Process for preparing intermediate of antibody drug conjugate

Abstract

The present disclosure relates to a process for preparing an intermediate of antibody-drug conjugate. Compared with the conventional art, the process for preparing an intermediate of the antibody-drug conjugate provided by the present disclosure significantly reduces the feed loss for drug moiety, such as MMAD/MMAE or MMAF, etc., as drug moiety is involved in the last step of the reaction, thereby effectively reducing production costs, as well as increasing production efficiency. In addition, the process provided by the present disclosure is simple, environmentally friendly and suitable for large-scale industrialization.

1 . A process for preparing an intermediate of antibody-drug conjugate comprising a linker and a drug moiety, in which the intermediate of antibody-drug conjugate is Py-MAA-Val-Cit-PAB-D, the Py-MAA-Val-Cit-PAB in the intermediate is the linker and the D in the intermediate represents the attached drug moiety, and the attached drug moiety contains free amino group, wherein it comprises the following reactions: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         2 . The process according to  claim 1 , wherein
 Reaction A: dissolving Py-MAA-Val-Cit-PAB-OH in a solvent, adding bis(4-nitrophenyl) carbonate, stirring until dissolved or the solution is slightly turbid, and then adding an organic base;   Reaction B: after completion of Reaction A, adding a triazole catalyst, the drug moiety D and an organic base, and after completion of the reaction, carrying out purification to obtain Py-MAA-Val-Cit-PAB-D.   
     
     
         3 . The process according to  claim 1 , wherein the drug moiety D is an auristatin class cytotoxic agent, an anthramycin class cytotoxic agent, an anthracycline class cytotoxic agent or a puromycin class cytotoxic agent. 
     
     
         4 . The process according to  claim 3 , wherein the auristatin class cytotoxic agent is selected from the group consisting of MMAE, MMAF, MMAD and a derivative thereof; the anthramycin class cytotoxic agent is anthramycin or a derivative thereof; the anthracycline class cytotoxic agent is selected from the group consisting of daunorubicin, doxorubicin, epirubicin, idarubicin, valrubicin, mitoxantrone and a derivative thereof; and the puromycin class cytotoxic agent is puromycin or a derivative thereof. 
     
     
         5 . The process according to  claim 4 , wherein the structure of the Py-MAA-Val-Cit-PAB-D is represented by Formulas (1-11): 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
     
     
         6 . The process according to  claim 2 , wherein the solvent is a polar solvent and/or a non-polar solvent, the polar solvent is one or more selected from the group consisting of DMF, DMA and NMP; the non-polar solvent is one or more selected from the group consisting of dichloromethane and carbon tetrachloride. 
     
     
         7 . The process according to  claim 1 , wherein the organic base is one or more selected from the group consisting of N,N-diisopropylethylamine, triethylamine and pyridine, preferably one or two selected from the group consisting of N,N-diisopropylethylamine and pyridine. 
     
     
         8 . The process according to  claim 1 , wherein the triazole catalyst is one or more selected from the group consisting of 1-hydroxybenzotriazole, 1-hydroxy-7-azabenzotriazole and ethyl 1-hydroxy-1H-1,2,3-triazole-4-carboxylate, preferably 1-hydroxybenzotriazole. 
     
     
         9 . The process according to  claim 1 , comprising: in the Reaction A, controlling the temperature of the reaction system to be in the range from 5 to 15° C. prior to the addition of bis(4-nitrophenyl) carbonate, preferably 10° C.; and further preferably, in the Reaction A, controlling the temperature of the reaction system to be in the range from 20 to 35° C. after addition of the organic base, preferably 30° C. 
     
     
         10 . The process according to  claim 1 , comprising: in the Reaction B, controlling the temperature of the reaction system to be in the range from 5 to 15° C. prior to the addition of the triazole catalyst, preferably 10° C.; further preferably, in the Reaction B, controlling the temperature of the reaction system to be in the range from 15 to 30° C. after the addition of the organic base, preferably 20° C. 
     
     
         11 . The preparation process according to  claim 1 , wherein, in the Reaction A, the molar ratio of Py-MAA-Val-Cit-PAB-OH. bis(4-nitrophenyl) carbonate and the organic base is 1:1-5:1-3. 
     
     
         12 . The process according to  claim 1 , wherein, in the Reaction B, the molar ratio of the triazole catalyst, MMAE, the organic base and Py-MAA-Val-Cit-PAB-OH is 1-3:1-3:1.5-30:1. 
     
     
         13 . The process according to  claim 1 , comprising: after completion of the Reaction B, carrying out pre-HPLC purification to obtain Py-MAA-Val-Cit-PAB-D. 
     
     
         14 . The process according to  claim 1 , wherein purification is carried out in Reaction A by the following method to obtain Py-MAA-Val-Cit-PAB-PNP:
 (1) centrifuging the reaction solution of Reaction A to obtain a supernatant;   (2) adding solvent 1 to the supernatant, and stirring well;   (3) adding solvent 2 dropwise at 0 to 10° C., and stirring well;   (4) filtering under suction to obtain a filter cake;   (5) re-dissolving the filter cake in a mixed solution of solvent 3 and solvent 4;   (6) adding the resultant dropwise to solvent 5 at 0 to 10° C., and stirring;   (7) filtering under suction to obtain an off-white powder, which is purified Py-MAA-Val-Cit-PAB-PNP;   wherein the solvent 1 is a moderately polar solvent, preferably selected from the group consisting of ethyl acetate, dichloromethane, methanol, methyl tert-butyl ether and the like, most preferably ethyl acetate; the solvent 2 is a weakly polar solvent, preferably selected from the group consisting of petroleum ether, n-hexane, n-pentane, cyclohexane and the like, most preferably petroleum ether; the solvent 3 and solvent 4 are solvents in which Py-MAA-Val-Cit-PAB-PNP is easy to dissolve, preferably selected from the group consisting of acetic acid, trifluoroacetic acid, formic acid, methanol, ethanol and the like, most preferably acetic acid and methanol; the solvent 5 is preferably selected from the group consisting of acetonitrile, ethyl acetate, dichloromethane, water and the like, most preferably water.   
     
     
         15 . The process according to  claim 1 , wherein the reactions are carried out under the protection of nitrogen.