Products of chiral synthesis of cis-imidazoline compounds and their use

Abstract

This invention provides a method for enantioselective synthesis of cis-imidazolines and related structures through chiral resolution. A chiral acid is used to separate enantiomeric precursors of the cis-imidazolines from a racemic mixture by selective crystallization. Both enantiomers can be cyclized into the desired cis-imidazoline by complementary pathways. Compounds can be synthesized according to the invention with an enantiomeric excess as high as 99%. Cis-imidazolines such as Nutlin-3a prepared according to this invention may be used for treating cancer, killing senescent cells, or treating senescence-associated conditions.

What is claimed is: 
     
         1 . A unit dose of a pharmaceutical composition for treatment of osteoarthritis,
 wherein the unit dose contains an effective amount of a cis-imidazoline formulated as a pharmaceutical composition for administration into an osteoarthritic joint of a subject in need thereof,   wherein the formulation of the composition and the amount of the cis-imidazoline in the unit dose configure the unit dose to be effective in treating the osteoarthritic joint by removing senescent cells from the joint, thereby decreasing severity of one or more signs or symptoms of osteoarthritis in the joint without causing adverse effects when administered to the joint as a single dose,   wherein the cis-imidazoline has an enantiomeric excess (ee) of at least 99% as a result of having been prepared by a synthesis method that includes the steps of Process 1 or Process 2,   wherein Process 1 comprises:   (a) obtaining a racemic mixture of a precursor according to Formula (A);   
       
         
           
           
               
               
           
         
         wherein X 1  and X 2  are both halogen, the first nitrogen is bonded to R 1  which is a first substituent having the formula —C(═O)—R 2 where R 2  an optionally substituted carbocycle or heterocycle group, and the second nitrogen is a primary amine; 
         (b) combining the racemic mixture of the precursor with a chiral aromatic acid according to Formula (B):
   HOOC—CH(OH)—R 3    (B)
 
 
         wherein R 3  is an optionally substituted aryl or heteroaryl group, 
         whereby a first stereoisomer of the precursor associates with the chiral aromatic acid, and a second stereoisomer of the precursor does not; 
         (c) separating and recovering the first stereoisomer from the chiral aromatic acid; 
         (d) selectively derivatizing the second nitrogen of the first stereoisomer with a second substituent having the formula —C(═O)—R 4 , wherein R 4  is an optionally substituted carbocycle or heterocycle group; and then 
         (e) performing a ring closing reaction in which the first nitrogen joins with the second nitrogen, thereby forming the cis-imidazoline with an enantiomeric excess (ee) of at least 99%. 
         wherein Process 2 comprises: 
         (a) obtaining a racemic mixture of a precursor according to Formula (A), 
       
       
         
           
           
               
               
           
         
         wherein X 1  and X 2  are both halogen, the first nitrogen is bonded to R 1  which is a nitrogen protecting group, and the second nitrogen is a primary amine; 
         (b) combining the racemic mixture of the precursor with a chiral aromatic acid according to Formula (B),
   HOOC—CH(OH)—R 3    (B)
 
 
         wherein R 3  is an optionally substituted aryl or heteroaryl group, 
         whereby a first stereoisomer of the precursor associates with the chiral aromatic acid, and a second stereoisomer of the precursor does not; 
         (c) separating and recovering the first stereoisomer from the chiral aromatic acid; 
         (d) selectively derivatizing the second nitrogen of the first stereoisomer with a second substituent having the formula —C(═O)—R 4 , wherein R 4  is an optionally substituted carbocycle or heterocycle group; 
         (e) deprotecting the first nitrogen; 
         (f) selectively derivatizing the first nitrogen of the first stereoisomer with a first substituent having the formula —C(═O)—R 2 , wherein R 2  is an optionally substituted carbocycle or heterocycle group, and then 
         (g) performing a ring closing reaction on the first stereoisomer in which the first nitrogen joins with the second nitrogen, thereby forming the cis-imidazoline with an enantiomeric excess (ee) of at least 99%. 
       
     
     
         2 . The unit dose according to  claim 1 , wherein the first or the second substituent is 
       
         
           
           
               
               
           
         
       
     
     
         3 . The unit dose according to  claim 1 , wherein the first or the second substituent is 
       
         
           
           
               
               
           
         
       
     
     
         4 . The unit dose according to  claim 1 , wherein R 3  is phenyl. 
     
     
         5 . The unit dose according to  claim 1 , wherein X 1  and X 2  are both chloride. 
     
     
         6 . The unit dose according to  claim 1 , wherein the chiral aromatic acid is D-mandelic acid or L-mandelic acid. 
     
     
         7 . The unit dose according to  claim 1 , wherein the separating includes crystallizing molecules of the precursor with the chiral aromatic acid, and recovering the first stereoisomer from crystals formed thereby. 
     
     
         8 . The unit dose according to  claim 1 , wherein the cis-imidazoline synthesized thereby is 4-[[(4S ,5R)-4,5-bis(4-chlorophenyl)-4,5-dihydro -2-[4-methoxy-2-(1-methylethoxy)phenyl]-1H-imidazol-1-yl]carbonyl]-2-piperazinone (BM1197). 
     
     
         9 . The unit dose according to  claim 1 , packaged with information about its use in treating osteoarthritis. 
     
     
         10 . A method for preparing a pharmaceutical composition containing a cis-imidazoline having an enantiomeric excess (ee) of at least 95%, comprising compounding the cis-imidazoline with a pharmaceutically compatible excipient, wherein the cis-imidazoline has an enantiomeric excess (ee) of at least 95% as a result of having been prepared by a synthetic method that includes the steps of Process 1 or Process 2:
 wherein Process 1 comprises:   (a) obtaining a racemic mixture of a precursor according to Formula (A);   
       
         
           
           
               
               
           
         
         wherein X 1  and X 2  are both halogen, the first nitrogen is bonded to R 1  which is a first substituent having the formula —C(═O)—R 2  where R 2  an optionally substituted carbocycle or heterocycle group, and the second nitrogen is a primary amine; 
         (b) combining the racemic mixture of the precursor with a chiral aromatic acid according to Formula (B):
   HOOC—CH(OH)—R 3    (B)
 
 
         wherein R 3  is an optionally substituted aryl or heteroaryl group, 
         whereby a first stereoisomer of the precursor associates with the chiral aromatic acid, and a second stereoisomer of the precursor does not; 
         (c) separating and recovering the first stereoisomer from the chiral aromatic acid; 
         (d) selectively derivatizing the second nitrogen of the first stereoisomer with a second substituent having the formula —C(═O)—R 4 , wherein R 4  is an optionally substituted carbocycle or heterocycle group; and then 
         (e) performing a ring closing reaction in which the first nitrogen joins with the second nitrogen, thereby forming the cis-imidazoline with an enantiomeric excess (ee) of at least 95%; 
         wherein Process 2 comprises: 
         (a) obtaining a racemic mixture of a precursor according to Formula (A), 
       
       
         
           
           
               
               
           
         
         wherein X 1  and X 2  are both halogen, the first nitrogen is bonded to R 1  which is a nitrogen protecting group, and the second nitrogen is a primary amine; 
         (b) combining the racemic mixture of the precursor with a chiral aromatic acid according to Formula (B),
   HOOC—CH(OH)—R 3    (B)
 
 
         wherein R 3  is an optionally substituted aryl or heteroaryl group, 
         whereby a first stereoisomer of the precursor associates with the chiral aromatic acid, and a second stereoisomer of the precursor does not; 
         (c) separating and recovering the first stereoisomer from the chiral aromatic acid; 
         (d) selectively derivatizing the second nitrogen of the first stereoisomer with a second substituent having the formula —C(═O)—R 4 , wherein R 4  is an optionally substituted carbocycle or heterocycle group; 
         (e) deprotecting the first nitrogen; 
         (f) selectively derivatizing the first nitrogen of the first stereoisomer with a first substituent having the formula —C(═O)—R 2 , wherein R 2  is an optionally substituted carbocycle or heterocycle group, and then 
         (g) performing a ring closing reaction on the first stereoisomer in which the first nitrogen joins with the second nitrogen, thereby forming the cis-imidazoline with an enantiomeric excess (ee) of at least 95%. 
       
     
     
         11 . The method of  claim 10 , wherein the cis-imidazoline has an enantiomeric excess if at least 99%. 
     
     
         12 . A method of manufacturing a pharmaceutical product, comprising packaging the pharmaceutical composition prepared according to the method of  claim 11  with information about use of the composition for treating osteoarthritis. 
     
     
         13 . A method of selectively removing a senescent cell from a mixed cell population or tissue, comprising combining the mixed cell population or tissue with a pharmaceutical composition that has been prepared according to the method of  claim 10 . 
     
     
         14 . A method of selectively removing a cancer cell from a mixed cell population or tissue, comprising combining the mixed cell population or tissue with a pharmaceutical composition that has been prepared according to the method of  claim 10 . 
     
     
         15 . A method of treating a senescence-associated condition in an individual, comprising administering to the individual a pharmaceutical composition that has been prepared according to the method of  claim 10 . 
     
     
         16 . The method of  claim 15 , wherein the cis-imidazoline is 4-[[(4S,5R)-4,5-bis(4-chlorophenyl)-4,5-dihydro-2-[4-methoxy-2-(1-methylethoxy)phenyl]-1H-imidazol-1-yl]carbonyl]-2-piperazinone (Nutlin-3a). 
     
     
         17 . The method of  claim 15 , wherein the senescence-associated condition is osteoarthritis. 
     
     
         18 . A method of treating cancer in an individual, comprising administering to the individual a pharmaceutical composition that has been prepared according to the method of  claim 10 . 
     
     
         19 . A cis-imidazoline precursor that has an enantiomeric excess (ee) of at least 99% as a result of being prepared by a synthesis method that includes the following steps: (a) combining a racemic mixture of a precursor according to Formula (A) with a chiral aromatic acid under conditions whereby crystals selectively form between a first stereoisomer of the precursor and the chiral aromatic acid, leaving a second stereoisomer of the precursor in solution; 
       
         
           
           
               
               
           
         
         (b) separating the crystals from the solution; and 
         (c) recovering the first stereoisomer from the crystals, thereby enantiomerically enriching the cis-imidazoline precursor; 
         wherein X 1  and X 2  are both chloride, R 1  is —C(═O)—R 2  or an amine protecting group, and R 2  is an optionally substituted carbocycle or heterocycle group; and 
         wherein the chiral aromatic acid is HOOC—CH(OH)—R 3 wherein R 3  is a substituted or an unsubstituted aryl or heteroaryl group. 
       
     
     
         20 . The precursor of  claim 19 , wherein R 1  is BOC, another amine protecting group,