Oxysterol-therapeutic agent derivative for bone healing

Abstract

Oxysterol-therapeutic agent derivatives or OXY133-therapeutic agent derivative compounds and methods of synthesizing the same are provided for use in promoting osteogenesis, osteoinduction and/or osteoconduction. Methods of synthesizing in a single container OXY133-therapeutic agent derivatives having high yields and improved process safety are also provided. Methods for synthesizing OXY133-therapeutic agent derivatives that are stereoselective are also provided.

1 . A method of making a derivative of an oxysterol, the method comprising (i) reacting a pregnenolone derivative of formula I: 
       
         
           
           
               
               
           
         
         with an organometallic compound to form a diol derivative of formula II: 
       
       
         
           
           
               
               
           
         
         (ii) reacting the diol derivative of formula II with a borane compound to form an oxysterol or a pharmaceutically acceptable salt thereof of formula III: 
       
       
         
           
           
               
               
           
         
         (iii) reacting the compound of formula III with a therapeutic agent or a fragment of a therapeutic agent to form an oxysterol derivative of formula IV: 
       
       
         
           
           
               
               
           
         
         wherein R 1  is a protecting group, R 3  is an aliphatic or cyclic substituent having at least one carbon and R 4  is a bisphosphonate moiety, an antibiotic moiety, a protein or a protein fragment, wherein the diol derivative of formula II is in monohydrate form. 
       
     
     
         2 . The method of  claim 1 , wherein the organometallic compound corresponds to the formula R 3 MgX or R 3 Li where X is a halide and R 3  is an aliphatic or cyclic substituent having at least one carbon. 
     
     
         3 . The method of  claim 1 , further comprising optionally deprotecting the compound of formula IV of R 1  to obtain a compound of formula IVb: 
       
         
           
           
               
               
           
         
         by treatment with an iodine or a fluoride source. 
       
     
     
         4 . The method of  claim 1 , wherein R 1  is methyl, ethyl, silyl or carbamate group and R 3  is (C 6 -C 26 ) alkyl or heteroalkyl, a (C 2 -C 20 ) aryl or heteroaryl, a (C 6 -C 26 ) arylalkyl or heteroalkyl or a (C 5 -C 20 ) arylalkyl or heteroaryl-heteroalkyl, a (C 4 -C 10 ) alkyldiyl or heteroalkyldiyl, a (C 4 -C 10 ) alkyleno or heteroalkyleno or carbamate. 
     
     
         5 . The method of  claim 1 , wherein the pregnenolone derivative of formula II is prepared by reacting pregnenolone with R 1 X in a base, wherein R 1  is methyl, ethyl, silyl or carbamate, X is a halide, wherein the base is NaOH, KOH or Ca(OH) 2 . 
     
     
         6 . The method of  claim 1 , wherein R 3 MgX is n-hexyl magnesium chloride and is reacted in tetrahydrofuran to obtain a diol derivative of the formula IIa: 
       
         
           
           
               
               
           
         
       
     
     
         7 . The method of  claim 6 , wherein the compound of formula IIa is reacted with BH 3  to form a borane intermediate, the borane intermediate is reacted with hydrogen peroxide to form an OXY133 derivative of formula IIIa: 
       
         
           
           
               
               
           
         
       
     
     
         8 . The method of  claim 7 , further comprising (i) reacting the compound of formula IIIa with a therapeutic agent R 4 , wherein R 4  is a bisphosphonate moiety, an antibiotic moiety or a protein fragment to form a compound of formula IVa: 
       
         
           
           
               
               
           
         
         (ii) optionally, deprotecting the compound of formula IVa to obtain a compound of formula IVc: 
       
       
         
           
           
               
               
           
         
       
     
     
         9 . The method of  claim 6 , wherein the pregnenolone derivative of formula IIa is prepared by reacting pregnenolone with R 1 X in a base, wherein R 1  is methyl, ethyl, silyl or carbamate, X is a halide, and the base is NaOH, KOH or Ca(OH) 2 . 
     
     
         10 . The method of  claim 7 , further comprising reacting the compound of formula IIIa with a compound comprising a linker L, the linker L comprising aspartate based linkers, succinate based linkers or urethane based linkers; coupling with a therapeutic agent R 4  to obtain a compound of formula VIII: 
       
         
           
           
               
               
           
         
         wherein R 4  is a bisphosphonate moiety, an antibiotic moiety, or a protein fragment; 
         optionally, deprotecting the compound of formula VIII with an iodine source or a fluoride source to obtain a compound of formula VIIIa: 
       
       
         
           
           
               
               
           
         
       
     
     
         11 . The method of  claim 10 , wherein when L is a succinate based linker and the oxysterol derivative is a compound of the formula IXa: 
       
         
           
           
               
               
           
         
       
     
     
         12 . The method of  claim 10 , wherein the iodine source is trimethylsilyl iodide or the fluoride source is tetra-n-butylammonium fluoride or HF pyridine complex. 
     
     
         13 . The method of  claim 7 , further comprising reacting the compound of formula IIIa with a succinate based linker; and coupling with a compound of formula V: 
       
         
           
           
               
               
           
         
         to obtain a compound of formula VIb: 
       
       
         
           
           
               
               
           
         
       
     
     
         14 . The method of  claim 13 , further comprising deprotecting the compound of formula VIb of R 1  by treatment with an iodine source or a fluoride source to obtain a compound of formula VI (OXY 149): 
       
         
           
           
               
               
           
         
       
     
     
         15 . The method of  claim 14 , wherein the iodine source is trimethylsilyl iodide, the fluoride source is tetra-n-butylammonium fluoride or HF pyridine complex. 
     
     
         16 . A method of making OXY149 methyl ether, the method comprising forming pregnenolone methyl ether of formula Ia: 
       
         
           
           
               
               
           
         
         by reacting pregnenolone with CH 3 X in a base, wherein X is a halide and the base is NaOH, KOH or Ca(OH) 2 ; 
         reacting pregnenolone methyl ether of formula Ia with hexyl magnesium chloride in tetrahydrofuran to form pregnenolone diol methyl ether of formula IIb: 
       
       
         
           
           
               
               
           
         
         reacting pregnenolone diol methyl ether of formula IIb with BH 3  and reacting the resulting borane intermediate with hydrogen peroxide to form an OXY133 methyl ether or a pharmaceutically acceptable salt thereof of formula IIIb: 
       
       
         
           
           
               
               
           
         
         reacting the OXY133 methyl ether of formula IIIb with succinic anhydride to provide a succinate based linker and further reacting with a compound of formula V 
       
       
         
           
           
               
               
           
         
         to obtain a compound of formula VIa (OXY149 methyl ether) 
       
       
         
           
           
               
               
           
         
       
       wherein the pregnenolone diol methyl ether of formula IIb is in monohydrate form. 
     
     
         17 . The method of  claim 1 , wherein R 4  is a kanamycin moiety. 
     
     
         18 . The method of  claim 9 , wherein R 4  is a kanamycin moiety. 
     
     
         19 . The method of  claim 17 , wherein all reactions are carried out in a single container. 
     
     
         20 . A compound corresponding to the structure of formula X: 
       
         
           
           
               
               
           
         
         wherein R 1  is methyl, ethyl, silyl or carbamate group and R 3  is (C 6 -C 26 ) alkyl or heteroalkyl, a (C 2 -C 20 ) aryl or heteroaryl, a (C 6 -C 26 ) arylalkyl or heteroalkyl and a (C 5 -C 20 ) arylalkyl or heteroaryl-heteroalkyl, a (C 4 -C 10 ) alkyldiyl or heteroalkyldiyl, or a (C 4 -C 10 ) alkyleno or heteroalkyleno, carbamate, and L is a linker moiety, the linker moiety comprising an aspartate based linker, a succinate based linker or a urethane based linker and R 4  is a derivative of a therapeutic agent, the therapeutic agent comprising a bisphosphonate moiety, an antibiotic moiety, a protein or a protein fragment.