30 °C.

[0342] In some embodiments, in step m-1), when the above PG2 is a benzyloxycarbonyl group (Cbz), the compound of formula IV-2 or a salt thereof removes the protecting group PG2 under a metal reagent-hydrogen system. The above metal reagent is a palladium-based reagent or a platinum-based reagent, preferably palladium on carbon, platinum on carbon, platinum dioxide, palladium hydroxide, for example, palladium on carbon, palladium hydroxide.

[0343] In some embodiments, in step m-1), when the above PG2 is a benzyloxycarbonyl group (Cbz), the mass ratio of the compound of formula IV-2 to the metal reagent is 1:0.01 to 1, preferably 1:0.03 to 0.5, for example 1:0.3.

[0344] In some embodiments, in step m-1), when the above PG2 is a benzyloxycarbonyl group (Cbz), the hydrogen gas used is 1 atm to 50 atm, preferably 1 to 4 atm.

[0345] In some embodiments, in step m-1), when the above PG2 is a benzyloxycarbonyl group (Cbz), the reaction temperature is 0°C to 100°C, preferably 20°C to 70°C.

[0346] In some embodiments, in step m-1), when the above PG2 is a benzyloxycarbonyl group (Cbz), the reaction solvent is selected from any one of alcohol-based, ether-based, ester-based, amide-based or water, or a mixture of any proportion of the above substances, preferably methanol, ethanol, tetrahydrofuran, ethyl acetate, DMF, DMAc, NMP or water, for example methanol, tetrahydrofuran.

[0347] In some embodiments, in step m-1), when the above PG2 is a benzyloxycarbonyl group (Cbz), the mass-to-volume ratio (g / mL) of the compound of formula IV-2 or a salt thereof to the selected reaction solvent is selected from 1:3 to 1:50, preferably 1:10 to 1:30.

[0348] In some embodiments, in step m-1), when the above PG2 is an allyloxycarbonyl group (Alloc), the compound of formula IV-2 or a salt thereof removes the protecting group PG2 under the conditions of a metal reagent. The above metal reagent is a palladium-based reagent, preferably tetrakistriphenylphosphine palladium or bistriphenylphosphine dichloropalladium.

[0349] In some embodiments, in step m-2), a compound of formula X-3 or a salt thereof is obtained by a condensation reaction of a compound of formula X-3-1 or a salt thereof with a compound of formula X-1 or a salt thereof.

[0350] In some embodiments, in step m-2), when E is a hydroxy group, the reaction occurs under basic or neutral conditions under the action of a condensing agent, and the above condensing agent is a reagent well known to those skilled in the art, preferably DMTMM, HATU, HBTU, COMU, N-ethynyl-N-methylmethanesulfonamide, more preferably DMTMM, HBTU.

[0351] In some embodiments, in step m-2), when E is a hydroxy group, the above base is selected from organic bases or inorganic bases, preferably triethylamine, N,N-diisopropylethylamine, N-methylmorpholine, preferably N,N-diisopropylethylamine.

[0352] In some embodiments, in step m-2), when E is a hydroxy group, the molar ratio of the compound of formula X-1 or a salt thereof to the above condensing agent is selected from 1:1 to 1:5, preferably 1:1 to 1:1.5.

[0353] In some embodiments, in step m-2), when E is a hydroxy group, the molar ratio of the compound of formula X-3-1 or a salt thereof to the compound of formula X-1 or a salt thereof is selected from 1:0.9 to 1:1.2.

[0354] In some embodiments, in step m-2), when E is a hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, methanol, dichloromethane and water, or any combination thereof, preferably DMF.

[0355] In some embodiments, in step m-2), when E is a hydroxy group, the reaction temperature is selected from -20 to 100 °C, for example -20 to 30 °C, preferably 0 to 30 °C.

[0356] In some embodiments, in step m-2), when E is selected from halogen (for example, chlorine, fluorine or bromine), the compound of formula X-3-1 or its salt and the compound of formula X-1 or its salt react under basic conditions. The base is selected from triethylamine, N,N-diisopropylethylamine, DBU and N-methylmorpholine, preferably N,N-diisopropylethylamine.

[0357] In some embodiments, in step m-2), when E is selected from halogen (for example, chlorine, fluorine or bromine), the molar ratio of the compound of formula X-1 or its salt to the base described in the reaction is selected from 1:0.1 to 1:5, for example 1:1 to 1:5, preferably 1:0.2 to 1:1.

[0358] In some embodiments, in step m-2), when E is halogen (for example, chlorine, fluorine or bromine), the molar ratio of the compound of formula X-1 or its salt to the compound of formula X-3-1 or its salt is selected from 1:0.8 to 1:2.0, preferably 1:0.9 to 1:1.2.

[0359] In some embodiments, in step m-2), when E is halogen (for example, chlorine, fluorine or bromine), the reaction solvent is selected from one of DMF, tetrahydrofuran, dichloromethane, acetonitrile, or any combination, preferably acetonitrile.

[0360] In some embodiments, in step m-2), when E is a halogen (for example, chlorine, fluorine or bromine), the mass-to-volume ratio (g / mL) of the compound of formula X-1 or a salt thereof to the selected reaction solvent is selected from 1:2 to 1:50, preferably 1:3 to 1:10.

[0361] In some embodiments, in step m-2), when E is a halogen (for example, chlorine, fluorine or bromine), the reaction temperature is selected from -20 to 100 °C, preferably 0 to 30 °C.

[0362] In some embodiments, in step m-2), when E is an activated hydroxy group, the molar ratio of the compound of formula X-3-1 or a salt thereof to the compound of formula X-1 or a salt thereof is selected from 1:0.9 to 1:1.2.

[0363] In some embodiments, in step m-2), when E is an activated hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran and dichloromethane, or any combination thereof.

[0364] In some embodiments, in step m-2), when E is an activated hydroxy group, the compound of formula X-3-1 or a salt thereof reacts with the compound of formula X-1 or a salt thereof under basic conditions. The base is selected from an organic base or an inorganic base, preferably pyridine, triethylamine, N,N-diisopropylethylamine and N-methylmorpholine.

[0365] In another aspect, the present application provides a method for preparing a compound of IV-2-2 or a salt thereof,

[0366] q-1) A compound of formula IV-2-2-3 or a salt thereof is obtained from the reaction of a compound of formula IV-2-2-1 or a salt thereof with a compound of formula IV-2-2-2 or a salt thereof,

[0367]

Chemical formula

[0368] q-2) The protecting group is removed from the compound of formula IV-2-2-3 or a salt thereof to obtain the compound of formula IV-2-2-4 or a salt thereof.

[0369]

Chemical formula

[0370] q-3) The compound of formula IV-2-2 or a salt thereof is obtained from the compound of formula IV-2-2-4 or a salt thereof.

[0371]

Chemical formula

[0372] In the formula, L 3-2-1 and L 3-2-2 are each independently selected from an amino acid residue or a short peptide consisting of 2 to 3 amino acid residues, and the amino acid residue is selected from a natural amino acid residue, a non-natural amino acid residue, or the amino acid residue shown in AA 1 or a stereoisomer thereof. E1 is a hydroxy group, a halogen, an activated hydroxy group, for example, a hydroxy group, chlorine, bromine,

[0373]

Chemical formula

[0374] selected from PG4 is selected from amino protecting groups and is selected from benzyloxycarbonyl group (Cbz), tert-butoxycarbonyl group (Boc), 9-fluorenylmethoxycarbonyl group (Fmoc), allyloxycarbonyl group (Alloc), trimethylsilylethoxycarbonyl group (Teoc), methoxycarbonyl group or ethoxycarbonyl group. Preferably, PG4 is selected from tert-butoxycarbonyl group (Boc), 9-fluorenylmethoxycarbonyl group (Fmoc), allyloxycarbonyl group (Alloc). More preferably, PG4 is tert-butoxycarbonyl group (Boc), and PG4 is different from PG2. The definitions of PG2 and E are as described in any one of the forms of the present application.

[0375] In some embodiments, in step q-1), a compound of formula IV-2-2-3 or a salt thereof is obtained by a condensation reaction between a compound of formula IV-2-2-1 or a salt thereof and a compound of formula IV-2-2-2 or a salt thereof.

[0376] In some embodiments, in step q-1), when E is an activated hydroxy group, the molar ratio of the compound of formula IV-2-2-1 or a salt thereof to the compound of formula IV-2-2-2 or a salt thereof is selected from 1:0.9 to 1:1.2.

[0377] In some embodiments, in step q-1), when E is an activated hydroxy group, the compound of formula IV-2-2-1 or a salt thereof reacts with the compound of formula IV-2-2-2 or a salt thereof under basic conditions. The base is selected from organic bases or inorganic bases. Preferably, it is sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, and more preferably sodium bicarbonate.

[0378] In some embodiments, in step q-1), when E is an activated hydroxy group, the molar ratio of the compound of formula IV-2-2-1 or a salt thereof to the base is selected from 1:1 to 1:8, preferably from 1:1 to 1:4.

[0379] In some embodiments, in step q-1), when E is an activated hydroxy group, the reaction solvent may be selected from one of ketone-based, chloroalkane-based, ether-based, ester-based, nitrile-based, amide-based and water, or any combination thereof, preferably selected from one of acetone, tetrahydrofuran, ethyl acetate, dichloromethane, methyl tert-butyl ether and water, or any combination thereof, and more preferably a mixed solvent of acetone, tetrahydrofuran, dichloromethane and water.

[0380] In some embodiments, in step q-1), when E is an activated hydroxy group, the reaction temperature is selected from 0 to 50 °C, preferably selected from 15 to 30 °C.

[0381] In some embodiments, in step q-1), when E is a hydroxy group, the reaction occurs under basic or neutral conditions under the action of a condensing agent, and the condensing agent is a reagent well-known to those skilled in the art, preferably DMTMM, HATU, HBTU, COMU, N-ethynyl-N-methylmethanesulfonamide.

[0382] In some embodiments, in step q-1), when E is a hydroxy group, the molar ratio of the compound of formula IV-2-2-1 or a salt thereof to the above condensing agent is selected from 1:1 to 1:5, preferably 1:1 to 1:1.5.

[0383] In some embodiments, in step q-1), when E is a hydroxy group, the base is selected from an organic base or an inorganic base, preferably triethylamine, N,N-diisopropylethylamine, N-methylmorpholine.

[0384] In some embodiments, in step q-1), when E is a hydroxy group, the molar ratio of the compound of formula IV-2-2-1 or a salt thereof to the compound of formula IV-2-2-2 or a salt thereof is selected from 1:0.9 to 1:1.2.

[0385] In some embodiments, in step q-1), when E is a hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, methanol, dichloromethane and water, or any combination thereof, preferably DMF.

[0386] In some embodiments, in step q-1), when E is a hydroxy group, the reaction temperature is selected from -20 to 100 °C, preferably 0 to 30 °C.

[0387] In some embodiments, in step q-2), the compound of formula IV-2-2-3 or a salt thereof gives the compound of formula IV-2-2-4 or a salt thereof by a deprotection reaction.

[0388] In some embodiments, in step q-2), when PG4 is Boc, the compound of formula IV-2-2-3 or a salt thereof removes the protecting group under acidic conditions, and the acid is a protic acid, selected from hydrochloric acid, trifluoroacetic acid, hydrobromic acid, sulfuric acid, hydrogen chloride / dioxane, hydrogen chloride / ethyl acetate, preferably hydrochloric acid, hydrogen chloride / dioxane, hydrogen chloride / ethyl acetate, more preferably hydrochloric acid.

[0389] In some embodiments, in step q-2), when PG4 is Boc, the molar ratio of the compound of formula IV-2-2-3 or a salt thereof to the acid is selected from 1:1 to 1:50, preferably 1:1 to 1:30, for example 1:1 to 1:20, more preferably 1:1 to 1:5.

[0390] In some embodiments, in step q-2), when PG4 is Boc, the reaction solvent is one of an ether solvent, an ester solvent, an alkyl halide solvent, and water, or any combination thereof, preferably selected from one of tetrahydrofuran, 1,4-dioxane, and water, or any combination thereof. For example, 1,4-dioxane or tetrahydrofuran, preferably a mixed solvent of tetrahydrofuran and water.

[0391] In some embodiments, in step q-2), when PG4 is Boc, the reaction temperature is 0 to 120 °C, preferably 25 to 80 °C.

[0392] In some embodiments, in step q-3), the compound of formula IV-2-2-4 or a salt thereof is subjected to a reductive amination reaction with an aldehyde under the action of a reducing agent under acidic or neutral conditions to obtain the compound of formula IV-2-2 or a salt thereof.

[0393] In some embodiments, in step q-3), the reducing agent is selected from sodium borohydride, potassium borohydride, sodium cyanoborohydride, and sodium triacetoxyborohydride, preferably sodium cyanoborohydride and / or sodium triacetoxyborohydride.

[0394] In some embodiments, in step q-3), the acid is selected from acetic acid, formic acid, propionic acid, trifluoroacetic acid, and hydrochloric acid, preferably acetic acid or hydrochloric acid.

[0395] In some embodiments, in step q-3), the molar ratio of the compound of formula IV-2-2-4 or a salt thereof to the selected reducing agent is selected from 1:2 to 1:10, preferably 1:2 to 1:4.

[0396] In some embodiments, in step q-3), the molar ratio of the compound of formula IV-2-2-4 or a salt thereof to the aldehyde is selected from 1:1 to 1:10, preferably 1:3 to 1:5.

[0397] In some embodiments, in step q-3), the molar ratio of the compound of formula IV-2-2-4 or a salt thereof to the acid is selected from 1:1 to 1:10, preferably 1:1 to 1:5.

[0398] In some embodiments, in step q-3), the reaction solvent is selected from one of alcohol-based, ether-based and water, or any combination thereof, preferably selected from one of methanol, ethanol, tetrahydrofuran and water, or any combination thereof, preferably a mixed solvent of tetrahydrofuran and water.

[0399] In some embodiments, in step q-3), the reaction temperature is -10 to 50 °C, preferably 0 to 30 °C.

[0400] Intermediate In one aspect, the present application provides a compound of formula IV-1 or a salt thereof,

[0401]

Chemical formula

[0402] Wherein, L 3-1 , the definitions of PG1 and R8 are as described in any one form of the present application.

[0403] In another aspect, the present application provides a compound of formula IV-2-1 or a salt thereof,

[0404]

Chemical formula

[0405] Wherein, L 3-1, the definition of R8 is as described in any one of the forms of the present application.

[0406] In another aspect, the present application provides a compound of formula IV-2 or a salt thereof,

[0407]

Chemical formula

[0408] wherein L 3 , PG2, and the definition of R8 are as described in any one of the forms of the present application.

[0409] In another aspect, the present application provides a compound of formula X-3-1 or a salt thereof,

[0410]

Chemical formula

[0411] wherein L 3 , and the definition of R8 are as described in any one of the forms of the present application.

[0412] In another aspect, the present application provides a compound of formula X-3 or a salt thereof,

[0413]

Chemical formula

[0414] wherein Lg, L 1 , L 2 , L 3 , and the definition of R8 are as described in any one of the forms of the present application.

[0415] In another aspect, the present application provides the use of a compound of formula IV-1 or a salt thereof in the preparation of a compound of formula IV-2 or a salt thereof, a compound of formula IV-2-1 or a salt thereof, a compound of formula X-3-1 or a salt thereof, a compound of formula X-3 or a salt thereof, a compound of formula II or a salt thereof, or a compound of formula I or a salt thereof,

[0416]

Chemical formula

[0417] wherein L 3-1 , PG1, and R8 are as defined in any one of the forms of the present application.

[0418] In another aspect, the present application provides the use of a compound of formula IV-2-1 or a salt thereof in the preparation of a compound of formula IV-2 or a salt thereof, a compound of formula X-3-1 or a salt thereof, a compound of formula X-3 or a salt thereof, a compound of formula II or a salt thereof, or a compound of formula I or a salt thereof,

[0419]

Chemical formula

[0420] wherein L 3-1 , and R8 are as defined in any one of the forms of the present application.

[0421] In another aspect, the present application provides the use of a compound of formula IV-2 or a salt thereof in the preparation of a compound of formula X-3 or a salt thereof, a compound of formula X-3-1 or a salt thereof, a compound of formula II or a salt thereof, or a compound of formula I or a salt thereof,

[0422]

Chemical formula

[0423] wherein L 3, the definitions of PG2 and R8 are as described in any one of the forms of the present application.

[0424] In another aspect, the present application provides the use of a compound of formula X-3 or a salt thereof, a compound of formula II or a salt thereof, or a compound of formula I or a salt thereof in the preparation of a compound of formula X-3-1 or a salt thereof,

[0425]

Chemical formula

[0426] wherein L 3 , the definitions of R8 are as described in any one of the forms of the present application.

[0427] In another aspect, the present application provides the use of a compound of formula X-3 or a salt thereof in the preparation of a compound of formula II or a salt thereof, or a compound of formula I or a salt thereof,

[0428]

Chemical formula

[0429] wherein Lg, L 1 , L 2 , L 3 , the definitions of R8 are as described in any one of the forms of the present application.

[0430] In another aspect, the present application provides the use of a compound of formula I or a salt thereof in the preparation of an ADC drug,

[0431]

Chemical formula

[0432] wherein Lg, L 1 , L 2 , L 3 and the definitions of D are as described in any one of the forms of the present application.

[0433] In another aspect, the present application provides the use of a compound of formula II or a salt thereof in the preparation of an ADC drug,

[0434]

Chemical formula

[0435] wherein the definitions of Lg, L 1 , L 2 and L 3 are as described in any one of the forms of the present application.

[0436] In some embodiments of the present application, the compound of formula IV-1 or a salt thereof has the following structure:

[0437]

Chemical formula

[0438]

Chemical formula

[0439] selected from.

[0440] In some embodiments of the present application, the compound of formula IV-2-1 or a salt thereof has the following structure:

[0441]

Chemical formula

[0442] selected from.

[0443] In some embodiments of the present application, the compound of formula IV-2 or a salt thereof has the following structure:

[0444]

Chemical formula

[0445]

Chem.

[0446]

Chem.

[0447]

Chem.

[0448] is selected from.

[0449] In some embodiments of the present application, the compound of formula X-3-1 or a salt thereof has the following structure:

[0450]

Chem.

[0451]

Chem.

[0452]

Chem.

[0453] is selected from.

[0454] In some embodiments of the present application, the compound of formula X-3 or a salt thereof has the following structure:

[0455]

Chem.

[0456]

Chem.

[0457]

Chem.

[0458]

Chem.

[0459]

Chem.

[0460]

Chem.

[0461]

Chem.

[0462]

Chem.

[0463] is selected from.

[0464] In some embodiments of the present application, the compound represented by the above formula II or a salt thereof has the following structure:

[0465]

Chem.

[0466] is selected from.

[0467] Definitions and Terms Unless otherwise indicated, the terms and phrases used in this specification have the meanings listed below. A particular term or phrase should not be considered uncertain or unclear unless specifically defined, but should be construed according to the meaning generally understood by those skilled in the art. When a trade name appears in this specification, it is intended to refer to the corresponding product or its active ingredient.

[0468] In this application, unless otherwise indicated or the context does not suggest otherwise, words in the singular form include their plural forms. Thus, references to terms in the singular form and to "the" or "said" generally include the plural forms of the respective terms. The terms "comprising" and "including" should be construed inclusively rather than exclusively.

[0469] In this application, unless otherwise indicated or the context does not suggest otherwise, the term "its salt" as used herein refers to the salt form of a compound (e.g., a compound of Formula 1, etc.). The salt form of a compound has one or more inner salt forms and / or contains another molecule. The counterion of the salt form of a compound is usually an organic or inorganic moiety that stabilizes the charge on the parent compound. The salt form of a compound has one or more charged atoms in its structure. When multiple charged atoms are part of the salt form, there are multiple counterions and / or multiple charged counterions. Thus, the salt form of a compound usually has the non-salt form of the compound and one or more charged atoms corresponding to one or more counterions. In some embodiments, the non-salt form of the compound contains at least one amino group or other basic moiety, so an acid addition salt having a basic moiety is obtained in the presence of an acid. In other embodiments, the non-salt form of the compound contains at least one carboxylic acid group or other acidic moiety, so a carboxylate or other anionic moiety is obtained in the presence of a base.

[0470] Unless otherwise specified, the scientific and technical terms used in this application have meanings commonly understood by those skilled in the art. Also, the laboratory procedures for cell culture, molecular genetics, nucleic acid chemistry, and immunology used in this application are all common procedures widely used in the art. At the same time, to better understand this application, the definitions and interpretations of related terms are provided below.

[0471] As used herein, the term "stereoisomer" means an isomer formed by at least one asymmetric center. In a compound having one or more (e.g., 1, 2, 3, or 4) asymmetric centers, racemic mixtures, single enantiomers, diastereomeric mixtures, and individual diastereomers can be produced. Certain individual molecules may exist as geometric isomers (cis / trans). Similarly, the compounds of the present invention may exist as mixtures of two or more structurally different forms (usually called tautomers) in rapid equilibrium. Representative examples of tautomers include keto-enol tautomers, phenol-keto tautomers, nitroso-oxime tautomers, imine-enamine tautomers, and the like. It is understood that the scope of this application encompasses all such isomers or mixtures thereof in any proportion (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%).

[0472] The carbon-carbon bonds of the compounds of the present invention can be depicted in the present application using a solid line (―), a solid wedged line, or a dashed wedged line. The use of a solid line to depict a bond to an asymmetric carbon atom is intended to indicate that all possible stereoisomers (e.g., a particular enantiomer, a racemic mixture, etc.) at that carbon atom are included. The use of a solid or dashed wedged line to depict a bond to an asymmetric carbon atom is intended to indicate the presence of the depicted stereoisomer. When present in a racemic mixture, solid and dashed wedged lines are used to define relative stereochemistry rather than absolute stereochemistry. The compounds of the present invention, unless otherwise indicated, are intended to exist in the form of stereoisomers (including cis and trans isomers, optical isomers (e.g., R and S enantiomers), diastereomers, geometric isomers, rotational isomers, conformational isomers, atropisomers, and mixtures thereof). The compounds of the present invention can exhibit one or more types of isomerism and consist of mixtures thereof (e.g., racemic mixtures and diastereomeric pairs).

[0473] In the present application, the term "bioactive molecule" means a substance that inhibits or prevents the function of cells and / or a substance that causes cell death or destruction. In some embodiments of the present application, the bioactive molecule in the complex is a molecule having antitumor bioactivity. For example, radioisotopes such as radioisotopes of At211 and Lu, metal platinum complexes, metal gold complexes, metal complexes such as oxaliplatin, glycopeptide antibiotics such as bleomycin and pingyangmycin, topoisomerase 1 inhibitors, camptothecin, hydroxycamptothecin, 9-aminocamptothecin, SN-38, irinotecan, topotecan, belotecan, rubitecan, topoisomerase II inhibitors, DNA topoisomerase inhibitors such as actinomycin D, adriamycin, doxorubicin, duocarmycin, daunorubicin, mitoxantrone, podophyllotoxin, etoposide, interference DNA synthesis drugs such as methotrexate, 5-fluorouracil, cytarabine, gemcitabine, mercaptopurine, pentostatin, fludarabine, cladribine, nelarabine, tubulin inhibitors, vinca alkaloids, drugs acting on structural proteins such as vincristine, vinblastine, paclitaxel, docetaxel, cabazitaxel, serine / threonine kinase inhibitors, tyrosine kinase inhibitors, tumor signal pathway inhibitors such as aspartic acid kinase inhibitors or histidine kinase inhibitors, proteasome inhibitors, histone deacetylase inhibitors, tumor angiogenesis inhibitors, cyclin inhibitors, maytansine derivatives, calicheamicin derivatives, auristatin derivatives, PBD derivatives, melphalan, mitomycin C, or active substances, enzymes and fragments thereof that inhibit the growth of tumor cells and promote apoptosis and necrosis of tumor cells.

[0474] In the present application, the term "drug" means a substance that inhibits or prevents the function of cells and / or a substance that causes cell death or destruction.

[0475] In the present application, the term "linker" means a fragment that links a fragment of a bioactive compound (drug molecule) to an antibody moiety.

[0476] In the present application, the term "antibody" is taken in its broadest sense to include intact monoclonal antibodies, polyclonal antibodies, and multispecific antibodies (e.g., bispecific antibodies) formed from at least two intact antibodies, so long as they have the desired biological activity. In the present application, the terms "antibody" and "immunoglobulin" can be used interchangeably.

[0477] In the present application, the term "monoclonal antibody" means an antibody derived from a substantially homogeneous population of antibodies, i.e., the individual antibodies comprising the population are identical except for the possible presence of minor natural variations. Monoclonal antibodies have high specificity for one determinant (epitope) of an antigen, whereas polyclonal antibodies on the other hand contain different antibodies for different determinants (epitopes). The advantage of monoclonal antibodies is, in addition to specificity, that they are not contaminated by other antibodies during synthesis. Here, the modifier "monoclonal" is meant to characterize that the antibody is derived from a substantially homogeneous population of antibodies, and should not be understood as requiring that it be made by a particular method.

[0478] In the present application, unless otherwise clearly indicated, the description methods "each... is independently selected" and "... are each independently selected" adopted throughout the present application are interchangeable with each other and should both be understood in a broad sense, and may mean that the specific options represented between the same or different reference signs do not affect each other in different groups, or may mean that the specific options represented between the same or different reference signs do not affect each other in the same group.

[0479] In the present application, AA 1 the structure of the amino acid residue shown in

[0480]

Chemical formula

[0481] In the case where r is 0, AA 1 The structure of the amino acid residue shown in

[0482]

Chemical formula

[0483] will be understood by those skilled in the art to be as follows. AA 1 The structure of the amino acid residue shown in

[0484]

Chemical formula

[0485] In the case of, R a and R b together with the carbon atom to which they are both attached form a 4- to 10-membered heterocyclic ring, and the above 4- to 10-membered heterocyclic ring is optionally substituted with one or more R 0 where the term "the above 4- to 10-membered heterocyclic ring is optionally substituted with one or more R 0 " means that the above 4- to 10-membered heterocyclic ring may not be substituted, or may be substituted with one or more R 0 and in the case of the above plurality of R 0 each R 0 may have the same or different definitions. Other similar definitions can be understood by referring to the above content.

[0486] In each part of this specification, the substituents of the compounds of the present application are disclosed by the type or range of the groups. In particular, the present application includes each independent secondary combination of each member of the type and range of these groups. For example, the term "C1-6 alkyl group" particularly refers to the independently disclosed methyl group, ethyl group, C3 alkyl group, C4 alkyl group, C5 alkyl group, and C6 alkyl group.

[0487] The terms "comprising", "including", "having", "containing", or "relating to" and other variations thereof in this specification are inclusive or open-ended and do not exclude other elements or method steps not recited.

[0488] In the present application, the "parent ring" is

[0489]

Chemical formula

[0490] as follows.

[0491] In the present application, the term "C1-30 alkyl group" refers to a linear or branched alkyl group containing 1 to 30 carbon atoms, including, for example, "C1-6 alkyl groups". The term "C1-6 alkyl group" refers to a linear or branched alkyl group containing 1 to 6 carbon atoms, including, for example, "C1-3 alkyl groups" or "C1-4 alkyl groups", methyl group, ethyl group, etc. Specific examples include, but are not limited to, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group.

[0492] In the present application, the term "C2-6 alkenyl group" refers to a linear, branched or cyclic alkenyl group containing at least one double bond and having 2 to 6 carbon atoms, including, for example, "C2-4 alkenyl groups". Examples thereof include, but are not limited to, vinyl group, 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, 1,3-butadienyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 1,3-pentadienyl group, 1,4-pentadienyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 1,4-hexadienyl group, cyclopentenyl group, 1,3-cyclopentadienyl group, cyclohexenyl group, 1,4-cyclohexadienyl group, etc.

[0493] In the present application, the term "C2-6 alkynyl group" refers to a linear or branched alkynyl group having at least one triple bond and 2 to 6 carbon atoms, including, for example, "C2-4 alkynyl group". Examples thereof include, but are not limited to, ethynyl group, propynyl group, 2-butynyl group, 2-pentynyl group, 3-pentynyl group, 4-methyl-2-pentynyl group, 2-hexynyl group, 3-hexynyl group, 5-methyl-2-hexynyl group, etc.

[0494] In the present application, the term "halogen" includes fluorine, chlorine, bromine, and iodine.

[0495] In the present application, the term "C3-7 cycloalkyl group" refers to a saturated cyclic alkyl group containing 3 to 7 carbon atoms, and the term "C3-6 cycloalkyl group" refers to a saturated cyclic alkyl group containing 3 to 6 carbon atoms. Optionally, a carbon atom in the cyclic structure may be substituted with an oxo group. Examples include cyclopropane group (i.e., cyclopropyl group), cyclobutane group (i.e., cyclobutyl group), cyclopentane group (i.e., cyclopentyl group), cyclohexyl group.

[0496] In the present application, the term "C1-6 alkoxy group" means an alkyl group as defined above that is linked to the parent molecular moiety via an oxygen atom and includes, for example, "C1-3 alkoxy group" or "C1-4 alkoxy group". Specific examples include, but are not limited to, methoxy group, ethoxy group, propoxy group, isopropoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, etc.

[0497] In the present application, the term "C1-6 haloalkyl group" refers to an alkyl group as defined above that is linked to the parent molecular moiety via a halogen and includes, for example, "C1-3 haloalkyl group" or "C1-4 haloalkyl group". Specific examples include, but are not limited to, chloromethyl group, fluoroethyl group, bromopropyl group, etc.

[0498] In the present application, the term "3- to 20-membered heterocyclic group" refers to a cyclic group containing 3 to 20 ring atoms, at least one of which is a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. The term "4- to 10-membered heterocyclic group" refers to a cyclic group containing 4 to 10 ring atoms, at least one of which is a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. The term "3- to 6-membered heterocyclic group" refers to a cyclic group containing 3 to 6 ring atoms, at least one of which is a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. The term "5- to 6-membered heterocyclic group" refers to a cyclic group containing 5 to 6 ring atoms, at least one of which is a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. Optionally, the ring atoms (e.g., carbon atoms, nitrogen atoms, or sulfur atoms) in the cyclic structure may be substituted with oxo groups. The "4- to 8-membered heterocyclic group" includes, for example, "4- to 8-membered nitrogen-containing heterocyclic group", "4- to 8-membered oxygen-containing heterocyclic group", "4- to 7-membered heterocyclic group", "4- to 7-membered oxygen-containing heterocyclic group", "4- to 7-membered heterocyclic group", "4- to 6-membered heterocyclic group", "5- to 7-membered heterocyclic group", "5- to 6-membered heterocyclic group", "5- to 6-membered nitrogen-containing heterocyclic group", and includes, but is not limited to, oxetanyl group, pyrrolidinyl group, tetrahydrofuranyl group, piperidinyl group, piperazinyl group, tetrahydropyranyl group, homopiperazinyl group, etc.

[0499] In the present application, the term "4- to 10-membered heterocyclic ring" refers to a ring containing 4 to 10 ring atoms, at least one of which is a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. The term "3- to 6-membered heterocyclic ring" refers to a ring containing 3 to 6 ring atoms, at least one of which is a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. The term "5- to 6-membered heterocyclic ring" refers to a ring containing 5 to 6 ring atoms, at least one of which is a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. Optionally, the ring atoms (e.g., carbon atoms, nitrogen atoms, or sulfur atoms) in the cyclic structure may be substituted with oxo groups. Examples include, but are not limited to, rings such as pyrrolidine, tetrahydrofuran, piperidine, piperazine, and tetrahydropyran.

[0500] In the present application, the term "aryl group" means a monocyclic or polycyclic hydrocarbon group having aromaticity, such as a 6- to 10-membered aryl group or a 5- to 8-membered aryl group. Specific examples include, but are not limited to, a phenyl group, a naphthyl group, an anthracenyl group, and a phenanthryl group. The above "6- to 10-membered aryl group" means an aryl group containing 6 to 10 ring atoms. The above "C6-10 aryl group" means an aryl group containing 6 to 10 carbon atoms.

[0501] In the present application, the term "heteroaryl group" means an aromatic cyclic group in which at least one ring atom is a heteroatom such as a nitrogen atom, an oxygen atom or a sulfur atom. Optionally, the ring atoms (e.g., carbon atoms, nitrogen atoms, or sulfur atoms) in the cyclic structure may be substituted with oxo groups. Specific examples include, but are not limited to, 5- to 10-membered heteroaryl groups, 5- to 6-membered heteroaryl groups, 5- to 10-membered nitrogen-containing heteroaryl groups, 6- to 10-membered oxygen-containing heteroaryl groups, 6- to 8-membered nitrogen-containing heteroaryl groups, 5- to 8-membered oxygen-containing heteroaryl groups, etc. For example, furyl group, thienyl group, pyrrolyl group, thiazolyl group, isothiazolyl group, thiadiazolyl group, oxazolyl group, isoxazolyl group, oxadiazolyl group, imidazolyl group, pyrazolyl group, 1,2,3-triazolyl group, 1,2,4-triazolyl group, 1,2,3-oxadiazolyl group, 1,2,4-oxadiazolyl group, 1,2,5-oxadiazolyl group, 1,3,4-oxadiazolyl group, pyridyl group, 2-pyridonyl group, 4-pyridonyl group, pyrimidinyl group, 1,4-dioxacyclohexadienyl group, 2H-1,2-oxazinyl group, 4H-1,2-oxazinyl group, 6H-1,2-oxazinyl group, 4H-1,3-oxazinyl group, 6H-1,3-oxazinyl group, 4H-1,4-oxazinyl group, pyridazinyl group, pyrazinyl group, 1,2,3-triazinyl group, 1,3,5-triazinyl group, 1,2,4,5-tetrazinyl group, azacycloheptatrienyl group, 1,3-diazacycloheptatrienyl group, azacyclooctatetraenyl group, etc.

[0502] In the present application, the bond in the structural formula represented by the wavy line "~~" means that the structure represents a cis or trans isomer, or a mixture of cis and trans isomers in any ratio.

[0503] In the present application, the term "room temperature" means 25 ± 5°C.

[0504] In the present application, the above-mentioned protecting groups and the methods for their linkage or removal can be realized using conventional methods in the art. The method may be a one-step reaction or a multi-step reaction. For example, without limitation, it can be achieved by referring to "Greene’s Protective Groups in Organic Synthesis - 4th Edition" published by Wiley Publishing House or "Chemistry of Protecting Groups" published by Chemical Industry Press.

[0505] In the present application, the term "amino protecting group" means a group that protects the amino group in a compound and can be selected from amino protecting groups known in the art. The medium for the protecting reaction described in the present application is preferably selected from aprotic solvents, and preferably dichloromethane. The upper protecting group reaction for protecting the amino group can be carried out using conventional reaction conditions well-known to those skilled in the art. The reaction for removing the protecting group on the amino group can be carried out using conventional reaction conditions well-known to those skilled in the art. Preferably, the amino protecting group used in the present invention is selected from unsubstituted or substituted alkoxycarbonyl protecting groups, for example, benzyloxycarbonyl group, tert-butoxycarbonyl group, fluorenylmethoxycarbonyl group, allyloxycarbonyl group, trimethylsilylethoxycarbonyl group, methoxycarbonyl group or ethoxycarbonyl group.

[0506] In the present application, the term "hydroxy protecting group" means a group that protects the hydroxy group in a compound and can be selected from hydroxy protecting groups known in the art. The upper protecting group reaction for protecting the hydroxy group can be carried out using conventional reaction conditions well-known to those skilled in the art. The reaction for removing the protecting group on the hydroxy group can be carried out using conventional reaction conditions well-known to those skilled in the art. Preferably, the hydroxy protecting group used in the present invention is selected from unsubstituted or substituted benzyl groups, for example, benzyl group, p-nitrobenzyl group, p-methoxybenzyl group.

[0507] In the present application, when the term "about" is used with a numerical value or numerical range, the numerical value or numerical range is adjusted by extending the boundaries of the numerical value upward and / or downward. For example, the term "about" is intended to modify a numerical value by up to 20% or less, more preferably 10% or less, above and below that value.

[0508] In the present application, when the name and structural formula of a compound are given simultaneously for one compound, if they do not match, the structure of the compound shall prevail unless it is indicated by the context that the name is correct although the structure of the compound is not accurate.

[0509] In the present disclosure, a compound may be in the form of a specific geometric or stereoisomer. The present application assumes that all compounds, including cis and trans isomers, (-)- and (+)-enantiomers, (R)- and (S)-enantiomers, diastereomers, (D)-isomers, (L)-isomers, as well as racemic mixtures and other mixtures such as mixtures enriched in enantiomers or diastereomers, are included within the scope of the present disclosure. Substituents such as alkyl groups may have other asymmetric carbon atoms. All of these isomers and their mixtures are included within the scope of the present invention.

[0510] All reagents and raw materials used in the present invention are commercially available.

[0511] The positive progressive effects of the present invention are as follows: As a result of numerous studies, the present disclosure has developed a synthetic method for preparing a drug linker complex containing an azaacetal structure

[0512]

Chemical Formula

[0513] The preparation method has the following advantages: 1) The substrate has broad applicability. It has very good applicability to molecules containing groups that are unstable in the presence of Pb(OAc)4 (for example, amino groups, substituted amino groups). It also has very good applicability to substrates that are unstable under basic conditions (for example, camptothecin-based compounds).

[0514] 2) The isolation and purification of the compound are simple in operation, with high yields (the yield of the important step is as high as 95%), and are suitable for industrial production.

[0515] 3) The reaction conditions are mild, carried out at normal pressure, and the reaction temperature is easy to control.

[0516] 4) Such raw materials are easily available and inexpensive.

[0517] 5) Using A1.9 (that is, Compound III of the present application) as the starting material, the target molecule can be obtained through only one-step reaction, and the reaction steps involving highly active molecules (the original route has three steps) are significantly reduced.

[0518] 6) The reaction yield is greatly improved. Based on A1.9 (that is, Compound III of the present application), the total yield of the original route is less than 5%, and the total yield of the new route is greater than 50%.

[0519] 7) The purification methods of all intermediates are simple, and scale-up is easy.

[0520] 8) All intermediates have high stability and do not form polymers.

[0521] 9) The whole process is environmentally friendly, does not use Class 1 and Class 2A metals, and has no influence on the residual of elemental impurities in the reaction and the final product (for example, in the prior art, when using Pb(OAc)4, Pb remains, causing poisoning of the metal catalyst for the removal of the amino protecting group by subsequent metal-catalyzed hydrogenation, resulting in low reaction yield).

[0522] 10) The overall process (especially when using the Cbz protecting group, it is more suitable for liquid-phase reactions) has better stability of the corresponding intermediates, more environmentally friendly reaction conditions, and easier removal of toluene as a by-product.

Mode for Carrying Out the Invention

[0523] Sequence Information The information of the sequence according to the present application is described in the following table.

[0524]

Table 1

[0525] All the features disclosed in this specification, or the steps in all the methods or processes disclosed, can be combined in any way, except for features and / or steps that are mutually exclusive.

[0526] Any of the features disclosed in this specification can be replaced by other equivalent or similar features having the same or similar purposes, unless otherwise specified. That is, each feature is only an example of a series of equivalent or similar features, unless otherwise specified.

[0527] The implementation conditions adopted in the examples can be further adjusted according to specific requirements, and the implementation conditions not noted are generally the conditions in ordinary experiments.

[0528] All the chemical reagents used in the following examples are commercially available chemical reagents.

[0529] In the conventional synthesis methods, as well as in the synthesis examples of the examples and intermediates, the meanings of each abbreviation or English are shown in the following table:

[0530]

Table 2

[0531] In an exemplary embodiment of the present invention, the drug linker complex IIa is synthesized using the following routes:

[0532] Route (1)

[0533]

Chemical formula

[0534] Route (2)

[0535]

Chemical formula

[0536] Route (3)

[0537]

Chemical formula

[0538] Route (4)

[0539]

Chemical formula

[0540] Route (5)

[0541]

Chemical formula

[0542] Preparative HPLC chromatography conditions 1 Column: C18 preparative column (100 mm × 250 mm, 10 μm), wavelength: 214 nm, flow rate: 250 mL / min, mobile phase A: 0.1% aqueous formic acid solution, mobile phase B: acetonitrile Gradient table:

[0543]

Table 3

[0544] Fractional HPLC Chromatography Conditions 2 Step 1: Purification

[0545] [Table 4]

[0546] Step 2: Desalting and Concentration

[0547] [Table 5]

[0548] HPLC Chromatography Conditions (Method 1)

[0549] [Table 6]

[0550] Chiral HPLC Chromatography Conditions

[0551] [Table 7]

[0552] Synthesis of Drug-Linker Complex IIa Example 1: Synthesis of Intermediate III Step 1: Preparation of 4-(6-Nitrobenzo[d][1,3]dioxolan-5-yl)but-3-yn-1-ol (III-2)

[0553] [Chemical Formula]

[0554] Compound III-1 (100 g, 408 mmol) and 3-butyn-1-ol (11.4 g, 163 mmol) were dissolved in NMP (300 mL), triethylamine (102 g, 1.02 mol, 141 mL) was added, and the mixture was protected with nitrogen gas. Further, CuI (3.88 g, 20.4 mmol) and Pd(PPh3)2Cl2 (2.9 g, 4.1 mmol) were added in sequence, and the reaction was carried out at 50 °C for 0.5 h. 3-Butyn-1-ol (22.8 g, 326 mmol) was added dropwise. After the addition was complete, the reaction was continued at 50 °C for 4 h. The reaction solution was cooled to room temperature, water (4.5 L) containing aqueous ammonia (3.26 mol) was poured in to precipitate a solid, and the mixture was stirred for 0.5 h. It was filtered by suction, the filter cake was added to water (4.5 L), and the mixture was stirred for 0.5 h. It was filtered by suction, the filter cake was added to water (4.5 L), and the mixture was stirred for 0.5 h. It was filtered by suction, and the filter cake was dried to obtain 85.0 g of the target product III-2, with a yield of 88%. LCMS (ESI) [M+H] + = 236.0 1 H NMR (400 MHz, DMSO-d6) δ 7.66 (s, 1H), 7.18 (s, 1H), 6.25 (s, 2H), 4.91 (t, J = 5.6 Hz, 1H), 3.59 (dd, J = 12.6, 6.7 Hz, 2H), 2.59 (t, J = 6.9 Hz, 2H). Step 2: Preparation of 1-(6-aminobenzod][1,3]dioxolan-5-yl)-4-hydroxybutan-1-one (III-3)

[0555]

Chemical Structure

[0556] Compound III-2 (8.42 g, 35.79 mmol) was dissolved in a solution of EtOH / H2O (v:v = 9:1, 152 mL). After adding Sn (8.46 g, 71.58 mmol) and Na2S·9H2O (2.58 g, 10.74 mmol), concentrated hydrochloric acid (30 mL, 358 mmol) was added, and the mixture was stirred at 78 °C for 1 hour. The reaction mixture was suction filtered through diatomaceous earth while it was hot, and the filtrate was concentrated to obtain a crude product. Ethyl acetate (20 mL) was added to form a slurry, and it was suction filtered. The filter cake was washed twice with ethyl acetate (5 mL) to obtain a crude product. Water (50 mL) was added to the crude product, and saturated sodium bicarbonate solution was added dropwise until the pH value reached 8.0, and it was stirred at room temperature for 1 hour. It was suction filtered, and the filtrate was extracted with ethyl acetate (50 mL × 2). After concentration, a solid was obtained. The obtained solid was combined with the filter cake, dried, and 3.6 g of the target product III-3 was obtained. LCMS (ESI) [M-18+H] + =206.2 1 H NMR (400 MHz, CD3OD) δ 7.18 (s, 1H), 6.24 (s, 1H), 5.87 (s, 2H), 3.62 (t, J = 6.7 Hz, 2H), 2.95-2.84 (m, 2H), 1.95-1.82 (m, 2H). Step 3: Preparation of (S)-7-ethyl-7-hydroxy-14-(3-hydroxypropyl)-10,13-dihydro-11H-[1,3]dioxolo[4,5-g]pyrano[3’,4’:6,7]indolizino[1,2-b]quinoline-8,11(7H)-dione (III)

[0557]

Chemical formula

[0558] Compound III-3 (41.80 g, 0.19 mol), III-4 (110.00 g, 0.42 mol) and p-toluenesulfonic acid monohydrate (31.90 g, 0.17 mol) were added to a three-necked flask, 550 mL of NMP was weighed and added to the flask, and it was protected with nitrogen gas. It was heated and stirred at 110 °C, and III-3 (31.35 g, 0.14 mol) was added to the reaction system a total of 3 times every 0.5 hour. After the addition was completed, stirring was continued for 1 hour. Isopropyl alcohol (110 mL) was added to the reaction solution, and further water (1.32 L) was added dropwise. The temperature was lowered to 5 °C and stirred for 1.0 hour. It was suction filtered, the filter cake was washed with water, slurried with water (13.75 L) for 2 hours, suction filtered, and the filter cake was washed with water again. The filter cake was added to the reaction flask, DMF (165 mL) and methanol (1.32 L) were added in sequence, stirred at 25 °C for 12 hours, suction filtered, the filter cake was washed with methanol, and vacuum dried at 50 °C for 48 hours to obtain 184.0 g of the target product III. LCMS (ESI) [M+H] + = 451.4 1 H NMR (400 MHz, DMSO-d6) δ 7.59 (s, 1H), 7.49 (s, 1H), 7.25 (s, 1H), 6.49 (s, 1H), 6.30 (s, 2H), 5.54 - 5.36 (m, 2H), 5.19 (s, 2H), 4.68 (t, J = 5.0 Hz, 1H), 3.51 (q, J = 5.6 Hz, 2H), 3.14 (t, J = 7.6 Hz, 2H), 1.99-1.73 (m, 4H), 0.92 (t, J = 7.3 Hz, 3H).

[0559] Example 2: Synthesis of Intermediate IV-2-2 1. Synthesis of Intermediate IV-2-2-A Step 1: N 2 -((9H-Fluoren-9-yl)methoxy)carbonyl)-L-valine)-N 6 -(tert-Butoxycarbonyl)-L-lysine (IV-2-2-A-3) Preparation

[0560] [Chemistry]

[0561] Compound IV-2-2-A-1 (100 g, 0.229 mol) and Compound IV-2-2-A-2 (56.4 g, 0.229 mol) were placed in a reaction flask, and acetone / water (1 L, v:v = 1:1) was added under stirring conditions. Further, NaHCO3 (76.95 g, 0.916 mol) was added. The mixture was stirred overnight at room temperature. The insoluble matter was removed by filtration, the filtrate was concentrated, hydrochloric acid (4 N) was added to the concentrated solution to adjust the pH to 5, and the mixture was extracted with ethyl acetate (0.75 L × 2). The combined organic phases were washed with saturated brine (300 mL × 2), dried over anhydrous sodium sulfate, and the filtrate was concentrated under reduced pressure to obtain 117 g of the target compound IV-2-2-A-3, with a yield of 90%. LCMS (ESI) [M+H] + = 568.3 1 H NMR (400 MHz, DMSO-d6) δ 7.91 (d, J = 7.5 Hz, 2H), 7.82 - 7.73 (m, 2H), 7.64 (d, J = 6.9 Hz, 1H), 7.58 (d, J = 9.1 Hz, 1H), 7.44 (t, J = 7.4 Hz, 2H), 7.40 - 7.31 (m, 2H), 6.68 (brs, 1H), 4.38 - 4.21 (m, 3H), 3.99 - 3.91 (m, 1H), 3.87 (dd, J = 8.8, 6.8 Hz, 1H), 2.92 - 2.80 (m, 2H), 2.17 - 2.01 (m, 1H), 1.70 - 1.67 (m, 1H), 1.64 - 1.52 (m, 1H), 1.42 - 1.16 (m, 13H), 0.93 - 0.83 (m, 6H). Step 2: Preparation of ((9H-fluoren-9-yl)methoxy)carbonyl)-L-valine-L-lysine hydrochloride (IV-2-2-A-4)

[0562] [Chemistry]

[0563] Dioxane (1.5 L) was added to compound IV-2-2-A-3 (117 g, 206.2 mmol), and the mixture was stirred for 10 minutes. Then, HCl / dioxane (0.75 L, 4 mol / L) was added, and the mixture was stirred at room temperature for 12 hours. Methyl tert-butyl ether (2 L) was added to the reaction mixture, and the mixture was stirred for 30 minutes, filtered, and the filter cake was dried to obtain 94 g of the target compound IV-2-2-A-4 in a yield of 91%. LCMS (ESI) [M+H] + = 468.3 1 H NMR (400 MHz, DMSO-d6) δ 8.24 (d, J = 7.3 Hz, 1H), 8.07 (brs, 3H), 7.90 (d, J = 7.5 Hz, 2H), 7.77 (dd, J = 7.1, 3.4 Hz, 2H), 7.47-7.37 (m, 3H), 7.34 (td, J = 7.4, 1.7 Hz, 2H), 4.34-4.17 (m, 4H), 3.96 (dd, J = 8.6, 7.4 Hz, 1H), 2.83-2.65 (m, 2H), 2.04 (dd, J = 13.5, 6.7 Hz, 1H), 1.82-1.52 (m, 4H), 1.51-1.30 (m, 2H), 0.96-0.84 (m, 6H). Step 3 N 2 Preparation of ((((9H-Fluoren-9-yl)methoxy)carbonyl)-L-valine)-N 6 、N 6 -Dipropyl-L-lysine (IV-2-2-A)

[0564]

Chemical formula

[0565] Compound IV-2-2-A-4 (55.0 g, 109.1 mmol) and acetic acid (10 mL) were dissolved in a methanol (500 mL) solution. Under an ice-water bath, n-propionaldehyde (25.35 g, 436.4 mmol) was added to the reaction solution, and the reaction was carried out with stirring at room temperature for 30 minutes. Then, under the ice-water bath, sodium cyanoborohydride (27.43 g, 436.4 mmol) was further added to the reaction solution, and the reaction was carried out with stirring at room temperature for 1 hour. LCMS indicated that the raw materials had not completely reacted. n-Propionaldehyde (12.67 g, 218.2 mmol) and sodium cyanoborohydride (13.72 g, 218.2 mmol) were added, and the reaction was continued for 0.5 hour. The reaction solution was filtered, and the filtrate was concentrated. Purified water (300 mL) was added to the concentrated solution, and extraction was carried out with DCM (300 mL × 2). The organic phase was washed with saturated brine and dried over anhydrous Na2SO4, and then concentrated to obtain a crude product. The crude product was purified by column chromatography (the eluent was MeOH and DCM) to obtain 39 g of Compound IV-2-2-A, with a yield of 65%. LCMS (ESI) [M+H] + = 552.3 1 H NMR (400 MHz, DMSO-d6) δ 7.95-7.85 (m, 3H), 7.76 (t, J = 7.3 Hz, 2H), 7.51-7.40 (m, 3H), 7.35 (t, J = 7.4 Hz, 2H), 4.34-4.22 (m, 3H), 4.13 (dd, J = 12.6, 7.2 Hz, 1H), 3.91 (dd, J = 8.8, 7.1 Hz, 1H), 2.52 - 2.41 (m, 6H), 2.03 (dt, J = 13.5, 6.7 Hz, 1H), 1.79-1.67 (m, 1H), 1.66-1.56 (m, 1H), 1.42-1.36 (m, 6H), 1.36-1.21 (m, 2H), 0.90 (t, J = 6.9 Hz, 6H), 0.82 (t, J = 6.9 Hz, 6H).

[0566] II. Synthesis of Intermediate IV-2-2-B Step 1: Synthesis of N-((Benzyloxy)carbonyl)-L-valine)-N-(tert-butoxycarbonyl)-L-lysine (IV-2-2-B-3)

[0567]

Chemical formula

[0568] Method 1: Weighed compound IV-2-2-B-1 (50.0 g, 143.53 mmol) and compound IV-2-2-A-2 (35.35 g, 143.53 mmol), dissolved them in acetone (250 mL) and water (250 mL), added NaHCO3 (48.23 g, 574.12 mmol) further, and stirred overnight at room temperature. Filtered by suction, concentrated the filtrate until the acetone was gone, then adjusted the pH to 5 with hydrochloric acid (4 mol / L) to precipitate a large amount of solid. Filtered by suction, rinsed the filter cake with water (100 mL), slurried the obtained filter cake with DCM (700 mL) for 30 minutes, then filtered by suction, and dried the filter cake at 50 °C to obtain 65.0 g of the target product IV-2-2-B-3 with a yield of 94.5%.

[0569] Method 2: Weighed compound IV-2-2-A-2 (35.35 g, 143.53 mmol), added it to an aqueous solution of NaHCO3 (24.12 g, 287.06 mmol) in water (250 mL), and dropped a DCM (250 mL) solution of IV-2-2-B-1 (50.0 g, 143.53 mmol) dropwise under an ice-water bath. After the dropping was completed, the reaction system was stirred at room temperature for 10 hours. Adjusted the reaction system to pH = 5 with hydrochloric acid (4 mol / L), stirred for 1 hour, then filtered by suction, and dried the filter cake to obtain 65.0 g of the target product IV-2-2-B-3 with a yield of 94.5%.

[0570] Method 3: Compound IV-2-2-A-2 (35.35 g, 143.53 mmol) was weighed and added to an aqueous solution of NaHCO₃ (24.12 g, 287.06 mmol) in water (250 mL). A solution of IV-2-2-B-1 (50.0 g, 143.53 mmol) in THF (250 mL) was added dropwise under an ice-water bath. After the addition was complete, the reaction mixture was stirred at room temperature for 4 hours. The reaction solution was concentrated to remove the organic solvent, and then adjusted to pH = 5 with hydrochloric acid (4 mol / L). After stirring for 1 hour, suction filtration was performed. The filter cake was slurried with DCM (700 mL) for 30 minutes and then suction filtered again. The filter cake was dried to obtain 65.0 g of the target product IV-2-2-B-3 with a yield of 94.5%. LCMS(ESI)[M + H - Boc] + = 380.31 1 H NMR (400 MHz, DMSO-d6) δ 8.07 (d, J = 8.0 Hz, 1H), 7.36 - 7.30 (m, 5H), 7.23 (d, J = 8.0 Hz, 1H), 6.74 (t, J = 8 Hz, 1H), 5.04 (s, 2H), 4.18 - 4.12 (m, 1H), 3.94 - 3.90 (m, 1H), 2.91 - 2.87 (m, 2H), 1.97 - 1.85 (m, 1H), 1.74 - 1.64 (m, 1H), 1.62 - 1.52 (m, 1H), 1.42 - 1.23 (m, 13H), 0.90 - 0.83 (m, 6H). Step 2: Synthesis of ((benzyloxy)carbonyl)-L-valine-L-lysine hydrochloride (IV-2-2-B-4)

[0571]

Chemical Structure

[0572] Method 1: Dioxane (520 mL) was added to Compound IV-2-2-B-3 (65.0 g, 135.54 mmol), and the mixture was stirred for 10 minutes. Then, 260 mL of HCl (4 mol / L in Dioxane) was added, and the mixture was stirred at room temperature overnight. MTBE (1300 mL) was added to the reaction solution, and after stirring for 30 minutes, the mixture was filtered. The filter cake was dried to obtain 52 g of the target compound IV-2-2-B-4, with a yield of 93%.

[0573] Method 2: Compound IV-2-2-B-3 (50.0 g, 104.26 mmol) was weighed and added to tetrahydrofuran (20 mL). Then, concentrated hydrochloric acid (17.2 mL, 206.40 mmol) was added, and the mixture was reacted with heating at 60 °C for 1 hour. The reaction solution was cooled to room temperature and used directly in the next reaction. LCMS (ESI) [M+H] + =380.42 1 H NMR (400 MHz, DMSO-d6) δ 12.59 (s, 1H), 8.19 (d, J = 8.0 Hz, 1H), 7.96 (s, 3H), 7.40 - 7.34 (m, 5H), 8.27 (d, J = 8.0 Hz, 1H), 5.06 (s, 2H), 4.22 - 4.17 (m, 1H), 3.96 - 3.92 (m, 1H), 2.80 - 2.77 (m, 2H), 2.04-2.00 (m, 1H), 1.63 - 1.57 (m, 4H), 1.41 - 1.39 (m, 2H), 0.93 - 0.87 (m, 6H).

[0574] Step 3: Synthesis of N-((Benzyloxy)carbonyl)-L-propionyl)-N,N-dipropyl-L-lysine (IV-2-2-B)

[0575]

Chemical Structure

[0576] Method 1: The compound IV-2-2-B-4 (52 g, 125.03 mmol) obtained by Method 1 of Step 2 was dissolved in methanol (520 mL) and stirred until dissolved. Then, sodium cyanoborohydride (15.71 g, 250.06 mmol) was added to the reaction solution, followed by the addition of n-propionaldehyde (14.52 g, 250.06 mmol), and the mixture was reacted for 1 hour. n-Propanal (14.52 g, 250.06 mmol) was added and the reaction was carried out for 1 hour. Water (45 mL, 2.5 mol) was added to the reaction solution, and the mixture was stirred for 10 minutes and then concentrated. THF (200 mL) was added to the concentrated solution, and after concentration, water was removed. The above operation was repeated once. DCM (250 mL) was added to the residue to dissolve it, the insoluble matter was removed by filtration, the filtrate was concentrated, and the crude product of the target compound IV-2-2-B was directly used in the next reaction, calculated based on a yield of 100%.

[0577] Method 2: THF (300 mL) was added to the solution obtained by Method 2 of Step 2. Under an ice-water bath, sodium cyanoborohydride (19.7 g, 312.78 mmol) was added, followed by the addition of n-propionaldehyde (24.3 g, 417.04 mmol). The temperature was raised to room temperature and the reaction was carried out with stirring for 1 hour. Hydrochloric acid was added to adjust the pH to 4 - 5, and the mixture was stirred for 30 minutes. The reaction system was concentrated to remove THF, water (200 mL) and DCM (200 mL) were added, and the organic phase was collected. 60.0 g of anhydrous sodium sulfate was added to the aqueous phase, and extraction was carried out again with DCM (100 mL). The organic phases were combined, dried over anhydrous sodium sulfate, the insoluble matter was removed by filtration, and concentrated to obtain 38.0 g of the target compound. The yield of the two steps was 78.6%. LCMS(ESI)[M+H] + =464.44 11H NMR (400 MHz, DMSO-d6) δ 7.93 (d, J = 8.0 Hz, 1H), 7.35 - 7.26 (m, 6H), 5.03 (s, 2H), 4.15 - 4.10 (m, 1H), 3.91 - 3.87 (m, 1H), 2.76 - 2.58 (m, 6H), 2.00 - 1.96 (m, 1H), 1.82 - 1.19 (m, 10H), 0.89 - 0.84(m, 12H).

[0578] Example 3: Synthesis of Intermediate IV-1 I. Synthesis of IV-1-A Route 1:

[0579] [Chemical Structure]

[0580] Method 1: Compound IV-1-A-1 (5 g, 17.84 mmol) was added to trifluoroethanol (30 mL), protected with argon gas, stirred and dissolved at 40 °C, then a DMF solution of HCl (2.1 mL, 0.4 mol / L) was added, and the mixture was stirred at 40 °C for 2.5 hours. After the reaction solution was cooled to room temperature, 200 mL of ethyl acetate was added for dilution, and the organic phase was washed and extracted with a 2% sodium bicarbonate solution (200 mL), and the organic phase was collected. The organic phase was washed with a saturated aqueous sodium chloride solution (200 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was rotary evaporated until dryness to obtain 5.5 g of the target compound IV-1-A, with a yield of 96.3%.

[0581] Method 2: Compound IV-1-A-1 (5 g, 17.84 mmol) was added to trifluoroethanol (30 mL), protected with argon gas, stirred and dissolved at 40 °C, then a DMF solution of HCl (2.1 mL, 0.4 mol / L) was added, and the mixture was stirred at 40 °C for 2.5 hours. After the reaction solution was cooled to room temperature, it was added to 120 mL of an aqueous sodium bicarbonate solution (1%, w / v), stirred, suction filtered, and the filter cake was dried to obtain 5.3 g of the target compound IV-1-A with a yield of 92.8%. 1 H NMR (400 MHz, DMSO-d6) δ 8.88 (t, J = 6.5 Hz, 1H), 7.54 (t, J = 6.0 Hz, 1H), 7.40 - 7.32 (m, 5H), 5.07 (s, 2H), 4.70 (d, J = 6.8 Hz, 2H), 4.03 (q, J = 9.4 Hz, 2H), 3.68 (d, J = 6.1 Hz, 2H).

[0582] Route 2:

[0583]

Chemical Structure

[0584] Step 1: Synthesis of Benzyl (2-((hydroxymethyl)amino)-2-oxoethyl)carbamate (IV-1-A-3) Method 1: Water (156 mL), aqueous formaldehyde solution (7.3 g, 90 mmol), and K2CO3 (0.69 g, 5 mmol) were added to IV-1-A-2 (10.4 g, 50 mmol), and the mixture was reacted at room temperature for 14 hours. It was filtered, washed twice with water (50 mL), and vacuum dried at 40 °C for 4 hours to obtain 9.23 g of the product. Yield: 77.5%.

[0585] Method 2: To IV-1-A-2 (10.4 g, 50 mmol), water (156 mL), aqueous formaldehyde solution (6.0 g, 75 mmol), and K2CO3 (0.69 g, 5 mmol) were added, and the mixture was reacted at room temperature for 14 h. It was filtered, washed twice with water (50 mL), and dried in vacuo at 40 °C to obtain 7.38 g of the product. Yield: 62%. LCMS (ESI) [M+Na] + = 261.2 1 1H NMR (400 MHz, DMSO-d6): δ 8.48 (t, J = 6.1 Hz, 1H), 7.47 (t, J = 6.0 Hz, 1H), 7.44 - 7.25 (m, 5H), 5.60 (t, J = 6.6 Hz, 1H), 5.06 (s, 2H), 4.54 (t, J = 6.4 Hz, 2H), 3.62 (d, J = 6.1 Hz, 2H).

[0586] Step 2: Synthesis of Benzyl (2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)carbamate (IV-1-A) Method 1: To compound IV-1-A-3 (2.38 g, 10 mmol), trifluoroethanol (14.4 mL, 6V) and HCl-DMF (1.25 mL, 0.5 mmol, 0.4 mol / L) were added, and the mixture was reacted at 40 °C for 3 h. The reaction system was cooled to 20 °C, dropped into 2% aqueous NaHCO3 solution (58 mL), stirred for 0.5 h, filtered, washed twice with water (12 mL), and dried in vacuo at 40 °C for 2 h to obtain 2.61 g of the product. Yield: 81.5%. Purity 98%.

[0587] Method 2: To compound IV-1-A-3 (10.0 g, 42 mmol), trifluoroethanol (60 mL) and BF3-Et2O (0.3 g, 2.1 mmol, 48%) were added, and the mixture was reacted at 40 °C for 3 h. The reaction system was cooled to 20 °C, dropped into 2% aqueous NaHCO3 solution (245 mL), stirred for 0.5 h, filtered, washed twice with water (50 mL), and dried in vacuo to obtain 10.6 g of the product. Yield: 78.8%. Purity 97%.

[0588] Method 3: To compound IV-1-A-3 (10.0 g, 42 mmol), trifluoroethanol (60 mL) and HCl-DMF (63 mL, 25.2 mmol, 0.4 mol / L) were added, and the mixture was reacted at 40 °C for 3 hours. The reaction system was cooled to 20 °C, dropped into 2% aqueous NaHCO3 solution (245 mL), stirred for 0.5 hour, filtered, washed twice with water (50 mL), and dried in vacuo at 40 °C to obtain 9.5 g of the product. Yield: 70.6%. Purity 88%. LCMS (ESI) [M+Na] + = 343.2 1H NMR (400 MHz, DMSO-d6): δ 8.91 (t, J = 6.8 Hz, 1H), 7.57 (t, J = 6.1 Hz, 1H), 7.46 - 7.27 (m, 5H), 5.07 (s, 2H), 4.71 (d, J = 6.8 Hz, 2H), 4.04 (q, J = 9.4 Hz, 2H), 3.70 (d, J = 6.1 Hz, 2H).

[0589] II. Synthesis of IV-1-B

[0590]

Chemical formula

[0591] To IV-1-A-3 (20.0 g, 84 mmol), methanol (120 mL) and HCl-DMF solution (10.5 mL, 0.4 mol / L) were added, and the mixture was reacted at 40 °C for 4 hours. The reaction solution was dropped into aqueous sodium bicarbonate solution (720 mL, 2% wt), concentrated under reduced pressure in a 40 °C water bath to remove MeOH, extracted twice with EA (200 mL), the organic phases were combined, washed once with saturated aqueous sodium chloride solution (100 mL), dried over anhydrous sodium sulfate for 0.5 hour, concentrated under reduced pressure until dry, and the obtained product was dried in vacuo to obtain 19.4 g of IV-1-B. Yield: 91.5%. LCMS (ESI) [M+Na] + = 275.19 1 1H NMR (400 MHz, DMSO-d6): δ 8.67 (s, 1H), 7.53 (s, 1H), 7.46 - 7.25 (m, 5H), 5.07 (s, 2H), 4.50 (s, 2H), 3.67 (s, 2H), 3.19 (s, 3H).

[0592] III. Synthesis of IV-1-C Step 1: Preparation of (9H-fluoren-9-yl)methyl (2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)carbamate (IV-1-C)

[0593] [Chemical formula]

[0594] Compound IV-1-C-1 (10.00 g, 27.15 mmol) was added to 2,2,2-trifluoroethanol (60 mL), stirred and dissolved at 40 °C. Then, HCl / DMF (3.4 mL, 0.4 M) was added to the reaction solution, and the reaction solution was stirred at 40 °C for 2.0 hours. Ethyl acetate (200 mL) was added to the reaction solution, stirred and diluted, washed and extracted with 2% sodium hydrogen carbonate solution (200 mL) and saturated brine solution (200 mL). The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain 10.51 g of the target product (IV-1-C) with a yield of 94.8%. 11H NMR (400 MHz, DMSO-d6) δ 8.87 (t, J = 6.8 Hz, 1H), 7.92 (d, J = 7.5 Hz, 2H), 7.74 (d, J = 7.5 Hz, 2H), 7.62 (t, J = 6.3 Hz, 1H), 7.45 (t, J = 7.4 Hz, 2H), 7.36 (td, J = 7.4, 1.2 Hz, 2H), 4.70 (d, J = 6.8 Hz, 2H), 4.33 (d, J = 6.9 Hz, 2H), 4.29 - 4.22 (m, 1H), 4.03 (q, J = 9.4 Hz, 2H), 3.68 (t, J = 3.1 Hz, 2H). 4. Synthesis of IV-1-D Step 1: Synthesis of (9H-fluoren-9-yl)methyl (2-(((benzyloxy)methyl)amino)-2-oxoethyl)carbamate (IV-1-D)

[0595]

Chemical Structure

[0596] Compound IV-1-C-1 (50.0 g, 0.135 mol) was weighed and dissolved in DMF (300 mL), and benzyl alcohol (17.6 g, 0.163 mol) was added. While stirring at 25 °C, HCl / EA (4 mol / L, 20.36 mL) was added at once, and stirring was continued for 4 hours for the reaction. Ethyl acetate (1.5 L) was added to the reaction solution, and it was washed with 2% sodium bicarbonate (1 L), water (1 L × 2), and brine (1 L), dried over anhydrous sodium sulfate, and concentrated to dryness to obtain a crude product. It was purified by silica gel column chromatography (eluent: EA / PE = 4 / 6), dried, and 40.0 g of the target product IV-1-D was obtained, with a yield of 71%. LCMS (ESI) [M+H] + = 417.2

[0597] 5. Synthesis of IV-1-E Step 1: Synthesis of (9H-fluoren-9-yl)methyl (2-((isopropoxymethyl)amino)-2-oxoethyl)carbamate (IV-1-E)

[0598]

Chem.

[0599] Compound IV-1-C-1 (10.00 g, 27.15 mmol) was added to isopropanol (60 mL), stirred and dissolved at 40 °C. Then, HCl / DMF (3.4 mL, 0.4 M) was added to the reaction solution, and the reaction solution was stirred at 40 °C for 2.0 h. Ethyl acetate (200 mL) was added to the reaction solution, stirred and diluted, washed with 2% sodium hydrogen carbonate solution (200 mL) and saturated brine solution (200 mL) for extraction. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain 9.50 g of the target product with a yield of 95.0%. 1 H NMR (400 MHz, DMSO-d6) δ 8.56 (t, J = 6.6 Hz, 1H), 7.92 (d, J = 7.5 Hz, 2H), 7.75 (d, J = 7.4 Hz, 2H), 7.56 (t, J = 6.2 Hz, 1H), 7.45 (t, J = 7.4 Hz, 2H), 7.36 (t, J = 7.4 Hz, 2H), 4.57 (d, J = 6.5 Hz, 2H), 4.37 - 4.21 (m, 3H), 3.77 - 3.60 (m, 3H), 1.09 (dd, J = 6.2, 1.9 Hz, 6H).

[0600] 5. Synthesis of IV-1-F Step 1: Synthesis of (9H-fluoren-9-yl)methyl (2-oxo-2-(((2,2,3,3,3-pentafluoropropoxy)methyl)amino)ethyl)carbamate (IV-1-F)

[0601]

Chem.

[0602] Compound IV-1-C-1 (10.00 g, 27.15 mmol) was added to 2,2,3,3,3-pentafluoro-1-propanol (40 mL), stirred and dissolved at 40 °C. Then, HCl / DMF (3.4 mL, 0.4 M) was added to the reaction solution, and the reaction solution was stirred at 40 °C for 2.0 h. Ethyl acetate (200 mL) was added to the reaction solution, stirred and diluted, washed with 2% sodium hydrogen carbonate solution (200 mL) and saturated brine solution (200 mL) for extraction. The organic phase was separated, dried over anhydrous sodium sulfate, filtered, and concentrated to obtain 8.75 g of the target product with a yield of 70.3%. 1 H NMR (400 MHz, DMSO-d6) δ 8.86 (t, J = 8.0 Hz, 1H), 7.90 (d, J = 8.0 Hz, 2H), 7.73 - 7.71 (d, J = 8.0, 2H), 7.60 (t, J = 8.0, 2H), 7.44 - 7.40 (m, 2H), 7.35 - 7.30(m, 2H), 4.70 - 4.68 (m, 2H), 4.31 - 4.20 (m, 2H), 4.25 - 4.22 (m, 1H), 4.13 - 4.06 (m, 2H), 3.67 - 3.65 (m, 2H).

[0603] Example 4: Synthesis of Intermediate IV-2-1 I. Synthesis of Intermediate IV-2-1-A Route 1: Synthesis of 2-amino-N-((2,2,2-trifluoroethoxy)methyl)acetamide (IV-2-1-A)

[0604]

Chemical Structure

[0605] Method 1: Compound IV-1-A (1.00 g, 3.29 mmol) was dissolved in THF (10 mL), and 10% Pd(OH)2 / C (100 mg) was further added. After replacing with hydrogen gas, the reaction was carried out at room temperature for 3 hours. DMF (10 mL) was added to the reaction solution, filtered, and concentrated to remove THF, and a DMF solution of the target compound IV-2-1-A was obtained and used directly in the next reaction. The yield was calculated based on 100%.

[0606] Method 2: Compound IV-1-A (1.00 g, 3.29 mmol) was dissolved in THF (5 mL), and 5% Pd / C (50 mg) was further added. After replacing with hydrogen gas, the reaction was carried out at room temperature for 3 hours. DMF (5 mL) was added to the reaction solution, filtered, and concentrated to remove THF, and a DMF solution of the target compound IV-2-1-A was obtained and used directly in the next reaction. The yield was calculated based on 100%.

[0607] Method 3: Compound IV-1-A (15.0 g, 49.35 mmol) was dissolved in THF (75 mL), and 5% Pd / C (750 mg) was further added. After replacing with hydrogen gas, the reaction was carried out at room temperature for 3 hours. DMF (75 mL) was added to the reaction solution, filtered, and concentrated to remove THF, and a DMF solution of the target compound IV-2-1-A was obtained and used directly in the next reaction. The yield was calculated based on 100%. The 1H NMR spectrum of the HOBt salt of compound Ia-A-3 is 1 H NMR (400 MHz, DMSO-d6) δ 9.18 (br, 1H), 7.79 - 7.71 (m, 1H), 7.49 - 7.41 (m, 1H), 7.25 - 7.18 (m, 2H), 4.74 (d, J = 4.9 Hz, 2H), 4.06 (q, J = 9.4 Hz, 2H), 3.47 (s, 2H).

[0608] Route 2: Preparation of 2-amino-N-((2,2,2-trifluoroethoxy)methyl)acetamide (IV-2-1-A)

[0609]

Chemical Structure

[0610] IV-1-C (57.0 g, 139.57 mmol) was dissolved in a solution of DMF (350 mL) and diethylamine (17.5 mL). It was stirred at 25 ± 5 °C for 1 hour and concentrated under reduced pressure at 35 °C for 30 minutes. A DMF solution of 2-amino-N-((2,2,2-trifluoroethoxy)methyl)acetamide (IV-2-1-A) was obtained and used directly in the next reaction. The conversion rate was calculated based on 100%.

[0611] 2. Synthesis of Intermediate IV-2-1-B Synthesis of 2-amino-N-(methoxymethyl)acetamide (IV-2-1-B)

[0612]

Chemical Structure

[0613] To compound IV-1-B (11.0 g, 43.6 mmol), THF (40 mL), MeOH (40 mL), and Pd / C (550 mg, 10%, 55% water) were added, and the reaction was carried out at 30 °C for 7 hours under a hydrogen gas atmosphere. After completion of the reaction, DMF (55 mL) was added, and it was concentrated under reduced pressure to remove THF and MeOH and directly charged into the next step without purification. The yield was calculated based on 100%. LCMS (ESI) [M+H] + = 119.21

[0614] 3. Synthesis of Intermediate IV-2-1-D Synthesis of 2-amino-N-((benzyloxy)methyl)acetamide (IV-2-1-D)

[0615]

Chemical Structure

[0616] Compound IV-1-D (38.0 g, 0.091 mol) was dissolved in a solution of DMF (240 mL) and diethylamine (12 mL). The mixture was stirred at 25 °C for 1 hour, and the reaction solution was concentrated under reduced pressure at 35 °C for 30 minutes. The obtained DMF solution of IV-2-1-D was used directly in the next reaction. The conversion rate was calculated based on 100%.

[0617] 4. Synthesis of Intermediate IV-2-1-E Synthesis of 2-Amino-N-((isopropoxy)methyl)acetamide (IV-2-1-E)

[0618]

Chemical Structure

[0619] Compound IV-1-E (22.0 g, 59.83 mmol) was dissolved in a solution of DMF (150 mL) and diethylamine (7.5 mL). The mixture was stirred at 25 °C for 1 hour. After the completion of the reaction, the reaction solution was concentrated under reduced pressure at 35 °C for 30 minutes to obtain a DMF solution of IV-2-1-E, which was used directly in the next reaction (the conversion rate was calculated based on 100%).

[0620] 5. Synthesis of Intermediate IV-2-1-F Synthesis of 2-Amino-N-((2,2,3,3,3-pentafluoropropoxy)methyl)acetamide (IV-2-1-F)

[0621]

Chemical Structure

[0622] Compound IV-1-F (466.0 mg, 1.00 mmol) was dissolved in a solution of DMF (10 mL) and diethylamine (0.5 mL). The mixture was stirred at 25 °C for 1 hour, and the reaction solution was concentrated under reduced pressure at 35 °C for 30 minutes to obtain a DMF solution of 2-Amino-N-((2,2,3,3,3-pentafluoropropoxy)methyl)acetamide (IV-2-1-F), which was used directly in the next reaction (the conversion rate was calculated based on 100%).

[0623] Example 5: Synthesis of Intermediate IV-2 1. Synthesis of IV-2-A Synthesis of Benzyl ((10S,13S)-10-(4-(Dipropylamino)butyl)-1,1,1-trifluoro-14-methyl-6,9,12-trioxo-3-oxa-5,8,11-triazapentadecan-13-yl)carbamate (IV-2-A)

[0624]

Chemical Structure

[0625] Method 1: Compound IV-2-2-B (1.52 g, 3.29 mmol) was added to a DMF solution of Compound IV-2-1-A (3.29 mmol) obtained in the previous step. The temperature was controlled at -10 °C, DMTMM (1.16 g, 3.98 mmol) was added, and the reaction was carried out for 1.5 hours. EA (50 mL) was added to the reaction system, and it was washed successively with saturated aqueous NaHCO3 solution (15 mL × 3) and saturated brine (15 mL). The organic phase was dried over anhydrous sodium sulfate, suction filtered, and the filtrate was concentrated to dryness. The obtained residue was dissolved in EA (3 mL), added to n-heptane (30 mL), stirred to precipitate a solid, and suction filtered. The filter cake was 1.55 g of the target compound, with a yield of 74.9%.

[0626] Method 2: Compound IV-2-2-A (33.4 g, 72.3 mmol) was added to a DMF solution of Compound IV-2-1-A (139.57 mmol) obtained in the previous step. The temperature was controlled at -15 °C, DMTMM (23.2 g, 79.6 mmol) was added, and the reaction was carried out for 1.5 hours. EA (1000 mL) was added to the reaction system, and it was washed successively with saturated aqueous NaHCO3 solution (300 mL × 3) and saturated brine (300 mL). The organic phase was dried over anhydrous sodium sulfate, suction filtered, and the filtrate was concentrated to dryness. The obtained residue was dissolved in MTBE (60 mL), added to n-heptane (600 mL), stirred to precipitate a solid, and suction filtered. The filter cake was 31.2 g of the target compound, with a yield of 75.4%. LCMS (ESI) [M+H] += 632.3. 1 1H NMR (400 MHz, DMSO-d6) δ 8.85 - 8.73 (m, 1H), 8.37 - 8.26 (m, 1H), 8.03 (d, J = 7.0 Hz, 1H), 7.40 - 7.32 (m, 6H), 5.10 - 5.01 (m, 2H), 4.73 - 4.66 (m, 2H), 4.29 - 4.20 (m, 1H), 4.02 (q, J = 9.4 Hz, 2H), 3.93 (dd, J = 13.8, 6.6 Hz, 1H), 3.85 - 3.67 (m, 2H), 2.38 - 2.32 (m, 6H), 2.02 - 1.96 (m, 1H), 1.75 - 1.51 (m, 2H), 1.46 - 1.23 (m, 8H), 0.90 - 0.82 (m, 12H).

[0627] 2. Synthesis of IV-2-B ((9S,12S)-9-(4-(Dipropylamino)butyl)-13-methyl-5,8,11-trioxo-2-oxa-4,7,10-triazatetradecan-12-yl)benzyl carbamate (IV-2-B) synthesis

[0628]

Chemical Structure

[0629] To a DMF solution of IV-2-1-B (43.6 mmol) from the previous step, add IV-2-2-B (23.6 g, 45.8 mmol, 90% wt), cool to -15 °C, control the temperature at -15 to -10 °C, add DMTMM monohydrate (12.9 g, 43.6 mmol), and react for 3 hours. Add an aqueous NaHCO3 solution (500 mL, 5% wt) to the reaction solution, extract with EA (200 mL × 4), combine the organic phases, wash once with a saturated aqueous sodium chloride solution (200 mL), dry over anhydrous sodium sulfate, concentrate under reduced pressure to obtain a crude product, and purify by column chromatography (MeOH / DCM = 1% - 10%) to obtain 17.5 g of IV-2-B. Yield: 71.2%. LCMS (ESI) [M+H] + = 564.46 Formate: 1 H NMR(400MHz,DMSO-d6)δ 8.57(t,J=6.6Hz,1H),8.33-8.21(m,2H),8.05(d,J=7.3Hz,1H),7.50-7.15(m,6H),5.11-4.98(m,2H),4.54-4.37(m,2H),4.31-4.14(m,1H),3.96-3.83(m,1H),3.81-3.57(m,2H),3.15(s,3H),2.49(s,6H),2.05-1.10(m,11H),0.93-0.75(m,12H).

[0630] 3. Synthesis of IV-2-C Synthesis of (9H-fluoren-9-yl)methyl ((10S,13S)-10-(4-(dipropylamino)butyl)-1,1,1-trifluoro-14-methyl-6,9,12-trioxo-3-oxo-5,8,11-triazapentadecan-13-yl)carbamate (IV-2-C)

[0631]

Chemical Structure

[0632] A solution of IV-2-1-A (139.57 mmol) in DMF was added to IV-2-2-A (70.0 g, 126.88 mmol) and DMF (350 mL). The reaction mixture was cooled to -15 °C, DMTMM (42.13 g, 152.26 mmol) was added, and the reaction was carried out at -10 °C for 2 hours with stirring. The reaction mixture was poured into DCM (2000 mL), and the organic phase was washed with 2% aqueous NaHCO3 solution (1000 mL × 3), water (1000 mL), and saturated NaCl aqueous solution (500 mL). The organic phase was dried over anhydrous sodium sulfate, insoluble matters were removed by filtration, and concentrated to obtain a crude product, which was purified by silica gel column chromatography (eluent: 0 - 7% MeOH / DCM) to obtain 70 g of (9H-fluoren-9-yl)methyl ((10S,13S)-10-(4-(dipropylamino)butyl-1,1,1-trifluoro-14-methyl-6,9,12-trioxo-3-oxo-5,8,11-triazapentadecan-13-yl)carbamate (IV-2-C) in a yield of 81%. LCMS (ESI) [M+H] + =720.5 1 H NMR (400 MHz, DMSO-d6) δ 8.78 (t, J = 8.0 Hz, 1H), 8.28 (t, J = 8.0 Hz, 1H), 8.02 (d, J = 4.0 Hz, 1H), 7.90 - 7.88 (m, 2H), 7.72 (t, J = 8.0 Hz, 2H), 7.46 - 7.39 (m, 3H), 7.34 - 7.30(m, 2H), 4.71 - 4.62 (m, 2H), 4.30 - 4.24 (m, 4H), 4.03 - 3.96 (m, 2H), 3.90 - 3.86 (m, 1H), 3.80 - 3.66 (m, 2H), 2.35 - 2.15 (m, 6H), 1.99 - 1.94 (m, 1H), 1.66 - 1.63 (m, 1H), 1.56 - 1.53 (m, 1H), 1.36 - 1.26 (m, 8H), 0.89 - 0.77 (m, 12H).

[0633] 4. Synthesis of IV-2-D Synthesis of (9H-Fluoren-9-yl)methyl ((9S,12S)-9-(4-(dipropylamino)butyl)-13-methyl-5,8,11-trioxo-1-phenyl-2-oxo-4,7,10-triazatetradecan-12-yl)carbamate (IV-2-D)

[0634] [Chemical formula]

[0635] To a DMF solution of IV-2-1-D (0.091 mol), IV-2-2-A (49.3 g, 0.089 mmol) was added. The reaction solution was cooled to -15 °C, and DMTMM (26.9 g, 0.091 mol) was added. The mixture was stirred at -15 °C for 2 hours. The reaction solution was poured into DCM (720 mL) and washed successively with 2% aqueous NaHCO3 solution (500 mL × 2) and saturated NaCl aqueous solution (500 mL). The organic phase was concentrated, and the crude product was purified by silica gel column chromatography (eluent: 0 - 7% MeOH / DCM) to obtain 55 g of (9H-Fluoren-9-yl)methyl ((9S,12S)-9-(4-(dipropylamino)butyl)-13-methyl-5,8,11-trioxo-1-phenyl-2-oxo-4,7,10-triazatetradecan-12-yl)carbamate (IV-2-D) with a yield of 85%. LCMS (ESI) [M+H] + =728.6 11H NMR (400 MHz, DMSO-d6) δ 8.69 (t, J = 6.8 Hz, 1H), 8.27(t, J = 5.8 Hz, 1H), 8.03 (d, J = 7.2 Hz, 1H), 7.93-7.87 (m, 2H), 7.75 (t, J = 7.0 Hz, 2H), 7.48-7.30 (m, 10H), 4.71-4.56 (m, 2H), 4.47 (s, 2H), 4.30-4.25 (m, 4H), 3.93-3.69(m, 3H), 2.32-2.27 (m, 6H), 2.03-1.98 (m, 1H), 1.71-1.55 (m, 2H), 1.40-1.30 (m, 8H), 0.92-0.80(m, 12H).

[0636] 5. Synthesis of IV-2-E Synthesis of (9H-fluoren-9-yl)methyl ((10S,13S)-10-(4-(dipropylamino)butyl)-2,14-dimethyl-6,9,12-trioxo-3-oxo-5,8,11-triazapentadecane-13-yl)carbamate (IV-2-E)

[0637]

Chemical Structure

[0638] To a DMF solution of IV-2-1-E (59.83 mmol) was added IV-2-2-A (30.0 g, 54.38 mmol). The reaction solution was cooled to -15 °C, DMTMM (18.0 g, 65.26 mmol) was added, and the reaction was carried out at -10 °C with stirring for 2 hours. The reaction solution was poured into DCM (1 L). The organic phase was washed successively with 2% aqueous NaHCO3 solution (500 mL × 3), water (500 mL), and saturated NaCl aqueous solution (500 mL). The organic phase was concentrated, and the crude product was subjected to silica gel column chromatography (eluent: 0 - 7% MeOH / DCM) to obtain 30.0 g of the target product IV-2-E in a yield of 81%. LCMS (ESI) [M+H] + = 680.5 11H NMR (400 MHz, DMSO-d6) δ 8.54 (t, J = 8.0 Hz, 1H), 8.27 (t, J = 8.0 Hz, 1H), 8.08 (d, J = 8.0 Hz, 1H), 7.90 - 7.88 (m, 2H), 7.75 - 7.73 (m, 2H), 7.46 - 7.40 (m, 3H), 7.34 - 7.30(m, 2H), 4.56 - 4.52 (m, 2H), 4.34 - 4.19 (m, 4H), 3.91 - 3.87 (m, 1H), 3.71 - 3.63 (m, 3H), 3.00 - 2.75 (m, 6H), 2.02 - 1.97 (m, 1H), 1.75 - 1.54 (m, 8H), 1.37 - 1.24 (m, 2H), 1.06 - 1.04 (m, 6H), 0.93 - 0.77 (m, 12H).

[0639] 6. Synthesis of IV-2-F Synthesis of (9H-Fluoren-9-yl)methyl ((11S,14S)-11-(4-(dipropylamino)butyl)-1,1,1,2,2-pentafluoro-15-methyl-7,10,13-trioxo-4-oxa-6,9,12-triazadecane-14-yl)carbamate (IV-2-F)

[0640]

Chemical Structure

[0641] To a solution of IV-2-1-F (1.00 mmol) was added IV-2-2-A (500.0 mg, 0.91 mmol). The reaction solution was cooled to -15 °C, DMTMM (300.0 mg, 1.09 mmol) was added, and the reaction was carried out at -10 °C with stirring for 2 hours. The reaction solution was poured into DCM (50 mL). The organic phase was washed successively with 2% aqueous NaHCO3 solution (20 mL × 3), water (10 mL), and saturated NaCl aqueous solution (10 mL). The organic phase was concentrated, and the crude product was subjected to silica gel column chromatography (eluent: 0 - 7% MeOH / DCM) to obtain 440.0 mg of the target product (IV-2-F) with a yield of 67%. LCMS (ESI) [M+H] + = 770.48 1 H NMR (400 MHz, DMSO-d6) δ 8.79 (t, J = 8.0 Hz, 1H), 8.27 (t, J = 4.0 Hz, 1H), 8.00 (d, J = 8.0 Hz, 1H), 7.90-7.88 (m, 2H), 7.73-7.70 (m, 2H), 7.45-7.39 (m, 3H), 7.33-7.30(m, 2H), 4.71-4.63 (m, 2H), 4.33-4.22 (m, 4H), 4.11-4.04 (m, 2H), 3.90-3.86 (m, 1H), 3.79-3.67 (m, 2H), 2.30-2.20 (m, 6H), 2.01-1.94 (m, 1H), 1.66-1.52 (m, 2H), 1.35-1.23 (m, 8H), 0.86-0.76 (m, 12H).

[0642] 7. Synthesis of IV-2-G (9H-Fluoren-9-yl)methyl ((S)-1-((S)-6-(dipropylamino)-1-((2-((hydroxymethyl)amino)-2-oxoethyl)amino)-1-oxohexan-2-yl)amino)-3-methyl-1-oxobutan-2-yl)carbamate (IV-2-G) synthesis

[0643]

Chemical Structure

[0644] IV-2-D (73 mg, 0.10 mmol) was dissolved in tetrahydrofuran (1.4 mL), 10% palladium on carbon (28 mg) and HCl / EA (4 mol / L, 25 μL) were added in sequence, replaced with hydrogen gas three times, and stirred at 25 °C for 12 hours under a hydrogen gas atmosphere. The insoluble matter was removed by filtration, the filtrate was concentrated, and purified by prep-HPLC (chromatography conditions: acetonitrile / 0.05% aqueous FA solution: 5% - 40%) to obtain 345 mg of the formate salt of IV-3-G, with a yield of 54%. LCMS (ESI) [M+H] + =638.4 1 H NMR (400 MHz, DMSO-d6) δ 9.09(s, 1H), 8.47-8.46 (m, 1H), 8.24-8.23 (m, 1H), 8.12-8.08 (m, 1H), 7.95-7.72 (m, 2H), 7.78-7.75 (m, 2H), 7.52-7.33 (m, 5H), 4.58-4.50 (m,3H), 4.36-4.31 (m, 2H), 4.27-4.21(m, 2H), 3.92-3.89 (m, 1H), 3.72-3.71 (m, 2H), 2.99-2.96 (m, 6H), 2.03-1.98(m, 1H), 1.74-1.72 (m, 1H), 1.60-1.58 (m, 7H), 1.33 (s, 2H), 0.89-0.90 (m, 12H).

[0645] Example 6: Synthesis of X-3-1 1. Synthesis of X-3-1-A Route 1: Synthesis of (S)-2-((S)-2-amino-3-methylbutanamido)-6-(dipropylamino)-N-(2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)hexanamide (X-3-1-A)

[0646]

Chemical Structure

[0647] Method 1: Compound IV-2-A (3.4 g, 5.4 mmol) was dissolved in 34 mL of MeOH, 680 mg of 10% Pd(OH)2 / C was added, and after purging with hydrogen gas, the mixture was reacted overnight. An additional 680 mg of 10% Pd(OH)2 / C as a catalyst was added and the reaction was carried out for 24 hours. After filtering the reaction solution, the filtrate was concentrated under reduced pressure to obtain 2.5 g of the target compound X-3-1-A, with a yield of 93.5%.

[0648] Method 2: Compound IV-2-A (4 g, 6.3 mmol) was dissolved in 100 mL of methanol. Using palladium hydroxide supported on aluminum oxide as a catalyst by a fully automatic micro reaction hydrogenation apparatus, the program was set as follows: temperature 50 °C, pressure 2.5 Mpa, flow rate of the raw material liquid 0.3 mL / min, and flow rate of hydrogen gas 30 mL / min. The effluent was concentrated under reduced pressure to obtain 3.0 g of the target compound X-3-1-A, with a yield of 95.1%. LCMS (ESI) [M+H] + = 498.3. 1 H NMR (400 MHz, DMSO-d6) δ 8.89 - 8.77 (m, 1H), 8.42 - 8.30 (m, 1H), 8.14 (s, 1H), 4.70 (p, J = 10.3 Hz, 2H), 4.28 (s, 1H), 4.02 (q, J = 9.4 Hz, 2H), 3.80 (dd, J = 15.7, 4.9 Hz, 1H), 3.75 - 3.67 (m, 1H), 3.20 (brs, 2H), 3.11 (d, J = 4.8 Hz, 1H), 2.35 (dd, J = 14.4, 7.3 Hz, 6H), 2.04 - 1.90 (m, 1H), 1.76 - 1.51 (m, 2H), 1.45 - 1.20 (m, 8H), 0.95 - 0.77 (m, 12H).

[0649] Route 2: Synthesis of (S)-2-((S)-2-amino-3-methylbutanamide)-6-(dipropylamino)-N-(2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)hexanamide (X-3-1-A)

[0650]

Chemical Structure

[0651] Compound IV-2-C (1.7 g, 2.4 mmol) was dissolved in DMF (10 mL), DEA (0.5 mL) was added, and the reaction mixture was stirred at 25 °C for 1 hour. Tetrahydrofuran (15 mL) was added to the reaction mixture, and it was concentrated under reduced pressure. This operation was repeated 3 times to obtain a DMF solution of the target compound X-3-1-A, which was used directly in the next reaction (the conversion rate was calculated based on 100%). LCMS (ESI) [M+H] + = 498.3

[0652] 2. Synthesis of X-3-1-B (S)-2-((S)-2-Amino-3-methylbutanamide)-6-(dipropylamino)-N-(2-((2-methoxymethyl)amino)-2-oxoethyl)hexanamide (X-3-1-B) synthesis

[0653]

Chemical Structure

[0654] To compound IV-2-B (7.0 g, 12.4 mmol), MeOH (70 mL) and Pd / C (2.1 g, 10%, 55% water) were added, and the reaction was carried out at 30 °C for 48 hours. The reaction was monitored by LCMS. After completion of the reaction, it was concentrated to remove MeOH, 63 mL of ACN was added, and it was used directly in the next step without purification (calculated based on 100% yield). LCMS (ESI) [M+H] + = 430.51 11H NMR (400 MHz, DMSO-d6) δ 8.59 (t, J = 6.6 Hz, 1H), 8.33 (t, J = 5.9 Hz, 1H), 8.21 (d, J = 7.1 Hz, 1H), 4.52 - 4.36 (m, 2H), 4.32 - 4.13 (m, 1H), 3.80 - 3.57 (m, 2H), 3.18 - 3.03 (m, 4H), 2.44 - 2.23 (m, 6H), 2.06 - 1.91 (m, 1H), 1.76 - 1.47 (m, 2H), 1.45 - 1.13 (m, 8H), 0.96 - 0.71 (m, 12H).

[0655] Example 7: Synthesis of X-3 I. Synthesis of X-3a Synthesis of N-((10S,13S)-10-(4-(dipropylamino)butyl)-1,1,1-trifluoro-14-methyl-6,9,12-trioxo-3-oxa-5,8,11-triazapentadecan-13-yl)-6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynamide (X-3a)

[0656] [Chemical Structure Diagram]

[0657] Method 1: Under argon gas protection, X-1-B (2.95 g, 11.0 mmol), DCM (20 mL) and thionyl chloride (3.93 g, 33.0 mmol) were sequentially added to the reaction flask and stirred at room temperature for 3 hours. The solvent was distilled off under reduced pressure to obtain X-1-A, which was directly used in the next reaction (the conversion rate was calculated based on 100%). Compound X-3-1-A (5.0 g, 10.0 mmol) was dissolved in 35 mL of acetonitrile, cooled to 10 °C, DIPEA (0.26 g, 2.0 mmol) was added, and a solution of Compound X-1-A (11.0 mmol) in acetonitrile (15 mL) was added dropwise. The reaction was carried out for 1 hour, methyl tert-butyl ether (500 mL) was added to the reaction solution to precipitate a solid, which was collected by suction filtration, and the filter cake was dried to obtain 7.13 g of the hydrochloride salt of the target compound with a yield of 91.0%.

[0658] Method 2: Under argon gas protection, X-1-B (32.2 g, 120 mmol), DCM (220 mL) and thionyl chloride (42.9 g, 360 mmol) were sequentially added to the reaction flask and stirred at room temperature for 3 hours. The solvent was distilled off under reduced pressure to obtain X-1-A, which was used directly in the next reaction (the conversion rate was calculated based on 100%). Compound X-3-1-A (50.0 g, 100 mmol) was dissolved in 350 mL of acetonitrile, cooled to 10 °C, DIPEA (3.25 g, 25 mmol) was added, and a solution of Compound X-1-A (prepared from the acid and thionyl chloride and used immediately) (120 mmol) in acetonitrile (150 mL) was added dropwise. The reaction was carried out for 1 hour, 2-methyltetrahydrofuran (2.1 L) was added to the reaction solution to precipitate a solid, which was collected by suction filtration, and the filter cake was dried to obtain 71.8 g of the hydrochloride salt of the target compound with a yield of 91.6%. LCMS (ESI) [M+H] + = 748.4 11H NMR (400 MHz, DMSO-d6) δ 9.15 (s, 2H), 8.78 (t, J = 6.8 Hz, 1H), 8.24 (t, J = 5.8 Hz, 1H), 8.05 (d, J = 7.3 Hz, 1H), 7.95 (d, J = 8.6 Hz, 1H), 4.75 - 4.66 (m, 2H), 4.24 - 4.19 (m, 2H), 4.03 (q, J = 9.4 Hz, 2H), 3.78 - 3.76 (m, 2H), 3.44 (s, 3H), 2.58 (t, J = 7.1 Hz, 2H), 2.46 - 2.29 (m, 8H), 2.03 - 1.95 (m, 1H), 1.89 - 1.81 (m, 2H), 1.73 - 1.66 (m, 1H), 1.62 - 1.56 (m, 1H), 1.41 - 1.36 (m, 6H), 1.31 - 1.25 (m, 2H), 0.89 - 0.83 (m, 12H).

[0659] II. Synthesis of X-3b Synthesis of N-((9S,12S)-9-(4-(dipropylamino)butyl)-13-methyl-5,8,11-trioxo-2-oxa-4,7,10-triazatetradecan-12-yl)-6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynamide (X-3b)

[0660]

Chemical Structure

[0661] DIPEA (321 mg, 2.48 mmol) was added to a solution of compound X-3-1-B (12.4 mmol) in ACN and prepared for use. Compound X-1-B (3.66 g, 13.6 mmol) was added to dichloromethane (40 mL), thionyl chloride (4.85 g, 40.8 mmol) was added, and the reaction was carried out at 30 °C with stirring for 3.0 h. It was concentrated to dryness under reduced pressure in a 40 °C water bath, ACN (7 mL) was added and dissolved, the temperature was controlled at 10 - 15 °C, and it was added dropwise to the ACN solution of the prepared compound X-3-1-B. After reacting for 2 h, MTBE (490 mL) was added, filtered, and dried to obtain the compound (5.40 g, 7.5 mmol). Yield: 60.5%. LCMS (ESI) [M+H] + =680.42 1 H NMR (400 MHz, DMSO-d6) δ 9.12 (s, 2H), 8.51 (t, J = 6.6 Hz, 1H), 8.27 (s, 1H), 8.19 (t, J = 5.9 Hz, 1H), 8.04 (d, J = 7.3 Hz, 1H), 7.95 (d, J = 8.6 Hz, 1H), 4.57 - 4.35 (m, 2H), 4.25 - 4.04 (m, 2H), 3.82 - 3.62 (m, 2H), 3.41 (s, 3H), 3.14 (s, 3H), 2.54 (t, J = 7.1 Hz, 2H), 2.43 - 2.18 (m, 8H), 2.02 - 1.88 (m, 1H), 1.87 - 1.73 (m, 2H), 1.72 - 1.45 (m, 2H), 1.43 - 1.16 (m, 8H), 0.92 - 0.73 (m, 12H).

[0662] III. Synthesis of X-3a Synthesis of N-((10S,13S)-10-(4-(dipropylamino)butyl)-1,1,1-trifluoro-14-methyl-6,9,12-trioxo-3-oxa-5,8,11-triazapentadecane-13-yl)-6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynamide (X-3a)

[0663]

Chemical Structure

[0664] At 25 °C, X-1-B (772 mg, 2.9 mmol) and DMTMM (849 mg, 2.9 mmol) were sequentially added to the DMF solution of X-3-1-A obtained in Step 1, and stirring was continued for 1 hour for reaction. The reaction solution was purified by prep-HPLC and freeze-dried to obtain 1.3 g of N-((10S,13S)-10-(4-(dipropylamino)butyl)-1,1,1-trifluoro-14-methyl-6,9,12-trioxo-3-oxa-5,8,11-triazapentadecan-13-yl)-6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynylamide (X-3a) in a yield of 76.5%. LCMS (ESI) [M+H] + = 748.4 1 H NMR (400 MHz, DMSO-d6) δ 9.15 (s, 2H), 8.78 (t, J = 6.8 Hz, 1H), 8.24 (t, J = 5.8 Hz, 1H), 8.05 (d, J = 7.3 Hz, 1H), 7.95 (d, J = 8.6 Hz, 1H), 4.75-4.66 (m, 2H), 4.24-4.19 (m, 2H), 4.03 (q, J = 9.4 Hz, 2H), 3.78-3.76 (m, 2H), 3.44 (s, 3H), 2.58 (t, J = 7.1 Hz, 2H), 2.46-2.29 (m, 8H), 2.03-1.95 (m, 1H), 1.89-1.81 (m, 2H), 1.73-1.66 (m, 1H), 1.62-1.56 (m, 1H), 1.41-1.36 (m, 6H), 1.31-1.25 (m, 2H), 0.89-0.83 (m, 12H).

[0665] Example 8: Synthesis of IIa Route 1: Synthesis of N-((11S,14S)-11-(4-(Dipropylamino)butyl)-1-((S)-7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3’,4’:6,7]indolizino[1,2-b]quinolin-14-yl)-15-methyl-7,10,13-trio xo-4-oxa-6,9,12-triazapentadecan-14-yl)-6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynylamide (IIa)

[0666]

Chem.

[0667] Method 1: At room temperature, compound III (2.0 g, 4.4 mmol) was dissolved in dry DMF (10 mL), and a DMF solution of HCl (3.3 mL, 4.02 mol / L) was added, followed by stirring until dissolution. The hydrochloride salt of X-3a (6.97 g, 8.8 mmol) obtained in Step 8 was added, and the reaction was stirred at room temperature for 3 hours under nitrogen gas protection. DCM (72 mL) was added to the reaction solution, and an acetonitrile / water mixed solution (72 mL, v:v = 30:70) was added. The layers were separated, and the aqueous and organic phases were collected separately. The organic phase was washed with a 2% aqueous sodium hydrogen carbonate solution (72 mL), the two aqueous phases were combined, and extracted twice with DCM (72 mL × 2). The three organic phases were combined, washed successively with pure water (72 mL) and saturated brine (72 mL), dried over anhydrous sodium sulfate, and filtered. The filtrate was allowed to stand at -20 °C for 12 hours, the insoluble matter was removed by filtration, and the filtrate was concentrated to obtain a crude product. The crude product was separated and purified by preparative HPLC to obtain 2.5 g of the formate salt of the target product IIa, with a yield of 51.2%. LCMS (ESI) [M+H] + = 1098.7 11H NMR (400 MHz, DMSO-d6) δ 9.10 (s, 2H), 8.59 (t, J = 6.6 Hz, 1H), 8.25 - 8.14 (m, 2H), 8.02 (d, J = 7.4 Hz, 1H), 7.93 (d, J = 8.5 Hz, 1H), 7.58 (s, 1H), 7.50 (s, 1H), 7.24 (s, 1H), 6.28 (s, 2H), 5.42 (d, J = 2.2 Hz, 2H), 5.23 (s, 2H), 4.66 - 4.52 (m, 2H), 4.26 - 4.11 (m, 2H), 3.80 - 3.64 (m, 2H), 3.49 (t, J = 6.0 Hz, 2H), 3.40 (s, 3H), 3.15 - 3.06 (m, 2H), 2.54 (d, J = 7.3 Hz, 2H), 2.44 - 2.25 (m, 8H), 1.99 - 1.77 (m, 7H), 1.73 - 1.45 (m, 2H), 1.39 - 1.20 (m, 8H), 0.89 - 0.77 (m, 15H).

[0668] Method 2: 200 mL of toluene was added to the solids of Compound III (10.0 g, 22.2 mmol) and the hydrochloride salt of X-3a (35.0 g, 44.4 mmol), and the mixture was stirred and refluxed at 110 °C for 2.0 hours using a water separator to remove water. Toluene was removed by rotary evaporation, 60 mL of DMF was added, and further boron trifluoride diethyl etherate (9.5 g, 66.6 mmol) was added. The mixture was stirred at 30 °C for 16 hours to react. 360 mL of DCM was added to the reaction solution, stirred and diluted, and washed with (2% sodium hydrogen carbonate:saturated brine = 7:3) 300 mL × 2 and (water:saturated brine = 7:3) 300 mL. The organic phase was dried, filtered, and concentrated until dry to obtain a crude product. The crude product was separated and purified by prep-HPLC to obtain 16.7 g of the formate salt of the target product IIa, with a yield of 68.3%. LCMS (ESI) [M+H] + = 1098.7 11H NMR (400 MHz, DMSO-d6) δ 9.09 (s, 2H), 8.57 (t, J = 6.6 Hz, 1H), 8.22-8.12 (m, 2H), 7.99 (d, J = 7.4 Hz, 1H), 7.91 (d, J = 8.6 Hz, 1H), 7.57 (s, 1H), 7.49 (s, 1H), 7.24 (s, 1H), 6.45 (s, 1H), 6.28 (s, 2H), 5.42 (d, J = 3.1 Hz, 2H), 5.23 (s, 2H), 4.58 (q, J = 10.2, 8.3 Hz, 2H), 4.26-4.11 (m, 2H), 3.81-3.64 (m, 2H), 3.50 (t, J = 6.1 Hz, 2H), 3.40 (s, 3H), 3.10 (t, J = 8.1 Hz, 2H), 2.54 (d, J = 7.1 Hz, 2H), 2.42-2.25 (m, 8H), 2.00-1.74 (m, 7H), 1.70-1.48 (m, 2H), 1.40-1.22 (m, 8H), 0.91 -0.74 (m, 15H).

[0669] Method 3: 200 mL of toluene was added to the solids of compound III (10.0 g, 22.2 mmol) and the hydrochloride salt of X-3a (35.0 g, 44.4 mmol), and the mixture was stirred and refluxed at 110 °C for 2.0 h using a water separator to remove water. Toluene was removed by rotary evaporation, 60 mL of NMP was added, and the mixture was stirred at 120 °C for 5 h for reaction. The reaction solution was cooled to room temperature, dropped into 360 mL of EA, stirred for 1 h, suction filtered, and the filter cake was purified by column chromatography (MeOH / DCM = 1% - 20%) to obtain 16.4 g of the hydrochloride salt I of the target product I, with a yield of 67.2%. LCMS (ESI) [M+H] + = 1098.7 11H NMR (400 MHz, DMSO-d6) δ 9.81 (s, 1H), 9.11 (s, 2H), 8.65 (t, J = 6.6 Hz, 1H), 8.23 (t, J = 5.8 Hz, 1H), 8.10 (d, J = 7.4 Hz, 1H), 7.97 (d, J = 8.5 Hz, 1H), 7.58 (s, 1H), 7.50 (s, 1H), 7.24 (s, 1H), 6.49 (s, 1H), 6.28 (d, J = 1.8 Hz, 2H), 5.42 (s, 2H), 5.22 (s, 2H), 4.65 - 4.52 (m, 2H), 4.25 (q, J = 7.3 Hz, 1H), 4.15 (dd, J = 8.5, 6.8 Hz, 1H), 3.74 (d, J = 5.9 Hz, 2H), 3.49 (t, J = 6.1 Hz, 2H), 3.40 (s, 3H), 3.13 - 3.03 (m, 2H), 2.95 (dt, J = 11.5, 5.0 Hz, 6H), 2.54 (t, J = 7.0 Hz, 2H), 2.36 (dq, J = 24.7, 7.4 Hz, 2H), 2.04 - 1.54 (m, 15H), 1.37 - 1.25 (m, 2H), 0.94 - 0.72 (m, 15H).

[0670] Route 2: (Synthesis of N-((11S,14S)-11-(4-(dipropylamino)butyl)-1-((S)-7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3’,4’:6,7]indolizino[1,2-b]quinolin-14-yl)-15-methyl-7,10,13-trioxo-4-oxa-6,9,12-triazahexadecane-14-yl)-6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynamide (IIa))

[0671]

Chem.

[0672] DMF (1.35 mL) was added to X-3b (816 mg, 1.2 mmol), and III (300 mg, 90% purity, 0.6 mmol) and HCl-DMF (4 mol / L, 0.45 mL) were added. The reaction was carried out at 30 °C for 3 hours. DCM (12 mL) was added to the reaction solution, and an acetonitrile / water mixed solution (12 mL, v:v = 30:70) was added. The layers were separated, and the aqueous phase and the organic phase were collected separately. The organic phase was washed with a 2% aqueous sodium hydrogen carbonate solution (12 mL), the two aqueous phases were combined, and extracted twice with DCM (12 mL × 2). The three organic phases were combined, washed successively with pure water (12 mL) and saturated brine (12 mL), the organic phase was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated to obtain a crude product. The crude product was separated and purified by preparative HPLC to obtain 347 mg of the formate salt of the target product IIa, with a yield of 50.6%. LCMS (ESI) [M+H] + = 1098.7 1 H NMR (400 MHz, DMSO-d6) δ 9.09 (s, 2H), 8.57 (t, J = 6.6 Hz, 1H), 8.22 - 8.12 (m, 2H), 7.99 (d, J = 7.4 Hz, 1H), 7.91 (d, J = 8.6 Hz, 1H), 7.57 (s, 1H), 7.49 (s, 1H), 7.24 (s, 1H), 6.45 (s, 1H), 6.28 (s, 2H), 5.42 (d, J = 3.1 Hz, 2H), 5.23 (s, 2H), 4.58 (q, J = 10.2, 8.3 Hz, 2H), 4.26 - 4.11 (m, 2H), 3.81 - 3.64 (m, 2H), 3.50 (t, J = 6.1 Hz, 2H), 3.40 (s, 3H), 3.10 (t, J = 8.1 Hz, 2H), 2.54 (d, J = 7.1 Hz, 2H), 2.42 - 2.25 (m, 8H), 2.00 - 1.74 (m, 7H), 1.70 - 1.48 (m, 2H), 1.40 - 1.22 (m, 8H), 0.91 - 0.74 (m, 15H).

[0673] Synthesis of Other Linkers and Drug-Linker Conjugates Example 1: Synthesis of (S)-1-Ethyl-4-(3-methyl-2-(6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynylamido)butanamido)-N-(2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)piperidine-4-carboxamide (L1)

[0674]

Chemical Structure

[0675] Step 1: A DMF solution (3 mL) of IV-2-1-A (495.85 mg, 2.66 mmol) was taken, and L1-1 (900 mg, 2.22 mmol) was added thereto. The reaction solution was cooled to -15 °C, DMTMM (785.19 mg, 2.66 mmol) was added, and the reaction was carried out at -10 °C with stirring for 2 hours. The reaction solution was poured into DCM (200 mL), and the organic phase was washed successively with 2% aqueous NaHCO3 solution (100 mL × 3), water (100 mL), and saturated NaCl aqueous solution (50 mL). The organic phase was dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated to obtain a crude product, which was purified by silica gel column chromatography (eluent: 0 - 7% MeOH / DCM) to obtain the target compound L1-2 (900 mg). LCMS (ESI) [M+H] + = 574.6.

[0676] Step 2: Compound L1-2 (900 mg, 1.57 mmol) was dissolved in MeOH (10 mL), Pd(OH)2 / C (270 mg) was added, and the reaction was carried out with stirring at 25 °C overnight under a hydrogen gas atmosphere. After filtration, the filtrate was concentrated to obtain the target compound L1-3 (620 mg). LCMS (ESI) [M+H] + = 440.2.

[0677] Step 3: At 25 °C, after dissolving L1-3 (200 mg, 0.45 mmol) in DMF (2 mL), 6-(2-(methylsulfonyl)pyrimidin-5-yl)hex-5-ynoic acid (121 mg, 0.45 mmol) and DMTMM (133 mg, 0.45 mmol) were added in sequence, and stirring was continued for 1 hour for reaction. The reaction solution was purified by preparative HPLC to obtain the target compound L1 (180 mg). LCMS (ESI) [M+H] + = 690.4. 1 H NMR (400 MHz, DMSO-d6) δ 9.11 (s, 2H), 8.43 (s, 1H), 8.37 (t, J = 6.8 Hz, 1H), 8.18 - 8.16 (m, 2H), 8.01 (t, J = 6.0 Hz, 1H), 4.71 (dd, J = 10.3, 7.1 Hz, 1H), 4.60 (dd, J = 10.3, 6.4 Hz, 1H), 4.07 - 4.11 (m, 1H), 4.03 - 3.95 (m, 2H), 3.76 - 3.57 (m, 1H), 3.41 (s, 3H), 2.77 - 2.67 (m, 2H), 2.58 - 2.50 (m, 2H), 2.41 - 2.26 (m, 5H), 2.19 - 2.03 (m, 3H), 1.99 - 1.89 (m, 1H), 1.90 - 1.70 (m, 4H), 0.99 (t, J = 7.1 Hz, 3H), 0.96 - 0.90 (m, 6H).

[0678] Example 2: Synthesis of (S)-2-((S)-2-(6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanamido)-3-methylbutanamido)-6-(dipropylamino)-N-(2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)hexanamide (L2)

[0679]

Chemical formula

[0680] L2-1 (300 mg, 0.97 mmol) and X-3-1-A (531 mg, 1.07 mmol) were placed in a reaction flask, and further DMF (5 mL) was added and dissolved. DIPEA (151 mg, 1.16 mmol) was added to the mixture at room temperature, and the reaction was continued at room temperature for 3 hours. Water (50 mL) and DCM (20 mL) were added to the reaction solution and extracted twice, and the organic phases were combined. After drying the organic phase over anhydrous Na2SO4, it was filtered, and the filtrate was concentrated to 5 mL and purified by silica gel column chromatography (MeOH:DCM = 0~15%) to obtain the target compound L2 (300 mg). LCMS (ESI) [M+H] + = 691.6; 1 H NMR (400 MHz, DMSO-d6) δ 8.82 (t, J = 6.8 Hz, 1H), 8.25 (t, J = 5.8 Hz, 1H), 8.06 (t, J = 9.9 Hz, 1H), 7.80 (t, J = 10.7 Hz, 1H), 7.03 (s, 2H), 4.75 - 4.65 (m, 2H), 4.31 - 4.22 (m, 1H), 4.13 (dd, J = 15.4, 7.3 Hz, 1H), 4.02 (q, J = 9.4 Hz, 2H), 3.82 - 3.71 (m, 2H), 3.40 (t, J = 7.1 Hz, 2H), 3.06 - 2.98 (m, 6H), 2.26 - 2.06 (m, 2H), 2.03 - 1.90 (m, 1H), 1.68 - 1.60 (m, 8H), 1.53 - 1.48 (m, 3H), 1.37 - 1.26 (m, 3H), 1.24 - 1.18 (m, 2H), 0.93 (t, J = 7.3 Hz, 6H), 0.85 (t, J = 7.0 Hz, 6H).

[0681] Example 3: Synthesis of (S)-4-(2-(6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanamido)-3-methylbutanamido)-1-ethyl-N-(2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)piperidine-4-carboxamide (L3).

[0682]

Chem.

[0683] At 25 °C, L1-3 (200 mg, 0.46 mmol) was dissolved in DMF (2 mL), then L2-1 (170 mg, 0.55 mmol) and DIPEA (71 mg, 0.55 mmol) were added in sequence. After the addition was completed, the mixture was stirred at room temperature for 1 hour to react, and the reaction was monitored by LC-MS. The reaction solution was purified by preparative high-performance liquid chromatography (acetonitrile: H2O containing 0.05% FA = 5% - 50%) to obtain the target compound INT4 (200 mg). LCMS (ESI) [M+H] + = 633.45. 1 H NMR (400 MHz, DMSO-d6) δ 8.42 (s, 1H), 8.35 (t, J = 6.8 Hz, 1H), 8.22 (s, 1H), 8.13 - 8.02 (m, 2H), 7.03 (s, 2H), 4.73 (dd, J = 10.3, 7.1 Hz, 1H), 4.62 (dd, J = 10.3, 6.4 Hz, 1H), 4.10 - 3.98 (m, 3H), 3.76 - 3.70 (m, 2H), 3.63 - 3.58 (m, 1H), 3.41 - 3.37 (m, 2H), 2.74 - 2.71 (m, 2H), 2.36 (q, J = 7.2 Hz, 2H), 2.30 - 2.04 (m, 6H), 1.98 - 1.93 (m, 1H), 1.86 - 1.84 (m, 1H), 1.53 - 1.43 (m, 4H), 1.25 - 1.14 (m, 2H), 1.02 (t, J = 7.1 Hz, 3H), 0.95 - 0.92 (m, 6H).

[0684] Example 4: Synthesis of (S)-6-(dimethylamino)-2-((S)-3-methyl-2-(6-(4-(2-(methylsulfonyl)pyrimidin-5-yl)-1H-1,2,3-triazol-1-yl)hexanamido)butanamido)-N-(2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)hexanamide (L4)

[0685]

Chemical formula

[0686] Step 1: Dissolve compound IV-2-2-B-4 (20 g, 48.09 mmol) in tetrahydrofuran (200 mL), cool the solution to 5 °C with stirring, add sodium cyanoborohydride (9.07 g, 144.27 mmol) to the solution, raise the temperature to 10 °C, then add aqueous formaldehyde solution (15.61 g, 192.36 mmol), transfer the reaction solution to room temperature, react with stirring for 2 hours, monitor the reaction by HPLC, add concentrated hydrochloric acid (12 mL) and water (20 mL) to the reaction solution to quench it, and stir at 30 °C overnight. Concentrate the reaction solution under reduced pressure until the dripping of liquid droplets stops, add water (200 mL), dichloromethane (200 mL), and anhydrous sodium sulfate (60 g), stir and dissolve at 40 °C, let it stand, separate the layers, extract the aqueous phase with dichloromethane (200 mL), adjust the pH of the aqueous phase to 7, add dichloromethane (200 mL), saturated aqueous sodium chloride solution (100 mL), and anhydrous sodium sulfate (90 g) in sequence to dissolve completely, let it stand, separate the layers, add dichloromethane (200 mL) to the aqueous phase to extract, combine the organic phases, dry over anhydrous sodium sulfate, filter, concentrate the organic phase under reduced pressure, and obtain the target compound L4-2 (16 g). LCMS (ESI) [M+H] + =408.54.

[0687] Step 2: Compound L4-2 (16 g, 28.67 mmol) was dissolved in the reaction solution system of compound IV-2-1-A (4.85 g, 26.06 mmol), the temperature was lowered to -12 °C, DMTMM (7.21 g, 26.06 mmol) was added, and the reaction was carried out while maintaining the temperature at -12 °C for 2 hours. The reaction was monitored by HPLC. EA (425 mL) was added to the reaction solution, and it was filtered. The filtrate was washed with 2% aqueous sodium bicarbonate solution (200 mL × 2). The organic phase was concentrated under reduced pressure until the dripping of the liquid droplets stopped. Acetonitrile (30 mL) was added to the crude product and dissolved, and it was added dropwise to an aqueous solution (300 mL) of citric acid (12.5 g, 65.15 mmol) at 5 - 10 °C. It was stirred for 30 minutes and filtered. The pH value of the filtrate was adjusted to 10 with sodium carbonate. DCM (300 mL) was added for extraction. The organic phase was concentrated under reduced pressure until the dripping of the liquid droplets stopped. Methyl tert-butyl ether (45 mL) was added and dissolved, and it was added dropwise to n-heptane (900 mL), and a large amount of solid was precipitated. It was filtered, and the filter cake was dried to obtain the target compound L4-3 (4.3 g). LCMS (ESI) [M+H] + =576.38.

[0688] Step 3: Compound L4-3 (800 mg, 1.04 mmol) was dissolved in methanol (8 mL). Under the protection of nitrogen gas, palladium hydroxide (0.15 g, 1.04 mmol) was added, and it was replaced with hydrogen gas three times. Under a hydrogen gas atmosphere, it was stirred at room temperature overnight. The reaction was monitored by LCMS, and the reaction solution was directly filtered. The filtrate was concentrated under reduced pressure to obtain the target compound L4-4 (460 mg). LCMS (ESI) [M+H] + =442.5.

[0689] Step 4: Compound L4-4 (460 mg, 1.05 mmol) was dissolved in DMF (5 mL), compound L4-5 (0.36 g, 1.05 mmol) was added, the temperature was lowered to 5 °C with stirring, DMTMM (0.29 g, 1.05 mmol) was added all at once, the temperature was maintained at -12 °C and the reaction was carried out for 2 hours. The reaction was monitored by LCMS, and the reaction solution was directly purified by preparative high performance liquid chromatography (acetonitrile: H2O containing 0.05% FA = 5% - 50%) to obtain the target compound L4 (400 mg). LCMS (ESI) [M+H] + =763.53. 1 H NMR (400 MHz, DMSO-d6) δ 9.48 (s, 2H), 8.94 (s, 1H), 8.76 (t, J = 6.8 Hz, 1H), 8.29 - 8.15 (m, 2H), 8.00 (d, J = 7.3 Hz, 1H), 7.82 (d, J = 8.7 Hz, 1H), 4.74 - 4.57 (m, 2H), 4.47 (t, J = 7.0 Hz, 2H), 4.24 - 4.09 (m, 2H), 3.99 (q, J = 9.4 Hz, 2H), 3.82 - 3.63 (m, 2H), 3.44 (s, 3H), 2.27 - 2.08 (m, 10H), 1.92 (m, 2H), 1.73 - 1.47 (m, 4H), 1.43 - 1.19 (m, 6H), 0.80 (t, J = 7.3 Hz, 6H).

[0690] Example 5: Synthesis of (S)-2-((S)-2-(2,2-dimethyl-4-(4-(2-(methylsulfonyl)pyrimidin-5-yl)-1H-1,2,3-triazol-1-yl)butanamido)-3-methylbutanamido)-6-(dimethylamino)-N-(2-oxo-2-(((2,2,2-trifluoroethoxy)methyl)amino)ethyl)hexanamide (L5)

[0691]

Chemical Structure

[0692] Compound L4-4 (300 mg, 0.68 mmol) was dissolved in DMF (5 mL), compound L5-1 (0.23 g, 0.68 mmol) was added, the temperature was lowered to -12 °C, DMTMM (0.19 g, 0.68 mmol) was added, and the reaction was carried out at -12 °C for 1 hour. The reaction was monitored by LCMS. The reaction solution was directly purified by preparative high-performance liquid chromatography (acetonitrile: H2O containing 0.05% FA = 5% - 50%) to obtain the target compound L5 (170 mg). LCMS (ESI) [M+H] + =763.55. 1 H NMR (400 MHz, DMSO-d6) δ 9.51 (s, 2H), 8.97 (s, 1H), 8.81 (t, J = 6.9 Hz, 1H), 8.32 (t, J = 5.9 Hz, 1H), 8.24 (s, 1H), 8.05 (d, J = 7.3 Hz, 1H), 7.45 (d, J = 8.5 Hz, 1H), 4.68 (m, 2H), 4.51 - 4.38 (m, 2H), 4.29 (q, J = 7.2 Hz, 1H), 4.17 (t, J = 8.2 Hz, 1H), 4.01 (q, J = 9.4 Hz, 2H), 3.75 (t, J = 5.0 Hz, 2H), 3.47 (s, 3H), 2.29 - 2.01 (m, 10H), 1.78 - 1.51 (m, 2H), 1.46 - 1.18 (m, 10H), 0.90 (t, J = 6.7 Hz, 6H).

[0693] Example 6: Synthesis of (S)-N-(10-benzyl-1,1,1-trifluoro-6,9,12,15-tetraoxo-3-oxa-5,8,11,14-tetraazapentadecane-16-yl)-6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanamide (L6)

[0694]

Chemical formula

[0695] Step 1: Weighed 225.22 mg (1.21 mmol) of compound L6-1 and added it to a single-neck flask. Added 5 mL of anhydrous DMF, stirred at room temperature for 5 minutes until it became clear, then added 500 mg (1.21 mmol) of compound IV-2-1-A. After stirring at room temperature for 5 minutes, cooled the temperature to -10 °C and stirred for 5 minutes. Added 392.25 mg (1.33 mmol) of DMTMM to the reaction solution, continued the reaction at -10 °C for 1 hour, and monitored the reaction by LCMS. Added 30 mL of DCM to the reaction solution to dissolve it, added 30 mL of saturated aqueous NaHCO3 solution, stirred for 5 minutes, allowed it to stand and separated the layers. Re-extracted the aqueous phase with 20 mL of DCM, combined the organic phases, washed the organic phase with 50 mL of water, concentrated it under reduced pressure to 10 mL, and then directly purified it by flash column chromatography (MeOH:DCM = 0~10%) to obtain 300 mg of the target compound L6-2. LCMS (ESI) [M+Na] + =604.28.

[0696] Step 2: Dissolved 300 mg (0.52 mmol) of compound L6-2 in 10 mL of methanol, added 73.02 mg (0.052 mmol) of Pd / C under nitrogen gas protection, replaced it with hydrogen gas three times, then reacted overnight under a hydrogen gas atmosphere, and monitored the reaction by LCMS. Filtered the reaction solution, concentrated the filtrate under reduced pressure to obtain 210 mg of the target compound L6-3. LCMS (ESI) [M+H] + =448.28.

[0697] Step 3: Dissolved 210 mg (0.47 mmol) of compound L6-3 and 72.89 mg (0.56 mmol) of DIPEA in 2 mL of DMF, added 144.9 mg (0.47 mmol) of L2-1, stirred at room temperature for 3 hours, and monitored the reaction by LCMS. Purified the reaction solution directly by preparative high-performance liquid chromatography (acetonitrile: H2O containing 0.05% FA = 5%~50%) to obtain 200 mg of the target compound L6. LCMS (ESI) [M+Na] + =663.41. 1 H NMR (400 MHz, DMSO-d6) δ 8.71 (t, J = 6.7 Hz, 1H), 8.33 (t, J = 5.8 Hz, 1H), 8.14 (d, J = 8.0 Hz, 1H), 8.08 (t, J = 5.5 Hz, 1H), 8.01 (t, J = 5.5 Hz, 1H), 7.31-7.18 (m, 5H), 7.02 (s, 2H), 4.71 (d, J = 6.8 Hz, 2H), 4.56-4.50 (m, 1H), 4.04 (q, J = 9.4 Hz, 2H), 3.83-3.59 (m, 6H), 3.40 (t, J = 7.1 Hz, 2H), 3.12-3.06 (m, 1H), 2.88-2.80 (m, 1H), 2.14 (t, J = 7.4 Hz, 2H), 1.57-1.45 (m, 4H), 1.28-1.18 (m, 2H).

[0698] Example 7: Synthesis of (S)-2-((S)-2-(6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanamido)-3-methylbutanamido)-6-(dipropylamino)-N-(2-(((3-((S)-7-ethyl-7-hydroxy-8,11-dioxo-7,8,11,13-tetrahydro-10H-[1,3]dioxolo[4,5-g]pyrano[3’,4’:6,7]indolizino[1,2-b]quinolin-14-yl)propoxy)methyl)amino)-2-oxoethyl)hexanamide (IIb)

[0699]

Chemical Structure

[0700] Compound L2 (10 mg, 0.022 mmol) and compound III (30 mg, 0.044 mmol) were dissolved in DMF (0.2 mL), and HCl / DMF (1 N, 0.11 mL) was added. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was directly purified by preparative high performance liquid chromatography to obtain the target compound IIb (8 mg). LCMS (ESI) [M / 2+H] + =521.7; 1 H NMR (400 MHz, DMSO-d6) δ 8.59 (t, J = 6.4 Hz, 1H), 8.23 (s, 1H), 8.17 (t, J = 5.7 Hz, 1H), 7.95 (t, J = 8.0 Hz, 1H), 7.81 (d, J = 8.5 Hz, 1H), 7.61 (s, 1H), 7.53 (s, 1H), 7.27 (s, 1H), 7.01 (s, 2H), 6.50 (s, 1H), 6.31 (s, 2H), 5.50 - 5.40 (m, 2H), 5.26 (s, 2H), 4.66-4.60 (m, 2H), 4.22 (dd, J = 13.4, 7.5 Hz, 1H), 4.14 (t, J = 7.8 Hz, 1H), 3.80-3.70 (m, 3H), 3.54- 3.51 (m, 2H), 3.16 - 3.11 (m, 2H), 2.38 - 2.32 (m, 6H), 2.22 - 2.06 (m, 2H), 1.98 - 1.85 (m, 5H), 1.72- 1.65 (m, 1H), 1.55- 1.52 (m, 1H), 1.51-1.45 (m, 4H), 1.40 - 1.35 (m, 7H), 1.29 - 1.17 (m, 4H), 0.90 (t, J = 7.3 Hz, 3H), 0.84- 0.80 (m, 12H).

[0701] Preparation of ADC Example 1: Preparation of ADC-01 After codon optimization and gene synthesis (Shanghai Sangon Biotech Co., Ltd.) of the heavy chain amino acid sequence (SEQ ID NO: 1) of 2E3-02, it was constructed into the PTT5 vector and named PPT5-02-CH. After codon optimization and gene synthesis (Shanghai Sangon Biotech Co., Ltd.) of the light chain amino acid sequence (SEQ ID NO: 2) of 2E3-02, it was constructed into the PTT5 vector and named PTT5-02-CL. The anti-B7H3 antibody expression plasmids PTT5-02-CH / PTT5-02-CL were co-transfected into HEK293F cells (ATCC) with the PEI max reagent, and expressed at 37°C in a 5% CO2 shaker for 7 days. The supernatant was collected and purified by ProA magnetic beads, and the anti-B7H3 antibody 2E3-02 (whose heavy chain sequence is SEQ ID NO: 1 and light chain sequence is SEQ ID NO: 2) was obtained.

[0702] 25 mL of 2E3-02 antibody (anti-B7H3, concentration 28.5 mg / mL, 20 mM acetate buffer) was taken, 25 mL of 20 mM acetate buffer was added thereto for dilution, then 1 mL of an aqueous solution containing 0.25 M EDTA was added and mixed uniformly. After adjusting the pH of the sample to 7.6 with 0.5 M disodium hydrogen phosphate aqueous solution, a 4.5-fold equivalent amount of 20 mM TCEP (tris(2-carboxyethyl)phosphine hydrochloride) solution of the antibody was added and mixed uniformly, and reacted at room temperature for 90 minutes. Finally, 10-fold equivalent amount of IIa dissolved in DMSO was added to the antibody, and after mixing uniformly, the reaction was continued at room temperature for 2 hours. After the reaction was completed, the sample was replaced with 10 mM histidine buffer at pH 5.5 using a 30 kDa ultrafiltration tube to remove low molecular weight substances, and finally the sample was concentrated to obtain a solution containing the anti-B7H3 antibody ADC composition (ADC-01). By mass spectrometry, the DAR value was measured to be 7.98.

[0703]

Chemical formula

[0704] In the formula, Ab is the B7H3 antibody 2E3-02.

[0705] The method for measuring the DAR value is as follows: Chromatography conditions: Column: PLRP-S, 2.1×50 mm, 5 μm, Mobile phase A: 0.1% FA / H2O, Mobile phase B: 0.1% FA / ACN Column temperature: 30 °C, Sample chamber temperature: 8 °C, Flow rate: 0.6 mL / min, Injection volume: 2 μL

[0706]

Table 8

[0707] Sample treatment: Take 50 μg of ADC-01 sample, add 2 μL of 1 M DTT, add ultrapure water up to 50 μL to dilute to a concentration of about 1.0 mg / mL, mix uniformly, and reduce at room temperature for 30 minutes. LC / MS model: Agilent 1290-6545XT Q-TOF. Mass spectrometry conditions: Gas temp: 320 °C, Drying Gas: Nebulizer: 35 psi, Sheath Gas Temp: 350 °C, sheath Gas Flow: 11 L / min, m / z 500~3000. The detection results are shown below.

[0708]

Table 9

[0709] In the table, mAb represents the uncoupled antibody, LC represents the antibody light chain, HC represents the antibody heavy chain, DAR1 represents the complex containing the light chain or heavy chain and coupled with one toxin molecule, DAR2 represents the complex containing the light chain or heavy chain and coupled with two toxin molecules, DAR3 represents the complex containing the light chain or heavy chain and coupled with three toxin molecules. Among them, the theoretical molecular weight of the monoclonal antibody is calculated with the G0F glycoform. The explanations of the following mAb, LC, HC, DAR1, DAR2, and DAR3 are as above.

[0710] By measurement, the light chain of the 2E3-02 antibody was coupled with 0 to 1 toxin molecule (the ratios of LC and DAR1 were 1.0% and 99.0% respectively), and the heavy chain was coupled with 0 to 3 toxin molecules (the ratios of mAb, DAR1, DAR2, and DAR3 were 0%, 0%, 0%, and 100% respectively). Thereby, the antibody-drug conjugation ratio (DAR value) of ADC-01 was calculated to be 7.98.

[0711] ADC Bioactivity Test Example 1: Efficacy Test of ADC against NCI-HT29 Xenograft Tumors 1. Experimental Materials Test Compound: ADC-01 Experimental Cells: NCI-HT29 cells purchased from ATCC Experimental Animals: Balb / c nu nude mice, female, 5 - 6 weeks old, purchased from Vital River Laboratory Animal Technology Co., Ltd.

[0712] 2. Experimental Plan 2.1. Cell Treatment NCI-HT29 cells were cultured in a 15 cm diameter culture dish using 1640 medium containing 10% FBS. After reaching a confluence of about 80 - 90%, they were digested with trypsin-EDTA, washed twice with PBS, centrifuged, resuspended in pre-cooled PBS, counted using a cell counter, and diluted with PBS to a cell concentration of 5×10 7 / mL.

[0713] 2.2. Tumor Cell Transplantation Balb / c nu mice were acclimated to the laboratory environment for 2 - 5 days. NCI-HT29 cells were inoculated subcutaneously under the right rib at a cell inoculation amount of 5×10 6 / mouse and an inoculation volume of 0.2 mL (containing 50% Matrigel). When the tumor grew to about 250 mm 3 in size, the experiment was conducted.

[0714] 2.3. Animal Administration and Detection The tumor-bearing nude mice were grouped and administered according to the following plan:

[0715]

Table 10

[0716] After the administration cycle ended, observation was continued for 1 to 2 weeks. After the last tumor volume measurement, the tumors were isolated, the tumor weights were accurately weighed, and photographs were taken and recorded.

[0717] 2.4. Measurement of tumor volume and body weight: The tumor volume and body weight were measured twice a week, and the TGI% was calculated. Calculation formula for tumor volume (V): V = 1 / 2 × L 長 × L 短 2 .

[0718] 3. Experimental results Table 1. NCI-HT29 xenograft tumor model data (tumor volume mm 3 )

[0719]

Table 11

[0720] Conclusion: As shown in Table 1, the ADC of the present application has an extremely strong tumor inhibitory effect. During administration, there was no obvious weight loss and no obvious drug toxicity in the animals of each group.

[0721] The present invention is not limited to the specific embodiments described above. The present invention extends to any new feature or any new combination disclosed herein, as well as any new method or process step or any new combination disclosed.

Claims

1. A method for preparing a compound of formula II or a salt thereof, comprising step i) of reacting a compound of formula III or a salt thereof with a compound of formula X-3 or a salt thereof to obtain a compound of formula II or a salt thereof, 【Chemical Formula 1】 wherein L １ is 【Chemical Formula 2】 selected from, the 1-position is linked to Lg, and the 2-position is linked to L ２ thereto, Lg is a leaving group when reacting with an antibody, and Lg is selected from halogen, sulfone group, tertiary amine base (Me ３ N ＋ 、Et ３ N ＋ ), diazonium base, -OMs, MeSO ２ -, CF ３ SO ３ -, preferably, Lg is selected from F, Cl, MeSO ２ -, more preferably, Lg is MeSO ２ -, When L １ is 【Chemical Formula 3】 then Lg does not exist, When L ２ is 【Chemical Formula 4】 selected from, the 1-position is linked to L １ thereto, and the 2-position is linked to L ３ thereto, n4 is selected from any integer between 0 and 10, Y is selected from -CH ２ -, -OCH ２ CH ２ -, Z is selected from CR ｍ R ｎ 、NR ｍ selected from, R ｍ 、R ｎEach is independently selected from H, deuterium, a C1-C4 alkyl group, a C2-C4 alkenyl group, a C2-C4 alkynyl group, a C3-C6 cycloalkyl group, and a 3- to 6-membered heterocyclic group, or R ｍ and R ｎ together with the carbon atom to which they are both attached form a 3- to 6-membered carbocyclic ring or a 3- to 6-membered heterocyclic ring, L ３ is Val-Ala, AA １ -Val-Ala, Val-AA １ -Gly, Ala-AA １ -Gly, Gly-AA １ -Gly, Val-AA １ -Ala, Val-AA １ -Val, Ala-AA １ -Ala, Ala-AA １ -Val, Gly-AA １ -Ala, Gly-AA １ -Val, Ala-Ala-Ala, Ala-Ala-Asn, Gly-Gly-Phe-Gly, and Gly-Gly-Val-Ala, AA １ The structure of the amino acid residue shown in is as follows: [Chemical Formula 5] In the formula, R ａ and R ｂ are each independently H and [Chemical Formula 6] and are selected from, and R ａ and R ｂ are not H at the same time, or R ａ and R ｂ together with the carbon atom to which they are both attached form a 4- to 10-membered heterocyclic ring, and the above 4- to 10-membered heterocyclic ring is optionally substituted with one or more R ０ s, r is 0 and r １ is 4, R ｍ１ and R ｎ１Each is independently selected from H, a C1-6 alkyl group, and a C3-6 cycloalkyl group, or R ｍ１ and R ｎ１ together with the nitrogen atom to which they are both attached form a 4- to 10-membered heterocyclic ring, and the 4- to 10-membered heterocyclic ring is optionally substituted with one or more R ０’ ; R ０ and R ０’ are each independently selected from a C1-6 alkyl group, a C3-6 cycloalkyl group, -NR ｍ２ R ｎ２ and a 4- to 10-membered heterocyclic group optionally substituted with a C1-6 alkyl group; R ｍ２ and R ｎ２ are each independently selected from H and a C1-6 alkyl group; R ８ is selected from hydrogen, a C1-30 alkyl group, a C3-7 cycloalkyl group, a 3- to 20-membered heterocyclic group, a C1-6 alkyl group-C3-6 cycloalkyl group, a C1-6 alkyl group-4- to 6-membered heterocyclic group, a C1-6 alkyl group-C5-10 heteroaryl group, and a C1-6 alkyl group-C6-10 aryl group, and the alkyl group, cycloalkyl group, heterocyclic group, and aryl group are optionally substituted with one or more R ｘ ; R ｘ is selected from hydrogen, deuterium, fluorine, chlorine, bromine, a methyl group, a methoxy group, an amino group, a dimethylamino group, a nitro group, a cyano group, and an azide group, and a method for preparing a compound of formula II or a salt thereof.

2. (1) L １ is 【Chemical Formula 7】 selected from, the 1-position is linked to Lg, the 2-position is linked to L ２ , preferably, L １ is 【Chemical Formula 8】 wherein the 1-position is linked to Lg and the 2-position is linked to L ２ ; or L １is [Chemical Formula 9] selected from, and the second position is L ２ linked to (2) Y is -CH ２ -, and (3) n4 is selected from 0, 1, 2, 3, (4) Z is -CH ２ -, -C(CH ３ ) ２ -, -N(CH ３ ) - and -NH- selected from, (5) R ｍ , R ｎ are each independently selected from H, C1-4 alkyl group, C2-4 alkenyl group, C2-4 alkynyl group, C3-6 cycloalkyl group, 3-6 membered heterocyclic group, or R ｍ and R ｎ together with the carbon atom to which they are both linked form a 3-6 membered carbocyclic or 3-6 membered heterocyclic ring, Preferably, R ｍ , R ｎ are each independently selected from H, Me, (6) L ３ is Val-AA １ -Gly, Ala-AA １ -Gly, Gly-AA １ -Gly, Val-AA １ -Ala, Val-AA １ -Val, Ala-AA １ -Ala, Ala-AA １ -Val, Gly-AA １ -Ala, Gly-AA １ -Val, Ala-Ala-Ala, Ala-Ala-Asn, and Gly-Gly-Phe-Gly selected from, Preferably, L ３ is selected from Ala-Ala-Ala, Ala-Ala-Asn, Val-AA １ -Gly and Gly-Gly-Phe-Gly, more preferably, L ３ is Val-AA １ -Gly, and (7) R ａ One of R ｂ and R 【Chemical Formula 10】 is H, and the other is ａ R ｂ and R ０ together with the carbon atom to which they are both attached form a 5- or 6-membered heterocyclic ring substituted with R ａ R ｂ and R ０ together with the carbon atom to which they are both attached form a piperidine ring or a piperazine ring substituted with R ａ R ｂ and R ０ together with the carbon atom to which they are both attached form a piperidine ring substituted with R ａ R ｂ and R 【Chemical Formula 11】 to form, and the first carbon atom is the carbon atom to which R ａ and R ｂ are both attached), (8) R ｍ１ R ｎ１ are each independently H and a C1-6 alkyl group (preferably, R ｍ１ R ｎ１ are each independently selected from H, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group), or R ｍ１ R ｎ１ and R ０’ together with the nitrogen atom to which they are both attached form an optionally R ｍ１ R ｎ１ and R ０’ substituted 5- or 6-membered heterocyclic ring (preferably, R ｍ１ R ｎ１ and R 【Chemical Formula 12】 forms, and the first nitrogen atom is an R ｍ１ and R ｎ１ and is a nitrogen atom that is commonly linked to), (9) R ０ , R ０’ are each independently a C1-6 alkyl group, -NR ｍ２ R ｎ２ and a 5-6 membered heterocyclic group optionally substituted with a C1-6 alkyl group, Preferably, R ０ is selected from a C1-6 alkyl group and a 5-6 membered heterocyclic group substituted with a C1-6 alkyl group, and the 5-6 membered heterocyclic group is selected from a piperidinyl group and a piperazinyl group. More preferably, R ０ is selected from a methyl group, an ethyl group, and a 5-6 membered heterocyclic group substituted with a methyl group, and the 5-6 membered heterocyclic group is a piperidinyl group. Even more preferably, R ０ is a methyl group, an ethyl group, and [Chemical Formula 13] selected from, Preferably, R ０’ is selected from a C1-6 alkyl group and -NR ｍ２ R ｎ２ and more preferably, R ０’ is selected from a methyl group and -NR ｍ２ R ｎ２ selected from, (10) R ｍ２ , R ｎ２ is a methyl group, (11) R ８ is selected from hydrogen, a C1-30 alkyl group (for example, a C1-6 alkyl group), and a C1-6 alkyl group-C6-10 aryl group. The alkyl group and aryl group are optionally substituted with one or more R ｘ , and R ｘ is selected from hydrogen, fluorine, a methyl group, and a methoxy group. Preferably, R ８ is selected from hydrogen, a methyl group, an ethyl group, an isopropyl group, a tert-butyl group, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoro-1-propyl, and a benzyl group. More preferably, R ８ is selected from hydrogen, isopropyl group, tert-butyl group, 2,2,2-trifluoroethyl, 2,2,3,3,3-pentafluoro-1-propyl, and benzyl group, characterized by satisfying one or more of the following conditions, A method for preparing the compound of formula II or a salt thereof according to claim 1.

3. (1) When L １ -L ２ is 【Chemical Formula 14】 selected from, the 1-position is linked to Lg, the 2-position is linked to L ３ or, L １ -L ２ is 【Chemical Formula 15】 selected from, the 2-position is linked to L ３ in the formula, L ２ is preferably 【Chemical Formula 16】 selected from, the 1-position is linked to L １ the 2-position is linked to L ３ L ２ is more preferably 【Chemical Formula 17】 selected from, the 1-position is linked to L １ the 2-position is linked to L ３ L ２ is even more preferably 【Chemical Formula 18】 and the 1-position is linked to L １ the 2-position is linked to L ３ Preferably, L １ -L ２ is 【Chemical Formula 19】 selected from, the 1-position is linked to Lg, the 2-position is linked to L ３ or, 【Chemical Formula 20】 selected from, the 2-position is linked to L ３ ​linked to, more preferably, L １ -L ２ is 【Chemical Formula 21】 selected from, the 1-position is linked to Lg, the 2-position is linked to L ３ linked to, or 【Chemical Formula 22】 selected from, the 2-position is linked to L ３ linked to, for example, L １ -L ２ is 【Chemical Formula 23】 and the 1-position is linked to Lg, the 2-position is linked to L ３ linked to, (2) L ３ is 【Chemical Formula 24】 selected from, the 1-position is linked to L ２ linked to, the 2-position is linked to NH, preferably, L ３ is 【Chemical Formula 25】 and the 1-position is linked to L ２ linked to, the 2-position is linked to NH, characterized by satisfying one or more of the following conditions A process for preparing a compound of formula II or a salt thereof according to claim 1.

4. (1) In step i), a compound of formula III or a salt thereof is reacted with a compound of formula X-3 or a salt thereof after azeotropic dehydration to obtain a compound of formula II or a salt thereof. Preferably, in step i), the azeotropic solvent is selected from toluene, xylene, chloroform, acetonitrile, ethyl acetate, dichloroethane, preferably toluene and xylene. (2) In step i), a compound of formula III or a salt thereof and a compound of formula X-3 or a salt thereof are reacted under the condition of not adding an acid to obtain a compound of formula II or a salt thereof, and the reaction temperature is selected from 110-150 °C, preferably 120-130 °C. (3) In step i), the compound of formula III or a salt thereof and the compound of formula X-3 or a salt thereof are reacted under acidic conditions to obtain the compound of formula II or a salt thereof. The reaction temperature is preferably selected from 0 to 80°C, more preferably from 15 to 40°C, and even more preferably from 20 to 35°C. Preferably, in step i), the acid is a protonic acid or a Lewis acid, such as hydrogen chloride, hydrobromic acid, sulfuric acid, boron trifluoride diethyl ether, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl ３ ), ferric chloride (FeCl ３ ), ytterbium trifluoromethanesulfonate (Yb(OTf) ３ ), triethylamine hydrochloride, boron trifluoride acetonitrile, boron trifluoride tetrahydrofuran, hydrogen chloride pyridine, hydrobromic acid pyridine. Preferably, hydrogen chloride, hydrobromic acid, sulfuric acid, trifluoroacetic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl ３ ), ferric chloride (FeCl ３ ), boron trifluoride diethyl ether (BF ３ ·Et ２ O) and ytterbium trifluoromethanesulfonate (Yb(OTf) ３ ). Also, for example, hydrogen chloride or boron trifluoride diethyl ether. More preferably, hydrogen chloride, sulfuric acid. Most preferably, boron trifluoride diethyl ether. Preferably, in step i), the molar ratio of the compound of formula III or a salt thereof to the acid selected for the reaction is selected from 1:0.2 to 1:6, preferably 1:2 to 1:5, such as 1:2.5, 1:3 or 1:

5. (4) In step i), the molar ratio of the compound of formula III or a salt thereof to the compound of formula X-3 or a salt thereof is selected from 1:1 to 1:5, preferably 1:2 to 1:

3. (5) In step i), the reaction solvent is selected from among ether solvents, nitrile solvents, amide solvents, sulfone solvents, or water, or any combination thereof, preferably an amide or sulfone solvent, more preferably N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), or dimethyl sulfoxide (DMSO), still more preferably N,N-dimethylformamide. Preferably, in step i), the mass-volume ratio (g / mL) of the compound of formula III or a salt thereof to the selected solvent is selected from 1:2 to 1:10, preferably 1:2.5 to 1:

7. characterized by satisfying one or more of the conditions A method for preparing the compound of formula II or a salt thereof according to claim 1.

5. The method for preparing the compound of formula II or a salt thereof removing the protecting group PG on the amino group from the compound of formula IV-2 or a salt thereof ２ to obtain the compound of formula X-3-1 or a salt thereof in step m-1); 【Chemical formula 26】 further comprising a method for preparing the compound of formula X-3 or a salt thereof, including step m-2) of obtaining the compound of formula X-3 or a salt thereof by a condensation reaction of the compound of formula X-3-1 or a salt thereof and the compound of formula X-1 【Chemical formula 27】 wherein E is selected from a hydroxy group, a halogen, an activated hydroxy group, for example, a hydroxy group, chlorine, bromine 【Chemical formula 28】 selected from PG ２ is selected from amino protecting groups, preferably PG ２is selected from a benzyloxycarbonyl group (Cbz), a tert-butoxycarbonyl group (Boc), a 9-fluorenylmethoxycarbonyl group (Fmoc), an allyloxycarbonyl group (Alloc), a trimethylsilylethoxycarbonyl group (Teoc), a methoxycarbonyl group or an ethoxycarbonyl group, and more preferably, PG ２ is a 9-fluorenylmethoxycarbonyl group (Fmoc), or PG ２ is a benzyloxycarbonyl group (Cbz), Lg, L １ L ２ L ３ R ８ is as defined in any one of Forms of Claims 1 to 3, characterized in that A method for preparing the compound of Formula II or a salt thereof according to Claim 1.

6. (1) In Step m-1), it is removed under acidic conditions, and the acid preferably includes a protonic acid and an aprotic acid, or is removed under basic conditions, and the base includes an organic base and an inorganic base, or is removed under the conditions of a metal reagent, and the metal reagent is preferably selected from a palladium-based reagent or a platinum-based reagent, and more preferably is selected from palladium on carbon, platinum on carbon, platinum dioxide, palladium hydroxide, Preferably, in Step m-1), the PG ２ When it is a 9-fluorenylmethoxycarbonyl group (Fmoc), the compound of Formula IV-2 or a salt thereof removes the protecting group PG ２ under basic conditions, and the base is preferably selected from piperidine, diethylamine, morpholine, DBU, and more preferably is diethylamine. The molar ratio of the compound of Formula IV-2 or a salt thereof to the selected base is preferably selected from 1:0.2 to 1:40, and more preferably is 1:1 to 1:10, Preferably, in Step m-1), the PG ２ When it is a benzyloxycarbonyl group (Cbz), the compound of Formula IV-2 or a salt thereof removes the protecting group PG ２Remove it, and the metal reagent is a palladium-based reagent or a platinum-based reagent. Preferably, it is palladium on carbon, platinum on carbon, platinum dioxide, palladium hydroxide, for example, palladium on carbon, palladium hydroxide. The mass ratio of the compound of Formula IV-2 to the metal reagent is preferably 1:0.01 to 1, preferably 1:0.03 to 0.5, for example 1:0.

03. The hydrogen gas used is preferably 1 atm to 50 atm, for example 1 to 4 atm. (2) In step m-1), the PG ２ When it is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction solvent is selected from DMF, dichloromethane, tetrahydrofuran, 1,4-dioxane, preferably DMF. Preferably, the mass-to-volume ratio (g / mL) of the compound of Formula IV-2 or its salt to the selected reaction solvent is selected from 1:5 to 1:50, preferably 1:6 to 1:

20. (3) In step m-1), the PG ２ When it is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction temperature is selected from 0 to 50 °C, preferably 15 to 30 °C. (4) In step m-1), the PG ２ When it is a benzyloxycarbonyl group (Cbz), the reaction temperature is 0 °C to 100 °C, preferably 20 °C to 70 °C. (5) In step m-1), the PG ２ When it is a benzyloxycarbonyl group (Cbz), the reaction solvent is selected from any one of alcohol-based, ether-based, ester-based, amide-based or water, or a mixture of any ratio of the above substances. Preferably, it is methanol, ethanol, tetrahydrofuran, ethyl acetate, DMF, DMAc, NMP or water, for example methanol, tetrahydrofuran. The mass-to-volume ratio (g / mL) of the compound of Formula IV-2 or its salt to the selected reaction solvent is preferably selected from 1:3 to 1:50, for example 1:10 to 1:

30. (6) In step m-2), a compound of Formula X-3 or its salt is obtained by a condensation reaction of a compound of Formula X-3-1 or its salt and a compound of Formula X-1 or its salt. (7) In step m-2), when E is a hydroxy group, the reaction occurs under basic or neutral conditions under the action of a condensing agent, The condensing agent is preferably DMTMM, HATU, HBTU, COMU, N-ethynyl-N-methylmethanesulfonamide, more preferably DMTMM, HBTU, The base is selected from organic bases or inorganic bases, preferably triethylamine, N,N-diisopropylethylamine, N-methylmorpholine, more preferably N,N-diisopropylethylamine, The molar ratio of the compound of formula X-1 or its salt to the condensing agent is preferably selected from 1:1 to 1:5, more preferably 1:1 to 1:1.5, (8) In step m-2), when E is a hydroxy group, the molar ratio of the compound of formula X-3-1 or its salt to the compound of formula X-1 or its salt is selected from 1:0.9 to 1:1.2, (9) In step m-2), when E is a hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, methanol, dichloromethane and water, or any combination thereof, preferably DMF, (10) In step m-2), when E is a hydroxy group, the reaction temperature is selected from -20 to 100 °C, for example, -20 to 30 °C, preferably 0 to 30 °C, (11) In step m-2), when E is selected from halogens (for example, chlorine, fluorine or bromine), the compound of formula X-3-1 or its salt and the compound of formula X-1 or its salt react under basic conditions, The base is preferably selected from triethylamine, N,N-diisopropylethylamine, DBU and N-methylmorpholine, more preferably N,N-diisopropylethylamine, The molar ratio of the compound of formula X-1 or its salt to the base described in the reaction is preferably selected from 1:0.1 to 1:5, for example 1:1 to 1:5, more preferably 1:0.2 to 1:1, (12) In step m-2), when E is a halogen (for example, chlorine, fluorine or bromine), the molar ratio of the compound of formula X-1 or a salt thereof to the compound of formula X-3-1 or a salt thereof is selected from 1:0.8 to 1:2.0, preferably 1:0.9 to 1:1.2, (13) In step m-2), when E is a halogen (for example, chlorine, fluorine or bromine), the reaction solvent is selected from one or any combination of DMF, tetrahydrofuran, dichloromethane, and acetonitrile, preferably acetonitrile, and the mass-volume ratio (g / mL) of the compound of formula X-1 or a salt thereof to the selected reaction solvent is preferably selected from 1:2 to 1:50, preferably 1:3 to 1:10, (14) In step m-2), when E is a halogen (for example, chlorine, fluorine or bromine), the reaction temperature is selected from -20 to 100 °C, preferably 0 to 30 °C, Characterized by satisfying one or more of the conditions, A method for preparing the compound of formula II or a salt thereof according to claim 5.

7. The method for preparing the compound of formula X-3 or a salt thereof is R ８ When it is not H, Removing the protecting group PG on the amino group from the compound of formula IV-1 or a salt thereof to obtain the compound of formula IV-2-1 or a salt thereof in step k-1), １ And step k-2) of obtaining the compound of formula IV-2 or a salt thereof by a condensation reaction of the compound of formula IV-2-1 or a salt thereof with the compound of formula IV-2-2 or a salt thereof, further including a method for preparing the compound of formula IV-2 or a salt thereof, 【Chemical formula 29】 Wherein PG-L is, that is, PG-L-L, 【Chemical formula 30】 PG ２ -L ３ That is, PG １ -L ３－２ -L ３－１ And in the formula, Wherein, L ３－１is selected from amino acid residues, and the amino acid residue is 【Chemical Formula 31】 selected from, and the 1-position is L ３－２ linked to, and the 2-position is linked to NH, preferably, L ３－１ is selected from amino acid residues, and the amino acid residue is 【Chemical Formula 32】 selected from, and the 1-position is L ３－２ linked to, and the 2-position is linked to NH, more preferably, L ３－１ is Gly, PG １ is selected from amino protecting groups, and PG １ is preferably selected from benzyloxycarbonyl group (Cbz), tert-butoxycarbonyl group (Boc), 9-fluorenylmethoxycarbonyl group (Fmoc), allyloxycarbonyl group (Alloc), trimethylsilylethoxycarbonyl group (Teoc), methoxycarbonyl group or ethoxycarbonyl group, preferably, PG １ is selected from benzyloxycarbonyl group (Cbz), 9-fluorenylmethoxycarbonyl group (Fmoc), more preferably, PG １ is 9-fluorenylmethoxycarbonyl group (Fmoc), for example, PG １ is benzyloxycarbonyl group (Cbz), L ３－２ is Val, Val-AA １ Ala-AA １ Gly-AA １ Ala-Ala, AA １ -Val, Gly-Gly-Val and Gly-Gly-Phe, preferably, L ３－２ is Val-AA １ Ala-Ala and Gly-Gly-Phe, for example, L ３－２ is Val-AA １ and is Specifically, L ３－２ is 【Chemical Formula 33】 selected from, and the 1-position is L ２ is linked to, and the 2-position is L ３－１ is linked to, and more preferably, L ３－２ is 【Chemical Formula 34】 and the 1-position is L ２ is linked to, and the 2-position is L ３－１ is linked to L ３ , R ８ , and the definitions of E are as described in any one of Forms of Claims 1 to 3, PG ２ and the definition of is as described in any one of Forms of Claim 5, characterized in that A method for preparing the compound of Formula II or a salt thereof according to Claim 5.

8. (1) In step k-1), it is removed under acidic conditions, and the acid includes a protonic acid and an aprotic acid, or removed under basic conditions, and the base includes an organic base and an inorganic base, or removed under the conditions of a metal reagent, and the metal reagent is preferably selected from palladium-based reagents or platinum-based reagents, and more preferably selected from palladium on carbon, platinum on carbon, platinum dioxide, and palladium hydroxide, Preferably, in step k-1), when the PG １ is a 9-fluorenylmethoxycarbonyl group (Fmoc), the compound of Formula IV-1 or a salt thereof removes the protecting group PG １ under basic conditions, and the base is selected from an organic base or an inorganic base, preferably selected from piperidine, diethylamine, morpholine, diisopropylamine, DBU, triethylamine, and N,N-diisopropylethylamine, more preferably piperidine, diethylamine, or morpholine, such as diethylamine, DBU, and the molar ratio of the compound of Formula IV-1 or a salt thereof to the selected base is preferably selected from 1:0.2 to 1:40, such as 1:0.2 to 1:2, preferably 1:1 to 1:10, such as 1:0.4, Preferably, in step k-1), the PG １When it is a benzyloxycarbonyl group (Cbz), the compound of formula IV-1 or a salt thereof has a protecting group PG under a metal reagent-hydrogen system １ removed, and the metal reagent is selected from a palladium-based reagent or a platinum-based reagent, preferably palladium on carbon, platinum on carbon, platinum dioxide, palladium hydroxide, for example, palladium on carbon, palladium hydroxide, and the mass ratio of the compound of formula IV-1 to the metal reagent is preferably 1:0.01 to 1, preferably 1:0.03 to 0.5, for example 1:0.05, 1:0.1, and the hydrogen gas used is preferably 1 atm to 50 atm, (2) In step k-1), the PG １ When it is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction solvent is selected from one of DMF, DMAc, NMP, dichloromethane, tetrahydrofuran, 1,4-dioxane, acetonitrile, or any combination thereof, for example, DMF, tetrahydrofuran, and the mass-volume ratio (g / mL) of the compound of formula IV-1 or a salt thereof to the selected reaction solvent is preferably selected from 1:5 to 1:50, preferably 1:6 to 1:20, (3) In step k-1), the PG １ When it is a 9-fluorenylmethoxycarbonyl group (Fmoc), the reaction temperature is selected from 0 to 50 °C, preferably 15 to 30 °C, (4) In step k-1), the PG １ When it is a benzyloxycarbonyl group (Cbz), the reaction temperature is 0 °C to 100 °C, preferably 20 °C to 70 °C, (5) In step k-1), the PG １When it is a benzyloxycarbonyl group (Cbz), the reaction solvent is selected from any one of alcohol-based, ether-based, ester-based, amide-based or water, or is a mixture of any proportion of the above substances. Preferably, it is methanol, ethanol, tetrahydrofuran, ethyl acetate, DMF, DMAc, NMP or water, such as methanol and tetrahydrofuran. The mass-volume ratio (g / mL) of the compound of formula IV-1 or its salt to the selected reaction solvent is preferably selected from 1:3 to 1:20, and preferably 1:5 to 1:

10. (6) In step k-2), when E is a hydroxy group, the reaction occurs under basic or neutral conditions under the action of a condensing agent and / or a racemization inhibitor. Preferably, when E is a hydroxy group, the reaction occurs under neutral conditions under the action of a condensing agent. The condensing agent is preferably DMTMM, HATU, HBTU, EDCI, COMU, N-ethynyl-N-methylmethanesulfonamide, EEDQ and T ３ P, more preferably DMTMM and HBTU. The racemization inhibitor is preferably selected from HOAt and HOBt. The base is preferably selected from DBU, triethylamine, N,N-diisopropylethylamine and N-methylmorpholine. The molar ratio of the compound of formula IV-2-2 or its salt to the condensing agent is preferably selected from 1:1 to 1:5, and preferably 1:1 to 1:1.

5. (7) In step k-2), when E is a hydroxy group, the molar ratio of the compound of formula IV-2-1 or its salt to the compound of formula IV-2-2 or its salt is selected from 1:0.8 to 1:3, and preferably 1:0.8 to 1:1.

2. (8) In step k-2), when E is a hydroxy group, the reaction solvent is selected from one of DMF, acetonitrile, tetrahydrofuran, methanol, dichloromethane, and water, or any combination thereof, preferably DMF or tetrahydrofuran. The mass-volume ratio (g / mL) of the compound of formula IV-2-1 or its salt to the selected reaction solvent is preferably selected from 1:5 to 1:

20. (9) In step k-2), when E is a hydroxy group, the reaction temperature is selected from -20 to 100 °C, preferably -15 to 50 °C, and most preferably lower than -15 °C. Characterized by satisfying one or more of the conditions. A method for preparing the compound of formula II or its salt according to claim 7.

9. The method for preparing the compound of formula IV-2 or its salt is as follows: Reacting the compound of formula IV-1-1 or its salt with the compound of formula R ８ OH or its salt under acidic or basic conditions to obtain the compound of formula IV-1 or its salt in step j), Method 1. [Chemical formula 35] The following steps: Reacting the compound of formula IV-1-2 or its salt with formaldehyde in water and under basic conditions to obtain the compound of formula IV-1-3 or its salt in step j-1), and [Chemical formula 36] Reacting the compound of formula IV-1-3 or its salt with the compound of formula R ８ OH or its salt under acidic conditions to obtain the compound of formula IV-1 or its salt in step j-2), Method 2. Further comprising the method for preparing the compound of formula IV-1 or its salt as described above. [Chemical formula 37] Wherein L ３－１ , PG １ , R ８ are defined as described in any one of the forms of claim 7. A method for preparing the compound of formula II or a salt thereof according to claim 7.

10. (1) In step j), the acid is a protic acid or an aprotic acid, preferably hydrogen chloride, hydrobromic acid, sulfuric acid, trifluoroacetic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl ３ ), ferric chloride (FeCl ３ ), boron trifluoride diethyl ether (BF ３ ·Et ２ O) and ytterbium trifluoromethanesulfonate (Yb(OTf) ３ ), more preferably hydrogen chloride, sulfuric acid, zinc acetate, such as hydrogen chloride. In step j), the molar ratio of the compound of formula IV-1-1 or a salt thereof to the acid selected for the reaction is preferably selected from 1:0.01 to 1:0.2, for example 1:0.

05. (2) In step j), the base is an organic base or an inorganic base, preferably sodium hydroxide, potassium tert-butoxide, potassium carbonate, triethylamine (Et ３ N), N,N-diisopropylethylamine (DIPEA) and pyridine, preferably potassium tert-butoxide. The molar ratio of the compound of formula IV-1-1 or a salt thereof to the base selected for the reaction is preferably selected from 1:0.9 to 1:

5. (3) In step j), the molar ratio of the compound of formula IV-1-1 or a salt thereof to the compound of formula R ８ OH or a salt thereof is selected from 1:1 to 1:20, preferably 1:2 to 1:

15. (4) In step j), the reaction solvent is selected from alcohol-based, ether-based, haloalkane-based, aromatic hydrocarbon-based, nitrile-based, amide-based or sulfone-based solvents, preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, ethylene glycol diethyl ether, tetrahydrofuran, 1,4-dioxane, dichloromethane, 1,2-dichloroethane, toluene, acetonitrile, DMF, DMAc, NMP or DMSO, more preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, toluene, tetrahydrofuran, acetonitrile, DMF, DMAc, NMP, for example, 2,2,2-trifluoroethanol, DMF. The mass-volume ratio (g / mL) of the compound of formula IV-1-1 or its salt to the selected solvent is preferably selected from 1:2 to 1:10, preferably 1:2.5 to 1:

7. (5) In step j), the reaction temperature is selected from 0 to 120 °C, for example 10 to 50 °C. (6) In step j-1), the base is selected from potassium carbonate, potassium hydrogen carbonate, potassium phosphate, sodium carbonate, sodium hydrogen carbonate, triethylamine, diisopropylethylamine, preferably potassium carbonate. (7) In step j-1), the molar ratio of the compound of formula IV-1-2 or its salt to the base is selected from 1:0.05 to 1:1, preferably 1:0.1 to 1:0.

5. (8) In step j-1), the molar ratio of the compound of formula IV-1-2 or its salt to formaldehyde is 1:0.5 to 1:2.5, preferably 1:1 to 1:2, for example 1:1.

8. (9) In step j-1), the mass-volume ratio (g / mL) of the compound of formula IV-1-2 or its salt to water is preferably 1:3 to 1:50, preferably 1:5 to 1:20, for example 1:

15. (10) In step j-1), the reaction temperature is 0 to 80°C, preferably 10 to 50°C, (11) In step j-2), the acid is a protic acid or an aprotic acid, preferably hydrogen chloride, hydrobromic acid, sulfuric acid, trifluoroacetic acid, p-toluenesulfonic acid, pyridinium p-toluenesulfonate, zinc acetate, aluminum trichloride (AlCl3), ferric chloride (FeCl3), boron trifluoride diethyl ether (BF3·Et2O), and ytterbium trifluoromethanesulfonate (Yb(OTf)3), more preferably hydrogen chloride, sulfuric acid, zinc acetate, for example hydrogen chloride. The molar ratio of the compound of formula IV-1-3 or its salt to the acid selected for the reaction is preferably selected from 1:0.01 to 1:0.2, for example 1:0.

05. (12) In step j-2), the molar ratio of the compound of formula IV-1-3 or its salt to the compound of formula R ８ OH or its salt is selected from 1:1 to 1:50, preferably 1:2 to 1:

30. (13) In step j-2), the reaction solvent is selected from alcohol-based, ether-based, haloalkane-based, aromatic hydrocarbon-based, nitrile-based, amide-based, or sulfone-based solvents, more preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, ethylene glycol diethyl ether, tetrahydrofuran, 1,4-dioxane, dichloromethane, 1,2-dichloroethane, toluene, acetonitrile, DMF, DMAc, NMP, or DMSO, even more preferably isopropanol, benzyl alcohol, tert-butanol, 2,2,2-trifluoroethanol, 2,2,3,3,3-pentafluoro-1-propanol, toluene, tetrahydrofuran, acetonitrile, DMF, DMAc, NMP, for example, 2,2,2-trifluoroethanol, DMF. The mass-volume ratio (g / mL) of the compound of formula IV-1-3 or its salt to the selected solvent is preferably selected from 1:2 to 1:10, preferably 1:2.5 to 1:

7. (14) In step j-2), the reaction temperature is selected from 0 to 120 °C, for example 0 to 50 °C, characterized by satisfying one or more of the conditions, A process for preparing a compound of formula II or a salt thereof according to claim 9.

11. The process for preparing the compound of formula II or a salt thereof specifically includes reacting a compound of formula III or a salt thereof with a compound of formula X-3a or a salt thereof by azeotropic dehydration to obtain a compound of formula IIa or a salt thereof, which is a process for preparing a compound of formula IIa or a salt thereof, 【Chemical formula 38】 Preferably, the process for preparing the compound of formula IIa or a salt thereof is removing the protecting group Cbz from the compound of formula IV-2-A or a salt thereof under a metal reagent-hydrogen system to obtain a compound of formula X-3-1-A or a salt thereof in step m-1); 【Chemical formula 39】 further including a process for preparing a compound of formula X-3a or a salt thereof, which includes reacting a compound of formula X-3-1-A or a salt thereof with a compound of formula X-1-A under basic conditions to obtain a compound of formula X-3a or a salt thereof in step m-2), 【Chemical formula 40】 More preferably, the process for preparing the compound of formula IIa or a salt thereof is removing the protecting group Cbz from the compound of formula IV-1-A or a salt thereof under a metal reagent-hydrogen system to obtain a compound of formula IV-2-1-A or a salt thereof in step k-1); 【Chemical formula 41】 further including a process for preparing a compound of formula IV-2a or a salt thereof, which includes reacting a compound of formula IV-2-1-A or a salt thereof with a compound of formula IV-2-2-B or a salt thereof under basic or neutral conditions under the action of a condensing agent and / or a racemization inhibitor to obtain a compound of formula IV-2-A or a salt thereof in step k-2), 【Chemical formula 42】 More preferably, the process for preparing the compound of formula IIa or a salt thereof is Step j-1) of reacting a compound of formula IV-1-A-2 or a salt thereof with formaldehyde in water and under basic conditions to obtain a compound of formula IV-1-A-3 or a salt thereof, 【Chemical Formula 43】 reacting a compound of formula IV-1-A-3 or a salt thereof with CF ３ CH ２ OH under acidic conditions to obtain a compound of formula IV-1-A or a salt thereof, and step j-2), and further comprising a method for preparing a compound of formula IV-1a or a salt thereof, 【Chemical Formula 44】 A method for preparing a compound of formula II or a salt thereof according to claim 1, characterized in that.

12. A method for preparing a compound of formula X-3 or a salt thereof, removing the protecting group PG on the amino group from a compound of formula IV-2 or a salt thereof to obtain a compound of formula X-3-1 or a salt thereof, step m-1), ２ and step m-2) of obtaining a compound of formula X-3 or a salt thereof by a condensation reaction of a compound of formula X-3-1 or a salt thereof with a compound of formula X-1, 【Chemical Formula 45】 wherein the definitions of E, PG 【Chemical Formula 46】 In the formula, E, PG ２ 、Lg、L １ 、L ２ 、L ３ 、R ８ are as defined in any one of claims 5, The method for preparing the compound of formula X-3 or a salt thereof is characterized in that the conditions and operations are as described in any one of claims 5 to 10, A method for preparing a compound of formula X-3 or a salt thereof.

13. A method for preparing a compound of formula IV-2 or a salt thereof, wherein when R ８ is not H, removing the protecting group PG on the amino group from a compound of formula IV-1 or a salt thereof １Step k-1) of removing and obtaining the compound of formula IV-2-1 or a salt thereof; 【Chemical Formula 47】 Step k-2) of obtaining the compound of formula IV-2 or a salt thereof by a condensation reaction between the compound of formula IV-2-1 or a salt thereof and the compound of formula IV-2-2 or a salt thereof, 【Chemical Formula 48】 wherein, PG ２ -L ３ that is, PG ２ -L ３－２ -L ３－１ is; wherein, L ３－１ L ３－２ L ３ PG １ PG ２ R ８ the definitions of E are as described in any one of the forms of claim 7; The method for preparing the compound of formula IV-2 or a salt thereof is such that the conditions and operations are as described in any one of the forms of claims 7 to 10. Characterized in that A method for preparing the compound of formula IV-2 or a salt thereof.

14. A method for preparing the compound of formula IV-1 or a salt thereof, reacting the compound of formula IV-1-1 or a salt thereof with the compound of formula R ８ OH or a salt thereof under acidic conditions or basic conditions to obtain the compound of formula IV-1 or a salt thereof, Method 1 including step j); 【Chemical Formula 49】 The following steps: Step j-1) of reacting the compound of formula IV-1-2 or a salt thereof with formaldehyde in water and under basic conditions to obtain the compound of formula IV-1-3 or a salt thereof; 【Chemical Formula 50】 reacting the compound of formula IV-1-3 or a salt thereof with the compound of formula R ８Method 2, which includes step j-2) of reacting with a compound of OH or a salt thereof to obtain a compound of formula IV-1 or a salt thereof, 【Chemical Formula 51】 wherein L ３－１ , PG １ , R ８ are as defined in any one of the forms of claim 9, The method for preparing the compound of formula IV-1 or a salt thereof is characterized in that the conditions and operations are as described in any one of the forms of claims 9 to 10. A method for preparing a compound of formula IV-1 or a salt thereof.

15. A compound of formula IV-1 or a salt thereof, a compound of formula IV-2-1 or a salt thereof, a compound of formula IV-2 or a salt thereof, a compound of formula X-3-1 or a salt thereof, a compound of formula X-3 or a salt thereof, wherein 【Chemical Formula 52】 Lg, L １ , L ２ , L ３ , R ８ are as defined in any one of the forms of claims 1 to 3, PG ２ is as defined in any one of the forms of claim 5, L ３－１ , PG １ are as defined in any one of the forms of claim 7, Preferably, The compound of formula IV-1 or a salt thereof has the following structure: 【Chemical Formula 53】 selected from The compound of formula IV-2-1 or a salt thereof has the following structure: 【Chemical Formula 54】 selected from The compound of formula IV-2 or a salt thereof has the following structure: 【Chemical Formula 55】 selected from The compound of the formula X-3-1 or a salt thereof has the following structure: 【Chemical Formula 56】 selected from The compound of the formula X-3 or a salt thereof has the following structure: 【Chemical Formula 57】 The compound of the formula IV-1 or a salt thereof, the compound of the formula IV-2-1 or a salt thereof, the compound of the formula IV-2 or a salt thereof, the compound of the formula X-3-1 or a salt thereof, the compound of the formula X-3 or a salt thereof, selected from

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